void UseBuffer(bool useBuffer) { m_useBuffer = useBuffer; Refresh(); }
bool UsesBuffer() const { return m_useBuffer; }
+ void UseBgBitmap(bool useBgBmp)
+ {
+ m_useBgBmp = useBgBmp;
+ SetBackgroundBitmap(m_useBgBmp ? GetBgBitmap() : wxBitmap());
+
+ Refresh();
+ }
+
void EraseBgInPaint(bool erase) { m_eraseBgInPaint = erase; Refresh(); }
private:
void OnPaint( wxPaintEvent &event );
- void OnChar( wxKeyEvent &event );
void OnEraseBackground( wxEraseEvent &event );
void DoPaint(wxDC& dc);
+ // Create an easily recognizable background bitmap.
+ static wxBitmap GetBgBitmap()
+ {
+ static const int BMP_SIZE = 40;
+
+ wxBitmap bmp(BMP_SIZE, BMP_SIZE);
+ wxMemoryDC dc(bmp);
+ dc.SetBackground(*wxCYAN);
+ dc.Clear();
+
+ dc.SetPen(*wxBLUE_PEN);
+ dc.DrawLine(0, BMP_SIZE/2, BMP_SIZE/2, 0);
+ dc.DrawLine(BMP_SIZE/2, 0, BMP_SIZE, BMP_SIZE/2);
+ dc.DrawLine(BMP_SIZE, BMP_SIZE/2, BMP_SIZE/2, BMP_SIZE);
+ dc.DrawLine(BMP_SIZE/2, BMP_SIZE, 0, BMP_SIZE/2);
+
+ return bmp;
+ }
wxBitmap m_bitmap;
- wxString m_text;
// use wxMemoryDC in OnPaint()?
bool m_useBuffer;
+ // use background bitmap?
+ bool m_useBgBmp;
+
// erase background in OnPaint()?
bool m_eraseBgInPaint;
private:
void OnUseBuffer(wxCommandEvent& event);
+ void OnUseBgBitmap(wxCommandEvent& event);
void OnEraseBgInPaint(wxCommandEvent& event);
void OnChangeBgStyle(wxCommandEvent& event);
void OnQuit(wxCommandEvent& event);
DECLARE_EVENT_TABLE()
};
+class ControlWithTransparency : public wxWindow
+{
+public:
+ ControlWithTransparency(wxWindow *parent,
+ const wxPoint& pos,
+ const wxSize& size)
+ : wxWindow(parent, wxID_ANY, pos, size, wxBORDER_NONE)
+ {
+ Connect(wxEVT_PAINT,
+ wxPaintEventHandler(ControlWithTransparency::OnPaint));
+ }
+
+ virtual bool HasTransparentBackground() { return true; }
+
+private:
+ void OnPaint( wxPaintEvent& WXUNUSED(event) )
+ {
+ wxPaintDC dc(this);
+
+ dc.SetPen(*wxRED_PEN);
+ dc.SetBrush(*wxTRANSPARENT_BRUSH);
+ dc.DrawRectangle(GetClientSize());
+
+ dc.SetTextForeground(*wxBLUE);
+ dc.SetBackgroundMode(wxTRANSPARENT);
+ dc.DrawText("This is custom control with transparency", 0, 2);
+ }
+};
// ----------------------------------------------------------------------------
// constants
{
// menu items
Erase_Menu_UseBuffer = 100,
+ Erase_Menu_UseBgBitmap,
Erase_Menu_EraseBgInPaint,
Erase_Menu_BgStyleErase,
Erase_Menu_BgStyleSystem,
BEGIN_EVENT_TABLE(MyFrame, wxFrame)
EVT_MENU(Erase_Menu_UseBuffer, MyFrame::OnUseBuffer)
+ EVT_MENU(Erase_Menu_UseBgBitmap, MyFrame::OnUseBgBitmap)
EVT_MENU(Erase_Menu_EraseBgInPaint, MyFrame::OnEraseBgInPaint)
