/////////////////////////////////////////////////////////////////////////////
// Name:        src/msw/textctrl.cpp
// Purpose:     wxTextCtrl
// Author:      Julian Smart
// Created:     04/01/98
// Copyright:   (c) Julian Smart
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

// ============================================================================
// declarations
// ============================================================================

// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------

// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"

#if wxUSE_TEXTCTRL

#ifndef WX_PRECOMP
    #include "wx/textctrl.h"
    #include "wx/settings.h"
    #include "wx/brush.h"
    #include "wx/dcclient.h"
    #include "wx/utils.h"
    #include "wx/intl.h"
    #include "wx/log.h"
    #include "wx/app.h"
    #include "wx/menu.h"
    #include "wx/math.h"
    #include "wx/module.h"
    #include "wx/wxcrtvararg.h"
#endif

#include "wx/fontutil.h"
#include "wx/scopedptr.h"
#include "wx/stack.h"
#include "wx/sysopt.h"

#if wxUSE_CLIPBOARD
    #include "wx/clipbrd.h"
    #include "wx/dataobj.h"
#endif

#include "wx/textfile.h"

#include <windowsx.h>

#include "wx/msw/private.h"
#include "wx/msw/winundef.h"

#include <string.h>
#include <stdlib.h>

#include <sys/types.h>

#if wxUSE_RICHEDIT
    #include <richedit.h>
    #include <richole.h>

    // MinGW32 doesn't have tom.h and doesn't define the interfaces and the
    // constants we need, so we can't use ITextDocument::Undo() with it. All
    // the other compilers do have this header.
    #ifndef __MINGW32_TOOLCHAIN__
        #define wxHAS_TOM_H
    #endif

    #ifdef wxHAS_TOM_H
        #include <tom.h>
    #endif

    #include "wx/msw/ole/oleutils.h"

    #include "wx/msw/private/comptr.h"

    #if wxUSE_SPELLCHECK
        #include "wx/msw/wrapwin.h"

        // Add defines that are missing in MinGW.
        #ifndef IMF_SPELLCHECKING
            #define IMF_SPELLCHECKING 0x0800
        #endif
        #ifndef SES_USECTF
            #define SES_USECTF 0x00010000
        #endif
        #ifndef SES_CTFALLOWEMBED
            #define SES_CTFALLOWEMBED 0x00200000
        #endif
        #ifndef SES_CTFALLOWSMARTTAG
            #define SES_CTFALLOWSMARTTAG 0x00400000
        #endif
        #ifndef SES_CTFALLOWPROOFING
            #define SES_CTFALLOWPROOFING 0x00800000
        #endif
    #endif // wxUSE_SPELLCHECK
#endif // wxUSE_RICHEDIT

#if wxUSE_RICHEDIT2
    // Note that some MinGW headers define PFN_BULLET but not the rest of them,
    // so test for something else.
    #ifndef PFN_ARABIC
        #define PFN_BULLET      1
        #define PFN_ARABIC      2
        #define PFN_LCLETTER    3
        #define PFN_UCLETTER    4
        #define PFN_LCROMAN     5
        #define PFN_UCROMAN     6
    #endif

    #ifndef PFNS_PAREN
        #define PFNS_PAREN      0x0000
        #define PFNS_PARENS     0x0100
        #define PFNS_PERIOD     0x0200
        #define PFNS_PLAIN      0x0300
        #define PFNS_NONUMBER   0x0400
        #define PFNS_NEWNUMBER  0x8000
    #endif
#endif // wxUSE_RICHEDIT2

#if wxUSE_INKEDIT
    #include <wx/dynlib.h>
#endif

#include "wx/msw/missing.h"

#ifndef CFM_BACKCOLOR
    #define CFM_BACKCOLOR 0x04000000
#endif

#ifndef CFE_AUTOBACKCOLOR
    #define CFE_AUTOBACKCOLOR 0x04000000
#endif

// missing defines for MinGW build
#ifndef CFM_UNDERLINETYPE
    #define CFM_UNDERLINETYPE       0x00800000
#endif

#ifndef CFU_UNDERLINENONE
    #define CFU_UNDERLINENONE       0
#endif

#ifndef CFU_UNDERLINE
    #define CFU_UNDERLINE           1
#endif

#ifndef CFU_UNDERLINEDOUBLE
    #define CFU_UNDERLINEDOUBLE     3
#endif

#ifndef CFU_UNDERLINEWAVE
    #define CFU_UNDERLINEWAVE       8
#endif

#if wxUSE_DRAG_AND_DROP && wxUSE_RICHEDIT

// dummy value used for m_dropTarget, different from any valid pointer value
// (which are all even under Windows) and nullptr
static wxDropTarget *
    wxRICHTEXT_DEFAULT_DROPTARGET = reinterpret_cast<wxDropTarget *>(1);

#endif // wxUSE_DRAG_AND_DROP && wxUSE_RICHEDIT

#if wxUSE_OLE
// This must be the last header included to only affect the DEFINE_GUID()
// occurrences below but not any GUIDs declared in the standard files included
// above.
#include <initguid.h>

namespace
{

// Normally the IRichEditOleCallback interface and its IID are defined in
// richole.h header file included in the platform SDK but MinGW doesn't
// have the IID symbol (but does have the interface). Work around it by
// defining it ourselves.
DEFINE_GUID(wxIID_IRichEditOleCallback,
    0x00020d03, 0x0000, 0x0000, 0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x46);

} // anonymous namespace

#ifdef wxHAS_TOM_H

// This one is not defined in the standard libraries at all and MSDN just says
// to define it explicitly, so we do it for IID_XXX constant itself and not our
// own wxIID_XXX.
DEFINE_GUID(IID_ITextDocument,
    0x8cc497c0, 0xa1df, 0x11ce, 0x80, 0x98, 0x00, 0xaa, 0x00, 0x47, 0xbe, 0x5d);

#endif // wxHAS_TOM_H

#endif // wxUSE_OLE

// ----------------------------------------------------------------------------
// private classes
// ----------------------------------------------------------------------------

#if wxUSE_RICHEDIT

// this module initializes RichEdit DLL(s) if needed
class wxRichEditModule : public wxModule
{
public:
    enum Version
    {
        Version_1,          // riched32.dll
        Version_2or3,       // both use riched20.dll
        Version_41,         // msftedit.dll (XP SP1 and Windows 2003)
        Version_Max
    };

    virtual bool OnInit() override;
    virtual void OnExit() override;

    // load the richedit DLL for the specified version of rich edit
    static bool Load(Version version);

#if wxUSE_INKEDIT
    // load the InkEdit library
    static bool LoadInkEdit();
#endif

private:
    // the handles to richedit 1.0 and 2.0 (or 3.0) DLLs
    static HINSTANCE ms_hRichEdit[Version_Max];

#if wxUSE_INKEDIT
    static wxDynamicLibrary ms_inkEditLib;
    static bool             ms_inkEditLibLoadAttemped;
#endif

    wxDECLARE_DYNAMIC_CLASS(wxRichEditModule);
};

HINSTANCE wxRichEditModule::ms_hRichEdit[Version_Max] = { nullptr, nullptr, nullptr };

#if wxUSE_INKEDIT
wxDynamicLibrary wxRichEditModule::ms_inkEditLib;
bool             wxRichEditModule::ms_inkEditLibLoadAttemped = false;
#endif

wxIMPLEMENT_DYNAMIC_CLASS(wxRichEditModule, wxModule);

#if wxUSE_OLE

extern wxMenu *wxCurrentPopupMenu;

class wxTextCtrlOleCallback : public IRichEditOleCallback
{
public:
    wxTextCtrlOleCallback(wxTextCtrl *text) : m_textCtrl(text), m_menu(nullptr) {}
    virtual ~wxTextCtrlOleCallback() { DeleteContextMenuObject(); }

    wxSTDMETHODIMP ContextSensitiveHelp(BOOL WXUNUSED(enterMode)) override { return E_NOTIMPL; }
    wxSTDMETHODIMP DeleteObject(LPOLEOBJECT WXUNUSED(oleobj)) override { return E_NOTIMPL; }
    wxSTDMETHODIMP GetClipboardData(CHARRANGE* WXUNUSED(chrg), DWORD WXUNUSED(reco), LPDATAOBJECT* WXUNUSED(dataobj)) override { return E_NOTIMPL; }
    wxSTDMETHODIMP GetDragDropEffect(BOOL WXUNUSED(drag), DWORD WXUNUSED(grfKeyState), LPDWORD WXUNUSED(effect)) override { return E_NOTIMPL; }
    wxSTDMETHODIMP GetInPlaceContext(LPOLEINPLACEFRAME* WXUNUSED(frame), LPOLEINPLACEUIWINDOW* WXUNUSED(doc), LPOLEINPLACEFRAMEINFO WXUNUSED(frameInfo)) override { return E_NOTIMPL; }
    wxSTDMETHODIMP GetNewStorage(LPSTORAGE *WXUNUSED(stg)) override { return E_NOTIMPL; }
    wxSTDMETHODIMP QueryAcceptData(LPDATAOBJECT WXUNUSED(dataobj), CLIPFORMAT* WXUNUSED(format), DWORD WXUNUSED(reco), BOOL WXUNUSED(really), HGLOBAL WXUNUSED(hMetaPict)) override { return E_NOTIMPL; }
    wxSTDMETHODIMP QueryInsertObject(LPCLSID WXUNUSED(clsid), LPSTORAGE WXUNUSED(stg), LONG WXUNUSED(cp)) override { return E_NOTIMPL; }
    wxSTDMETHODIMP ShowContainerUI(BOOL WXUNUSED(show)) override { return E_NOTIMPL; }

    wxSTDMETHODIMP GetContextMenu(WORD WXUNUSED(seltype), LPOLEOBJECT WXUNUSED(oleobj), CHARRANGE* WXUNUSED(chrg), HMENU *menu) override
    {
        // 'menu' will be shown and destroyed by the caller. We need to keep
        // its wx counterpart, the wxMenu instance, around until it is
        // dismissed, though, so store it in m_menu and destroy sometime later.
        DeleteContextMenuObject();
        m_menu = m_textCtrl->MSWCreateContextMenu();
        *menu = m_menu->GetHMenu();

        // Make wx handle events from the popup menu correctly:
        m_menu->SetInvokingWindow(m_textCtrl);
        wxCurrentPopupMenu = m_menu;

        m_menu->UpdateUI();

        return S_OK;
    }

    DECLARE_IUNKNOWN_METHODS;

private:
    void DeleteContextMenuObject()
    {
        if ( m_menu )
        {
            m_menu->MSWDetachHMENU();
            if ( wxCurrentPopupMenu == m_menu )
                wxCurrentPopupMenu = nullptr;
            wxDELETE(m_menu);
        }
    }

    wxTextCtrl *m_textCtrl;
    wxMenu *m_menu;

    wxDECLARE_NO_COPY_CLASS(wxTextCtrlOleCallback);
};

BEGIN_IID_TABLE(wxTextCtrlOleCallback)
    ADD_IID(Unknown)
    ADD_RAW_IID(wxIID_IRichEditOleCallback)
END_IID_TABLE;

IMPLEMENT_IUNKNOWN_METHODS(wxTextCtrlOleCallback)

#endif // wxUSE_OLE

#endif // wxUSE_RICHEDIT

// a small class used to set m_updatesCount to 0 (to filter duplicate events if
// necessary) and to reset it back to -1 afterwards
class UpdatesCountFilter
{
public:
    UpdatesCountFilter(int& count)
        : m_count(count)
    {
        wxASSERT_MSG( m_count == -1 || m_count == -2,
                      wxT("wrong initial m_updatesCount value") );

        if (m_count != -2)
            m_count = 0;
        //else: we don't want to count how many update events we get as we're going
        //      to ignore all of them
    }

    ~UpdatesCountFilter()
    {
        m_count = -1;
    }

    // return true if an event has been received
    bool GotUpdate() const
    {
        return m_count == 1;
    }

private:
    int& m_count;

    wxDECLARE_NO_COPY_CLASS(UpdatesCountFilter);
};

namespace
{

// This stack stores the length of the text being currently inserted into the
// current control.
//
// It is used to pass information from DoWriteText() to AdjustSpaceLimit()
// and is global as text can only be inserted into a few text controls at a
// time (but possibly more than into one, if wxEVT_TEXT event handler does
// something that results in another text control update), and we don't want to
// waste space in every wxTextCtrl object for this field unnecessarily.
wxStack<int> gs_lenOfInsertedText;

} // anonymous namespace

// ----------------------------------------------------------------------------
// event tables and other macros
// ----------------------------------------------------------------------------

wxBEGIN_EVENT_TABLE(wxTextCtrl, wxTextCtrlBase)
    EVT_CHAR(wxTextCtrl::OnChar)
    EVT_KEY_DOWN(wxTextCtrl::OnKeyDown)
    EVT_DROP_FILES(wxTextCtrl::OnDropFiles)

    EVT_MENU(wxID_CUT, wxTextCtrl::OnCut)
    EVT_MENU(wxID_COPY, wxTextCtrl::OnCopy)
    EVT_MENU(wxID_PASTE, wxTextCtrl::OnPaste)
    EVT_MENU(wxID_UNDO, wxTextCtrl::OnUndo)
    EVT_MENU(wxID_REDO, wxTextCtrl::OnRedo)
    EVT_MENU(wxID_CLEAR, wxTextCtrl::OnDelete)
    EVT_MENU(wxID_SELECTALL, wxTextCtrl::OnSelectAll)

    EVT_UPDATE_UI(wxID_CUT, wxTextCtrl::OnUpdateCut)
    EVT_UPDATE_UI(wxID_COPY, wxTextCtrl::OnUpdateCopy)
    EVT_UPDATE_UI(wxID_PASTE, wxTextCtrl::OnUpdatePaste)
    EVT_UPDATE_UI(wxID_UNDO, wxTextCtrl::OnUpdateUndo)
    EVT_UPDATE_UI(wxID_REDO, wxTextCtrl::OnUpdateRedo)
    EVT_UPDATE_UI(wxID_CLEAR, wxTextCtrl::OnUpdateDelete)
    EVT_UPDATE_UI(wxID_SELECTALL, wxTextCtrl::OnUpdateSelectAll)

    EVT_SET_FOCUS(wxTextCtrl::OnSetFocus)
wxEND_EVENT_TABLE()

// ============================================================================
// implementation
// ============================================================================

// ----------------------------------------------------------------------------
// creation
// ----------------------------------------------------------------------------

void wxTextCtrl::Init()
{
#if wxUSE_RICHEDIT
    m_verRichEdit = 0;
    m_richDPIscale = 1;
#endif // wxUSE_RICHEDIT

#if wxUSE_INKEDIT && wxUSE_RICHEDIT
    m_isInkEdit = 0;
#endif

    m_privateContextMenu = nullptr;
    m_updatesCount = -1;
    m_isNativeCaretShown = true;
}

wxTextCtrl::wxTextCtrl()
{
    Init();
}

wxTextCtrl::wxTextCtrl(wxWindow *parent,
                       wxWindowID id,
                       const wxString& value,
                       const wxPoint& pos,
                       const wxSize& size,
                       long style,
                       const wxValidator& validator,
                       const wxString& name)
{
    Init();

