Move EmptyUndoBuffer() from wxTextEntry to wxTextCtrl

It seems unlikely that we're ever going to need this function in any
other classes inheriting from wxTextEntry (i.e. wxComboBox) and both
existing implementations are for wxTextCtrl only, so define this
function there.

If really necessary, we can always lower it to wxTextEntry later, while
moving it in the other direction wouldn't be easily possible due to
compatibility concerns.

This commit is best viewed with git --color-moved option.

include/wx/osx/textctrl.h

@@ -74,6 +74,8 @@ public:
     virtual void MarkDirty() wxOVERRIDE;
     virtual void DiscardEdits() wxOVERRIDE;
 
+    virtual void EmptyUndoBuffer() wxOVERRIDE;
+
     // text control under some platforms supports the text styles: these
     // methods apply the given text style to the given selection or to
     // set/get the style which will be used for all appended text

include/wx/osx/textentry.h

@@ -72,8 +72,6 @@ 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/textctrl.h

@@ -574,6 +574,8 @@ public:
             DiscardEdits();
     }
 
+    virtual void EmptyUndoBuffer() { }
+
 
     // styles handling
     // ---------------

include/wx/textentry.h

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

interface/wx/textctrl.h

@@ -1312,6 +1312,17 @@ public:
     */
     virtual void DiscardEdits();
 
+    /**
+        Delete the undo history.
+
+        Currently only implemented in wxMSW (for controls using wxTE_RICH2
+        style only) and wxOSX (for multiline text controls only), does nothing
+        in the other ports or for the controls not using the appropriate styles.
+
+        @since 3.1.6
+    */
+    virtual void EmptyUndoBuffer();
+
     /**
         This function inserts into the control the character which would have
         been inserted if the given key event had occurred in the text control.

interface/wx/textentry.h

@@ -165,17 +165,6 @@ public:
     */
     virtual bool CanUndo() const;
 
-    /**
-        Delete the undo history.
-
-        Currently only implemented in wxMSW (for controls using wxTE_RICH2
-        style only) and wxOSX (for multiline text controls only), does nothing
-        in the other ports or for the controls not using the appropriate styles.
-
-        @since 3.1.6
-    */
-    virtual void EmptyUndoBuffer();
-
     /**
         Sets the new text control value.
 

src/osx/textctrl_osx.cpp

@@ -259,6 +259,13 @@ void wxTextCtrl::DiscardEdits()
     m_dirty = false;
 }
 
+void wxTextCtrl::EmptyUndoBuffer()
+{
+    wxCHECK_RET( GetTextPeer(), "Must create the control first" );
+
+    GetTextPeer()->EmptyUndoBuffer() ;
+}
+
 int wxTextCtrl::GetNumberOfLines() const
 {
     return GetTextPeer()->GetNumberOfLines() ;

src/osx/textentry_osx.cpp

@@ -293,13 +293,6 @@ 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();