/////////////////////////////////////////////////////////////////////////////
// Name:        src/common/docview.cpp
// Purpose:     Document/view classes
// Author:      Julian Smart
// Modified by: Vadim Zeitlin
// Created:     01/02/97
// Copyright:   (c) Julian Smart
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

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

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

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


#if wxUSE_DOC_VIEW_ARCHITECTURE

#include "wx/docview.h"

#ifndef WX_PRECOMP
    #include "wx/list.h"
    #include "wx/string.h"
    #include "wx/utils.h"
    #include "wx/app.h"
    #include "wx/dc.h"
    #include "wx/dialog.h"
    #include "wx/menu.h"
    #include "wx/filedlg.h"
    #include "wx/intl.h"
    #include "wx/log.h"
    #include "wx/msgdlg.h"
    #include "wx/mdi.h"
    #include "wx/choicdlg.h"
#endif

#if wxUSE_PRINTING_ARCHITECTURE
    #include "wx/prntbase.h"
    #include "wx/printdlg.h"
#endif

#include "wx/confbase.h"
#include "wx/filename.h"
#include "wx/file.h"
#include "wx/ffile.h"
#include "wx/cmdproc.h"
#include "wx/tokenzr.h"
#include "wx/filename.h"
#include "wx/stdpaths.h"
#include "wx/vector.h"
#include "wx/scopedarray.h"
#include "wx/scopeguard.h"
#include "wx/except.h"

#if wxUSE_STD_IOSTREAM
    #include "wx/beforestd.h"
    #include <fstream>
    #include <iostream>
    #include "wx/afterstd.h"
#else
    #include "wx/wfstream.h"
#endif

#include <memory>

// ----------------------------------------------------------------------------
// wxWidgets macros
// ----------------------------------------------------------------------------

wxIMPLEMENT_ABSTRACT_CLASS(wxDocument, wxEvtHandler);
wxIMPLEMENT_ABSTRACT_CLASS(wxView, wxEvtHandler);
wxIMPLEMENT_ABSTRACT_CLASS(wxDocTemplate, wxObject);
wxIMPLEMENT_DYNAMIC_CLASS(wxDocManager, wxEvtHandler);
wxIMPLEMENT_CLASS(wxDocChildFrame, wxFrame);
wxIMPLEMENT_CLASS(wxDocParentFrame, wxFrame);

#if wxUSE_PRINTING_ARCHITECTURE
wxIMPLEMENT_DYNAMIC_CLASS(wxDocPrintout, wxPrintout);
#endif

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

// ----------------------------------------------------------------------------
// private helpers
// ----------------------------------------------------------------------------

namespace
{

wxString FindExtension(const wxString& path)
{
    wxString ext;
    wxFileName::SplitPath(path, nullptr, nullptr, &ext);

    // VZ: extensions are considered not case sensitive - is this really a good
    //     idea?
    return ext.MakeLower();
}

} // anonymous namespace

// ----------------------------------------------------------------------------
// Definition of wxDocument
// ----------------------------------------------------------------------------

wxDocument::wxDocument(wxDocument *parent)
{
    m_documentModified = false;
    m_documentTemplate = nullptr;

    m_documentParent = parent;
    if ( parent )
        parent->m_childDocuments.push_back(this);

    m_commandProcessor = nullptr;
    m_savedYet = false;
}

bool wxDocument::DeleteContents()
{
    return true;
}

wxDocument::~wxDocument()
{
    delete m_commandProcessor;

    if (GetDocumentManager())
        GetDocumentManager()->RemoveDocument(this);

    if ( m_documentParent )
        m_documentParent->m_childDocuments.remove(this);

    // Not safe to do here, since it'll invoke virtual view functions
    // expecting to see valid derived objects: and by the time we get here,
    // we've called destructors higher up.
    //DeleteAllViews();
}

bool wxDocument::CanClose()
{
    if ( !OnSaveModified() )
        return false;

    // When the parent document closes, its children must be closed as well as
    // they can't exist without the parent, so ask them too.

    for ( auto& childDoc : m_childDocuments )
    {
        if ( !childDoc->OnSaveModified() )
        {
            // Leave the parent document opened if a child can't close.
            return false;
        }
    }

    return true;
}

bool wxDocument::Close()
{
    // First check if this document itself and all its children can be closed.
    if ( !CanClose() )
        return false;

    // Now that they all did, do close them: as m_childDocuments is modified as
    // we iterate over it, don't use the usual for-style iteration here.
    while ( !m_childDocuments.empty() )
    {
        wxDocument * const childDoc = m_childDocuments.front();

        // This will call OnSaveModified() once again but it shouldn't do
        // anything as the document was just saved or marked as not needing to
        // be saved by the call to OnSaveModified() that returned true above.
        if ( !childDoc->Close() )
        {
            wxFAIL_MSG( "Closing the child document unexpectedly failed "
                        "after its OnSaveModified() returned true" );
        }

        // Delete the child document by deleting all its views.
        childDoc->DeleteAllViews();
    }


    return OnCloseDocument();
}

bool wxDocument::OnCloseDocument()
{
    // Tell all views that we're about to close
    NotifyClosing();
    DeleteContents();
    Modify(false);
    return true;
}

// Note that this implicitly deletes the document when the last view is
// deleted.
bool wxDocument::DeleteAllViews()
{
    wxDocManager* manager = GetDocumentManager();

    // first check if all views agree to be closed
    const wxList::iterator end = m_documentViews.end();
    for ( wxList::iterator i = m_documentViews.begin(); i != end; ++i )
    {
        wxView *view = (wxView *)*i;
        if ( !view->Close() )
            return false;
    }

    // all views agreed to close, now do close them
    if ( m_documentViews.empty() )
    {
        // normally the document would be implicitly deleted when the last view
        // is, but if don't have any views, do it here instead
        if ( manager && manager->GetDocuments().Member(this) )
            delete this;
    }
    else // have views
    {
        // as we delete elements we iterate over, don't use the usual "from
        // begin to end" loop
        for ( ;; )
        {
            wxView *view = (wxView *)*m_documentViews.begin();

            bool isLastOne = m_documentViews.size() == 1;

            // this always deletes the node implicitly and if this is the last
            // view also deletes this object itself (also implicitly, great),
            // so we can't test for m_documentViews.empty() after calling this!
            delete view;

            if ( isLastOne )
                break;
        }
    }

    return true;
}

wxView *wxDocument::GetFirstView() const
{
    if ( m_documentViews.empty() )
        return nullptr;

    return static_cast<wxView *>(m_documentViews.GetFirst()->GetData());
}

void wxDocument::Modify(bool mod)
{
    if (mod != m_documentModified)
    {
        m_documentModified = mod;

        // Allow views to append asterix to the title
        wxView* view = GetFirstView();
        if (view) view->OnChangeFilename();
    }
}

wxDocManager *wxDocument::GetDocumentManager() const
{
    // For child documents we use the same document manager as the parent, even
    // though we don't have our own template (as children are not opened/saved
    // directly).
    if ( m_documentParent )
        return m_documentParent->GetDocumentManager();

    if ( m_documentTemplate )
        return m_documentTemplate->GetDocumentManager();

    // Fall back on the global manager if the document doesn't have a template,
    // code elsewhere, notably in DeleteAllViews(), relies on the document
    // always being managed by some manager.
    return wxDocManager::GetDocumentManager();
}

bool wxDocument::OnNewDocument()
{
    // notice that there is no need to either reset nor even check the
    // modified flag here as the document itself is a new object (this is only
    // called from CreateDocument()) and so it shouldn't be saved anyhow even
    // if it is modified -- this could happen if the user code creates
    // documents pre-filled with some user-entered (and which hence must not be
    // lost) information

    SetDocumentSaved(false);

    const wxString name = GetDocumentManager()->MakeNewDocumentName();
    SetTitle(name);
    SetFilename(name, true);

    return true;
}

bool wxDocument::Save()
{
    if ( AlreadySaved() )
        return true;

    if ( m_documentFile.empty() || !m_savedYet )
        return SaveAs();

    return OnSaveDocument(m_documentFile);
}

bool wxDocument::SaveAs()
{
    wxDocTemplate *docTemplate = GetDocumentTemplate();
    if (!docTemplate)
        return false;