    Create(parent, id, value, pos, size, style, validator, name);
}

wxTextCtrl::~wxTextCtrl()
{
#if wxUSE_DRAG_AND_DROP && wxUSE_RICHEDIT
    if ( m_dropTarget == wxRICHTEXT_DEFAULT_DROPTARGET )
    {
        // don't try to destroy this dummy pointer in the base class dtor
        m_dropTarget = nullptr;
    }
#endif // wxUSE_DRAG_AND_DROP && wxUSE_RICHEDIT

    delete m_privateContextMenu;
}

bool wxTextCtrl::Create(wxWindow *parent,
                        wxWindowID id,
                        const wxString& value,
                        const wxPoint& pos,
                        const wxSize& size,
                        long style,
                        const wxValidator& validator,
                        const wxString& name)
{
    // base initialization
    if ( !CreateControl(parent, id, pos, size, style, validator, name) )
        return false;

    if ( !MSWCreateText(value, pos, size) )
        return false;

#if wxUSE_DRAG_AND_DROP && wxUSE_RICHEDIT
    if ( IsRich() )
    {
        // rich text controls have a default associated drop target which
        // allows them to receive (rich) text dropped on them, which is nice,
        // but prevents us from associating a user-defined drop target with
        // them as we need to unregister the old one first
        //
        // to make it work, we set m_dropTarget to this special value initially
        // and check for it in our SetDropTarget()
        m_dropTarget = wxRICHTEXT_DEFAULT_DROPTARGET;
    }
#endif // wxUSE_DRAG_AND_DROP && wxUSE_RICHEDIT

    return true;
}

// returns true if the platform should explicitly apply a theme border
bool wxTextCtrl::CanApplyThemeBorder() const
{
    // Standard text control already handles theming
    return ((GetWindowStyle() & (wxTE_RICH|wxTE_RICH2)) != 0);
}

bool wxTextCtrl::MSWCreateText(const wxString& value,
                               const wxPoint& pos,
                               const wxSize& size)
{
    // translate wxWin style flags to MSW ones
    WXDWORD msStyle = MSWGetCreateWindowFlags();

    // do create the control - either an EDIT or RICHEDIT
    wxString windowClass = wxT("EDIT");

#if wxUSE_RICHEDIT
    if ( m_windowStyle & wxTE_AUTO_URL )
    {
        // automatic URL detection only works in RichEdit 2.0+
        m_windowStyle |= wxTE_RICH2;
    }

    if ( m_windowStyle & wxTE_RICH2 )
    {
        // using richedit 2.0 implies using wxTE_RICH
        m_windowStyle |= wxTE_RICH;
    }

    // we need to load the richedit DLL before creating the rich edit control
    if ( m_windowStyle & wxTE_RICH )
    {
        // versions 2.0, 3.0 and 4.1 of rich edit are mostly compatible with
        // each other but not with version 1.0, so we have separate flags for
        // the version 1.0 and the others (and so m_verRichEdit may be 0 (plain
        // EDIT control), 1 for version 1.0 or 2 for any higher version)
        //
        // notice that 1.0 has no Unicode support at all so in Unicode build we
        // must use another version

        m_verRichEdit = 2;

#if wxUSE_INKEDIT
        // First test if we can load an ink edit control. Normally, all edit
        // controls will be made ink edit controls if a tablet environment is
        // found (or if msw.inkedit != 0 and the InkEd.dll is present).
        // However, an application can veto ink edit controls by either specifying
        // msw.inkedit = 0 or by removing wxTE_RICH[2] from the style.
        //
        if ((wxSystemSettings::HasFeature(wxSYS_TABLET_PRESENT) || wxSystemOptions::GetOptionInt(wxT("msw.inkedit")) != 0) &&
            !(wxSystemOptions::HasOption(wxT("msw.inkedit")) && wxSystemOptions::GetOptionInt(wxT("msw.inkedit")) == 0))
        {
            if (wxRichEditModule::LoadInkEdit())
            {
                windowClass = INKEDIT_CLASS;

#if wxUSE_INKEDIT && wxUSE_RICHEDIT
                m_isInkEdit = 1;
#endif

                // Fake rich text version for other calls
                m_verRichEdit = 2;
            }
        }
#endif

#if wxUSE_INKEDIT
        if (!IsInkEdit())
#endif // wxUSE_INKEDIT
        {
            if ( m_verRichEdit == 2 )
            {
                if ( wxRichEditModule::Load(wxRichEditModule::Version_41) )
                {
                    // yes, class name for version 4.1 really is 5.0
                    windowClass = wxT("RICHEDIT50W");

                    m_verRichEdit = 4;
                }
                else if ( wxRichEditModule::Load(wxRichEditModule::Version_2or3) )
                {
                    windowClass = wxT("RichEdit20W");
                }
                else // failed to load msftedit.dll and riched20.dll
                {
                    m_verRichEdit = 1;
                }
            }

            if ( m_verRichEdit == 1 )
            {
                if ( wxRichEditModule::Load(wxRichEditModule::Version_1) )
                {
                    windowClass = wxT("RICHEDIT");
                }
                else // failed to load any richedit control DLL
                {
                    // only give the error msg once if the DLL can't be loaded
                    static bool s_errorGiven = false; // MT ok as only used by GUI

                    if ( !s_errorGiven )
                    {
                        wxLogError(_("Impossible to create a rich edit control, using simple text control instead. Please reinstall riched32.dll"));

                        s_errorGiven = true;
                    }

                    m_verRichEdit = 0;
                }
            }
        } // !useInkEdit
    }
#endif // wxUSE_RICHEDIT

    // we need to turn '\n's into "\r\n"s for the multiline controls
    wxString valueWin;
    if ( m_windowStyle & wxTE_MULTILINE )
    {
        valueWin = wxTextFile::Translate(value, wxTextFileType_Dos);
    }
    else // single line
    {
        valueWin = value;
    }

    // suppress events sent during control creation: we're called either from
    // the ctor and then we shouldn't generate any events for compatibility
    // with the other ports, or from SetWindowStyleFlag() and then we shouldn't
    // generate the events because our text doesn't really change, the fact
    // that we (sometimes) need to recreate the control is just an
    // implementation detail
    m_updatesCount = -2;

    if ( !MSWCreateControl(windowClass.t_str(), msStyle, pos, size, valueWin) )
    {
        // There is one case in which window creation may realistically fail
        // and this is when we create a plain EDIT control with too long text,
        // so try to detect this and transparently switch to using RICHEDIT in
        // this case (note that the exact length cut off is unknown and might
        // be system-dependent, but even though plain EDIT works for texts
        // longer than 64KiB, we don't lose much by trying to use RICHEDIT if
        // creating it failed).
        if ( !HasFlag(wxTE_RICH | wxTE_RICH2) && value.length() >= 0x10000 )
        {
            m_windowStyle |= wxTE_RICH2;
            return MSWCreateText(value, pos, size);
        }

        return false;
    }

    m_updatesCount = -1;

#if wxUSE_RICHEDIT
    if (IsRich())
    {
#if wxUSE_INKEDIT
        if (IsInkEdit())
        {
            // Pass IEM_InsertText (0) as wParam, in order to have the ink always
            // converted to text.
            ::SendMessage(GetHwnd(), EM_SETINKINSERTMODE, 0, 0);

            // Make sure the mouse can be used for input
            ::SendMessage(GetHwnd(), EM_SETUSEMOUSEFORINPUT, 1, 0);
        }
#endif

        // enable the events we're interested in: we want to get EN_CHANGE as
        // for the normal controls
        LPARAM mask = ENM_CHANGE;

        if (GetRichVersion() == 1 && !IsInkEdit())
        {
            // we also need EN_MSGFILTER for richedit 1.0 for the reasons
            // explained in its handler
           mask |= ENM_MOUSEEVENTS;

           // we also need to force the appearance of the vertical scrollbar
           // initially as otherwise the control doesn't refresh correctly
           // after resize: but once the vertical scrollbar had been shown
           // (even if it's subsequently hidden) it does
           //
           // this is clearly a bug and for now it has been only noticed under
           // Windows XP, so if we're sure it works correctly under other
           // systems we could do this only for XP
           SetSize(-1, 1); // 1 is small enough to force vert scrollbar
           SetInitialSize(size);
        }
        else if ( m_windowStyle & wxTE_AUTO_URL )
        {
            mask |= ENM_LINK;

            ::SendMessage(GetHwnd(), EM_AUTOURLDETECT, TRUE, 0);
        }

        ::SendMessage(GetHwnd(), EM_SETEVENTMASK, 0, mask);

        bool contextMenuConnected = false;
#if wxUSE_OLE
        if ( m_verRichEdit >= 4 )
        {
            wxTextCtrlOleCallback *cb = new wxTextCtrlOleCallback(this);
            if ( ::SendMessage(GetHwnd(), EM_SETOLECALLBACK, 0, (LPARAM)cb) )
            {
                // If we succeeded in setting up the callback, we don't need to
                // connect to wxEVT_CONTEXT_MENU to show the menu ourselves,
                // but we do need to connect to wxEVT_RIGHT_UP to generate
                // wxContextMenuEvent ourselves as we're not going to get it
                // from the control which consumes it.
                contextMenuConnected = true;
                Bind(wxEVT_RIGHT_UP, &wxTextCtrl::OnRightUp, this);
            }
        }
#endif
        if ( !contextMenuConnected )
            Bind(wxEVT_CONTEXT_MENU, &wxTextCtrl::OnContextMenu, this);

        // Determine the system DPI and the DPI of the display the rich control
        // is shown on, and calculate and apply the scaling factor.
        // When this control is created in a (wxFrame) constructor the zoom is
        // not correctly applied, use CallAfter to delay setting the zoom.
        m_richDPIscale = GetDPI().y / (float)::GetDeviceCaps(ScreenHDC(), LOGPIXELSY);
        CallAfter(&wxTextCtrl::MSWSetRichZoom);
    }
    else
#endif // wxUSE_RICHEDIT
    if ( HasFlag(wxTE_MULTILINE) && HasFlag(wxTE_READONLY) )
    {
        // non-rich read-only multiline controls have grey background by
        // default under MSW but this is not always appropriate, so forcefully
        // reset the background colour to normal default
        //
        // this is not ideal but, after a long discussion on wx-dev (see
        // http://thread.gmane.org/gmane.comp.lib.wxwidgets.devel/116360/) it
        // was finally deemed to be the best behaviour by default (and ideally
        // we'd have a way to change this, see #11521)
        SetBackgroundColour(GetClassDefaultAttributes().colBg);
    }

    // Without this, if we pass the size in the constructor and then don't change it,
    // the themed borders will be drawn incorrectly.
    SetWindowPos(GetHwnd(), nullptr, 0, 0, 0, 0,
                SWP_NOZORDER|SWP_NOMOVE|SWP_NOSIZE|SWP_NOACTIVATE|
                SWP_FRAMECHANGED);

    if ( IsSingleLine() )
    {
        // If we don't set the margins explicitly, their size depends on the
        // control initial size, see #2438. So explicitly set them to something
        // consistent. And for this we have 2 candidates: EC_USEFONTINFO (which
        // sets the left margin to 3 pixels, at least under Windows 7) or 0. We
        // use the former because it looks like it was meant to be used as the
        // default (what else would it be there for?) and 0 looks bad in
        // classic mode, i.e. without themes. Also, the margin can be reset to
        // 0 easily by calling SetMargins() explicitly but setting it to the
        // default value is not currently supported.
        //
        // Finally, notice that EC_USEFONTINFO is used differently for plain
        // and rich text controls.
        WPARAM wParam;
        LPARAM lParam;
        if ( IsRich() )
        {
            wParam = EC_USEFONTINFO;
            lParam = 0;
        }
        else // plain EDIT, EC_USEFONTINFO is used in lParam with them.
        {
            wParam = EC_LEFTMARGIN | EC_RIGHTMARGIN;
            lParam = MAKELPARAM(EC_USEFONTINFO, EC_USEFONTINFO);
        }

        ::SendMessage(GetHwnd(), EM_SETMARGINS, wParam, lParam);
    }

#if wxUSE_RICHEDIT
    // For RichEdit >= 4, SetFont(), called above from MSWCreateControl(), uses
    // EM_SETCHARFORMAT which affects the undo buffer, meaning that CanUndo()
    // for a newly created control returns true, which is unexpected, so clear
    // the undo buffer.
    if ( GetRichVersion() >= 4 )
    {
        EmptyUndoBuffer();
    }
#endif // wxUSE_RICHEDIT

    return true;
}

// Make sure the window style (etc.) reflects the HWND style (roughly)
void wxTextCtrl::AdoptAttributesFromHWND()
{
    wxWindow::AdoptAttributesFromHWND();

    HWND hWnd = GetHwnd();
    long style = ::GetWindowLong(hWnd, GWL_STYLE);

    // retrieve the style to see whether this is an edit or richedit ctrl
#if wxUSE_RICHEDIT
    wxString classname = wxGetWindowClass(GetHWND());

    if ( classname.IsSameAs(wxT("EDIT"), false /* no case */) )
    {
        m_verRichEdit = 0;
    }
    else // rich edit?
    {
        wxChar c;
        if ( wxSscanf(classname, wxT("RichEdit%d0%c"), &m_verRichEdit, &c) != 2 )
        {
            wxLogDebug(wxT("Unknown edit control '%s'."), classname);

            m_verRichEdit = 0;
        }
    }
#endif // wxUSE_RICHEDIT

    if (style & ES_MULTILINE)
        m_windowStyle |= wxTE_MULTILINE;
    if (style & ES_PASSWORD)
        m_windowStyle |= wxTE_PASSWORD;
    if (style & ES_READONLY)
        m_windowStyle |= wxTE_READONLY;
    if (style & ES_WANTRETURN)
        m_windowStyle |= wxTE_PROCESS_ENTER;
    if (style & ES_CENTER)
        m_windowStyle |= wxTE_CENTRE;
    if (style & ES_RIGHT)
        m_windowStyle |= wxTE_RIGHT;
}

WXDWORD wxTextCtrl::MSWGetStyle(long style, WXDWORD *exstyle) const
{
    long msStyle = wxControl::MSWGetStyle(style, exstyle);

    // styles which we always add by default
    if ( style & wxTE_MULTILINE )
    {
        msStyle |= ES_MULTILINE | ES_WANTRETURN;
        if ( !(style & wxTE_NO_VSCROLL) )
        {
            // always adjust the vertical scrollbar automatically if we have it
            msStyle |= WS_VSCROLL | ES_AUTOVSCROLL;

#if wxUSE_RICHEDIT
            // we have to use this style for the rich edit controls because
            // without it the vertical scrollbar never appears at all in
            // richedit 3.0 because of our ECO_NOHIDESEL hack (search for it)
            if ( style & wxTE_RICH2 )
            {
                msStyle |= ES_DISABLENOSCROLL;
            }
#endif // wxUSE_RICHEDIT
        }

        style |= wxTE_PROCESS_ENTER;
    }
    else // !multiline
    {
        // there is really no reason to not have this style for single line
        // text controls
        msStyle |= ES_AUTOHSCROLL;
    }

    // note that wxTE_DONTWRAP is the same as wxHSCROLL so if we have a horz
    // scrollbar, there is no wrapping -- which makes sense
    if ( style & wxTE_DONTWRAP )
    {
        // automatically scroll the control horizontally as necessary
        //
        // NB: ES_AUTOHSCROLL is needed for richedit controls or they don't
        //     show horz scrollbar at all, even in spite of WS_HSCROLL, and as
        //     it doesn't seem to do any harm for plain edit controls, add it
        //     always
        msStyle |= WS_HSCROLL | ES_AUTOHSCROLL;
    }

    if ( style & wxTE_READONLY )
        msStyle |= ES_READONLY;

    if ( style & wxTE_PASSWORD )
        msStyle |= ES_PASSWORD;

    if ( style & wxTE_NOHIDESEL )
        msStyle |= ES_NOHIDESEL;

