Add wxTextCtrl::EmptyUndoBuffer()

This is implemented for multi-line controls under macOS only currently.

include/wx/osx/cocoa/private/textimpl.h

@@ -140,6 +140,7 @@ public:
     virtual void Undo() wxOVERRIDE;
     virtual bool CanRedo() const wxOVERRIDE;
     virtual void Redo() wxOVERRIDE;
+    virtual void EmptyUndoBuffer() wxOVERRIDE;
 
 protected:
     void DoUpdateTextStyle();

include/wx/osx/core/private.h

@@ -730,6 +730,7 @@ public :
     virtual void Undo() ;
     virtual bool CanRedo() const;
     virtual void Redo() ;
+    virtual void EmptyUndoBuffer() ;
     virtual int GetNumberOfLines() const ;
     virtual long XYToPosition(long x, long y) const;
     virtual bool PositionToXY(long pos, long *x, long *y) const ;

include/wx/osx/textentry.h

@@ -72,6 +72,8 @@ public:
     virtual bool CanUndo() const wxOVERRIDE;
     virtual bool CanRedo() const wxOVERRIDE;
 
+    virtual void EmptyUndoBuffer() wxOVERRIDE;
+
     // Insertion point
     virtual void SetInsertionPoint(long pos) wxOVERRIDE;
     virtual void SetInsertionPointEnd() wxOVERRIDE;

include/wx/stc/stc.h

@@ -3642,7 +3642,7 @@ public:
     bool CanUndo() const wxOVERRIDE;
 
     // Delete the undo history.
-    void EmptyUndoBuffer();
+    void EmptyUndoBuffer() wxOVERRIDE;
 
     // Undo one action in the undo history.
     void Undo() wxOVERRIDE;

include/wx/textentry.h

@@ -81,6 +81,8 @@ public:
     virtual bool CanUndo() const = 0;
     virtual bool CanRedo() const = 0;
 
+    virtual void EmptyUndoBuffer() { }
+
 
     // insertion point
     // ---------------

interface/wx/textentry.h

@@ -165,6 +165,16 @@ public:
     */
     virtual bool CanUndo() const;
 
+    /**
+        Delete the undo history.
+
+        Currently only implemented under macOS and only for multiline text
+        controls, does nothing in the other ports.
+
+        @since 3.1.6
+    */
+    virtual void EmptyUndoBuffer();
+
     /**
         Sets the new text control value.
 

src/osx/cocoa/textctrl.mm

@@ -1070,6 +1070,14 @@ void wxNSTextViewControl::Redo()
     [m_undoManager redo];
 }
 
+void wxNSTextViewControl::EmptyUndoBuffer()
+{
+    if ( !m_undoManager )
+        return;
+
+    [m_undoManager removeAllActions];
+}
+
 void wxNSTextViewControl::DoUpdateTextStyle()
 {
     if ( m_useCharWrapping )

src/osx/textctrl_osx.cpp

@@ -700,6 +700,10 @@ void wxTextWidgetImpl::Redo()
 {
 }
 
+void wxTextWidgetImpl::EmptyUndoBuffer()
+{
+}
+
 long wxTextWidgetImpl::XYToPosition(long WXUNUSED(x), long WXUNUSED(y)) const
 {
     return 0 ;

src/osx/textentry_osx.cpp

@@ -293,6 +293,13 @@ bool wxTextEntry::CanRedo() const
     return GetTextPeer()->CanRedo() ;
 }
 
+void wxTextEntry::EmptyUndoBuffer()
+{
+    wxCHECK_RET( GetTextPeer(), "Must create the control first" );
+
+    return GetTextPeer()->EmptyUndoBuffer() ;
+}
+
 wxTextWidgetImpl * wxTextEntry::GetTextPeer() const
 {
     wxWindow * const win = const_cast<wxTextEntry *>(this)->GetEditableWindow();

src/stc/gen_iface.py

@@ -1094,6 +1094,7 @@ overrideNeeded = (
     'CanPaste',
     'CanRedo',
     'CanUndo',
+    'EmptyUndoBuffer',
     'Clear',
     'AppendText',
 )