#ifdef wxHAS_MULTIPLE_FILEDLG_FILTERS
    wxString filter = docTemplate->GetDescription() + wxT(" (") +
        docTemplate->GetFileFilter() + wxT(")|") +
        docTemplate->GetFileFilter();

    // Now see if there are some other template with identical view and document
    // classes, whose filters may also be used.
    if (docTemplate->GetViewClassInfo() && docTemplate->GetDocClassInfo())
    {
        wxList::compatibility_iterator
            node = docTemplate->GetDocumentManager()->GetTemplates().GetFirst();
        while (node)
        {
            wxDocTemplate *t = (wxDocTemplate*) node->GetData();

            if (t->IsVisible() && t != docTemplate &&
                t->GetViewClassInfo() == docTemplate->GetViewClassInfo() &&
                t->GetDocClassInfo() == docTemplate->GetDocClassInfo())
            {
                // add a '|' to separate this filter from the previous one
                if ( !filter.empty() )
                    filter << wxT('|');

                filter << t->GetDescription()
                       << wxT(" (") << t->GetFileFilter() << wxT(") |")
                       << t->GetFileFilter();
            }

            node = node->GetNext();
        }
    }
#else
    wxString filter = docTemplate->GetFileFilter() ;
#endif

    wxString defaultDir = docTemplate->GetDirectory();
    if ( defaultDir.empty() )
    {
        defaultDir = wxPathOnly(GetFilename());
        if ( defaultDir.empty() )
            defaultDir = GetDocumentManager()->GetLastDirectory();
    }

    wxString fileName = wxFileSelector(_("Save As"),
            defaultDir,
            wxFileNameFromPath(GetFilename()),
            docTemplate->GetDefaultExtension(),
            filter,
            wxFD_SAVE | wxFD_OVERWRITE_PROMPT,
            GetDocumentWindow());

    if (fileName.empty())
        return false; // cancelled by user

    // Files that were not saved correctly are not added to the FileHistory.
    if (!OnSaveDocument(fileName))
        return false;

    SetTitle(wxFileNameFromPath(fileName));
    SetFilename(fileName, true);    // will call OnChangeFileName automatically

    // A file that doesn't use the default extension of its document template
    // cannot be opened via the FileHistory, so we do not add it.
    if (docTemplate->FileMatchesTemplate(fileName))
    {
        GetDocumentManager()->AddFileToHistory(fileName);
    }
    //else: the user will probably not be able to open the file again, so we
    //      could warn about the wrong file-extension here

    return true;
}

bool wxDocument::OnSaveDocument(const wxString& file)
{
    if ( file.empty() )
        return false;

    if ( !DoSaveDocument(file) )
        return false;

    if ( m_commandProcessor )
        m_commandProcessor->MarkAsSaved();

    Modify(false);
    SetFilename(file);
    SetDocumentSaved(true);
    return true;
}

bool wxDocument::OnOpenDocument(const wxString& file)
{
    // notice that there is no need to check the modified flag here for the
    // reasons explained in OnNewDocument()

    if ( !DoOpenDocument(file) )
        return false;

    SetFilename(file, true);

    // stretching the logic a little this does make sense because the document
    // had been saved into the file we just loaded it from, it just could have
    // happened during a previous program execution, it's just that the name of
    // this method is a bit unfortunate, it should probably have been called
    // HasAssociatedFileName()
    SetDocumentSaved(true);

    UpdateAllViews();

    return true;
}

#if wxUSE_STD_IOSTREAM
std::istream& wxDocument::LoadObject(std::istream& stream)
#else
wxInputStream& wxDocument::LoadObject(wxInputStream& stream)
#endif
{
    return stream;
}

#if wxUSE_STD_IOSTREAM
std::ostream& wxDocument::SaveObject(std::ostream& stream)
#else
wxOutputStream& wxDocument::SaveObject(wxOutputStream& stream)
#endif
{
    return stream;
}

bool wxDocument::Revert()
{
    if ( wxMessageBox
         (
            _("Discard changes and reload the last saved version?"),
            wxTheApp->GetAppDisplayName(),
            wxYES_NO | wxCANCEL | wxICON_QUESTION,
            GetDocumentWindow()
          ) != wxYES )
        return false;

    if ( !DoOpenDocument(GetFilename()) )
        return false;

    Modify(false);
    UpdateAllViews();

    return true;
}


// Get title, or filename if no title, else unnamed
wxString wxDocument::GetUserReadableName() const
{
    return DoGetUserReadableName();
}

wxString wxDocument::DoGetUserReadableName() const
{
    if ( !m_documentTitle.empty() )
        return m_documentTitle;

    if ( !m_documentFile.empty() )
        return wxFileNameFromPath(m_documentFile);

    return _("unnamed");
}

wxWindow *wxDocument::GetDocumentWindow() const
{
    wxView * const view = GetFirstView();

    return view ? view->GetFrame() : wxTheApp->GetTopWindow();
}

wxCommandProcessor *wxDocument::OnCreateCommandProcessor()
{
    return new wxCommandProcessor;
}

// true if safe to close
bool wxDocument::OnSaveModified()
{
    if ( IsModified() )
    {
        wxMessageDialog dialogSave
            (
                GetDocumentWindow(),
                wxString::Format
                (
                    _("Do you want to save changes to %s?"),
                    GetUserReadableName()
                ),
                wxTheApp->GetAppDisplayName(),
                wxYES_NO | wxCANCEL | wxICON_QUESTION | wxCENTRE
            );
        dialogSave.SetYesNoCancelLabels
            (
                _("&Save"),
                _("&Discard changes"),
                _("Do&n't close")
            );

        switch ( dialogSave.ShowModal() )
        {
            case wxID_NO:
                Modify(false);
                break;

            case wxID_YES:
                return Save();

            case wxID_CANCEL:
                return false;
        }
    }

    return true;
}

void wxDocument::OnSaveBeforeForceClose()
{
    if ( !IsModified() )
        return;

    wxMessageDialog dialogSave
        (
            GetDocumentWindow(),
            wxString::Format
            (
                _("Do you want to save changes to %s before closing it?"),
                GetUserReadableName()
            ),
            wxTheApp->GetAppDisplayName(),
            wxYES_NO | wxICON_QUESTION | wxCENTRE
        );
    dialogSave.SetExtendedMessage(_("The document must be closed."));
    dialogSave.SetYesNoLabels(_("&Save"), _("&Discard changes"));

    if ( dialogSave.ShowModal() == wxID_YES )
    {
        while ( !Save() )
        {
            wxMessageDialog dialogRetry
                (
                    GetDocumentWindow(),
                    wxString::Format
                    (
                        _("Saving %s failed, would you like to retry?"),
                        GetUserReadableName()
                    ),
                    wxTheApp->GetAppDisplayName(),
                    wxYES_NO | wxICON_ERROR | wxCENTRE
                );
            dialogRetry.SetYesNoLabels(_("Retry"), _("Discard changes"));

            if ( dialogRetry.ShowModal() != wxID_YES )
                break;
        }
    }

    Modify(false);
}

bool wxDocument::Draw(wxDC& WXUNUSED(context))
{
    return true;
}

bool wxDocument::AddView(wxView *view)
{
    if ( !m_documentViews.Member(view) )
    {
        m_documentViews.Append(view);
        OnChangedViewList();
    }
    return true;
}

bool wxDocument::RemoveView(wxView *view)
{
    if ( !m_documentViews.DeleteObject(view) )
        return false;

    OnChangedViewList();
    return true;
}

bool wxDocument::OnCreate(const wxString& WXUNUSED(path), long flags)
{
    return GetDocumentTemplate()->CreateView(this, flags) != nullptr;
}