    // note that we can't do do "& wxTE_LEFT" as wxTE_LEFT == 0
    if ( style & wxTE_CENTRE )
        msStyle |= ES_CENTER;
    else if ( style & wxTE_RIGHT )
        msStyle |= ES_RIGHT;
    else
        msStyle |= ES_LEFT; // ES_LEFT is 0 as well but for consistency...

    return msStyle;
}

#if wxUSE_RICHEDIT && wxUSE_SPELLCHECK

bool wxTextCtrl::EnableProofCheck(const wxTextProofOptions& options)
{
    wxCHECK_MSG((m_windowStyle & wxTE_RICH2), false,
            "Unable to enable proof checking on a control "
            "that does not have wxTE_RICH2 style");

    LPARAM editStyle = SES_USECTF | SES_CTFALLOWEMBED
                        | SES_CTFALLOWSMARTTAG  | SES_CTFALLOWPROOFING;
    ::SendMessage(GetHwnd(), EM_SETEDITSTYLE, editStyle, editStyle);

    LRESULT langOptions = ::SendMessage(GetHwnd(), EM_GETLANGOPTIONS, 0, 0);

    if ( options.IsSpellCheckEnabled() )
        langOptions |= IMF_SPELLCHECKING;
    else
        langOptions &= ~IMF_SPELLCHECKING;

    ::SendMessage(GetHwnd(), EM_SETLANGOPTIONS, 0, langOptions);

   return GetProofCheckOptions().IsSpellCheckEnabled() == options.IsSpellCheckEnabled();
}

wxTextProofOptions wxTextCtrl::GetProofCheckOptions() const
{
    wxTextProofOptions opts = wxTextProofOptions::Disable();

    LRESULT langOptions = ::SendMessage(GetHwnd(), EM_GETLANGOPTIONS, 0, 0);

    if (langOptions & IMF_SPELLCHECKING)
        opts.SpellCheck();

    return opts;
}

#endif // wxUSE_SPELLCHECK

void wxTextCtrl::SetWindowStyleFlag(long style)
{
    // changing the alignment of the control dynamically works under Win2003
    // (but not older Windows version: it seems to work under some versions of
    // XP but not other ones, and we have no way to determine it so be
    // conservative here) and only for plain EDIT controls (not RICH ones) and
    // we have to recreate the control to make it always work
    if ( IsRich() )
    {
        const long alignMask = wxTE_LEFT | wxTE_CENTRE | wxTE_RIGHT;
        if ( (style & alignMask) != (GetWindowStyle() & alignMask) )
        {
            const wxString value = GetValue();
            const wxPoint pos = GetPosition();
            const wxSize size = GetSize();

            // delete the old window
            HWND hwnd = GetHwnd();
            DissociateHandle();
            ::DestroyWindow(hwnd);

            // create the new one with the updated flags
            m_windowStyle = style;
            MSWCreateText(value, pos, size);

            // and make sure it has the same attributes as before
            if ( m_hasFont )
            {
                // calling SetFont(m_font) would do nothing as the code would
                // notice that the font didn't change, so force it to believe
                // that it did
                wxFont font = m_font;
                m_font = wxNullFont;
                SetFont(font);
            }

            if ( m_hasFgCol )
            {
                wxColour colFg = m_foregroundColour;
                m_foregroundColour = wxNullColour;
                SetForegroundColour(colFg);
            }

            if ( m_hasBgCol )
            {
                wxColour colBg = m_backgroundColour;
                m_backgroundColour = wxNullColour;
                SetBackgroundColour(colBg);
            }

            // note that text styles are lost but this is probably not a big
            // problem: if you use styles, you probably don't use nor change
            // alignment flags anyhow

            return;
        }
    }

#if wxUSE_RICHEDIT
    // we have to deal with some styles separately because they can't be
    // changed by simply calling SetWindowLong(GWL_STYLE) but can be changed
    // using richedit-specific EM_SETOPTIONS
    if ( IsRich() &&
            ((style & wxTE_NOHIDESEL) != (GetWindowStyle() & wxTE_NOHIDESEL)) )
    {
        bool set = (style & wxTE_NOHIDESEL) != 0;

        ::SendMessage(GetHwnd(), EM_SETOPTIONS, set ? ECOOP_OR : ECOOP_AND,
                      set ? ECO_NOHIDESEL : ~ECO_NOHIDESEL);
    }
#endif // wxUSE_RICHEDIT

    wxControl::SetWindowStyleFlag(style);
}

// ----------------------------------------------------------------------------
// set/get the controls text
// ----------------------------------------------------------------------------

bool wxTextCtrl::IsEmpty() const
{
    // this is an optimization for multiline controls containing a lot of text
    if ( IsMultiLine() && GetNumberOfLines() != 1 )
        return false;

    return wxTextCtrlBase::IsEmpty();
}

wxString wxTextCtrl::GetValue() const
{
    // range 0..-1 is special for GetRange() and means to retrieve all text
    return GetRange(0, -1);
}

wxString wxTextCtrl::GetRange(long from, long to) const
{
    wxString str;

    if ( from >= to && to != -1 )
    {
        // nothing to retrieve
        return str;
    }

#if wxUSE_RICHEDIT
    if ( IsRich() )
    {
        int len = GetWindowTextLength(GetHwnd());
        if ( len > from )
        {
            if ( to == -1 )
                to = len;

            // alloc one extra WORD as needed by the control
            wxStringBuffer tmp(str, ++len);
            wxChar *p = tmp;

            TEXTRANGE textRange;
            textRange.chrg.cpMin = from;
            textRange.chrg.cpMax = to;
            textRange.lpstrText = p;

            (void)::SendMessage(GetHwnd(), EM_GETTEXTRANGE,
                                0, (LPARAM)&textRange);

            if ( m_verRichEdit > 1 )
            {
                // RichEdit 2.0 uses just CR ('\r') for the
                // newlines which is neither Unix nor Windows
                // style - convert it to something reasonable
                for ( ; *p; p++ )
                {
                    if ( *p == wxT('\r') )
                        *p = wxT('\n');
                }
            }

            if ( m_verRichEdit == 1 )
            {
                // convert to the canonical form - see comment below
                str = wxTextFile::Translate(str, wxTextFileType_Unix);
            }
        }
        //else: no text at all, leave the string empty
    }
    else
#endif // wxUSE_RICHEDIT
    {
        // retrieve all text: wxTextEntry method works even for multiline
        // controls and must be used for single line ones to account for hints
        str = wxTextEntry::GetValue();

        // need only a range?
        if ( from < to )
        {
            str = str.Mid(from, to - from);
        }

        // WM_GETTEXT uses standard DOS CR+LF (\r\n) convention - convert to the
        // canonical one (same one as above) for consistency with the other kinds
        // of controls and, more importantly, with the other ports
        str = wxTextFile::Translate(str, wxTextFileType_Unix);
    }

    return str;
}

void wxTextCtrl::DoSetValue(const wxString& value, int flags)
{
    // if the text is long enough, it's faster to just set it instead of first
    // comparing it with the old one (chances are that it will be different
    // anyhow, this comparison is there to avoid flicker for small single-line
    // edit controls mostly)
    if ( (value.length() > 0x400) || (value != DoGetValue()) )
    {
        DoWriteText(value, flags /* doesn't include SelectionOnly here */);

        // mark the control as being not dirty - we changed its text, not the
        // user
        DiscardEdits();

        // for compatibility, don't move the cursor when doing SetValue()
        SetInsertionPoint(0);
    }
    else // same text
    {
        // still reset the modified flag even if the value didn't really change
        // because now it comes from the program and not the user (and do it
        // before generating the event so that the event handler could get the
        // expected value from IsModified())
        DiscardEdits();

        // still send an event for consistency
        if (flags & SetValue_SendEvent)
            SendUpdateEvent();
    }
}

#if wxUSE_RICHEDIT

DWORD wxCALLBACK MSWEditStreamOutCallback(DWORD_PTR dwCookie, LPBYTE pbBuff,
    LONG cb, LONG* pcb)
{
    // write the text
    std::string* psEntry = reinterpret_cast<std::string*>(dwCookie);
    psEntry->append(reinterpret_cast<const char*>(pbBuff), cb);
    *pcb = cb;

    return 0;
}

wxString wxTextCtrl::GetRTFValue() const
{
    if ( !IsRich() )
    {
        wxFAIL_MSG("RTF support is only available for rich controls!");
        return wxEmptyString;
    }

    // The Rich Edit control must write to a char buffer,
    // which we will later convert to a Unicode wxString using the current code page.
    //
    // We will reserve enough space assuming that the RTF will be twice as large
    // as the unencoded content.
    std::string buffer;
    buffer.reserve(GetLastPosition() * 2);

    // Use a EDITSTREAMCALLBACK to stream text out from the control.
    EDITSTREAM es{ 0 };
    es.dwError = 0;
    es.pfnCallback = MSWEditStreamOutCallback;
    // our callback will write to a char buffer (i.e., std::string)
    es.dwCookie = reinterpret_cast<DWORD_PTR>(&buffer);

    // Do NOT call with "(CP_UTF8 << 16) | SF_USECODEPAGE", as this will format the
    // output RTF to UTF-8 with a "urtf1" header (note the 'u').
    // Although this is a more modern format, few programs
    // (including Microsoft Wordpad) recognize it.
    //
    // Instead, write the content to an ANSI string using the current code page
    // (which will use a "rtf1" header). The control will encode any Unicode values
    // outside of the current code page with "\'[0-9A-F][0-9A-F]" syntax that most
    // parsers would support.
    //
    // Finally, use SFF_PLAINRTF so that the generated RTF is more portable between
    // RTF readers.
    ::SendMessage(GetHwnd(), EM_STREAMOUT,
        (WPARAM)(SF_RTF | SFF_PLAINRTF), (LPARAM)&es);

    // Valid RTF is supposed to consist of 7-bit ASCII characters only,
    // anything else is escaped.
    return wxString::FromAscii(buffer.c_str(), buffer.length());
}

void wxTextCtrl::SetRTFValue(const wxString& val)
{
    wxCHECK_RET(IsRich(), "RTF support is only available for rich controls!");

    SETTEXTEX textInfo{ 0 };
    textInfo.flags = ST_DEFAULT | ST_UNICODE;
    textInfo.codepage = 1200;

    // Setting from Unicode will fail if control is read-only
    // (this is an undocumented "feature"), so we need to toggle that temporarily.
    const bool
        isReadOnly = (::GetWindowLong(GetHwnd(), GWL_STYLE) & ES_READONLY) != 0;
    if ( isReadOnly )
    {
        ::SendMessage(GetHwnd(), EM_SETREADONLY, FALSE, 0);
    }

    ::SendMessage(GetHwnd(), EM_SETTEXTEX, (WPARAM)&textInfo,
        (LPARAM)static_cast<const wchar_t*>(val.wc_str()));

    if ( isReadOnly )
    {
        ::SendMessage(GetHwnd(), EM_SETREADONLY, TRUE, 0);
    }

    SetInsertionPoint(0);
}

wxTextSearchResult wxTextCtrl::SearchText(const wxTextSearch& search) const
{
    // set up the flags
    WPARAM flags = 0;
    switch ( search.m_direction )
    {
        case wxTextSearch::Direction::Down:
            flags |= FR_DOWN;
            break;

        case wxTextSearch::Direction::Up:
            // Nothing to do this is (surprisingly) the default.
            break;
    }
    if (search.m_wholeWord)
    {
        flags |= FR_WHOLEWORD;
    }
    if (search.m_matchCase)
    {
        flags |= FR_MATCHCASE;
    }

    FINDTEXTEX findText;
    findText.chrg.cpMin = (search.m_startingPosition != -1) ?
        // user-provided start
        search.m_startingPosition :
        // if going down, then start from 0; otherwise, start from end
        (search.m_direction == wxTextSearch::Direction::Down) ? 0 : GetLastPosition();
    if (search.m_direction == wxTextSearch::Direction::Down)
    {
        // go to the end of the text
        findText.chrg.cpMax = -1;
    }
    else
    {
        // will search from the start of the selection and upward
        // to the start of the text
        findText.chrg.cpMax = 0;
    }

    findText.lpstrText = search.m_searchValue.wc_str();

    if (SendMessage(GetHwnd(), EM_FINDTEXTEXW, flags, (LPARAM)&findText) == -1)
    {
        return wxTextSearchResult();
    }

    return wxTextSearchResult{ findText.chrgText.cpMin, findText.chrgText.cpMax };
}

#endif // wxUSE_RICHEDIT

void wxTextCtrl::WriteText(const wxString& value)
{
    DoWriteText(value);
}

void wxTextCtrl::DoWriteText(const wxString& value, int flags)
{
    bool selectionOnly = (flags & SetValue_SelectionOnly) != 0;
    wxString valueDos;
    if ( m_windowStyle & wxTE_MULTILINE )
        valueDos = wxTextFile::Translate(value, wxTextFileType_Dos);
    else
        valueDos = value;

#if wxUSE_RICHEDIT
    if ( IsRich() )
    {
        // first, ensure that the new text will be in the default style
        if ( !m_defaultStyle.IsDefault() )
        {
            long start, end;
            GetSelection(&start, &end);
            SetStyle(start, end, m_defaultStyle);
        }
    }

#endif // wxUSE_RICHEDIT
    // in some cases we get 2 EN_CHANGE notifications after the SendMessage
    // call (this happens for plain EDITs with EM_REPLACESEL and under some
    // -- undetermined -- conditions with rich edit) and sometimes we don't
    // get any events at all (plain EDIT with WM_SETTEXT), so ensure that
    // we generate exactly one of them by ignoring all but the first one in
    // SendUpdateEvent() and generating one ourselves if we hadn't got any
    // notifications from Windows
    if ( !(flags & SetValue_SendEvent) )
        m_updatesCount = -2;        // suppress any update event

    UpdatesCountFilter ucf(m_updatesCount);

    // Remember the length of the text we're inserting so that
    // AdjustSpaceLimit() could adjust the limit to be big enough for it:
    // and also signal us whether it did it by resetting it to 0.
    gs_lenOfInsertedText.push(valueDos.length());

    ::SendMessage(GetHwnd(), selectionOnly ? EM_REPLACESEL : WM_SETTEXT,
                  // EM_REPLACESEL takes 1 to indicate the operation should be redoable
                  selectionOnly ? 1 : 0, wxMSW_CONV_LPARAM(valueDos));

    const int lenActuallyInserted = gs_lenOfInsertedText.top();
    gs_lenOfInsertedText.pop();

    if ( lenActuallyInserted == -1 )
    {
        // Text size limit has been hit and added text has been truncated.
        // But the max length has been increased by the EN_MAXTEXT message
        // handler, which also reset the top of the lengths stack to -1),
        // so we should be able to set it successfully now if we try again.
        if ( selectionOnly )
            Undo();

        ::SendMessage(GetHwnd(), selectionOnly ? EM_REPLACESEL : WM_SETTEXT,
                      selectionOnly ? 1 : 0, wxMSW_CONV_LPARAM(valueDos));
    }

    if ( !ucf.GotUpdate() && (flags & SetValue_SendEvent) )
    {
        SendUpdateEvent();
    }
}

void wxTextCtrl::AppendText(const wxString& text)
{
    wxTextEntry::AppendText(text);

