don't crash if (char*)c_str() is used twice in a row on the same string and both...

[wxWidgets.git] / include / wx / dcbuffer.h

diff --git a/include/wx/dcbuffer.h b/include/wx/dcbuffer.h
index ef5383bbdf2baa23f1c2d4d55756023946bfb832..1ef12f47b44813cbd74f7fd3dc94632bb08f6e7f 100644 (file)
--- a/include/wx/dcbuffer.h
+++ b/include/wx/dcbuffer.h
@@ -37,6 +37,10 @@
 // does not prepare the window DC
 #define wxBUFFER_CLIENT_AREA        0x02
 
+// Set when not using specific buffer bitmap. Note that this
+// is private style and not returned by GetStyle.
+#define wxBUFFER_USES_SHARED_BUFFER 0x04
+
 class WXDLLEXPORT wxBufferedDC : public wxMemoryDC
 {
 public:
@@ -98,25 +102,11 @@ public:
     // Usually called in the dtor or by the dtor of derived classes if the
     // BufferedDC must blit before the derived class (which may own the dc it's
     // blitting to) is destroyed.
-    void UnMask()
-    {
-        wxCHECK_RET( m_dc, _T("no underlying wxDC?") );
-        wxASSERT_MSG( m_buffer && m_buffer->IsOk(), _T("invalid backing store") );
-
-        wxCoord x = 0,
-                y = 0;
-
-        if ( m_style & wxBUFFER_CLIENT_AREA )
-            GetDeviceOrigin(&x, &y);
-
-        m_dc->Blit(0, 0, m_buffer->GetWidth(), m_buffer->GetHeight(),
-                   this, -x, -y );
-        m_dc = NULL;
-    }
+    void UnMask();
 
     // Set and get the style
     void SetStyle(int style) { m_style = style; }
-    int GetStyle() const { return m_style; }
+    int GetStyle() const { return m_style & ~wxBUFFER_USES_SHARED_BUFFER; }
 
 private:
     // common part of Init()s
@@ -173,7 +163,7 @@ public:
         if( buffer.IsOk() )
             Init(&m_paintdc, buffer, style);
         else
-            Init(&m_paintdc, window->GetClientSize(), style);
+            Init(&m_paintdc, GetBufferedSize(window, style), style);
     }
 
     // If no bitmap is supplied by the user, a temporary one will be created.
@@ -184,7 +174,7 @@ public:
         if (style & wxBUFFER_VIRTUAL_AREA)
             window->PrepareDC( m_paintdc );
 
-        Init(&m_paintdc, window->GetClientSize(), style);
+        Init(&m_paintdc, GetBufferedSize(window, style), style);
     }
 
     // default copy ctor ok.
@@ -196,6 +186,15 @@ public:
         UnMask();
     }
 
+protected:
+    // return the size needed by the buffer: this depends on whether we're
+    // buffering just the currently shown part or the total (scrolled) window
+    static wxSize GetBufferedSize(wxWindow *window, int style)
+    {
+        return style & wxBUFFER_VIRTUAL_AREA ? window->GetVirtualSize()
+                                             : window->GetClientSize();
+    }
+
 private:
     wxPaintDC m_paintdc;