// Called after a view is added or removed.
// The default implementation deletes the document if
// there are no more views.
void wxDocument::OnChangedViewList()
{
    if ( m_documentViews.empty() && OnSaveModified() )
        delete this;
}

void wxDocument::UpdateAllViews(wxView *sender, wxObject *hint)
{
    wxList::compatibility_iterator node = m_documentViews.GetFirst();
    while (node)
    {
        wxView *view = (wxView *)node->GetData();
        if (view != sender)
            view->OnUpdate(sender, hint);
        node = node->GetNext();
    }
}

void wxDocument::NotifyClosing()
{
    wxList::compatibility_iterator node = m_documentViews.GetFirst();
    while (node)
    {
        wxView *view = (wxView *)node->GetData();
        view->OnClosingDocument();
        node = node->GetNext();
    }
}

void wxDocument::SetFilename(const wxString& filename, bool notifyViews)
{
    m_documentFile = filename;
    OnChangeFilename(notifyViews);
}

void wxDocument::OnChangeFilename(bool notifyViews)
{
    if ( notifyViews )
    {
        // Notify the views that the filename has changed
        wxList::compatibility_iterator node = m_documentViews.GetFirst();
        while (node)
        {
            wxView *view = (wxView *)node->GetData();
            view->OnChangeFilename();
            node = node->GetNext();
        }
    }
}

bool wxDocument::DoSaveDocument(const wxString& file)
{
#if wxUSE_STD_IOSTREAM
    std::ofstream store(file.mb_str(), std::ios::binary);
    if ( !store )
#else
    wxFileOutputStream store(file);
    if ( store.GetLastError() != wxSTREAM_NO_ERROR )
#endif
    {
        wxLogError(_("File \"%s\" could not be opened for writing."), file);
        return false;
    }

    if (!SaveObject(store))
    {
        wxLogError(_("Failed to save document to the file \"%s\"."), file);
        return false;
    }

    return true;
}

bool wxDocument::DoOpenDocument(const wxString& file)
{
#if wxUSE_STD_IOSTREAM
    std::ifstream store(file.mb_str(), std::ios::binary);
    if ( !store )
#else
    wxFileInputStream store(file);
    if (store.GetLastError() != wxSTREAM_NO_ERROR || !store.IsOk())
#endif
    {
        wxLogError(_("File \"%s\" could not be opened for reading."), file);
        return false;
    }

#if wxUSE_STD_IOSTREAM
    LoadObject(store);
    if ( !store )
#else
    int res = LoadObject(store).GetLastError();
    if ( res != wxSTREAM_NO_ERROR && res != wxSTREAM_EOF )
#endif
    {
        wxLogError(_("Failed to read document from the file \"%s\"."), file);
        return false;
    }

    return true;
}


// ----------------------------------------------------------------------------
// Document view
// ----------------------------------------------------------------------------

wxView::wxView()
{
    m_viewDocument = nullptr;

    m_viewFrame = nullptr;

    m_docChildFrame = nullptr;
}

wxView::~wxView()
{
    if (m_viewDocument && GetDocumentManager())
        GetDocumentManager()->ActivateView(this, false);

    // reset our frame view first, before removing it from the document as
    // SetView(nullptr) is a simple call while RemoveView() may result in user
    // code being executed and this user code can, for example, show a message
    // box which would result in an activation event for m_docChildFrame and so
    // could reactivate the view being destroyed -- unless we reset it first
    if ( m_docChildFrame && m_docChildFrame->GetView() == this )
    {
        // prevent it from doing anything with us
        m_docChildFrame->SetView(nullptr);

        // it doesn't make sense to leave the frame alive if its associated
        // view doesn't exist any more so unconditionally close it as well
        //
        // notice that we only get here if m_docChildFrame is non-null in the
        // first place and it will be always nullptr if we're deleted because our
        // frame was closed, so this only catches the case of directly deleting
        // the view, as it happens if its creation fails in wxDocTemplate::
        // CreateView() for example
        m_docChildFrame->GetWindow()->Destroy();
    }

    if ( m_viewDocument )
        m_viewDocument->RemoveView(this);
}

void wxView::SetDocChildFrame(wxDocChildFrameAnyBase *docChildFrame)
{
    SetFrame(docChildFrame ? docChildFrame->GetWindow() : nullptr);
    m_docChildFrame = docChildFrame;
}

bool wxView::TryBefore(wxEvent& event)
{
    wxDocument * const doc = GetDocument();
    return doc && doc->ProcessEventLocally(event);
}

void wxView::OnActivateView(bool WXUNUSED(activate),
                            wxView *WXUNUSED(activeView),
                            wxView *WXUNUSED(deactiveView))
{
}

void wxView::OnPrint(wxDC *dc, wxObject *WXUNUSED(info))
{
    OnDraw(dc);
}

void wxView::OnUpdate(wxView *WXUNUSED(sender), wxObject *WXUNUSED(hint))
{
}

void wxView::OnChangeFilename()
{
    // GetFrame can return wxWindow rather than wxTopLevelWindow due to
    // generic MDI implementation so use SetLabel rather than SetTitle.
    // It should cause SetTitle() for top level windows.
    wxWindow *win = GetFrame();
    if (!win) return;

    wxDocument *doc = GetDocument();
    if (!doc) return;

    wxString label = doc->GetUserReadableName();
    if (doc->IsModified())
    {
       label += "*";
    }
    win->SetLabel(label);
}

void wxView::SetDocument(wxDocument *doc)
{
    m_viewDocument = doc;
    if (doc)
        doc->AddView(this);
}

bool wxView::Close(bool deleteWindow)
{
    return OnClose(deleteWindow);
}

void wxView::Activate(bool activate)
{
    if (GetDocument() && GetDocumentManager())
    {
        OnActivateView(activate, this, GetDocumentManager()->GetCurrentView());
        GetDocumentManager()->ActivateView(this, activate);
    }
}

bool wxView::OnClose(bool WXUNUSED(deleteWindow))
{
    return GetDocument() ? GetDocument()->Close() : true;
}

#if wxUSE_PRINTING_ARCHITECTURE
wxPrintout *wxView::OnCreatePrintout()
{
    return new wxDocPrintout(this);
}
#endif // wxUSE_PRINTING_ARCHITECTURE

// ----------------------------------------------------------------------------
// wxDocTemplate
// ----------------------------------------------------------------------------

wxDocTemplate::wxDocTemplate(wxDocManager *manager,
                             const wxString& descr,
                             const wxString& filter,
                             const wxString& dir,
                             const wxString& ext,
                             const wxString& docTypeName,
                             const wxString& viewTypeName,
                             wxClassInfo *docClassInfo,
                             wxClassInfo *viewClassInfo,
                             long flags)
    : m_fileFilter(filter)
    , m_directory(dir)
    , m_description(descr)
    , m_defaultExt(ext)
    , m_docTypeName(docTypeName)
    , m_viewTypeName(viewTypeName)
{
    m_documentManager = manager;
    m_flags = flags;
    m_documentManager->AssociateTemplate(this);

    m_docClassInfo = docClassInfo;
    m_viewClassInfo = viewClassInfo;
}

wxDocTemplate::~wxDocTemplate()
{
    m_documentManager->DisassociateTemplate(this);
}

// Tries to dynamically construct an object of the right class.
wxDocument *wxDocTemplate::CreateDocument(const wxString& path, long flags)
{
    // InitDocument() is supposed to delete the document object if its
    // initialization fails so don't use unique_ptr<> here: this is fragile
    // but unavoidable because the default implementation uses CreateView()
    // which may -- or not -- create a wxView and if it does create it and its
    // initialization fails then the view destructor will delete the document
    // (via RemoveView()) and as we can't distinguish between the two cases we
    // just have to assume that it always deletes it in case of failure
    wxDocument * const doc = DoCreateDocument();

    return doc && InitDocument(doc, path, flags) ? doc : nullptr;
}

bool
wxDocTemplate::InitDocument(wxDocument* doc, const wxString& path, long flags)
{
    wxTRY
    {
        doc->SetFilename(path);
        doc->SetDocumentTemplate(this);
        GetDocumentManager()->AddDocument(doc);
        doc->SetCommandProcessor(doc->OnCreateCommandProcessor());

        if ( doc->OnCreate(path, flags) )
            return true;