#if wxUSE_RICHEDIT
    // don't do this if we're frozen, saves some time
    if ( !IsFrozen() && IsMultiLine() && GetRichVersion() > 1 )
    {
        ::SendMessage(GetHwnd(), WM_VSCROLL, SB_BOTTOM, (LPARAM)nullptr);
    }
#endif // wxUSE_RICHEDIT
}

void wxTextCtrl::Clear()
{
    ::SetWindowText(GetHwnd(), wxEmptyString);

    if ( IsMultiLine() && !IsRich() )
    {
        // rich edit controls send EN_UPDATE from WM_SETTEXT handler themselves
        // but the normal ones don't -- make Clear() behaviour consistent by
        // always sending this event
        SendUpdateEvent();
    }
}

bool wxTextCtrl::EmulateKeyPress(const wxKeyEvent& event)
{
    SetFocus();

    size_t lenOld = GetValue().length();

    wxUint32 code = event.GetRawKeyCode();
    ::keybd_event((BYTE)code, 0, 0 /* key press */, 0);
    ::keybd_event((BYTE)code, 0, KEYEVENTF_KEYUP, 0);

    // assume that any alphanumeric key changes the total number of characters
    // in the control - this should work in 99% of cases
    return GetValue().length() != lenOld;
}

// ----------------------------------------------------------------------------
// Accessors
// ----------------------------------------------------------------------------

void wxTextCtrl::SetInsertionPointEnd()
{
    // we must not do anything if the caret is already there because calling
    // SetInsertionPoint() thaws the controls if Freeze() had been called even
    // if it doesn't actually move the caret anywhere and so the simple fact of
    // doing it results in horrible flicker when appending big amounts of text
    // to the control in a few chunks (see DoAddText() test in the text sample)
    const wxTextPos lastPosition = GetLastPosition();
    if ( GetInsertionPoint() == lastPosition )
    {
        return;
    }

    SetInsertionPoint(lastPosition);
}

long wxTextCtrl::GetInsertionPoint() const
{
#if wxUSE_RICHEDIT
    if ( IsRich() )
    {
        CHARRANGE range;
        range.cpMin = 0;
        range.cpMax = 0;
        ::SendMessage(GetHwnd(), EM_EXGETSEL, 0, (LPARAM) &range);
        return range.cpMin;
    }
#endif // wxUSE_RICHEDIT

    return wxTextEntry::GetInsertionPoint();
}

wxTextPos wxTextCtrl::GetLastPosition() const
{
    if ( IsMultiLine() )
    {
#if wxUSE_RICHEDIT
        if ( IsRich() )
        {
            GETTEXTLENGTHEX gtl;
            gtl.flags = GTL_NUMCHARS | GTL_PRECISE;
            gtl.codepage = GetRichVersion() > 1 ? 1200 : CP_ACP;
            return ::SendMessage(GetHwnd(), EM_GETTEXTLENGTHEX, (WPARAM)&gtl, 0);
        }
        else
#endif // wxUSE_RICHEDIT
        {
            return ::GetWindowTextLength(GetHwnd());
        }
    }

    return wxTextEntry::GetLastPosition();
}

// If the return values from and to are the same, there is no
// selection.
void wxTextCtrl::GetSelection(long *from, long *to) const
{
#if wxUSE_RICHEDIT
    if ( IsRich() )
    {
        CHARRANGE charRange;
        ::SendMessage(GetHwnd(), EM_EXGETSEL, 0, (LPARAM) &charRange);

        *from = charRange.cpMin;
        *to = charRange.cpMax;
    }
    else
#endif // !wxUSE_RICHEDIT
    {
        wxTextEntry::GetSelection(from, to);
    }
}

// ----------------------------------------------------------------------------
// selection
// ----------------------------------------------------------------------------

void wxTextCtrl::DoSetSelection(long from, long to, int flags)
{
    HWND hWnd = GetHwnd();

#if wxUSE_RICHEDIT
    if ( IsRich() )
    {
        // if from and to are both -1, it means (in wxWidgets) that all text
        // should be selected, translate this into Windows convention
        if ( (from == -1) && (to == -1) )
        {
            from = 0;
        }

        CHARRANGE range;
        range.cpMin = from;
        range.cpMax = to;
        ::SendMessage(hWnd, EM_EXSETSEL, 0, (LPARAM)&range);
    }
    else
#endif // wxUSE_RICHEDIT
    {
        wxTextEntry::DoSetSelection(from, to, flags);
    }

    if ( (flags & SetSel_Scroll) && !IsFrozen() )
    {
#if wxUSE_RICHEDIT
        // richedit 3.0 (i.e. the version living in riched20.dll distributed
        // with Windows 2000 and beyond) doesn't honour EM_SCROLLCARET when
        // emulating richedit 2.0 unless the control has focus or ECO_NOHIDESEL
        // option is set (but it does work ok in richedit 1.0 mode...)
        //
        // so to make it work we either need to give focus to it here which
        // will probably create many problems (dummy focus events; window
        // containing the text control being brought to foreground
        // unexpectedly; ...) or to temporarily set ECO_NOHIDESEL which may
        // create other problems too -- and in fact it does because if we turn
        // on/off this style while appending the text to the control, the
        // vertical scrollbar never appears in it even if we append tons of
        // text and to work around this the only solution I found was to use
        // ES_DISABLENOSCROLL
        //
        // this is very ugly but I don't see any other way to make this work
        long style = 0;
        if ( GetRichVersion() > 1 )
        {
            if ( !HasFlag(wxTE_NOHIDESEL) )
            {
                // setting ECO_NOHIDESEL also sets WS_VISIBLE and possibly
                // others, remember the style so we can reset it later if needed
                style = ::GetWindowLong(GetHwnd(), GWL_STYLE);
                ::SendMessage(GetHwnd(), EM_SETOPTIONS,
                              ECOOP_OR, ECO_NOHIDESEL);
            }
            //else: everything is already ok
        }
#endif // wxUSE_RICHEDIT

        ::SendMessage(hWnd, EM_SCROLLCARET, 0, (LPARAM)0);

#if wxUSE_RICHEDIT
        // restore ECO_NOHIDESEL if we changed it
        if ( GetRichVersion() > 1 && !HasFlag(wxTE_NOHIDESEL) )
        {
            ::SendMessage(GetHwnd(), EM_SETOPTIONS,
                          ECOOP_AND, ~ECO_NOHIDESEL);
            if ( style != ::GetWindowLong(GetHwnd(), GWL_STYLE) )
                ::SetWindowLong(GetHwnd(), GWL_STYLE, style);
        }
#endif // wxUSE_RICHEDIT
    }
}

// ----------------------------------------------------------------------------
// dirty status
// ----------------------------------------------------------------------------

bool wxTextCtrl::IsModified() const
{
    return ::SendMessage(GetHwnd(), EM_GETMODIFY, 0, 0) != 0;
}

void wxTextCtrl::MarkDirty()
{
    ::SendMessage(GetHwnd(), EM_SETMODIFY, TRUE, 0);
}

void wxTextCtrl::DiscardEdits()
{
    ::SendMessage(GetHwnd(), EM_SETMODIFY, FALSE, 0);
}

// ----------------------------------------------------------------------------
// Positions <-> coords
// ----------------------------------------------------------------------------

int wxTextCtrl::GetNumberOfLines() const
{
    return (int)::SendMessage(GetHwnd(), EM_GETLINECOUNT, 0, 0);
}

long wxTextCtrl::XYToPosition(long x, long y) const
{
    // This gets the char index for the _beginning_ of this line
    long charIndex;
    if ( IsMultiLine() )
    {
        charIndex = ::SendMessage(GetHwnd(), EM_LINEINDEX, y, 0);
        if ( charIndex == -1 )
            return -1;
    }
    else
    {
        if ( y != 0 )
            return -1;

        charIndex = 0;
    }

    // Line is identified by a character position!
    long lineLength = ::SendMessage(GetHwnd(), EM_LINELENGTH, charIndex, 0);

    // Notice that x == lineLength is still valid because it corresponds either
    // to the position of the LF at the end of any line except the last one or
    // to the last position, which is the position after the last character,
    // for the last line.
    if ( x > lineLength )
        return -1;

    return charIndex + x;
}

bool wxTextCtrl::PositionToXY(long pos, long *x, long *y) const
{
    HWND hWnd = GetHwnd();

    // This gets the line number containing the character
    long lineNo;
#if wxUSE_RICHEDIT
    if ( IsRich() )
    {
        lineNo = ::SendMessage(hWnd, EM_EXLINEFROMCHAR, 0, pos);
    }
    else
#endif // wxUSE_RICHEDIT
    {
        lineNo = ::SendMessage(hWnd, EM_LINEFROMCHAR, pos, 0);
    }

    if ( lineNo == -1 )
    {
        // no such line
        return false;
    }

    // This gets the char index for the _beginning_ of this line
    long charIndex = ::SendMessage(hWnd, EM_LINEINDEX, lineNo, 0);
    if ( charIndex == -1 )
    {
        return false;
    }

    // Line is identified by a character position!
    // New lines characters are not included.
    long lineLength = ::SendMessage(hWnd, EM_LINELENGTH, charIndex, 0);

    // To simplify further calculations, make position relative
    // to the beginning of the line.
    pos -= charIndex;

    // We need to apply different approach for the position referring
    // to the last line so check if the next line exists.
    long charIndexNextLn = IsMultiLine() ?
                           ::SendMessage(hWnd, EM_LINEINDEX, lineNo + 1, 0)
                           : -1;
    if ( charIndexNextLn == -1 )
    {
        // No next line. Char position refers to the last line so
        // the length of the line obtained with EM_LINELENGTH is
        // correct because there are no new line characters at the end.
        if ( pos > lineLength )
        {
            return false;
        }
    }
    else
    {
        // Next line found. Char position doesn't refer to the last line
        // so we need to take into account new line characters which were
        // not counted by EM_LINELENGTH.
        long lineLengthFull = charIndexNextLn - charIndex;
        // (lineLengthFull - lineLength) can be 0 (for wrapped line),
        // 1 (for \r new line mark) or 2 (for \r\n new line mark).
        if ( pos > lineLengthFull )
        {
            return false;
        }
        if ( pos > lineLength )
        {
            // Char position refers to the second character of the CR/LF mark
            // and its physical X-Y position is the same as the position
            // of the first one.
            pos = lineLength;
        }
    }

    // The X position is therefore a char position in the line.
    if ( x )
        *x = pos;
    if ( y )
        *y = lineNo;

    return true;
}

wxTextCtrlHitTestResult
wxTextCtrl::HitTest(const wxPoint& pt, long *posOut) const
{
    // first get the position from Windows
    LPARAM lParam;

#if wxUSE_RICHEDIT
    POINTL ptl;
    if ( IsRich() )
    {
        // for rich edit controls the position is passed iva the struct fields
        ptl.x = pt.x;
        ptl.y = pt.y;
        lParam = (LPARAM)&ptl;
    }
    else
#endif // wxUSE_RICHEDIT
    {
        // for the plain ones, we are limited to 16 bit positions which are
        // combined in a single 32 bit value
        lParam = MAKELPARAM(pt.x, pt.y);
    }

    LRESULT pos = ::SendMessage(GetHwnd(), EM_CHARFROMPOS, 0, lParam);

    if ( pos == -1 )
    {
        // this seems to indicate an error...
        return wxTE_HT_UNKNOWN;
    }

#if wxUSE_RICHEDIT
    if ( !IsRich() )
#endif // wxUSE_RICHEDIT
    {
        // for plain EDIT controls the higher word contains something else
        pos = LOWORD(pos);
    }


    // next determine where it is relatively to our point: EM_CHARFROMPOS
    // always returns the closest character but we need to be more precise, so
    // double check that we really are where it pretends
    POINTL ptReal;

#if wxUSE_RICHEDIT
    // FIXME: we need to distinguish between richedit 2 and 3 here somehow but
    //        we don't know how to do it
    if ( IsRich() )
    {
        ::SendMessage(GetHwnd(), EM_POSFROMCHAR, (WPARAM)&ptReal, pos);
    }
    else
#endif // wxUSE_RICHEDIT
    {
        LRESULT lRc = ::SendMessage(GetHwnd(), EM_POSFROMCHAR, pos, 0);

        if ( lRc == -1 )
        {
            // this is apparently returned when pos corresponds to the last
            // position
            ptReal.x =
            ptReal.y = 0;
        }
        else
        {
            ptReal.x = LOWORD(lRc);
            ptReal.y = HIWORD(lRc);
        }
    }

    wxTextCtrlHitTestResult rc;

    if ( pt.y > ptReal.y + GetCharHeight() )
        rc = wxTE_HT_BELOW;
    else if ( pt.x > ptReal.x + GetCharWidth() )
        rc = wxTE_HT_BEYOND;
    else
        rc = wxTE_HT_ON_TEXT;

    if ( posOut )
        *posOut = pos;

    return rc;
}

wxPoint wxTextCtrl::DoPositionToCoords(long pos) const
{
    // FIXME: This code is broken for rich edit version 2.0 as it uses the same
    // API as plain edit i.e. the coordinates are returned directly instead of
    // filling the POINT passed as WPARAM with them but we can't distinguish
    // between 2.0 and 3.0 unfortunately (see also the use of EM_POSFROMCHAR
    // above).
#if wxUSE_RICHEDIT
    if ( IsRich() )
    {
        POINT pt;
        LRESULT rc = ::SendMessage(GetHwnd(), EM_POSFROMCHAR, (WPARAM)&pt, pos);
        if ( rc != -1 )
            return wxPoint(pt.x, pt.y);
    }
    else
#endif // wxUSE_RICHEDIT
    {
        LRESULT rc = ::SendMessage(GetHwnd(), EM_POSFROMCHAR, pos, 0);
        if ( rc == -1 )
        {
            // Finding coordinates for the last position of the control fails
            // in plain EDIT control, try to compensate for it by finding it
            // ourselves from the position of the previous character.
            if ( pos < GetLastPosition() )
            {
                // It's not the expected correctable failure case so just fail.
                return wxDefaultPosition;
            }

            if ( pos == 0 )
            {
                // We're being asked the coordinates of the first (and last and
                // only) position in an empty control. There is no way to get
                // it directly with EM_POSFROMCHAR but EM_GETMARGINS returns
                // the correct value for at least the horizontal offset.
                rc = ::SendMessage(GetHwnd(), EM_GETMARGINS, 0, 0);

                // Text control seems to effectively add 1 to margin.
                return wxPoint(LOWORD(rc) + 1, 1);
            }

            // We do have a previous character, try to get its coordinates.
            rc = ::SendMessage(GetHwnd(), EM_POSFROMCHAR, pos - 1, 0);
            if ( rc == -1 )
            {
                // If getting coordinates of the previous character failed as
                // well, just give up.
                return wxDefaultPosition;
            }

            wxString prevChar = GetRange(pos - 1, pos);
            wxSize prevCharSize = GetTextExtent(prevChar);

            if ( prevChar == wxT("\n" ))
            {
                // 'pos' is at the beginning of a new line so its X coordinate
                // should be the same as X coordinate of the first character of
                // any other line while its Y coordinate will be approximately
                // (but we can't compute it exactly...) one character height
                // more than that of the previous character.
                LRESULT coords0 = ::SendMessage(GetHwnd(), EM_POSFROMCHAR, 0, 0);
                if ( coords0 == -1 )
                    return wxDefaultPosition;

                rc = MAKELPARAM(LOWORD(coords0), HIWORD(rc) + prevCharSize.y);
            }
            else
            {
                // Simple case: previous character is in the same line so this
                // one is just after it.
                rc += MAKELPARAM(prevCharSize.x, 0);
            }
        }

        // Notice that {LO,HI}WORD macros return WORDs, i.e. unsigned shorts,
        // while we want to have signed values here (the y coordinate of any
        // position above the first currently visible line is negative, for
        // example), hence the need for casts.
        return wxPoint(static_cast<short>(LOWORD(rc)),
                        static_cast<short>(HIWORD(rc)));
    }

    return wxDefaultPosition;
}


// ----------------------------------------------------------------------------
//
// ----------------------------------------------------------------------------

void wxTextCtrl::ShowPosition(long pos)
{
    HWND hWnd = GetHwnd();

    // To scroll to a position, we pass the number of lines and characters
    // to scroll *by*. This means that we need to:
    // (1) Find the line position of the current line.
    // (2) Find the line position of pos.
    // (3) Scroll by (pos - current).
    // For now, ignore the horizontal scrolling.

