implement new wxBG_STYLE_XXX semantics for wxMSW too

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@61086 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/window.h

@@ -185,7 +185,6 @@ public:
     // --------------
 
     void OnPaint(wxPaintEvent& event);
-    void OnEraseBackground(wxEraseEvent& event);
 #ifdef __WXWINCE__
     void OnInitDialog(wxInitDialogEvent& event);
 #endif

samples/erase/erase.cpp

@@ -59,6 +59,8 @@ public:
     void UseBuffer(bool useBuffer) { m_useBuffer = useBuffer; Refresh(); }
     bool UsesBuffer() const { return m_useBuffer; }
 
+    void EraseBgInPaint(bool erase) { m_eraseBgInPaint = erase; Refresh(); }
+
 private:
     void OnPaint( wxPaintEvent &event );
     void OnChar( wxKeyEvent &event );
@@ -73,6 +75,9 @@ private:
     // use wxMemoryDC in OnPaint()?
     bool m_useBuffer;
 
+    // erase background in OnPaint()?
+    bool m_eraseBgInPaint;
+
 
     DECLARE_EVENT_TABLE()
 };
@@ -84,6 +89,7 @@ public:
 
 private:
     void OnUseBuffer(wxCommandEvent& event);
+    void OnEraseBgInPaint(wxCommandEvent& event);
     void OnChangeBgStyle(wxCommandEvent& event);
     void OnQuit(wxCommandEvent& event);
     void OnAbout(wxCommandEvent& event);
@@ -113,6 +119,7 @@ enum
 {
     // menu items
     Erase_Menu_UseBuffer = 100,
+    Erase_Menu_EraseBgInPaint,
     Erase_Menu_BgStyleErase,
     Erase_Menu_BgStyleSystem,
     Erase_Menu_BgStylePaint,
@@ -144,7 +151,8 @@ bool MyApp::OnInit()
 // ----------------------------------------------------------------------------
 
 BEGIN_EVENT_TABLE(MyFrame, wxFrame)
-    EVT_MENU(Erase_Menu_UseBuffer,  MyFrame::OnUseBuffer)
+    EVT_MENU(Erase_Menu_UseBuffer, MyFrame::OnUseBuffer)
+    EVT_MENU(Erase_Menu_EraseBgInPaint, MyFrame::OnEraseBgInPaint)
     EVT_MENU_RANGE(Erase_Menu_BgStyleErase, Erase_Menu_BgStylePaint,
                    MyFrame::OnChangeBgStyle)
 
@@ -165,6 +173,8 @@ MyFrame::MyFrame()
 
     wxMenu *menuFile = new wxMenu("", wxMENU_TEAROFF);
     menuFile->AppendCheckItem(Erase_Menu_UseBuffer, "&Use memory DC\tCtrl-M");
+    menuFile->AppendCheckItem(Erase_Menu_EraseBgInPaint,
+                              "&Erase background in EVT_PAINT\tCtrl-R");
     menuFile->AppendSeparator();
     menuFile->AppendRadioItem(Erase_Menu_BgStyleErase,
                               "Use wxBG_STYLE_&ERASE\tCtrl-E");
@@ -194,6 +204,11 @@ void MyFrame::OnUseBuffer(wxCommandEvent& event)
     m_canvas->UseBuffer(event.IsChecked());
 }
 
+void MyFrame::OnEraseBgInPaint(wxCommandEvent& event)
+{
+    m_canvas->EraseBgInPaint(event.IsChecked());
+}
+
 void MyFrame::OnChangeBgStyle(wxCommandEvent& event)
 {
     int style = wxBG_STYLE_ERASE + event.GetId() - Erase_Menu_BgStyleErase;
@@ -233,6 +248,7 @@ MyCanvas::MyCanvas(wxFrame *parent)
         : wxScrolledWindow(parent, wxID_ANY)
 {
     m_useBuffer = false;
+    m_eraseBgInPaint = false;
 
     SetScrollbars( 10, 10, 40, 100, 0, 0 );
 
