made ProvideBackground() const

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_4_BRANCH@17329 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/generic/panelg.h

@@ -83,7 +83,7 @@ public:
 
 #ifdef __WXUNIVERSAL__
     virtual bool IsCanvasWindow() const { return TRUE; }
-    virtual bool ProvidesBackground() { return TRUE; }
+    virtual bool ProvidesBackground() const { return TRUE; }
 #endif
 
     WX_DECLARE_CONTROL_CONTAINER();

include/wx/univ/toplevel.h

@@ -143,7 +143,7 @@ public:
     virtual int GetMinWidth() const;
     virtual int GetMinHeight() const;
 
-    virtual bool ProvidesBackground() { return TRUE; }
+    virtual bool ProvidesBackground() const { return TRUE; }
     
 protected:
     // handle titlebar button click event

include/wx/univ/window.h

@@ -179,7 +179,7 @@ public:
     // to be used with function above: transparent windows get
     // their background from parents that return TRUE here,
     // so this is mostly for wxPanel, wxTopLevelWindow etc.
-    virtual bool ProvidesBackground() { return FALSE; }
+    virtual bool ProvidesBackground() const { return FALSE; }
 
     // return TRUE if this control can be highlighted when the mouse is over
     // it (the theme decides itself whether it is really highlighted or not)

src/univ/winuniv.cpp

@@ -109,7 +109,7 @@ void wxWindow::Init()
     m_isCurrent = FALSE;
 
     m_renderer = wxTheme::Get()->GetRenderer();
-    
+
     m_oldSize.x = -1;
     m_oldSize.y = -1;
 }
@@ -240,7 +240,7 @@ void wxWindow::OnErase(wxEraseEvent& event)
 
         return;
     }
-    
+
     DoDrawBackground(*event.GetDC());
 
     // if we have both scrollbars, we also have a square in the corner between
@@ -267,41 +267,42 @@ void wxWindow::OnErase(wxEraseEvent& event)
 bool wxWindow::DoDrawBackground(wxDC& dc)
 {
     wxRect rect;
-    
+
     wxSize size = GetSize();  // Why not GetClientSize() ?
     rect.x = 0;
     rect.y = 0;
     rect.width = size.x;
     rect.height = size.y;
-    
+
-    if (HasTransparentBackground() && GetParent() && GetParent()->ProvidesBackground())
+    wxWindow * const parent = GetParent();
+    if ( HasTransparentBackground() && parent && parent->ProvidesBackground() )
     {
         wxASSERT( !IsTopLevel() );
-    
+
         wxPoint pos = GetPosition();
-        
+
         AdjustForParentClientOrigin( pos.x, pos.y, 0 );
-        
+
         // Adjust DC logical origin
         wxCoord x,y;
         dc.GetLogicalOrigin( &x, &y );
         x += pos.x;
         y += pos.y;
         dc.SetLogicalOrigin( x, y );
-        
+
         // Adjust draw rect
         rect.x = pos.x;
         rect.y = pos.y;
-        
+
         // Let parent draw the background
-        GetParent()->EraseBackground( dc, rect );
+        parent->EraseBackground( dc, rect );
     }
     else
     {
         // Draw background ouselves
-         EraseBackground( dc, rect );
+        EraseBackground( dc, rect );
     }
-    
+
     return TRUE;
 }
 
@@ -315,10 +316,10 @@ void wxWindow::EraseBackground(wxDC& dc, const wxRect& rect)
         wxBitmap bmp = GetBackgroundBitmap(&alignment, &stretch);
         wxControlRenderer::DrawBitmap(dc, bmp, rect, alignment, stretch);
     }
-    else 
+    else
     {
         // Just fill it with bg colour if no bitmap
-    
+
         m_renderer->DrawBackground(dc, wxTHEME_BG_COLOUR(this),
                                    rect, GetStateFlags());
     }
@@ -478,28 +479,28 @@ int wxWindow::GetStateFlags() const
 void wxWindow::OnSize(wxSizeEvent& event)
 {
     event.Skip();
-    
+
     if ( m_scrollbarVert || m_scrollbarHorz )
     {
         PositionScrollbars();
     }
-    
+
 #if 0   // ndef __WXMSW__
     // Refresh the area (strip) previously occupied by the border
-    
+
     if (HasFlag( wxNO_FULL_REPAINT_ON_RESIZE ) && IsShown())
     {
         // This code assumes that wxSizeEvent.GetSize() returns
         // the area of the entire window, not just the client
         // area.
         wxSize newSize = event.GetSize();
-        
+
         if (m_oldSize.x == -1 && m_oldSize.y == -1)
         {
             m_oldSize = newSize;
             return;
         }
-        
+
         if (HasFlag( wxSIMPLE_BORDER ))
         {
             if (newSize.y > m_oldSize.y)
@@ -520,7 +521,7 @@ void wxWindow::OnSize(wxSizeEvent& event)
                 rect.width = newSize.x;
                 wxWindowNative::Refresh( TRUE, &rect );
             }
-            
+
             if (newSize.x > m_oldSize.x)
             {
                 wxRect rect;
@@ -561,7 +562,7 @@ void wxWindow::OnSize(wxSizeEvent& event)
                 rect.width = newSize.x;
                 wxWindowNative::Refresh( TRUE, &rect );
             }
-            
+
             if (newSize.x > m_oldSize.x)
             {
                 wxRect rect;
@@ -581,7 +582,7 @@ void wxWindow::OnSize(wxSizeEvent& event)
                 wxWindowNative::Refresh( TRUE, &rect );
             }
         }
-        
+
         m_oldSize = newSize;
     }
 #endif
@@ -915,7 +916,7 @@ void wxWindow::ScrollWindow(int dx, int dy, const wxRect *rect)
 
     wxWindowNative::ScrollWindow(dx, dy, rect);
 
-#else
+#else // !wxX11
 
     // before scrolling it, ensure that we don't have any unpainted areas
     Update();
@@ -933,11 +934,11 @@ void wxWindow::ScrollWindow(int dx, int dy, const wxRect *rect)
         r = ScrollNoRefresh(0, dy, rect);
         Refresh(TRUE /* erase bkgnd */, &r);
     }
-    
+
-    // scroll children accordingly:    
+    // scroll children accordingly:
     wxPoint offset(dx, dy);
-    
+
-    for (wxWindowList::Node *node = GetChildren().GetFirst(); 
+    for (wxWindowList::Node *node = GetChildren().GetFirst();
          node; node = node->GetNext())
     {
         wxWindow *child = node->GetData();
@@ -945,13 +946,13 @@ void wxWindow::ScrollWindow(int dx, int dy, const wxRect *rect)
             continue;
 
         // VS: Scrolling children has non-trivial semantics. If rect=NULL then
-        //     it is easy: we scroll all children. Otherwise it gets 
+        //     it is easy: we scroll all children. Otherwise it gets
         //     complicated:
         //       1. if scrolling in one direction only, scroll only
         //          those children that intersect shaft defined by the rectangle
         //          and scrolling direction
         //       2. if scrolling in both axes, scroll all children
-        
+
         if ( rect && (dx * dy == 0 /* moving in only one of x, y axis */) )
         {
             wxRect childRect = child->GetRect();
@@ -970,8 +971,8 @@ void wxWindow::ScrollWindow(int dx, int dy, const wxRect *rect)
         {
             child->Move(child->GetPosition() + offset);
         }
-    }    
+    }
-#endif
+#endif // wxX11/!wxX11
 }
 
 wxRect wxWindow::ScrollNoRefresh(int dx, int dy, const wxRect *rectTotal)