EVT_MENU_RANGE(Erase_Menu_BgStyleErase, Erase_Menu_BgStylePaint,
MyFrame::OnChangeBgStyle)
wxMenu *menuFile = new wxMenu("", wxMENU_TEAROFF);
menuFile->AppendCheckItem(Erase_Menu_UseBuffer, "&Use memory DC\tCtrl-M");
+ menuFile->AppendCheckItem(Erase_Menu_UseBgBitmap,
+ "Use background &bitmap\tCtrl-B");
menuFile->AppendCheckItem(Erase_Menu_EraseBgInPaint,
"&Erase background in EVT_PAINT\tCtrl-R");
menuFile->AppendSeparator();
m_canvas->UseBuffer(event.IsChecked());
}
+void MyFrame::OnUseBgBitmap(wxCommandEvent& event)
+{
+ m_canvas->UseBgBitmap(event.IsChecked());
+}
+
void MyFrame::OnEraseBgInPaint(wxCommandEvent& event)
{
m_canvas->EraseBgInPaint(event.IsChecked());
BEGIN_EVENT_TABLE(MyCanvas, wxScrolledWindow)
EVT_PAINT(MyCanvas::OnPaint)
- EVT_CHAR(MyCanvas::OnChar)
EVT_ERASE_BACKGROUND(MyCanvas::OnEraseBackground)
END_EVENT_TABLE()
: wxScrolledWindow(parent, wxID_ANY)
{
m_useBuffer = false;
+ m_useBgBmp = false;
m_eraseBgInPaint = false;
SetScrollbars( 10, 10, 40, 100, 0, 0 );
"right one drawn directly",
wxPoint(150, 20));
+ new ControlWithTransparency(this, wxPoint(65, 125), wxSize(300, 22));
+
SetFocusIgnoringChildren();
SetBackgroundColour(*wxCYAN);
}
-void MyCanvas::OnChar( wxKeyEvent &event )
-{
-#if wxUSE_UNICODE
- if (event.m_uniChar)
- {
- m_text += event.m_uniChar;
- Refresh();
- return;
- }
-#endif
-
- // some test cases
- switch (event.m_keyCode)
- {
- case WXK_UP: m_text += wxT( "<UP>" ); break;
- case WXK_LEFT: m_text += wxT( "<LEFT>" ); break;
- case WXK_RIGHT: m_text += wxT( "<RIGHT>" ); break;
- case WXK_DOWN: m_text += wxT( "<DOWN>" ); break;
- case WXK_RETURN: m_text += wxT( "<ENTER>" ); break;
- default: m_text += (wxChar)event.m_keyCode; break;
- }
-}
-
void MyCanvas::DoPaint(wxDC& dc)
{
if ( m_eraseBgInPaint )
"display corruption", 65, 110);
}
- dc.SetBrush( *wxBLACK_BRUSH );
- dc.DrawRectangle( 10,10,60,50 );
-
dc.DrawBitmap( m_bitmap, 20, 20, true );
- dc.SetTextForeground(*wxWHITE);
+ dc.SetTextForeground(*wxRED);
dc.DrawText("This text is drawn from OnPaint", 65, 65);
-
- wxString tmp;
- tmp.Printf("Hit any key to display more text: %s", m_text);
-
- int w,h;
- dc.GetTextExtent( tmp, &w, &h );
- dc.DrawRectangle( 65, 85, w, h );
- dc.DrawText( tmp, 65, 85 );
}
void MyCanvas::OnPaint( wxPaintEvent &WXUNUSED(event) )
void MyCanvas::OnEraseBackground( wxEraseEvent& event )
{
+ // We must not erase the background ourselves if we asked wxPanel to erase
+ // it using a background bitmap.
+ if ( m_useBgBmp )
+ {
+ event.Skip();
+ return;
+ }
+
wxASSERT_MSG
(
GetBackgroundStyle() == wxBG_STYLE_ERASE,