    // Is this where scrolling is relative to - the line containing the caret?
    // Or is the first visible line??? Try first visible line.
//    int currentLineLineNo1 = (int)::SendMessage(hWnd, EM_LINEFROMCHAR, -1, 0L);

    int currentLineLineNo = (int)::SendMessage(hWnd, EM_GETFIRSTVISIBLELINE, 0, 0);

    int specifiedLineLineNo = (int)::SendMessage(hWnd, EM_LINEFROMCHAR, pos, 0);

    int linesToScroll = specifiedLineLineNo - currentLineLineNo;

    if (linesToScroll != 0)
      ::SendMessage(hWnd, EM_LINESCROLL, 0, linesToScroll);
}

long wxTextCtrl::GetLengthOfLineContainingPos(long pos) const
{
    return ::SendMessage(GetHwnd(), EM_LINELENGTH, pos, 0);
}

int wxTextCtrl::GetLineLength(long lineNo) const
{
    long pos = XYToPosition(0, lineNo);

    if ( pos == -1 )
        return -1;

    return GetLengthOfLineContainingPos(pos);
}

wxString wxTextCtrl::GetLineText(long lineNo) const
{
    size_t len = (size_t)GetLineLength(lineNo) + 1;

    // there must be at least enough place for the length WORD in the
    // buffer
    len += sizeof(WORD);

    wxString str;
    {
        wxStringBufferLength tmp(str, len);
        wxChar *buf = tmp;

        *(WORD *)buf = (WORD)len;
        len = (size_t)::SendMessage(GetHwnd(), EM_GETLINE, lineNo, (LPARAM)buf);

#if wxUSE_RICHEDIT
        if ( IsRich() )
        {
            // remove the '\r' returned by the rich edit control, the user code
            // should never see it
            if ( buf[len - 2] == wxT('\r') && buf[len - 1] == wxT('\n') )
            {
                // richedit 1.0 uses "\r\n" as line terminator, so remove "\r"
                // here and "\n" below
                buf[len - 2] = wxT('\n');
                len--;
            }
            else if ( buf[len - 1] == wxT('\r') )
            {
                // richedit 2.0+ uses only "\r", replace it with "\n"
                buf[len - 1] = wxT('\n');
            }
        }
#endif // wxUSE_RICHEDIT

        // remove the '\n' at the end, if any (this is how this function is
        // supposed to work according to the docs)
        if ( len && buf[len - 1] == wxT('\n') )
        {
            len--;
        }

        buf[len] = 0;
        tmp.SetLength(len);
    }

    return str;
}

void wxTextCtrl::SetMaxLength(unsigned long len)
{
#if wxUSE_RICHEDIT
    if ( IsRich() )
    {
        ::SendMessage(GetHwnd(), EM_EXLIMITTEXT, 0, len ? len : 0x7fffffff);
    }
    else
#endif // wxUSE_RICHEDIT
    {
        wxTextEntry::SetMaxLength(len);
    }
}

// ----------------------------------------------------------------------------
// RTL support
// ----------------------------------------------------------------------------

void wxTextCtrl::SetLayoutDirection(wxLayoutDirection dir)
{
    // We only need to handle this specifically for plain EDIT controls, rich
    // edit ones behave like any other window.
    if ( IsRich() )
    {
        wxTextCtrlBase::SetLayoutDirection(dir);
    }
    else
    {
        if ( wxUpdateEditLayoutDirection(GetHwnd(), dir) )
        {
            // Update text layout by forcing the control to redo it, a simple
            // Refresh() is not enough.
            SendSizeEvent();
            Refresh();
        }
    }
}

wxLayoutDirection wxTextCtrl::GetLayoutDirection() const
{
    // Just as above, we need to handle plain EDIT controls specially.
    return IsRich() ? wxTextCtrlBase::GetLayoutDirection()
                    : wxGetEditLayoutDirection(GetHwnd());
}

// ----------------------------------------------------------------------------
// Undo/redo
// ----------------------------------------------------------------------------

void wxTextCtrl::Redo()
{
#if wxUSE_RICHEDIT
    if ( GetRichVersion() > 1 )
    {
        ::SendMessage(GetHwnd(), EM_REDO, 0, 0);
        return;
    }
#endif // wxUSE_RICHEDIT

    wxTextEntry::Redo();
}

bool wxTextCtrl::CanRedo() const
{
#if wxUSE_RICHEDIT
    if ( GetRichVersion() > 1 )
        return ::SendMessage(GetHwnd(), EM_CANREDO, 0, 0) != 0;
#endif // wxUSE_RICHEDIT

    return wxTextEntry::CanRedo();
}

#if wxUSE_RICHEDIT

void wxTextCtrl::EmptyUndoBuffer()
{
#if wxUSE_OLE && defined(wxHAS_TOM_H)
    // We need to use Undo(tomFalse) to clear the undo buffer, but calling it
    // also disables the undo buffer, so we need to enable it again immediately
    // after clearing by calling Undo(tomTrue).
    if ( GetRichVersion() >= 4 )
    {
        wxCOMPtr<IRichEditOle> pRichEditOle;
        if ( SendMessage(GetHwnd(), EM_GETOLEINTERFACE,
                         0, (LPARAM)&pRichEditOle) && pRichEditOle )
        {
            wxCOMPtr<ITextDocument> pDoc;
            HRESULT hr = pRichEditOle->QueryInterface
                                       (
                                        wxIID_PPV_ARGS(ITextDocument, &pDoc)
                                       );
            if ( SUCCEEDED(hr) )
            {
                hr = pDoc->Undo(tomFalse, nullptr);
                if ( SUCCEEDED(hr) )
                    pDoc->Undo(tomTrue, nullptr);
            }
        }
    }
#endif // wxUSE_OLE && wxHAS_TOM_H
}
#endif // wxUSE_RICHEDIT

// ----------------------------------------------------------------------------
// caret handling (Windows only)
// ----------------------------------------------------------------------------

bool wxTextCtrl::ShowNativeCaret(bool show)
{
    if ( show != m_isNativeCaretShown )
    {
        if ( !(show ? ::ShowCaret(GetHwnd()) : ::HideCaret(GetHwnd())) )
        {
            // not an error, may simply indicate that it's not shown/hidden
            // yet (i.e. it had been hidden/shown 2 times before)
            return false;
        }

        m_isNativeCaretShown = show;
    }

    return true;
}

// ----------------------------------------------------------------------------
// implementation details
// ----------------------------------------------------------------------------

void wxTextCtrl::Command(wxCommandEvent & event)
{
    SetValue(event.GetString());
    ProcessCommand (event);
}

void wxTextCtrl::OnDropFiles(wxDropFilesEvent& event)
{
    // By default, load the first file into the text window.
    if (event.GetNumberOfFiles() > 0)
    {
        LoadFile(event.GetFiles()[0]);
    }
}

// ----------------------------------------------------------------------------
// kbd input processing
// ----------------------------------------------------------------------------

bool wxTextCtrl::MSWShouldPreProcessMessage(WXMSG* msg)
{
    // Handle keys specific to (multiline) text controls here.
    if ( msg->message == WM_KEYDOWN && !(HIWORD(msg->lParam) & KF_ALTDOWN) )
    {
        switch ( msg->wParam )
        {
            case VK_RETURN:
                // This key must be handled only by multiline controls and only
                // if it's pressed on its own, not with some modifier.
                if ( !wxIsShiftDown() && !wxIsCtrlDown() && IsMultiLine() )
                    return false;
                break;

            case VK_BACK:
                if ( wxIsCtrlDown() && !wxIsShiftDown() &&
                        MSWNeedsToHandleCtrlBackspace() )
                    return false;
                break;
        }
    }

    // Delegate all the other checks to the base classes.
    return wxTextEntry::MSWShouldPreProcessMessage(msg) &&
                wxControl::MSWShouldPreProcessMessage(msg);
}

void wxTextCtrl::OnChar(wxKeyEvent& event)
{
    switch ( event.GetKeyCode() )
    {
        case WXK_RETURN:
        case WXK_NUMPAD_ENTER:
            // Single line controls only get this key code if they have
            // wxTE_PROCESS_ENTER style, but multiline ones always get it
            // because they need it for themselves. However we shouldn't
            // generate wxEVT_TEXT_ENTER for the controls without this style,
            // so test for it explicitly.
            if ( HasFlag(wxTE_PROCESS_ENTER) )
            {
                wxCommandEvent evt(wxEVT_TEXT_ENTER, m_windowId);
                InitCommandEvent(evt);
                evt.SetString(GetValue());
                if ( HandleWindowEvent(evt) )
                    return;
            }
            break;

        case WXK_TAB:
            // ok, so this is getting absolutely ridiculous but I don't see
            // any other way to fix this bug: when a multiline text control is
            // inside a wxFrame, we need to generate the navigation event as
            // otherwise nothing happens at all, but when the same control is
            // created inside a dialog, IsDialogMessage() *does* switch focus
            // all by itself and so if we do it here as well, it is advanced
            // twice and goes to the next control... to prevent this from
            // happening we're doing this ugly check, the logic being that if
            // we don't have focus then it had been already changed to the next
            // control
            //
            // the right thing to do would, of course, be to understand what
            // the hell is IsDialogMessage() doing but this is beyond my feeble
            // forces at the moment unfortunately
            if ( !(m_windowStyle & wxTE_PROCESS_TAB) || !IsEditable() )
            {
                if ( ::GetFocus() == GetHwnd() )
                {
                    int flags = wxNavigationKeyEvent::FromTab;
                    if (!event.ShiftDown())
                        flags |= wxNavigationKeyEvent::IsForward ;
                    if (event.ControlDown())
                        flags |= wxNavigationKeyEvent::WinChange ;
                    if (Navigate(flags))
                        return;
                }
            }
            else
            {
                // Insert tab since calling the default Windows handler
                // doesn't seem to do it
                WriteText(wxT("\t"));
                return;
            }
            break;
    }

    // no, we didn't process it
    event.Skip();
}

#if wxUSE_OLE

void wxTextCtrl::MSWProcessSpecialKey(wxKeyEvent& event)
{
    // It is not a good idea, in general, to manually call another event
    // handler, but here we need to do exactly the same thing as in OnChar()
    // above, so it doesn't seem to make much sense to add another function to
    // forward to when we can just call it directly.
    OnChar(event);
}

#endif // wxUSE_OLE

void wxTextCtrl::MSWDeleteWordBack()
{
    // Surprisingly the behaviour of Ctrl+Backspace is different in all three
    // cases where it's supported by MSW itself:
    //
    //  1. Rich edit controls simply ignore selection and handle it as usual.
    //  2. Plain edit controls don't do anything when there is selection.
    //  3. Notepad in Windows 10 1809 and later deletes just the selection.
    //
    // The latter behaviour seems the most useful, so do it like this here too.
    if ( HasSelection() )
    {
        RemoveSelection();
        return;
    }

    // This variable contains one end of the range to delete, the rest of this
    // function is concerned with finding the starting end of this range.
    const long end = GetInsertionPoint();

    long col, line;
    if ( !PositionToXY(end, &col, &line) )
        return;

    // We stop at the start of line, so remember it.
    const long start = XYToPosition(0, line);

    const wxString& text = GetLineText(line);

    // The way it works in rich text controls or when SHAutoComplete() is used
    // is that it deletes everything until the first span of alphanumeric
    // characters it finds (moving backwards). But the implementation of the
    // same shortcut in in notepad in Windows 10 versions 1809 and later
    // doesn't behave in quite the same way and doesn't handle alphanumeric
    // characters specially, i.e. it just stops on space. This seems more
    // useful and simpler to implement, and it probably will become standard in
    // the future, so do it like this here too.

    // First skip all space starting from the character to the left of the
    // current one.
    long current = end;
    for ( ;; )
    {
        if ( current == start )
        {
            // When there is nothing but spaces to the left until the start of
            // line, we need to delete these spaces (if any) as well as the new
            // line separating this line from the previous one (if any).
            if ( line > 0 )
            {
                // This function is only used with plain EDITs which use "\r\n"
                // and so we need to subtract 2 to account for the new line.
                current -= 2;
            }

            break;
        }

        // We start from the previous character.
        --current;

        // Did we find the end of the previous "word"?
        if ( text[current - start] != ' ' )
        {
            for ( ;; )
            {
                if ( current == start )
                {
                    // We don't delete the new line in this case, as we're going to
                    // delete some non-spaces in this line.
                    break;
                }

                --current;

                if ( text[current - start] == ' ' )
                {
                    // Don't delete the space itself.
                    ++current;
                    break;
                }
            }

            break;
        }
    }

    Remove(current, end);
}

bool wxTextCtrl::MSWNeedsToHandleCtrlBackspace() const
{
    // We want to handle the undocumented Ctrl+Backspace shortcut only if it's
    // not handled by the control itself, which is a bit tricky because it's
    // normally only handled by rich edit controls, but plain EDIT ones may
    // also handle it if they use SHAutoComplete().
    return !HasFlag(wxTE_READONLY) &&
                !IsRich() &&
                    !MSWUsesStandardAutoComplete();
}

void wxTextCtrl::OnKeyDown(wxKeyEvent& event)
{
    // Handle Ctrl+Backspace if necessary: this is not a documented standard
    // shortcut, but it's a de facto standard and people expect it to work.
    if ( MSWNeedsToHandleCtrlBackspace() &&
                event.GetModifiers() == wxMOD_CONTROL &&
                    event.GetKeyCode() == WXK_BACK )
    {
        MSWDeleteWordBack();
        return;
    }

    // richedit control doesn't send WM_PASTE, WM_CUT and WM_COPY messages
    // when Ctrl-V, X or C is pressed and this prevents wxClipboardTextEvent
    // from working. So we work around it by intercepting these shortcuts
    // ourselves and emitting clipboard events (which richedit will handle,
    // so everything works as before, including pasting of rich text):
    if ( IsRich() )
    {
        if ( event.GetModifiers() == wxMOD_CONTROL )
        {
            switch ( event.GetKeyCode() )
            {
                case 'C':
                case WXK_INSERT:
                    Copy();
                    return;
                case 'X':
                    Cut();
                    return;
                case 'V':
                    Paste();
                    return;
                default:
                    break;
            }
        }
        else if ( event.GetModifiers() == wxMOD_SHIFT )
        {
            switch ( event.GetKeyCode() )
            {
                case WXK_INSERT:
                    Paste();
                    return;
                case WXK_DELETE:
                    Cut();
                    return;
            }
        }
    }

    if ( IsMultiLine() )
    {
        // Default window procedure of multiline edit controls posts WM_CLOSE to
        // the parent window when it gets Escape key press for some reason, prevent
        // it from doing this as this resulted in dialog boxes being closed on
        // Escape even when they shouldn't be (we do handle Escape ourselves
        // correctly in the situations when it should close them).
        if ( event.GetKeyCode() == WXK_ESCAPE )
            return;

        // We also handle Ctrl-A as the native EDIT control doesn't do it by
        // default (but RICHEDIT one does, so there is no need to check for it
        // in the switch above), however it's a de facto standard accelerator
        // and people expect it to work.
        if ( event.GetModifiers() == wxMOD_CONTROL && event.GetKeyCode() == 'A' )
        {
            SelectAll();
            return;
        }
    }