        // The document may be already destroyed, this happens if its view
        // creation fails as then the view being created is destroyed
        // triggering the destruction of the document as this first view is
        // also the last one. However if OnCreate() fails for any reason other
        // than view creation failure, the document is still alive and we need
        // to clean it up ourselves to avoid having a zombie document.
        if ( GetDocumentManager()->GetDocuments().Member(doc) )
            doc->DeleteAllViews();

        return false;
    }
    wxCATCH_ALL(
        if ( GetDocumentManager()->GetDocuments().Member(doc) )
            doc->DeleteAllViews();
        throw;
    )
}

wxView *wxDocTemplate::CreateView(wxDocument *doc, long flags)
{
    std::unique_ptr<wxView> view(DoCreateView());
    if ( !view )
        return nullptr;

    view->SetDocument(doc);
    if ( !view->OnCreate(doc, flags) )
        return nullptr;

    return view.release();
}

// The default (very primitive) format detection: check is the extension is
// that of the template
bool wxDocTemplate::FileMatchesTemplate(const wxString& path)
{
    wxStringTokenizer parser (GetFileFilter(), wxT(";"));
    wxString anything = wxT ("*");
    while (parser.HasMoreTokens())
    {
        wxString filter = parser.GetNextToken();
        wxString filterExt = FindExtension (filter);
        if ( filter.IsSameAs (anything)    ||
             filterExt.IsSameAs (anything) ||
             filterExt.IsSameAs (FindExtension (path)) )
            return true;
    }
    return GetDefaultExtension().IsSameAs(FindExtension(path));
}

wxDocument *wxDocTemplate::DoCreateDocument()
{
    if (!m_docClassInfo)
        return nullptr;

    return static_cast<wxDocument *>(m_docClassInfo->CreateObject());
}

wxView *wxDocTemplate::DoCreateView()
{
    if (!m_viewClassInfo)
        return nullptr;

    return static_cast<wxView *>(m_viewClassInfo->CreateObject());
}

// ----------------------------------------------------------------------------
// wxDocManager
// ----------------------------------------------------------------------------

wxBEGIN_EVENT_TABLE(wxDocManager, wxEvtHandler)
    EVT_MENU(wxID_OPEN, wxDocManager::OnFileOpen)
    EVT_MENU(wxID_CLOSE, wxDocManager::OnFileClose)
    EVT_MENU(wxID_CLOSE_ALL, wxDocManager::OnFileCloseAll)
    EVT_MENU(wxID_REVERT, wxDocManager::OnFileRevert)
    EVT_MENU(wxID_NEW, wxDocManager::OnFileNew)
    EVT_MENU(wxID_SAVE, wxDocManager::OnFileSave)
    EVT_MENU(wxID_SAVEAS, wxDocManager::OnFileSaveAs)
    EVT_MENU(wxID_UNDO, wxDocManager::OnUndo)
    EVT_MENU(wxID_REDO, wxDocManager::OnRedo)

    // We don't know in advance how many items can there be in the MRU files
    // list so set up OnMRUFile() as a handler for all menu events and do the
    // check for the id of the menu item clicked inside it.
    EVT_MENU(wxID_ANY, wxDocManager::OnMRUFile)

    EVT_UPDATE_UI(wxID_OPEN, wxDocManager::OnUpdateFileOpen)
    EVT_UPDATE_UI(wxID_CLOSE, wxDocManager::OnUpdateDisableIfNoDoc)
    EVT_UPDATE_UI(wxID_CLOSE_ALL, wxDocManager::OnUpdateDisableIfNoDoc)
    EVT_UPDATE_UI(wxID_REVERT, wxDocManager::OnUpdateFileRevert)
    EVT_UPDATE_UI(wxID_NEW, wxDocManager::OnUpdateFileNew)
    EVT_UPDATE_UI(wxID_SAVE, wxDocManager::OnUpdateFileSave)
    EVT_UPDATE_UI(wxID_SAVEAS, wxDocManager::OnUpdateFileSaveAs)
    EVT_UPDATE_UI(wxID_UNDO, wxDocManager::OnUpdateUndo)
    EVT_UPDATE_UI(wxID_REDO, wxDocManager::OnUpdateRedo)

#if wxUSE_PRINTING_ARCHITECTURE
    EVT_MENU(wxID_PRINT, wxDocManager::OnPrint)
    EVT_MENU(wxID_PREVIEW, wxDocManager::OnPreview)
    EVT_MENU(wxID_PRINT_SETUP, wxDocManager::OnPageSetup)

    EVT_UPDATE_UI(wxID_PRINT, wxDocManager::OnUpdateDisableIfNoDoc)
    EVT_UPDATE_UI(wxID_PREVIEW, wxDocManager::OnUpdateDisableIfNoDoc)
    // NB: we keep "Print setup" menu item always enabled as it can be used
    //     even without an active document
#endif // wxUSE_PRINTING_ARCHITECTURE
wxEND_EVENT_TABLE()

wxDocManager* wxDocManager::sm_docManager = nullptr;

wxDocManager::wxDocManager(long WXUNUSED(flags), bool initialize)
{
    sm_docManager = this;

    m_defaultDocumentNameCounter = 1;
    m_currentView = nullptr;
    m_maxDocsOpen = INT_MAX;
    m_fileHistory = nullptr;
    if ( initialize )
        Initialize();
}

wxDocManager::~wxDocManager()
{
    Clear();
    delete m_fileHistory;
    sm_docManager = nullptr;
}

// closes the specified document
bool wxDocManager::CloseDocument(wxDocument* doc, bool force)
{
    if ( force )
    {
        // We need to close, but at least ask the user if the document should
        // be saved before doing it.
        doc->OnSaveBeforeForceClose();
    }
    else // Allow the user to cancel closing too.
    {
        if ( !doc->CanClose() )
            return false;
    }

    // Note that by now the document is certain not to be modified any longer.

    // Implicitly deletes the document when
    // the last view is deleted
    doc->DeleteAllViews();

    wxASSERT(!m_docs.Member(doc));

    return true;
}

bool wxDocManager::CloseDocuments(bool force)
{
    wxList::compatibility_iterator node = m_docs.GetFirst();
    while (node)
    {
        wxDocument *doc = (wxDocument *)node->GetData();
        wxList::compatibility_iterator next = node->GetNext();

        if (!CloseDocument(doc, force))
            return false;

        // This assumes that documents are not connected in
        // any way, i.e. deleting one document does NOT
        // delete another.
        node = next;
    }
    return true;
}

bool wxDocManager::Clear(bool force)
{
    if (!CloseDocuments(force))
        return false;

    m_currentView = nullptr;

    wxList::compatibility_iterator node = m_templates.GetFirst();
    while (node)
    {
        wxDocTemplate *templ = (wxDocTemplate*) node->GetData();
        wxList::compatibility_iterator next = node->GetNext();
        delete templ;
        node = next;
    }
    return true;
}

bool wxDocManager::Initialize()
{
    m_fileHistory = OnCreateFileHistory();
    return true;
}

wxString wxDocManager::GetLastDirectory() const
{
    // if we haven't determined the last used directory yet, do it now
    if ( m_lastDirectory.empty() )
    {
        // we're going to modify m_lastDirectory in this const method, so do it
        // via non-const self pointer instead of const this one
        wxDocManager * const self = const_cast<wxDocManager *>(this);

        // first try to reuse the directory of the most recently opened file:
        // this ensures that if the user opens a file, closes the program and
        // runs it again the "Open file" dialog will open in the directory of
        // the last file he used
        if ( m_fileHistory && m_fileHistory->GetCount() )
        {
            const wxString lastOpened = m_fileHistory->GetHistoryFile(0);
            const wxFileName fn(lastOpened);
            if ( fn.DirExists() )
            {
                self->m_lastDirectory = fn.GetPath();
            }
            //else: should we try the next one?
        }
        //else: no history yet

