Implemented wxStatusBar::Push/PopStatusText.

Implemented wxFrame::Push/PopSTatusText ( just forward to the status bar ).
Implemented wxFrame::DoGiveHelp, to show menu/toolbar help in the status bar.
Added Get/SetStatusBarPane to get/set the status bar pane the menu/toolbar help
  will be show in


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@15339 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/statusbr.h

@@ -20,6 +20,10 @@
 
 #if wxUSE_STATUSBAR
 
+#include "wx/list.h"
+
+WX_DECLARE_LIST(wxString, wxListString);
+
 // ----------------------------------------------------------------------------
 // wxStatusBar: a window near the bottom of the frame used for status info
 // ----------------------------------------------------------------------------
@@ -45,6 +49,9 @@ public:
     virtual void SetStatusText(const wxString& text, int number = 0) = 0;
     virtual wxString GetStatusText(int number = 0) const = 0;
 
+    void PushStatusText(const wxString& text, int number = 0);
+    void PopStatusText(int number = 0);
+
     // fields widths
     // -------------
 
@@ -82,15 +89,28 @@ protected:
     // reset the widths
     void ReinitWidths() { FreeWidths(); InitWidths(); }
 
+    // same, for text stacks
+    void InitStacks();
+    void FreeStacks();
+    void ReinitStacks() { FreeStacks(); InitStacks(); }
+
     // calculate the real field widths for the given total available size
     wxArrayInt CalculateAbsWidths(wxCoord widthTotal) const;
 
+    // use these functions to access the stacks of field strings
+    wxListString *GetStatusStack(int i) const;
+    wxListString *GetOrCreateStatusStack(int i);
+
     // the current number of fields
     int        m_nFields;
 
     // the widths of the fields in pixels if !NULL, all fields have the same
     // width otherwise
     int       *m_statusWidths;
+
+    // stacks of previous values for PushStatusText/PopStatusText
+    // this is created on demand, use GetStatusStack/GetOrCreateStatusStack
+    wxListString **m_statusTextStacks;
 };
 
 // ----------------------------------------------------------------------------