    // no, we didn't process it
    event.Skip();
}

void wxTextCtrl::Paste()
{
    // Before pasting, check that the pasted text will fit, unless an explicit
    // maximum length was set, to avoid only pasting some part of it.
    //
    // Note that rich text controls do not send WM_PASTE, so we can't do it in
    // response to it, but we could handle EN_PROTECTED (after requesting it by
    // specifying ENM_PROTECTED in EM_SETEVENTMASK argument) and check for the
    // message being WM_PASTE there, but this doesn't seem to be better than
    // the simpler approach used here.
    if ( IsRich() )
    {
        AdjustMaxLengthBeforePaste();
    }

    wxTextCtrlBase::Paste();
}

bool
wxTextCtrl::MSWHandleMessage(WXLRESULT *rc,
                             WXUINT nMsg,
                             WXWPARAM wParam,
                             WXLPARAM lParam)
{
    bool processed = wxTextCtrlBase::MSWHandleMessage(rc, nMsg, wParam, lParam);

    switch ( nMsg )
    {
        case WM_CHAR:
            // Handle the special case of "Enter" key: the user code needs to specify
            // wxTE_PROCESS_ENTER style to get it in the first place, but if this flag
            // is used, then even if the wxEVT_TEXT_ENTER handler skips the event, the
            // normal action of this key is not performed because IsDialogMessage() is
            // not called and, also, an annoying beep is generated by EDIT default
            // WndProc.
            //
            // Fix these problems by explicitly performing the default function of this
            // key (which would be done by MSWProcessMessage() if we didn't have
            // wxTE_PROCESS_ENTER) and preventing the default WndProc from getting it.
            if ( !processed && wParam == VK_RETURN && IsSingleLine() )
            {
                if ( ClickDefaultButtonIfPossible() )
                    processed = true;
            }
            break;

        case WM_GETDLGCODE:
            {
                // Ensure that the result value is initialized even if the base
                // class didn't handle WM_GETDLGCODE but just update the value
                // returned by it if it did handle it.
                if ( !processed )
                {
                    *rc = MSWDefWindowProc(nMsg, wParam, lParam);
                    processed = true;
                }

                // we always want the chars and the arrows: the arrows for
                // navigation and the chars because we want Ctrl-C to work even
                // in a read only control
                long lDlgCode = DLGC_WANTCHARS | DLGC_WANTARROWS;

                // we may have several different cases:
                // 1. normal: both TAB and ENTER are used for navigation
                // 2. ctrl wants TAB for itself: ENTER is used to pass to
                //    the next control in the dialog
                // 3. ctrl wants ENTER for itself: TAB is used for dialog
                //    navigation
                // 4. ctrl wants both TAB and ENTER: Ctrl-ENTER is used to
                //    go to the next control (we need some way to do it)

                // multiline controls should always get ENTER for themselves
                if ( HasFlag(wxTE_PROCESS_ENTER) || HasFlag(wxTE_MULTILINE) )
                    lDlgCode |= DLGC_WANTMESSAGE;

                if ( HasFlag(wxTE_PROCESS_TAB) )
                    lDlgCode |= DLGC_WANTTAB;

                *rc |= lDlgCode;

                if ( IsMultiLine() )
                {
                    // The presence of this style, coming from the default EDIT
                    // WndProc, indicates that the control contents should be
                    // selected when it gets focus, but we don't want this to
                    // happen for the multiline controls, so clear it.
                    *rc &= ~DLGC_HASSETSEL;
                }
            }
            break;

#if wxUSE_MENUS
        case WM_SETCURSOR:
            // rich text controls seem to have a bug and don't change the
            // cursor to the standard arrow one from the I-beam cursor usually
            // used by them even when a popup menu is shown (this works fine
            // for plain EDIT controls though), so explicitly work around this
            if ( IsRich() )
            {
                // wxCurrentPopupMenu stores the popup menu that will receive
                // WM_COMMAND, but it may be non-null even when the underlying
                // native menu is no longer shown. Use ::IsMenu() to check whether
                // the menu still exists.
                extern wxMenu *wxCurrentPopupMenu;
                if ( wxCurrentPopupMenu &&
                        wxCurrentPopupMenu->GetInvokingWindow() == this &&
                        ::IsMenu(GetHmenuOf(wxCurrentPopupMenu)) )
                    ::SetCursor(GetHcursorOf(*wxSTANDARD_CURSOR));
            }
            break;
#endif // wxUSE_MENUS

        case WM_PASTE:
            // Note that we get this message for plain EDIT controls only, rich
            // controls are dealt with in our own Paste().
            AdjustMaxLengthBeforePaste();
            break;
    }

    return processed;
}

// ----------------------------------------------------------------------------
// text control event processing
// ----------------------------------------------------------------------------

bool wxTextCtrl::SendUpdateEvent()
{
    switch ( m_updatesCount )
    {
        case 0:
            // remember that we've got an update
            m_updatesCount++;
            break;

        case 1:
            // we had already sent one event since the last control modification
            return false;

        default:
            wxFAIL_MSG( wxT("unexpected wxTextCtrl::m_updatesCount value") );
            wxFALLTHROUGH;

        case -1:
            // we hadn't updated the control ourselves, this event comes from
            // the user, don't need to ignore it nor update the count
            break;

        case -2:
            // the control was updated programmatically and we do NOT want to
            // send events
            return false;
    }

    return SendTextUpdatedEvent();
}

bool wxTextCtrl::MSWCommand(WXUINT param, WXWORD WXUNUSED(id))
{
    switch ( param )
    {
        case EN_CHANGE:
            SendUpdateEvent();
            break;

        case EN_MAXTEXT:
            // the text size limit has been hit -- try to increase it
            if ( !AdjustSpaceLimit() )
            {
                wxCommandEvent event(wxEVT_TEXT_MAXLEN, m_windowId);
                InitCommandEvent(event);
                event.SetString(GetValue());
                ProcessCommand(event);
            }
            break;

            // the other edit notification messages are not processed (or, in
            // the case of EN_{SET/KILL}FOCUS were already handled at WM_SET/
            // KILLFOCUS level)
        default:
            return false;
    }

    // processed
    return true;
}

WXHBRUSH wxTextCtrl::MSWControlColor(WXHDC hDC, WXHWND hWnd)
{
    if ( !IsThisEnabled() && !HasFlag(wxTE_MULTILINE) )
        return MSWControlColorDisabled(hDC);

    return wxTextCtrlBase::MSWControlColor(hDC, hWnd);
}

bool wxTextCtrl::HasSpaceLimit(unsigned int *len) const
{
    // HACK: we try to automatically extend the limit for the amount of text
    //       to allow (interactively) entering more than 64Kb of text under
    //       Win9x but we shouldn't reset the text limit which was previously
    //       set explicitly with SetMaxLength()
    //
    //       Unfortunately there is no EM_GETLIMITTEXTSETBYUSER and so we don't
    //       know the limit we set (if any). We could solve this by storing the
    //       limit we set in wxTextCtrl but to save space we prefer to simply
    //       test here the actual limit value: we consider that SetMaxLength()
    //       can only be called for small values while EN_MAXTEXT is only sent
    //       for large values (in practice the default limit seems to be 30000
    //       but make it smaller just to be on the safe side)
    *len = ::SendMessage(GetHwnd(), EM_GETLIMITTEXT, 0, 0);
    return *len < 10001;

}

bool wxTextCtrl::AdjustSpaceLimit()
{
    unsigned int limit;
    if ( HasSpaceLimit(&limit) )
        return false;

    unsigned int len = ::GetWindowTextLength(GetHwnd());
    if ( len >= limit )
    {
        unsigned long increaseBy;

        // We need to increase the size of the buffer and to avoid increasing
        // it too many times make sure that we make it at least big enough to
        // fit all the text we are currently inserting into the control, if
        // we're inserting any, i.e. if we're called from DoWriteText().
        if ( !gs_lenOfInsertedText.empty() )
        {
            increaseBy = gs_lenOfInsertedText.top();

            // Indicate to the caller that we increased the limit.
            gs_lenOfInsertedText.top() = -1;
        }
        else // Not inserting text, must be text actually typed by user.
        {
            increaseBy = 0;
        }

        // But also increase it by at least 32KB chunks -- again, to avoid
        // doing it too often -- and round it up to 32KB in any case.
        if ( increaseBy < 0x8000 )
            increaseBy = 0x8000;
        else
            increaseBy = (increaseBy + 0x7fff) & ~0x7fff;

        SetMaxLength(len + increaseBy);
    }

    // we changed the limit
    return true;
}

void wxTextCtrl::AdjustMaxLengthBeforePaste()
{
#if wxUSE_CLIPBOARD
    // We only need to do this for multi line controls, single lines should
    // never receive more text than fits into them by default anyhow.
    if ( IsSingleLine() )
        return;

    // Also don't override an explicitly set limit.
    unsigned int limit;
    if ( HasSpaceLimit(&limit) )
        return;

    // Otherwise check if we have enough space for clipboard data. We only do
    // it for plain text because this is all we know how to handle here.
    wxClipboardLocker lock;
    wxTextDataObject textData;
    if ( !wxTheClipboard->GetData(textData) )
        return;

    // Unfortunately we can't just get the length directly because we need to
    // convert EOLs, otherwise our calculation of the required length could be
    // way off when there are many lines.
    const unsigned long lenPasted =
         wxTextFile::Translate(textData.GetText(), wxTextFileType_Dos).length();

    long from, to;
    GetSelection(&from, &to);
    const unsigned long lenSel = to - from;

    const unsigned long lenCurrent = GetLastPosition();

    // We need enough space for all the current text and all the new
    // text, but the selection will be replaced.
    const unsigned long lenNeeded = lenCurrent - lenSel + lenPasted;
    if ( lenNeeded >= limit )
    {
        SetMaxLength(lenNeeded);
    }
#endif // wxUSE_CLIPBOARD
}

bool wxTextCtrl::AcceptsFocusFromKeyboard() const
{
    // we don't want focus if we can't be edited unless we're a multiline
    // control because then it might be still nice to get focus from keyboard
    // to be able to scroll it without mouse
    return (IsEditable() || IsMultiLine()) && wxControl::AcceptsFocus();
}

wxSize wxTextCtrl::DoGetBestSize() const
{
    return DoGetSizeFromTextSize( FromDIP(DEFAULT_ITEM_WIDTH) );
}

wxSize wxTextCtrl::DoGetSizeFromTextSize(int xlen, int ylen) const
{
    int cy;
    wxFont font = GetFont();
    font.WXAdjustToPPI(GetDPI());
    wxGetCharSize(GetHWND(), nullptr, &cy, font);

    DWORD wText = FromDIP(1);
    ::SystemParametersInfo(SPI_GETCARETWIDTH, 0, &wText, 0);
    wText += xlen;

    int hText = cy;
    if ( m_windowStyle & wxTE_MULTILINE )
    {
        // add space for vertical scrollbar
        if ( !(m_windowStyle & wxTE_NO_VSCROLL) )
            wText += wxGetSystemMetrics(SM_CXVSCROLL, m_parent);

        if ( ylen <= 0 )
        {
            hText *= wxMax(wxMin(GetNumberOfLines(), 10), 2);
            // add space for horizontal scrollbar
            if ( m_windowStyle & wxHSCROLL )
                hText += wxGetSystemMetrics(SM_CYHSCROLL, m_parent);
        }
    }
    // for single line control cy (height + external leading) is ok
    else
    {
        // Add the margins we have previously set
        wxPoint marg( GetMargins() );
        wText += wxMax(0, marg.x);
        hText += wxMax(0, marg.y);
    }

    // Text controls without border are special and have the same height as
    // static labels (they also have the same appearance when they're disable
    // and are often used as a sort of copyable to the clipboard label so it's
    // important that they have the same height as the normal labels to not
    // stand out).
    if ( !HasFlag(wxBORDER_NONE) )
    {
        wText += FromDIP(9); // borders and inner margins

        // we have to add the adjustments for the control height only once, not
        // once per line, so do it after multiplication above
        hText += EDIT_HEIGHT_FROM_CHAR_HEIGHT(cy) - cy;
    }

    // We should always use at least the specified height if it's valid.
    if ( ylen > hText )
        hText = ylen;

    return wxSize(wText, hText);
}

void wxTextCtrl::DoMoveWindow(int x, int y, int width, int height)
{
    // We reset the text of single line controls each time their width changes
    // because they don't adjust their horizontal offset on their own and there
    // doesn't seem to be any way to convince them to do it other than by just
    // setting the text again, see #18268.
    const bool resetText = IsSingleLine() && !IsShownOnScreen();
    int oldWidth = -1;
    if ( resetText )
    {
        oldWidth = GetSize().x;
    }

    wxTextCtrlBase::DoMoveWindow(x, y, width, height);

    if ( resetText && GetSize().x != oldWidth )
    {
        // We need to use DoWriteText() to avoid our own optimization in
        // ChangeValue() which does nothing when the text doesn't really
        // change.
        DoWriteText(DoGetValue(), 0 /* no flags for no events */);
    }
}

// ----------------------------------------------------------------------------
// standard handlers for standard edit menu events
// ----------------------------------------------------------------------------

void wxTextCtrl::OnCut(wxCommandEvent& WXUNUSED(event))
{
    Cut();
}

void wxTextCtrl::OnCopy(wxCommandEvent& WXUNUSED(event))
{
    Copy();
}

void wxTextCtrl::OnPaste(wxCommandEvent& WXUNUSED(event))
{
    Paste();
}

void wxTextCtrl::OnUndo(wxCommandEvent& WXUNUSED(event))
{
    Undo();
}

void wxTextCtrl::OnRedo(wxCommandEvent& WXUNUSED(event))
{
    Redo();
}

void wxTextCtrl::OnDelete(wxCommandEvent& WXUNUSED(event))
{
    RemoveSelection();
}

void wxTextCtrl::OnSelectAll(wxCommandEvent& WXUNUSED(event))
{
    SelectAll();
}

void wxTextCtrl::OnUpdateCut(wxUpdateUIEvent& event)
{
    event.Enable( CanCut() );
}

void wxTextCtrl::OnUpdateCopy(wxUpdateUIEvent& event)
{
    event.Enable( CanCopy() );
}

void wxTextCtrl::OnUpdatePaste(wxUpdateUIEvent& event)
{
    event.Enable( CanPaste() );
}

void wxTextCtrl::OnUpdateUndo(wxUpdateUIEvent& event)
{
    event.Enable( CanUndo() );
}

void wxTextCtrl::OnUpdateRedo(wxUpdateUIEvent& event)
{
    event.Enable( CanRedo() );
}

void wxTextCtrl::OnUpdateDelete(wxUpdateUIEvent& event)
{
    event.Enable( HasSelection() && IsEditable() );
}

void wxTextCtrl::OnUpdateSelectAll(wxUpdateUIEvent& event)
{
    event.Enable( !IsEmpty() );
}

void wxTextCtrl::OnSetFocus(wxFocusEvent& event)
{
    // be sure the caret remains invisible if the user had hidden it
    if ( !m_isNativeCaretShown )
    {
        ::HideCaret(GetHwnd());
    }

    event.Skip();
}

// the rest of the file only deals with the rich edit controls
#if wxUSE_RICHEDIT

void wxTextCtrl::OnRightUp(wxMouseEvent& eventMouse)
{
    wxContextMenuEvent eventMenu(wxEVT_CONTEXT_MENU,
                                 GetId(),
                                 ClientToScreen(eventMouse.GetPosition()));
    eventMenu.SetEventObject(this);

    if ( !ProcessWindowEvent(eventMenu) )
        eventMouse.Skip();
}

void wxTextCtrl::OnContextMenu(wxContextMenuEvent& event)
{
    if (IsRich())
    {
        if (!m_privateContextMenu)
            m_privateContextMenu = MSWCreateContextMenu();
        PopupMenu(m_privateContextMenu);
        return;
    }
    else
        event.Skip();
}

wxMenu *wxTextCtrl::MSWCreateContextMenu()
{
    wxMenu *m = new wxMenu;
    m->Append(wxID_UNDO, _("&Undo"));
    m->Append(wxID_REDO, _("&Redo"));
    m->AppendSeparator();
    m->Append(wxID_CUT, _("Cu&t"));
    m->Append(wxID_COPY, _("&Copy"));
    m->Append(wxID_PASTE, _("&Paste"));
    m->Append(wxID_CLEAR, _("&Delete"));
    m->AppendSeparator();
    m->Append(wxID_SELECTALL, _("Select &All"));
    return m;
}

void wxTextCtrl::MSWSetRichZoom()
{
    // nothing to scale
    if ( m_richDPIscale == 1 )
        return;