        // if we don't have any files in the history (yet?), use the
        // system-dependent default location for the document files
        if ( m_lastDirectory.empty() )
        {
            self->m_lastDirectory = wxStandardPaths::Get().GetAppDocumentsDir();
        }
    }

    return m_lastDirectory;
}

wxFileHistory *wxDocManager::OnCreateFileHistory()
{
    return new wxFileHistory;
}

void wxDocManager::OnFileClose(wxCommandEvent& WXUNUSED(event))
{
    wxDocument *doc = GetCurrentDocument();
    if (doc)
        CloseDocument(doc);
}

void wxDocManager::OnFileCloseAll(wxCommandEvent& WXUNUSED(event))
{
    CloseDocuments(false);
}

void wxDocManager::OnFileNew(wxCommandEvent& WXUNUSED(event))
{
    CreateNewDocument();
}

void wxDocManager::OnFileOpen(wxCommandEvent& WXUNUSED(event))
{
    if ( !CreateDocument(wxString()) )
    {
        OnOpenFileFailure();
    }
}

void wxDocManager::OnFileRevert(wxCommandEvent& WXUNUSED(event))
{
    wxDocument *doc = GetCurrentDocument();
    if (!doc)
        return;
    doc->Revert();
}

void wxDocManager::OnFileSave(wxCommandEvent& WXUNUSED(event))
{
    wxDocument *doc = GetCurrentDocument();
    if (!doc)
        return;
    doc->Save();
}

void wxDocManager::OnFileSaveAs(wxCommandEvent& WXUNUSED(event))
{
    wxDocument *doc = GetCurrentDocument();
    if (!doc)
        return;
    doc->SaveAs();
}

void wxDocManager::OnMRUFile(wxCommandEvent& event)
{
    if ( m_fileHistory )
    {
        // Check if the id is in the range assigned to MRU list entries.
        const int id = event.GetId();
        if ( id >= wxID_FILE1 &&
                id < wxID_FILE1 + static_cast<int>(m_fileHistory->GetCount()) )
        {
            DoOpenMRUFile(id - wxID_FILE1);

            // Don't skip the event below.
            return;
        }
    }

    event.Skip();
}

void wxDocManager::DoOpenMRUFile(unsigned n)
{
    wxString filename(GetHistoryFile(n));
    if ( filename.empty() )
        return;

    if ( wxFile::Exists(filename) )
    {
        // Try to open it but don't give an error if it failed: this could be
        // normal, e.g. because the user cancelled opening it, and we don't
        // have any useful information to put in the error message anyhow, so
        // we assume that in case of an error the appropriate message had been
        // already logged.
        (void)CreateDocument(filename, wxDOC_SILENT);
    }
    else // file doesn't exist
    {
        OnMRUFileNotExist(n, filename);
    }
}

void wxDocManager::OnMRUFileNotExist(unsigned n, const wxString& filename)
{
    // remove the file which we can't open from the MRU list
    RemoveFileFromHistory(n);

    // and tell the user about it
    wxLogError(_("The file '%s' doesn't exist and couldn't be opened.\n"
                 "It has been removed from the most recently used files list."),
               filename);
}

#if wxUSE_PRINTING_ARCHITECTURE

void wxDocManager::OnPrint(wxCommandEvent& WXUNUSED(event))
{
    wxView *view = GetAnyUsableView();
    if (!view)
        return;

    wxPrintout *printout = view->OnCreatePrintout();
    if (printout)
    {
        wxPrintDialogData printDialogData(m_pageSetupDialogData.GetPrintData());
        wxPrinter printer(&printDialogData);
        printer.Print(view->GetFrame(), printout, true);

        delete printout;
    }
}

void wxDocManager::OnPageSetup(wxCommandEvent& WXUNUSED(event))
{
    wxPageSetupDialog dlg(wxTheApp->GetTopWindow(), &m_pageSetupDialogData);
    if ( dlg.ShowModal() == wxID_OK )
    {
        m_pageSetupDialogData = dlg.GetPageSetupData();
    }
}

wxPreviewFrame* wxDocManager::CreatePreviewFrame(wxPrintPreviewBase* preview,
                                                 wxWindow *parent,
                                                 const wxString& title)
{
    return new wxPreviewFrame(preview, parent, title);
}

void wxDocManager::OnPreview(wxCommandEvent& WXUNUSED(event))
{
    wxBusyCursor busy;
    wxView *view = GetAnyUsableView();
    if (!view)
        return;

    wxPrintout *printout = view->OnCreatePrintout();
    if (printout)
    {
        wxPrintDialogData printDialogData(m_pageSetupDialogData.GetPrintData());

        // Pass two printout objects: for preview, and possible printing.
        wxPrintPreviewBase *
            preview = new wxPrintPreview(printout,
                                         view->OnCreatePrintout(),
                                         &printDialogData);
        if ( !preview->IsOk() )
        {
            delete preview;
            wxLogError(_("Print preview creation failed."));
            return;
        }

        wxPreviewFrame* frame = CreatePreviewFrame(preview,
                                                   wxTheApp->GetTopWindow(),
                                                   _("Print Preview"));
        wxCHECK_RET( frame, "should create a print preview frame" );

        frame->Centre(wxBOTH);
        frame->Initialize();
        frame->Show(true);
    }
}
#endif // wxUSE_PRINTING_ARCHITECTURE

void wxDocManager::OnUndo(wxCommandEvent& event)
{
    wxCommandProcessor * const cmdproc = GetCurrentCommandProcessor();
    if ( !cmdproc )
    {
        event.Skip();
        return;
    }

    cmdproc->Undo();
}

void wxDocManager::OnRedo(wxCommandEvent& event)
{
    wxCommandProcessor * const cmdproc = GetCurrentCommandProcessor();
    if ( !cmdproc )
    {
        event.Skip();
        return;
    }

    cmdproc->Redo();
}

// Handlers for UI update commands

void wxDocManager::OnUpdateFileOpen(wxUpdateUIEvent& event)
{
    // CreateDocument() (which is called from OnFileOpen) may succeed
    // only when there is at least a template:
    event.Enable( GetTemplates().GetCount()>0 );
}

void wxDocManager::OnUpdateDisableIfNoDoc(wxUpdateUIEvent& event)
{
    event.Enable( GetCurrentDocument() != nullptr );
}

void wxDocManager::OnUpdateFileRevert(wxUpdateUIEvent& event)
{
    wxDocument* doc = GetCurrentDocument();
    event.Enable(doc && doc->IsModified() && doc->GetDocumentSaved());
}

void wxDocManager::OnUpdateFileNew(wxUpdateUIEvent& event)
{
    // CreateDocument() (which is called from OnFileNew) may succeed
    // only when there is at least a template:
    event.Enable( GetTemplates().GetCount()>0 );
}

void wxDocManager::OnUpdateFileSave(wxUpdateUIEvent& event)
{
    wxDocument * const doc = GetCurrentDocument();
    event.Enable( doc && !doc->IsChildDocument() && !doc->AlreadySaved() );
}

void wxDocManager::OnUpdateFileSaveAs(wxUpdateUIEvent& event)
{
    wxDocument * const doc = GetCurrentDocument();
    event.Enable( doc && !doc->IsChildDocument() );
}

void wxDocManager::OnUpdateUndo(wxUpdateUIEvent& event)
{
    wxCommandProcessor * const cmdproc = GetCurrentCommandProcessor();
    if ( !cmdproc )
    {
        // If we don't have any document at all, the menu item should really be
        // disabled.
        if ( !GetCurrentDocument() )
            event.Enable(false);
        else // But if we do have it, it might handle wxID_UNDO on its own
            event.Skip();
        return;
    }
    event.Enable(cmdproc->CanUndo());
    cmdproc->SetMenuStrings();
}

void wxDocManager::OnUpdateRedo(wxUpdateUIEvent& event)
{
    wxCommandProcessor * const cmdproc = GetCurrentCommandProcessor();
    if ( !cmdproc )
    {
        // Use same logic as in OnUpdateUndo() above.
        if ( !GetCurrentDocument() )
            event.Enable(false);
        else
            event.Skip();
        return;
    }
    event.Enable(cmdproc->CanRedo());
    cmdproc->SetMenuStrings();
}

wxView *wxDocManager::GetAnyUsableView() const
{
    wxView *view = GetCurrentView();

    if ( !view && !m_docs.empty() )
    {
        // if we have exactly one document, consider its view to be the current
        // one
        //
        // VZ: I'm not exactly sure why is this needed but this is how this
        //     code used to behave before the bug #9518 was fixed and it seems
        //     safer to preserve the old logic
        wxList::compatibility_iterator node = m_docs.GetFirst();
        if ( !node->GetNext() )
        {
            wxDocument *doc = static_cast<wxDocument *>(node->GetData());
            view = doc->GetFirstView();
        }
        //else: we have more than one document
    }