@@ -269,6 +285,20 @@ void MyCanvas::OnChar( wxKeyEvent &event )
 
 void MyCanvas::DoPaint(wxDC& dc)
 {
+    if ( m_eraseBgInPaint )
+    {
+        dc.SetBackground(*wxLIGHT_GREY);
+        dc.Clear();
+
+        dc.DrawText("Background erased in OnPaint", 65, 110);
+    }
+    else if ( GetBackgroundStyle() == wxBG_STYLE_PAINT )
+    {
+        dc.SetTextForeground(*wxRED);
+        dc.DrawText("You must enable erasing background in OnPaint to avoid "
+                    "display corruption", 65, 110);
+    }
+
     dc.SetBrush( *wxBLACK_BRUSH );
     dc.DrawRectangle( 10,10,60,50 );
 

src/msw/window.cpp

@@ -413,7 +413,6 @@ wxCONSTRUCTOR_DUMMY(wxWindow)
 
 BEGIN_EVENT_TABLE(wxWindowMSW, wxWindowBase)
     EVT_SYS_COLOUR_CHANGED(wxWindowMSW::OnSysColourChanged)
-    EVT_ERASE_BACKGROUND(wxWindowMSW::OnEraseBackground)
 #ifdef __WXWINCE__
     EVT_INIT_DIALOG(wxWindowMSW::OnInitDialog)
 #endif
@@ -4705,52 +4704,59 @@ void wxWindowMSW::OnPaint(wxPaintEvent& event)
 }
 
 bool wxWindowMSW::HandleEraseBkgnd(WXHDC hdc)
-{
-    wxDCTemp dc(hdc, GetClientSize());
-    wxDCTempImpl *impl = (wxDCTempImpl*) dc.GetImpl();
-
-    impl->SetHDC(hdc);
-    impl->SetWindow((wxWindow *)this);
-
-    wxEraseEvent event(m_windowId, &dc);
-    event.SetEventObject(this);
-    bool rc = HandleWindowEvent(event);
-
-    // must be called manually as ~wxDC doesn't do anything for wxDCTemp
-    impl->SelectOldObjects(hdc);
-
-    return rc;
-}
-
-void wxWindowMSW::OnEraseBackground(wxEraseEvent& event)
 {
     // standard non top level controls (i.e. except the dialogs) always erase
     // their background themselves in HandleCtlColor() or have some control-
     // specific ways to set the colours (common controls)
     if ( IsOfStandardClass() && !IsTopLevel() )
+        return false;
+
+    switch ( GetBackgroundStyle() )
     {
-        event.Skip();
+        case wxBG_STYLE_ERASE:
-        return;
+            // we need to generate an erase background event
+            {
+                wxDCTemp dc(hdc, GetClientSize());
+                wxDCTempImpl *impl = (wxDCTempImpl*) dc.GetImpl();
+
+                impl->SetHDC(hdc);
+                impl->SetWindow((wxWindow *)this);
+
+                wxEraseEvent event(m_windowId, &dc);
+                event.SetEventObject(this);
+                bool rc = HandleWindowEvent(event);
+
+                // must be called manually as ~wxDC doesn't do anything for
+                // wxDCTemp
+                impl->SelectOldObjects(hdc);
+
+                if ( rc )
+                {
+                    // background erase by the user-defined handler
+                    return true;
+                }
+            }
+            // fall through
+
+        case wxBG_STYLE_SYSTEM:
+            if ( !DoEraseBackground(hdc) )
+            {
+                // let the default processing to take place if we didn't erase
+                // the background ourselves
+                return false;
+            }
+            break;
+
+        case wxBG_STYLE_PAINT:
+            // no need to do anything here at all, background will be entirely
+            // redrawn in WM_PAINT handler
+            break;
+
+        default:
+            wxFAIL_MSG( "unknown background style" );
     }
 
-    if ( GetBackgroundStyle() == wxBG_STYLE_CUSTOM )
+    return true;
-    {
-        // don't skip the event here, custom background means that the app
-        // is drawing it itself in its OnPaint(), so don't draw it at all
-        // now to avoid flicker
-        return;
-    }
-
-    wxDC *dc = event.GetDC();
-    if (!dc) return;
-    wxMSWDCImpl *impl = (wxMSWDCImpl*) dc->GetImpl();
-
-    // do default background painting
-    if ( !DoEraseBackground(GetHdcOf(*impl)) )
-    {
-        // let the system paint the background
-        event.Skip();
-    }
 }
 
 bool wxWindowMSW::DoEraseBackground(WXHDC hDC)