    // get the current zoom ratio
    UINT num = 1;
    UINT denom = 1;
    ::SendMessage(GetHWND(), EM_GETZOOM, (WPARAM)&num, (LPARAM)&denom);

    // combine the zoom ratio with the DPI scale factor
    float ratio = m_richDPIscale;
    if ( denom > 0 )
        ratio = ratio * (num / (float)denom);

    // apply the new zoom ratio, Windows uses a default denominator of 100, so
    // do it here as well
    num = UINT(100 * ratio);
    denom = 100;
    ::SendMessage(GetHWND(), EM_SETZOOM, (WPARAM)num, (LPARAM)denom);
}

void wxTextCtrl::MSWUpdateFontOnDPIChange(const wxSize& newDPI)
{
    // Don't use MSWUpdateFontOnDPIChange for the rich edit controls, they
    // (somehow?) update their appearance on their own and changing their
    // HFONT, as the base class version does, would reset all the styles used
    // by them when the DPI changes, which is unwanted.
    if ( !IsRich() )
    {
        wxTextCtrlBase::MSWUpdateFontOnDPIChange(newDPI);
    }
    // If the rich control is created on a screen with non-system DPI, an
    // initial zoom factor was applied. This needs to be reset after the first
    // DPI change. First invert the scale, then set it to 1 so it is not
    // applied again.
    else if ( m_richDPIscale != 1 )
    {
        m_richDPIscale = 1 / m_richDPIscale;
        MSWSetRichZoom();
        m_richDPIscale = 1;
    }
}

// ----------------------------------------------------------------------------
// EN_LINK processing
// ----------------------------------------------------------------------------

bool wxTextCtrl::MSWOnNotify(int idCtrl, WXLPARAM lParam, WXLPARAM *result)
{
    NMHDR *hdr = (NMHDR* )lParam;
    switch ( hdr->code )
    {
       case EN_MSGFILTER:
            {
                const MSGFILTER *msgf = (MSGFILTER *)lParam;
                UINT msg = msgf->msg;

                // this is a bit crazy but richedit 1.0 sends us all mouse
                // events _except_ WM_LBUTTONUP (don't ask me why) so we have
                // generate the wxWin events for this message manually
                //
                // NB: in fact, this is still not totally correct as it does
                //     send us WM_LBUTTONUP if the selection was cleared by the
                //     last click -- so currently we get 2 events in this case,
                //     but as I don't see any obvious way to check for this I
                //     leave this code in place because it's still better than
                //     not getting left up events at all
                if ( msg == WM_LBUTTONUP )
                {
                    WXUINT flags = msgf->wParam;
                    int x = GET_X_LPARAM(msgf->lParam),
                        y = GET_Y_LPARAM(msgf->lParam);

                    HandleMouseEvent(msg, x, y, flags);
                }
            }

            // return true to process the event (and false to ignore it)
            return true;

        case EN_LINK:
            {
                const ENLINK *enlink = (ENLINK *)hdr;

                switch ( enlink->msg )
                {
                    case WM_SETCURSOR:
                        // ok, so it is hardcoded - do we really nee to
                        // customize it?
                        {
                            wxCursor cur(wxCURSOR_HAND);
                            ::SetCursor(GetHcursorOf(cur));
                            *result = TRUE;
                            break;
                        }

                    case WM_MOUSEMOVE:
                    case WM_LBUTTONDOWN:
                    case WM_LBUTTONUP:
                    case WM_LBUTTONDBLCLK:
                    case WM_RBUTTONDOWN:
                    case WM_RBUTTONUP:
                    case WM_RBUTTONDBLCLK:
                        // send a mouse event
                        {
                            static const wxEventType eventsMouse[] =
                            {
                                wxEVT_MOTION,
                                wxEVT_LEFT_DOWN,
                                wxEVT_LEFT_UP,
                                wxEVT_LEFT_DCLICK,
                                wxEVT_RIGHT_DOWN,
                                wxEVT_RIGHT_UP,
                                wxEVT_RIGHT_DCLICK,
                            };

                            // the event ids are consecutive
                            wxMouseEvent
                                evtMouse(eventsMouse[enlink->msg - WM_MOUSEMOVE]);

                            InitMouseEvent(evtMouse,
                                           GET_X_LPARAM(enlink->lParam),
                                           GET_Y_LPARAM(enlink->lParam),
                                           enlink->wParam);

                            wxTextUrlEvent event(m_windowId, evtMouse,
                                                 enlink->chrg.cpMin,
                                                 enlink->chrg.cpMax);

                            InitCommandEvent(event);

                            *result = ProcessCommand(event);
                        }
                        break;
                }
            }
            return true;
    }

    // not processed, leave it to the base class
    return wxTextCtrlBase::MSWOnNotify(idCtrl, lParam, result);
}

#if wxUSE_DRAG_AND_DROP

void wxTextCtrl::SetDropTarget(wxDropTarget *dropTarget)
{
    if ( m_dropTarget == wxRICHTEXT_DEFAULT_DROPTARGET )
    {
        // get rid of the built-in drop target
        ::RevokeDragDrop(GetHwnd());
        m_dropTarget = nullptr;
    }

    wxTextCtrlBase::SetDropTarget(dropTarget);
}

#endif // wxUSE_DRAG_AND_DROP

// ----------------------------------------------------------------------------
// colour setting for the rich edit controls
// ----------------------------------------------------------------------------

bool wxTextCtrl::SetBackgroundColour(const wxColour& colour)
{
    if ( !wxTextCtrlBase::SetBackgroundColour(colour) )
    {
        // colour didn't really change
        return false;
    }

    if ( IsRich() )
    {
        // rich edit doesn't use WM_CTLCOLOR, hence we need to send
        // EM_SETBKGNDCOLOR additionally
        ::SendMessage(GetHwnd(), EM_SETBKGNDCOLOR, 0, wxColourToRGB(colour));
    }

    return true;
}

bool wxTextCtrl::SetForegroundColour(const wxColour& colour)
{
    if ( !wxTextCtrlBase::SetForegroundColour(colour) )
    {
        // colour didn't really change
        return false;
    }

    if ( IsRich() )
    {
        // change the colour of everything
        WinStruct<CHARFORMAT> cf;
        cf.dwMask = CFM_COLOR;
        cf.crTextColor = wxColourToRGB(colour);
        ::SendMessage(GetHwnd(), EM_SETCHARFORMAT, SCF_ALL, (LPARAM)&cf);
    }

    return true;
}

bool wxTextCtrl::SetFont(const wxFont& font)
{
    // Native text control sends EN_CHANGE when the font changes, producing
    // a wxEVT_TEXT event as if the user changed the value. This is not
    // the case, so suppress the event.
    wxEventBlocker block(this, wxEVT_TEXT);

    if ( !wxTextCtrlBase::SetFont(font) )
        return false;

    if ( GetRichVersion() >= 4 )
    {
        // Using WM_SETFONT is not enough with RichEdit 4.1: it does work but
        // for ASCII characters only and inserting a non-ASCII one into it
        // later reverts to the default font so use EM_SETCHARFORMAT to change
        // the default font for it.
        wxTextAttr attr;
        attr.SetFont(font);
        SetStyle(-1, -1, attr);
    }

    return true;
}

// ----------------------------------------------------------------------------
// styling support for rich edit controls
// ----------------------------------------------------------------------------

#if _RICHEDIT_VER >= 0x0800
static const wxColour gs_underlineColourMap[] =
{
    // The colours are coming from https://docs.microsoft.com/en-us/windows/desktop/api/tom/nf-tom-itextdocument2-geteffectcolor.
    wxNullColour,            // text colour
    wxColour(0,   0,   0  ), // black
    wxColour(0,   0,   255), // blue
    wxColour(0,   255, 255), // cyan
    wxColour(0,   255, 0  ), // green
    wxColour(255, 0,   255), // magenta
    wxColour(255, 0,   0  ), // red
    wxColour(255, 255, 0  ), // yellow
    wxColour(255, 255, 255), // white
    wxColour(0,   0,   128), // navy
    wxColour(0,   128, 128), // teal
    wxColour(0,   128, 0  ), // light green
    wxColour(128, 0,   128), // purple
    wxColour(128, 0,   0  ), // maroon
    wxColour(128, 128, 0  ), // olive
    wxColour(128, 128, 128), // grey
    wxColour(192, 192, 192), // light grey
};
#endif

bool wxTextCtrl::MSWSetCharFormat(const wxTextAttr& style, long start, long end)
{
    // initialize CHARFORMAT struct
#if wxUSE_RICHEDIT2
    CHARFORMAT2 cf;
#else
    CHARFORMAT cf;
#endif

    wxZeroMemory(cf);

    // we can't use CHARFORMAT2 with RichEdit 1.0, so pretend it is a simple
    // CHARFORMAT in that case
#if wxUSE_RICHEDIT2
    if ( m_verRichEdit == 1 )
    {
        // this is the only thing the control is going to grok
        cf.cbSize = sizeof(CHARFORMAT);
    }
    else
#endif
    {
        // CHARFORMAT or CHARFORMAT2
        cf.cbSize = sizeof(cf);
    }

    if ( style.HasFont() )
    {
        // VZ: CFM_CHARSET doesn't seem to do anything at all in RichEdit 2.0
        //     but using it doesn't seem to hurt either so leaving it for now

        cf.dwMask |= CFM_FACE | CFM_SIZE | CFM_CHARSET |
                     CFM_ITALIC | CFM_BOLD | CFM_UNDERLINE | CFM_STRIKEOUT;

        // fill in data from LOGFONT but recalculate lfHeight because we need
        // the real height in twips and not the negative number used inside
        // LOGFONT returns (this is correct in general and works with
        // the Windows font mapper, but not here)

        wxFont font(style.GetFont());

        LOGFONT lf = font.GetNativeFontInfo()->lf;
        cf.yHeight = LONG(20 * font.GetFractionalPointSize()); // 1 pt = 20 twips
        cf.bCharSet = lf.lfCharSet;
        cf.bPitchAndFamily = lf.lfPitchAndFamily;
        wxStrlcpy(cf.szFaceName, lf.lfFaceName, WXSIZEOF(cf.szFaceName));

        // also deal with underline/italic/bold attributes: note that we must
        // always set CFM_ITALIC &c bits in dwMask, even if we don't set the
        // style to allow clearing it
        if ( lf.lfItalic )
        {
            cf.dwEffects |= CFE_ITALIC;
        }

        if ( lf.lfWeight == FW_BOLD )
        {
            cf.dwEffects |= CFE_BOLD;
        }

        if ( lf.lfUnderline )
        {
            cf.dwEffects |= CFE_UNDERLINE;
        }
        if ( lf.lfStrikeOut )
        {
            cf.dwEffects |= CFE_STRIKEOUT;
        }
    }

    if ( style.HasFontUnderlined() )
    {
        cf.dwMask |= CFM_UNDERLINETYPE;
        BYTE underlineType = CFU_UNDERLINENONE;
        switch ( style.GetUnderlineType() )
        {
            case wxTEXT_ATTR_UNDERLINE_SOLID:
                underlineType = CFU_UNDERLINE;
                break;
            case wxTEXT_ATTR_UNDERLINE_DOUBLE:
                underlineType = CFU_UNDERLINEDOUBLE;
                break;
            case wxTEXT_ATTR_UNDERLINE_SPECIAL:
                underlineType = CFU_UNDERLINEWAVE;
                break;
            default:
                underlineType = CFU_UNDERLINENONE;
                break;
        }
        cf.bUnderlineType = underlineType;

#if _RICHEDIT_VER >= 0x0800
        BYTE colour = 0;
        const wxColour& col = style.GetUnderlineColour();
        for ( size_t c = 0; c < WXSIZEOF(gs_underlineColourMap); ++c )
        {
            if ( col == gs_underlineColourMap[c] )
            {
                colour = static_cast<BYTE>(c);
                break;
            }
        }
        cf.bUnderlineColor = colour;
#endif
    }

    if ( style.HasTextColour() )
    {
        cf.dwMask |= CFM_COLOR;
        cf.crTextColor = wxColourToRGB(style.GetTextColour());
    }

#if wxUSE_RICHEDIT2
    if ( m_verRichEdit != 1 && style.HasBackgroundColour() )
    {
        cf.dwMask |= CFM_BACKCOLOR;
        cf.crBackColor = wxColourToRGB(style.GetBackgroundColour());
    }
#endif // wxUSE_RICHEDIT2

    // Apply the style either to the selection or to the entire control.
    WPARAM selMode;
    if ( start != -1 || end != -1 )
    {
        DoSetSelection(start, end, SetSel_NoScroll);
        selMode = SCF_SELECTION;
    }
    else
    {
        selMode = SCF_ALL;
    }

    if ( !::SendMessage(GetHwnd(), EM_SETCHARFORMAT, selMode, (LPARAM)&cf) )
    {
        wxLogLastError(wxT("SendMessage(EM_SETCHARFORMAT)"));
        return false;
    }

    return true;
}

bool wxTextCtrl::MSWSetParaFormat(const wxTextAttr& style, long start, long end)
{
#if wxUSE_RICHEDIT2
    PARAFORMAT2 pf;
#else
    PARAFORMAT pf;
#endif

    wxZeroMemory(pf);

    // we can't use PARAFORMAT2 with RichEdit 1.0, so pretend it is a simple
    // PARAFORMAT in that case
#if wxUSE_RICHEDIT2
    if ( m_verRichEdit == 1 )
    {
        // this is the only thing the control is going to grok
        pf.cbSize = sizeof(PARAFORMAT);
    }
    else
#endif
    {
        // PARAFORMAT or PARAFORMAT2
        pf.cbSize = sizeof(pf);
    }

    if (style.HasAlignment())
    {
        pf.dwMask |= PFM_ALIGNMENT;
        if (style.GetAlignment() == wxTEXT_ALIGNMENT_RIGHT)
            pf.wAlignment = PFA_RIGHT;
        else if (style.GetAlignment() == wxTEXT_ALIGNMENT_CENTRE)
            pf.wAlignment = PFA_CENTER;
        else if (style.GetAlignment() == wxTEXT_ALIGNMENT_JUSTIFIED)
            pf.wAlignment = PFA_JUSTIFY;
        else
            pf.wAlignment = PFA_LEFT;
    }

    if (style.HasLeftIndent())
    {
        pf.dwMask |= PFM_STARTINDENT | PFM_OFFSET;

        // Convert from 1/10 mm to TWIPS
        pf.dxStartIndent = (int) (((double) style.GetLeftIndent()) * mm2twips / 10.0) ;
        pf.dxOffset = (int) (((double) style.GetLeftSubIndent()) * mm2twips / 10.0) ;
    }

    if (style.HasRightIndent())
    {
        pf.dwMask |= PFM_RIGHTINDENT;