    return view;
}

bool wxDocManager::TryBefore(wxEvent& event)
{
    wxView * const view = GetAnyUsableView();
    return view && view->ProcessEventLocally(event);
}

namespace
{

// helper function: return only the visible templates
wxDocTemplateVector GetVisibleTemplates(const wxList& allTemplates)
{
    // select only the visible templates
    const size_t totalNumTemplates = allTemplates.GetCount();
    wxDocTemplateVector templates;
    if ( totalNumTemplates )
    {
        templates.reserve(totalNumTemplates);

        for ( wxList::const_iterator i = allTemplates.begin(),
                                   end = allTemplates.end();
              i != end;
              ++i )
        {
            wxDocTemplate * const temp = (wxDocTemplate *)*i;
            if ( temp->IsVisible() )
                templates.push_back(temp);
        }
    }

    return templates;
}

} // anonymous namespace

void wxDocument::Activate()
{
    wxView * const view = GetFirstView();
    if ( !view )
        return;

    view->Activate(true);
    if ( wxWindow *win = view->GetFrame() )
        win->Raise();
}

wxDocument* wxDocManager::FindDocumentByPath(const wxString& path) const
{
    const wxFileName fileName(path);
    for ( wxList::const_iterator i = m_docs.begin(); i != m_docs.end(); ++i )
    {
        wxDocument * const doc = wxStaticCast(*i, wxDocument);

        if ( fileName == wxFileName(doc->GetFilename()) )
            return doc;
    }
    return nullptr;
}

wxDocument *wxDocManager::CreateDocument(const wxString& pathOrig, long flags)
{
    // this ought to be const but SelectDocumentType/Path() are not
    // const-correct and can't be changed as, being virtual, this risks
    // breaking user code overriding them
    wxDocTemplateVector templates(GetVisibleTemplates(m_templates));
    const size_t numTemplates = templates.size();
    if ( !numTemplates )
    {
        // no templates can be used, can't create document
        return nullptr;
    }


    // normally user should select the template to use but wxDOC_SILENT flag we
    // choose one ourselves
    wxString path = pathOrig;   // may be modified below
    wxDocTemplate *temp;
    if ( flags & wxDOC_SILENT )
    {
        wxASSERT_MSG( !path.empty(),
                      "using empty path with wxDOC_SILENT doesn't make sense" );

        temp = FindTemplateForPath(path);
        if ( !temp )
        {
            wxLogWarning(_("The format of file '%s' couldn't be determined."),
                         path);
        }
    }
    else // not silent, ask the user
    {
        // for the new file we need just the template, for an existing one we
        // need the template and the path, unless it's already specified
        if ( (flags & wxDOC_NEW) || !path.empty() )
            temp = SelectDocumentType(&templates[0], numTemplates);
        else
            temp = SelectDocumentPath(&templates[0], numTemplates, path, flags);
    }

    if ( !temp )
        return nullptr;

    // check whether the document with this path is already opened
    if ( !path.empty() )
    {
        wxDocument * const doc = FindDocumentByPath(path);
        if (doc)
        {
            // file already open, just activate it and return
            doc->Activate();
            return doc;
        }
    }

    // no, we need to create a new document


    // if we've reached the max number of docs, close the first one.
    if ( (int)GetDocuments().GetCount() >= m_maxDocsOpen )
    {
        if ( !CloseDocument((wxDocument *)GetDocuments().GetFirst()->GetData()) )
        {
            // can't open the new document if closing the old one failed
            return nullptr;
        }
    }


    // do create and initialize the new document finally
    wxDocument * const docNew = temp->CreateDocument(path, flags);
    if ( !docNew )
        return nullptr;

    docNew->SetDocumentName(temp->GetDocumentName());

    wxTRY
    {
        // call the appropriate function depending on whether we're creating a
        // new file or opening an existing one
        if ( !(flags & wxDOC_NEW ? docNew->OnNewDocument()
                                 : docNew->OnOpenDocument(path)) )
        {
            docNew->DeleteAllViews();
            return nullptr;
        }
    }
    wxCATCH_ALL( docNew->DeleteAllViews(); throw; )

    // add the successfully opened file to MRU, but only if we're going to be
    // able to reopen it successfully later which requires the template for
    // this document to be retrievable from the file extension
    if ( !(flags & wxDOC_NEW) && temp->FileMatchesTemplate(path) )
        AddFileToHistory(path);

    // at least under Mac (where views are top level windows) it seems to be
    // necessary to manually activate the new document to bring it to the
    // forefront -- and it shouldn't hurt doing this under the other platforms
    docNew->Activate();

    return docNew;
}

wxView *wxDocManager::CreateView(wxDocument *doc, long flags)
{
    wxDocTemplateVector templates(GetVisibleTemplates(m_templates));
    const size_t numTemplates = templates.size();

    if ( numTemplates == 0 )
        return nullptr;

    wxDocTemplate * const
    temp = numTemplates == 1 ? templates[0]
                             : SelectViewType(&templates[0], numTemplates);

    if ( !temp )
        return nullptr;

    wxView *view = temp->CreateView(doc, flags);
    if ( view )
        view->SetViewName(temp->GetViewName());
    return view;
}

// Not yet implemented
void
wxDocManager::DeleteTemplate(wxDocTemplate *WXUNUSED(temp), long WXUNUSED(flags))
{
}

// Not yet implemented
bool wxDocManager::FlushDoc(wxDocument *WXUNUSED(doc))
{
    return false;
}

wxDocument *wxDocManager::GetCurrentDocument() const
{
    wxView * const view = GetAnyUsableView();
    return view ? view->GetDocument() : nullptr;
}

wxCommandProcessor *wxDocManager::GetCurrentCommandProcessor() const
{
    wxDocument * const doc = GetCurrentDocument();
    return doc ? doc->GetCommandProcessor() : nullptr;
}

// Make a default name for a new document
wxString wxDocManager::MakeNewDocumentName()
{
    wxString name;

    name.Printf(_("unnamed%d"), m_defaultDocumentNameCounter);
    m_defaultDocumentNameCounter++;

    return name;
}

// Make a frame title (override this to do something different)
// If docName is empty, a document is not currently active.
wxString wxDocManager::MakeFrameTitle(wxDocument* doc)
{
    wxString appName = wxTheApp->GetAppDisplayName();
    wxString title;
    if (!doc)
        title = appName;
    else
    {
        wxString docName = doc->GetUserReadableName();
        title = docName + wxString(_(" - ")) + appName;
    }
    return title;
}


// Not yet implemented
wxDocTemplate *wxDocManager::MatchTemplate(const wxString& WXUNUSED(path))
{
    return nullptr;
}

// File history management
void wxDocManager::AddFileToHistory(const wxString& file)
{
    if (m_fileHistory)
        m_fileHistory->AddFileToHistory(file);
}

void wxDocManager::RemoveFileFromHistory(size_t i)
{
    if (m_fileHistory)
        m_fileHistory->RemoveFileFromHistory(i);
}

wxString wxDocManager::GetHistoryFile(size_t i) const
{
    wxString histFile;

    if (m_fileHistory)
        histFile = m_fileHistory->GetHistoryFile(i);

    return histFile;
}

void wxDocManager::FileHistoryUseMenu(wxMenu *menu)
{
    if (m_fileHistory)
        m_fileHistory->UseMenu(menu);
}

void wxDocManager::FileHistoryRemoveMenu(wxMenu *menu)
{
    if (m_fileHistory)
        m_fileHistory->RemoveMenu(menu);
}

#if wxUSE_CONFIG
void wxDocManager::FileHistoryLoad(const wxConfigBase& config)
{
    if (m_fileHistory)
        m_fileHistory->Load(config);
}

void wxDocManager::FileHistorySave(wxConfigBase& config)
{
    if (m_fileHistory)
        m_fileHistory->Save(config);
}
#endif

void wxDocManager::FileHistoryAddFilesToMenu(wxMenu* menu)
{
    if (m_fileHistory)
        m_fileHistory->AddFilesToMenu(menu);
}

void wxDocManager::FileHistoryAddFilesToMenu()
{
    if (m_fileHistory)
        m_fileHistory->AddFilesToMenu();
}

size_t wxDocManager::GetHistoryFilesCount() const
{
    return m_fileHistory ? m_fileHistory->GetCount() : 0;
}