        // Convert from 1/10 mm to TWIPS
        pf.dxRightIndent = (int) (((double) style.GetRightIndent()) * mm2twips / 10.0) ;
    }

    if (style.HasTabs())
    {
        pf.dwMask |= PFM_TABSTOPS;

        const wxArrayInt& tabs = style.GetTabs();

        pf.cTabCount = (SHORT)wxMin(tabs.GetCount(), MAX_TAB_STOPS);
        size_t i;
        for (i = 0; i < (size_t) pf.cTabCount; i++)
        {
            // Convert from 1/10 mm to TWIPS
            pf.rgxTabs[i] = (int) (((double) tabs[i]) * mm2twips / 10.0) ;
        }
    }

#if wxUSE_RICHEDIT2
    if ( style.HasLineSpacing() )
    {
        pf.dwMask |= PFM_LINESPACING;

        switch ( style.GetLineSpacing() )
            {
        case wxTEXT_ATTR_LINE_SPACING_NORMAL:
            pf.bLineSpacingRule = 0;
            break;
        case wxTEXT_ATTR_LINE_SPACING_HALF:
            pf.bLineSpacingRule = 1;
            break;
        case wxTEXT_ATTR_LINE_SPACING_TWICE:
            pf.bLineSpacingRule = 2;
            break;
            };
    }

    if ( style.HasParagraphSpacingAfter() )
    {
        pf.dwMask |= PFM_SPACEAFTER;

        // Convert from 1/10 mm to TWIPS
        pf.dySpaceAfter = (int) (((double) style.GetParagraphSpacingAfter()) * mm2twips / 10.0) ;
    }

    if ( style.HasParagraphSpacingBefore() )
    {
        pf.dwMask |= PFM_SPACEBEFORE;

        // Convert from 1/10 mm to TWIPS
        pf.dySpaceBefore = (int) (((double) style.GetParagraphSpacingBefore()) * mm2twips / 10.0) ;
    }

    if ( style.HasBulletStyle() )
    {
        pf.dwMask |= PFM_NUMBERINGSTYLE;
        pf.dwMask |= PFM_NUMBERING;

        // number/bullet formats
        if ((style.GetBulletStyle() & wxTEXT_ATTR_BULLET_STYLE_NONE) != 0)
            pf.wNumbering = 0;
        else if ((style.GetBulletStyle() & wxTEXT_ATTR_BULLET_STYLE_STANDARD) != 0)
            pf.wNumbering = PFN_BULLET;
        else if ((style.GetBulletStyle() & wxTEXT_ATTR_BULLET_STYLE_ARABIC) != 0)
            pf.wNumbering = PFN_ARABIC;
        else if ((style.GetBulletStyle() & wxTEXT_ATTR_BULLET_STYLE_LETTERS_LOWER) != 0)
            pf.wNumbering = PFN_LCLETTER;
        else if ((style.GetBulletStyle() & wxTEXT_ATTR_BULLET_STYLE_LETTERS_UPPER) != 0)
            pf.wNumbering = PFN_UCLETTER;
        else if ((style.GetBulletStyle() & wxTEXT_ATTR_BULLET_STYLE_ROMAN_LOWER) != 0)
            pf.wNumbering = PFN_LCROMAN;
        else if ((style.GetBulletStyle() & wxTEXT_ATTR_BULLET_STYLE_ROMAN_UPPER) != 0)
            pf.wNumbering = PFN_UCROMAN;

        // number display
        if ( style.HasBulletNumber() )
        {
            pf.dwMask |= PFM_NUMBERINGSTART;
            pf.wNumberingStart = style.GetBulletNumber();
            pf.wNumberingStyle = PFNS_NEWNUMBER;
        }
        else if ((style.GetBulletStyle() & wxTEXT_ATTR_BULLET_STYLE_RIGHT_PARENTHESIS) != 0)
            pf.wNumberingStyle = PFNS_PAREN;
        else if ((style.GetBulletStyle() & wxTEXT_ATTR_BULLET_STYLE_PARENTHESES) != 0)
            pf.wNumberingStyle = PFNS_PARENS;
        else if ((style.GetBulletStyle() & wxTEXT_ATTR_BULLET_STYLE_PERIOD) != 0)
            pf.wNumberingStyle = PFNS_PERIOD;
        else if ((style.GetBulletStyle() & wxTEXT_ATTR_BULLET_STYLE_STANDARD) != 0)
            pf.wNumberingStyle = PFNS_PLAIN;
    }
#endif // wxUSE_RICHEDIT2

#if wxUSE_RICHEDIT2
    if ( m_verRichEdit > 1 )
    {
        if ( GetLayoutDirection() == wxLayout_RightToLeft )
        {
            // Use RTL paragraphs in RTL mode to get proper layout
            pf.dwMask |= PFM_RTLPARA;
            pf.wEffects |= PFE_RTLPARA;
        }
    }
#endif // wxUSE_RICHEDIT2

    if ( pf.dwMask )
    {
        // Do format the selection.
        DoSetSelection(start, end, SetSel_NoScroll);

        if ( !::SendMessage(GetHwnd(), EM_SETPARAFORMAT, 0, (LPARAM) &pf) )
        {
            wxLogLastError(wxT("SendMessage(EM_SETPARAFORMAT)"));

            return false;
        }
    }

    return true;
}

bool wxTextCtrl::SetStyle(long start, long end, const wxTextAttr& style)
{
    if ( !IsRich() )
    {
        // can't do it with normal text control
        return false;
    }

    // the richedit 1.0 doesn't handle setting background colour, so don't
    // even try to do anything if it's the only thing we want to change
    if ( m_verRichEdit == 1 && !style.HasFont() && !style.HasTextColour() &&
        !style.HasLeftIndent() && !style.HasRightIndent() && !style.HasAlignment() &&
        !style.HasTabs() && !style.GetFontUnderlined() )
    {
        // nothing to do: return true if there was really nothing to do and
        // false if we failed to set bg colour
        return !style.HasBackgroundColour();
    }

    // order the range if needed
    if ( start > end )
        wxSwap(start, end);

    // we can only change the format of the selection, so select the range we
    // want and restore the old selection later, after MSWSetXXXFormat()
    // functions (possibly) change it.
    long startOld, endOld;
    GetSelection(&startOld, &endOld);

    bool ok = MSWSetCharFormat(style, start, end);
    if ( !MSWSetParaFormat(style, start, end) )
        ok = false;

    if ( start != startOld || end != endOld )
    {
        // restore the original selection
        DoSetSelection(startOld, endOld, SetSel_NoScroll);
    }

    return ok;
}

bool wxTextCtrl::SetDefaultStyle(const wxTextAttr& style)
{
    if ( !wxTextCtrlBase::SetDefaultStyle(style) )
        return false;

    if ( IsEditable() )
    {
        // we have to do this or the style wouldn't apply for the text typed by
        // the user
        wxTextPos posLast = GetLastPosition();
        SetStyle(posLast, posLast, m_defaultStyle);
    }

    return true;
}

bool wxTextCtrl::GetStyle(long position, wxTextAttr& style)
{
    if ( !IsRich() )
    {
        // can't do it with normal text control
        return false;
    }

    // initialize CHARFORMAT struct
#if wxUSE_RICHEDIT2
    CHARFORMAT2 cf;
#else
    CHARFORMAT cf;
#endif

    wxZeroMemory(cf);

    // we can't use CHARFORMAT2 with RichEdit 1.0, so pretend it is a simple
    // CHARFORMAT in that case
#if wxUSE_RICHEDIT2
    if ( m_verRichEdit == 1 )
    {
        // this is the only thing the control is going to grok
        cf.cbSize = sizeof(CHARFORMAT);
    }
    else
#endif
    {
        // CHARFORMAT or CHARFORMAT2
        cf.cbSize = sizeof(cf);
    }
    // we can only change the format of the selection, so select the range we
    // want and restore the old selection later
    long startOld, endOld;
    GetSelection(&startOld, &endOld);

    // but do we really have to change the selection?
    const bool changeSel = position != startOld;

    if ( changeSel )
    {
        DoSetSelection(position, position + 1, SetSel_NoScroll);
    }

    // get the selection formatting
    (void) ::SendMessage(GetHwnd(), EM_GETCHARFORMAT,
                            SCF_SELECTION, (LPARAM)&cf) ;


    LOGFONT lf;
    lf.lfWidth = 0;
    lf.lfCharSet = ANSI_CHARSET; // FIXME: how to get correct charset?
    lf.lfClipPrecision = 0;
    lf.lfEscapement = 0;
    wxStrcpy(lf.lfFaceName, cf.szFaceName);

    //NOTE:  we _MUST_ set each of these values to _something_ since we
    //do not call wxZeroMemory on the LOGFONT lf
    if (cf.dwEffects & CFE_ITALIC)
        lf.lfItalic = TRUE;
    else
        lf.lfItalic = FALSE;

    lf.lfOrientation = 0;
    lf.lfPitchAndFamily = cf.bPitchAndFamily;
    lf.lfQuality = 0;

    if (cf.dwEffects & CFE_STRIKEOUT)
        lf.lfStrikeOut = TRUE;
    else
        lf.lfStrikeOut = FALSE;

    if (cf.dwEffects & CFE_UNDERLINE)
        lf.lfUnderline = TRUE;
    else
        lf.lfUnderline = FALSE;

    if (cf.dwEffects & CFE_BOLD)
        lf.lfWeight = FW_BOLD;
    else
        lf.lfWeight = FW_NORMAL;

    // Determine the pointSize that was used in SetStyle. Don't worry about
    // lfHeight or PPI, style.SetFont() will lose this information anyway.
    wxFont font(wxNativeFontInfo(lf, this));
    font.SetFractionalPointSize(cf.yHeight / 20.0); // 1 pt = 20 twips
    if (font.IsOk())
    {
        style.SetFont(font);
    }
    style.SetTextColour(wxColour(cf.crTextColor));

#if wxUSE_RICHEDIT2
    if ( m_verRichEdit != 1 )
    {
        // Notice that, surprisingly, CFM_BACKCOLOR is still set in the mask
        // even when CFE_AUTOBACKCOLOR is set in the effects, indicating that
        // the background colour is not used.
        if ( !(cf.dwEffects & CFE_AUTOBACKCOLOR) && (cf.dwMask & CFM_BACKCOLOR) )
        {
            style.SetBackgroundColour(wxColour(cf.crBackColor));
        }
    }
#endif // wxUSE_RICHEDIT2

    wxTextAttrUnderlineType underlineType = wxTEXT_ATTR_UNDERLINE_NONE;
    switch ( cf.bUnderlineType )
    {
        case CFU_UNDERLINE:
            underlineType = wxTEXT_ATTR_UNDERLINE_SOLID;
            break;
        case CFU_UNDERLINEDOUBLE:
            underlineType = wxTEXT_ATTR_UNDERLINE_DOUBLE;
            break;
        case CFU_UNDERLINEWAVE:
            underlineType = wxTEXT_ATTR_UNDERLINE_SPECIAL;
            break;
        default:
            underlineType = wxTEXT_ATTR_UNDERLINE_NONE;
            break;
    }

    wxColour underlineColour;
#if _RICHEDIT_VER >= 0x0800
    if ( cf.bUnderlineColor < WXSIZEOF(gs_underlineColourMap) )
        underlineColour = gs_underlineColourMap[cf.bUnderlineColor];
#endif

    if ( underlineType != wxTEXT_ATTR_UNDERLINE_NONE )
        style.SetFontUnderlined(underlineType, underlineColour);

    // now get the paragraph formatting
    PARAFORMAT2 pf;
    wxZeroMemory(pf);
    // we can't use PARAFORMAT2 with RichEdit 1.0, so pretend it is a simple
    // PARAFORMAT in that case
#if wxUSE_RICHEDIT2
    if ( m_verRichEdit == 1 )
    {
        // this is the only thing the control is going to grok
        pf.cbSize = sizeof(PARAFORMAT);
    }
    else
#endif
    {
        // PARAFORMAT or PARAFORMAT2
        pf.cbSize = sizeof(pf);
    }

    // do format the selection
    (void) ::SendMessage(GetHwnd(), EM_GETPARAFORMAT, 0, (LPARAM) &pf) ;

    style.SetLeftIndent( (int) ((double) pf.dxStartIndent * twips2mm * 10.0), (int) ((double) pf.dxOffset * twips2mm * 10.0) );
    style.SetRightIndent( (int) ((double) pf.dxRightIndent * twips2mm * 10.0) );

    if (pf.wAlignment == PFA_CENTER)
        style.SetAlignment(wxTEXT_ALIGNMENT_CENTRE);
    else if (pf.wAlignment == PFA_RIGHT)
        style.SetAlignment(wxTEXT_ALIGNMENT_RIGHT);
    else if (pf.wAlignment == PFA_JUSTIFY)
        style.SetAlignment(wxTEXT_ALIGNMENT_JUSTIFIED);
    else
        style.SetAlignment(wxTEXT_ALIGNMENT_LEFT);

    wxArrayInt tabStops;
    size_t i;
    for (i = 0; i < (size_t) pf.cTabCount; i++)
    {
        tabStops.Add( (int) ((double) (pf.rgxTabs[i] & 0xFFFF) * twips2mm * 10.0) );
    }

    if ( changeSel )
    {
        // restore the original selection
        DoSetSelection(startOld, endOld, SetSel_NoScroll);
    }

    return true;
}

// ----------------------------------------------------------------------------
// wxRichEditModule
// ----------------------------------------------------------------------------

static const HINSTANCE INVALID_HINSTANCE = (HINSTANCE)-1;

bool wxRichEditModule::OnInit()
{
    // don't do anything - we will load it when needed
    return true;
}

void wxRichEditModule::OnExit()
{
    for ( size_t i = 0; i < WXSIZEOF(ms_hRichEdit); i++ )
    {
        if ( ms_hRichEdit[i] && ms_hRichEdit[i] != INVALID_HINSTANCE )
        {
            ::FreeLibrary(ms_hRichEdit[i]);
            ms_hRichEdit[i] = nullptr;
        }
    }
#if wxUSE_INKEDIT
    if (ms_inkEditLib.IsLoaded())
        ms_inkEditLib.Unload();
#endif
}

/* static */
bool wxRichEditModule::Load(Version version)
{
    if ( ms_hRichEdit[version] == INVALID_HINSTANCE )
    {
        // we had already tried to load it and failed
        return false;
    }

    if ( ms_hRichEdit[version] )
    {
        // we've already got this one
        return true;
    }

    static const wxChar *const dllnames[] =
    {
        wxT("riched32"),
        wxT("riched20"),
        wxT("msftedit"),
    };

    wxCOMPILE_TIME_ASSERT( WXSIZEOF(dllnames) == Version_Max,
                            RichEditDllNamesVersionsMismatch );

    ms_hRichEdit[version] = ::LoadLibrary(dllnames[version]);

    if ( !ms_hRichEdit[version] )
    {
        ms_hRichEdit[version] = INVALID_HINSTANCE;

        return false;
    }

    return true;
}

#if wxUSE_INKEDIT
// load the InkEdit library
bool wxRichEditModule::LoadInkEdit()
{
    if (ms_inkEditLibLoadAttemped)
        return ms_inkEditLib.IsLoaded();

    ms_inkEditLibLoadAttemped = true;

    wxLogNull logNull;
    return ms_inkEditLib.Load(wxT("inked"));
}
#endif // wxUSE_INKEDIT


#endif // wxUSE_RICHEDIT

#endif // wxUSE_TEXTCTRL