// Find out the document template via matching in the document file format
// against that of the template
wxDocTemplate *wxDocManager::FindTemplateForPath(const wxString& path)
{
    wxDocTemplate *theTemplate = nullptr;

    // Find the template which this extension corresponds to
    for (size_t i = 0; i < m_templates.GetCount(); i++)
    {
        wxDocTemplate *temp = (wxDocTemplate *)m_templates.Item(i)->GetData();
        if ( temp->FileMatchesTemplate(path) )
        {
            theTemplate = temp;
            break;
        }
    }
    return theTemplate;
}

// Prompts user to open a file, using file specs in templates.
// Must extend the file selector dialog or implement own; OR
// match the extension to the template extension.

wxDocTemplate *wxDocManager::SelectDocumentPath(wxDocTemplate **templates,
                                                int noTemplates,
                                                wxString& path,
                                                long WXUNUSED(flags),
                                                bool WXUNUSED(save))
{
#ifdef wxHAS_MULTIPLE_FILEDLG_FILTERS
    wxString descrBuf;

    for (int i = 0; i < noTemplates; i++)
    {
        if (templates[i]->IsVisible())
        {
            // add a '|' to separate this filter from the previous one
            if ( !descrBuf.empty() )
                descrBuf << wxT('|');

            descrBuf << templates[i]->GetDescription()
                << wxT(" (") << templates[i]->GetFileFilter() << wxT(") |")
                << templates[i]->GetFileFilter();
        }
    }
#else
    wxString descrBuf = wxT("*.*");
    wxUnusedVar(noTemplates);
#endif

    int FilterIndex = -1;

    wxString pathTmp = wxFileSelectorEx(_("Open File"),
                                        GetLastDirectory(),
                                        wxEmptyString,
                                        &FilterIndex,
                                        descrBuf,
                                        wxFD_OPEN | wxFD_FILE_MUST_EXIST);

    wxDocTemplate *theTemplate = nullptr;
    if (!pathTmp.empty())
    {
        if (!wxFileExists(pathTmp))
        {
            wxString msgTitle;
            if (!wxTheApp->GetAppDisplayName().empty())
                msgTitle = wxTheApp->GetAppDisplayName();
            else
                msgTitle = wxString(_("File error"));

            wxMessageBox(_("Sorry, could not open this file."),
                         msgTitle,
                         wxOK | wxICON_EXCLAMATION | wxCENTRE);

            path.clear();
            return nullptr;
        }

        SetLastDirectory(wxPathOnly(pathTmp));

        path = pathTmp;

        // first choose the template using the extension, if this fails (i.e.
        // wxFileSelectorEx() didn't fill it), then use the path
        if ( FilterIndex != -1 )
        {
            theTemplate = templates[FilterIndex];
            if ( theTemplate )
            {
                // But don't use this template if it doesn't match the path as
                // can happen if the user specified the extension explicitly
                // but didn't bother changing the filter.
                if ( !theTemplate->FileMatchesTemplate(path) )
                    theTemplate = nullptr;
            }
        }

        if ( !theTemplate )
            theTemplate = FindTemplateForPath(path);
        if ( !theTemplate )
        {
            // Since we do not add files with non-default extensions to the
            // file history this can only happen if the application changes the
            // allowed templates in runtime.
            wxMessageBox(_("Sorry, the format for this file is unknown."),
                         _("Open File"),
                         wxOK | wxICON_EXCLAMATION | wxCENTRE);
        }
    }
    else
    {
        path.clear();
    }

    return theTemplate;
}

wxDocTemplate *wxDocManager::SelectDocumentType(wxDocTemplate **templates,
                                                int noTemplates, bool sort)
{
    wxArrayString strings;
    wxScopedArray<wxDocTemplate *> data(noTemplates);
    int i;
    int n = 0;

    for (i = 0; i < noTemplates; i++)
    {
        if (templates[i]->IsVisible())
        {
            int j;
            bool want = true;
            for (j = 0; j < n; j++)
            {
                //filter out NOT unique documents + view combinations
                if ( templates[i]->m_docTypeName == data[j]->m_docTypeName &&
                     templates[i]->m_viewTypeName == data[j]->m_viewTypeName
                   )
                    want = false;
            }

            if ( want )
            {
                strings.Add(templates[i]->m_description);

                data[n] = templates[i];
                n ++;
            }
        }
    }  // for

    if (sort)
    {
        strings.Sort(); // ascending sort
        // Yes, this will be slow, but template lists
        // are typically short.
        int j;
        n = strings.Count();
        for (i = 0; i < n; i++)
        {
            for (j = 0; j < noTemplates; j++)
            {
                if (strings[i] == templates[j]->m_description)
                    data[i] = templates[j];
            }
        }
    }

    wxDocTemplate *theTemplate;

    switch ( n )
    {
        case 0:
            // no visible templates, hence nothing to choose from
            theTemplate = nullptr;
            break;

        case 1:
            // don't propose the user to choose if he has no choice
            theTemplate = data[0];
            break;

        default:
            // propose the user to choose one of several
            theTemplate = (wxDocTemplate *)wxGetSingleChoiceData
                          (
                            _("Select a document template"),
                            _("Templates"),
                            strings,
                            (void **)data.get()
                          );
    }

    return theTemplate;
}

wxDocTemplate *wxDocManager::SelectViewType(wxDocTemplate **templates,
                                            int noTemplates, bool sort)
{
    wxArrayString strings;
    wxScopedArray<wxDocTemplate *> data(noTemplates);
    int i;
    int n = 0;

    for (i = 0; i < noTemplates; i++)
    {
        wxDocTemplate *templ = templates[i];
        if ( templ->IsVisible() && !templ->GetViewName().empty() )
        {
            int j;
            bool want = true;
            for (j = 0; j < n; j++)
            {
                //filter out NOT unique views
                if ( templates[i]->m_viewTypeName == data[j]->m_viewTypeName )
                    want = false;
            }

            if ( want )
            {
                strings.Add(templ->m_viewTypeName);
                data[n] = templ;
                n ++;
            }
        }
    }

    if (sort)
    {
        strings.Sort(); // ascending sort
        // Yes, this will be slow, but template lists
        // are typically short.
        int j;
        n = strings.Count();
        for (i = 0; i < n; i++)
        {
            for (j = 0; j < noTemplates; j++)
            {
                if (strings[i] == templates[j]->m_viewTypeName)
                    data[i] = templates[j];
            }
        }
    }

    wxDocTemplate *theTemplate;

    // the same logic as above
    switch ( n )
    {
        case 0:
            theTemplate = nullptr;
            break;

        case 1:
            theTemplate = data[0];
            break;

        default:
            theTemplate = (wxDocTemplate *)wxGetSingleChoiceData
                          (
                            _("Select a document view"),
                            _("Views"),
                            strings,
                            (void **)data.get()
                          );

    }

    return theTemplate;
}

void wxDocManager::AssociateTemplate(wxDocTemplate *temp)
{
    if (!m_templates.Member(temp))
        m_templates.Append(temp);
}

void wxDocManager::DisassociateTemplate(wxDocTemplate *temp)
{
    m_templates.DeleteObject(temp);
}

wxDocTemplate* wxDocManager::FindTemplate(const wxClassInfo* classinfo)
{
   for ( wxList::compatibility_iterator node = m_templates.GetFirst();
         node;
         node = node->GetNext() )
   {
      wxDocTemplate* t = wxStaticCast(node->GetData(), wxDocTemplate);
      if ( t->GetDocClassInfo() == classinfo )
         return t;
   }

   return nullptr;
}

// Add and remove a document from the manager's list
void wxDocManager::AddDocument(wxDocument *doc)
{
    if (!m_docs.Member(doc))
        m_docs.Append(doc);
}

void wxDocManager::RemoveDocument(wxDocument *doc)
{
    m_docs.DeleteObject(doc);
}

// Views or windows should inform the document manager
// when a view is going in or out of focus
void wxDocManager::ActivateView(wxView *view, bool activate)
{
    if ( activate )
    {
        m_currentView = view;
    }
    else // deactivate
    {
        if ( m_currentView == view )
        {
            // don't keep stale pointer
            m_currentView = nullptr;
        }
    }
}

// ----------------------------------------------------------------------------
// wxDocChildFrameAnyBase
// ----------------------------------------------------------------------------

bool wxDocChildFrameAnyBase::TryProcessEvent(wxEvent& event)
{
    if ( !m_childView )
    {
        // We must be being destroyed, don't forward events anywhere as
        // m_childDocument could be invalid by now.
        return false;
    }

    // Store a (non-owning) pointer to the last processed event here to be able
    // to recognize this event again if it bubbles up to the parent frame, see
    // the code in wxDocParentFrameAnyBase::TryProcessEvent().
    m_lastEvent = &event;

    // Forward the event to the document manager which will, in turn, forward
    // it to its active view which must be our m_childView.
    //
    // Notice that we do things in this roundabout way to guarantee the correct
    // event handlers call order: first the document, then the view and then the
    // document manager itself. And if we forwarded the event directly to the
    // view, then the document manager would do it once again when we forwarded
    // it to it.
    return m_childDocument->GetDocumentManager()->ProcessEventLocally(event);
}

bool wxDocChildFrameAnyBase::CloseView(wxCloseEvent& event)
{
    if ( m_childView )
    {
        // notice that we must call wxView::Close() and OnClose() called from
        // it in any case, even if we know that we are going to close anyhow
        if ( !m_childView->Close(false) && event.CanVeto() )
        {
            event.Veto();
            return false;
        }

        m_childView->Activate(false);

        // it is important to reset m_childView frame pointer to nullptr before
        // deleting it because while normally it is the frame which deletes the
        // view when it's closed, the view also closes the frame if it is
        // deleted directly not by us as indicated by its doc child frame
        // pointer still being set
        m_childView->SetDocChildFrame(nullptr);
        wxDELETE(m_childView);
    }

    m_childDocument = nullptr;

    return true;
}

// ----------------------------------------------------------------------------
// wxDocParentFrameAnyBase
// ----------------------------------------------------------------------------

bool wxDocParentFrameAnyBase::TryProcessEvent(wxEvent& event)
{
    if ( !m_docManager )
        return false;

    // If we have an active view, its associated child frame may have
    // already forwarded the event to wxDocManager, check for this:
    if ( wxView* const view = m_docManager->GetAnyUsableView() )
    {
        wxDocChildFrameAnyBase* const childFrame = view->GetDocChildFrame();
        if ( childFrame && childFrame->HasAlreadyProcessed(event) )
            return false;
    }

    // But forward the event to wxDocManager ourselves if there are no views at
    // all or if this event hadn't been sent to the child frame previously.
    return m_docManager->ProcessEventLocally(event);
}

// ----------------------------------------------------------------------------
// Printing support
// ----------------------------------------------------------------------------

#if wxUSE_PRINTING_ARCHITECTURE

namespace
{

wxString GetAppropriateTitle(const wxView *view, const wxString& titleGiven)
{
    wxString title(titleGiven);
    if ( title.empty() )
    {
        if ( view && view->GetDocument() )
            title = view->GetDocument()->GetUserReadableName();
        else
            title = _("Printout");
    }

    return title;
}

} // anonymous namespace

wxDocPrintout::wxDocPrintout(wxView *view, const wxString& title)
             : wxPrintout(GetAppropriateTitle(view, title))
{
    m_printoutView = view;
}

bool wxDocPrintout::OnPrintPage(int WXUNUSED(page))
{
    wxDC *dc = GetDC();

    // Get the logical pixels per inch of screen and printer
    int ppiScreenX, ppiScreenY;
    GetPPIScreen(&ppiScreenX, &ppiScreenY);
    wxUnusedVar(ppiScreenY);
    int ppiPrinterX, ppiPrinterY;
    GetPPIPrinter(&ppiPrinterX, &ppiPrinterY);
    wxUnusedVar(ppiPrinterY);

    // This scales the DC so that the printout roughly represents
    // the screen scaling. The text point size _should_ be the right size
    // but in fact is too small for some reason. This is a detail that will
    // need to be addressed at some point but can be fudged for the
    // moment.
    double scale = double(ppiPrinterX) / ppiScreenX;

    // Now we have to check in case our real page size is reduced
    // (e.g. because we're drawing to a print preview memory DC)
    int pageWidth, pageHeight;
    int w, h;
    dc->GetSize(&w, &h);
    GetPageSizePixels(&pageWidth, &pageHeight);
    wxUnusedVar(pageHeight);

    // If printer pageWidth == current DC width, then this doesn't
    // change. But w might be the preview bitmap width, so scale down.
    double overallScale = scale * w / pageWidth;
    dc->SetUserScale(overallScale, overallScale);

    if (m_printoutView)
    {
        m_printoutView->OnDraw(dc);
    }
    return true;
}

bool wxDocPrintout::HasPage(int pageNum)
{
    return (pageNum == 1);
}

bool wxDocPrintout::OnBeginDocument(int startPage, int endPage)
{
    if (!wxPrintout::OnBeginDocument(startPage, endPage))
        return false;

    return true;
}

void wxDocPrintout::GetPageInfo(int *minPage, int *maxPage,
                                int *selPageFrom, int *selPageTo)
{
    *minPage = 1;
    *maxPage = 1;
    *selPageFrom = 1;
    *selPageTo = 1;
}

#endif // wxUSE_PRINTING_ARCHITECTURE

// ----------------------------------------------------------------------------
// Permits compatibility with existing file formats and functions that
// manipulate files directly
// ----------------------------------------------------------------------------

#if wxUSE_STD_IOSTREAM

bool wxTransferFileToStream(const wxString& filename, std::ostream& stream)
{
#if wxUSE_FFILE
    wxFFile file(filename, wxT("rb"));
#elif wxUSE_FILE
    wxFile file(filename, wxFile::read);
#endif
    if ( !file.IsOpened() )
        return false;

    do
    {
        char buf[4096];
        size_t nRead;
        nRead = file.Read(buf, WXSIZEOF(buf));
        if ( file.Error() )
            return false;

        stream.write(buf, nRead);
        if ( !stream )
            return false;
    }
    while ( !file.Eof() );

    return true;
}

bool wxTransferStreamToFile(std::istream& stream, const wxString& filename)
{
#if wxUSE_FFILE
    wxFFile file(filename, wxT("wb"));
#elif wxUSE_FILE
    wxFile file(filename, wxFile::write);
#endif
    if ( !file.IsOpened() )
        return false;

    char buf[4096];
    do
    {
        stream.read(buf, WXSIZEOF(buf));
        if ( !stream.bad() ) // fail may be set on EOF, don't use operator!()
        {
            if ( !file.Write(buf, stream.gcount()) )
                return false;
        }
    }
    while ( !stream.eof() );

    return true;
}

#else // !wxUSE_STD_IOSTREAM

bool wxTransferFileToStream(const wxString& filename, wxOutputStream& stream)
{
#if wxUSE_FFILE
    wxFFile file(filename, wxT("rb"));
#elif wxUSE_FILE
    wxFile file(filename, wxFile::read);
#endif
    if ( !file.IsOpened() )
        return false;

    char buf[4096];

    size_t nRead;
    do
    {
        nRead = file.Read(buf, WXSIZEOF(buf));
        if ( file.Error() )
            return false;

        stream.Write(buf, nRead);
        if ( !stream )
            return false;
    }
    while ( !file.Eof() );

    return true;
}

bool wxTransferStreamToFile(wxInputStream& stream, const wxString& filename)
{
#if wxUSE_FFILE
    wxFFile file(filename, wxT("wb"));
#elif wxUSE_FILE
    wxFile file(filename, wxFile::write);
#endif
    if ( !file.IsOpened() )
        return false;

    char buf[4096];
    for ( ;; )
    {
        stream.Read(buf, WXSIZEOF(buf));

        const size_t nRead = stream.LastRead();
        if ( !nRead )
        {
            if ( stream.Eof() )
                break;

            return false;
        }

        if ( !file.Write(buf, nRead) )
            return false;
    }

    return true;
}

#endif // wxUSE_STD_IOSTREAM/!wxUSE_STD_IOSTREAM

#endif // wxUSE_DOC_VIEW_ARCHITECTURE
