/////////////////////////////////////////////////////////////////////////////
-// Name: erase.cpp
+// Name: samples/erase/erase.cpp
// Purpose: Erase wxWidgets sample
-// Author: Robert Roebling
-// Modified by:
+// Author: Robert Roebling, Vadim Zeitlin
// Created: 04/01/98
// RCS-ID: $Id$
-// Copyright: (c) Robert Roebling
+// Copyright: (c) 1998 Robert Roebling
+// (c) 2009 Vadim Zeitlin
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
// headers
// ----------------------------------------------------------------------------
-#if defined(__GNUG__) && !defined(__APPLE__)
- #pragma implementation "erase.cpp"
- #pragma interface "erase.cpp"
-#endif
-
// For compilers that support precompilation, includes "wx/wx.h".
#include "wx/wxprec.h"
#include "wx/wx.h"
#endif
+#include "wx/dcbuffer.h"
+
// ----------------------------------------------------------------------------
// resources
// ----------------------------------------------------------------------------
class MyCanvas : public wxScrolledWindow
{
public:
- MyCanvas( wxFrame *parent );
+ MyCanvas(wxFrame *parent);
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 );
// use wxMemoryDC in OnPaint()?
bool m_useBuffer;
+ // erase background in OnPaint()?
+ bool m_eraseBgInPaint;
+
+
DECLARE_EVENT_TABLE()
};
public:
MyFrame();
+private:
void OnUseBuffer(wxCommandEvent& event);
+ void OnEraseBgInPaint(wxCommandEvent& event);
+ void OnChangeBgStyle(wxCommandEvent& event);
void OnQuit(wxCommandEvent& event);
void OnAbout(wxCommandEvent& event);
-private:
+ // we can only use double-buffering with wxBG_STYLE_PAINT
+ void OnUpdateUIUseBuffer(wxUpdateUIEvent& event)
+ {
+ event.Enable( m_canvas->GetBackgroundStyle() == wxBG_STYLE_PAINT );
+ }
+
+ void OnUpdateUIChangeBgStyle(wxUpdateUIEvent& event)
+ {
+ event.Enable( !m_canvas->UsesBuffer() );
+ }
+
MyCanvas *m_canvas;
DECLARE_EVENT_TABLE()
{
// menu items
Erase_Menu_UseBuffer = 100,
+ Erase_Menu_EraseBgInPaint,
+ Erase_Menu_BgStyleErase,
+ Erase_Menu_BgStyleSystem,
+ Erase_Menu_BgStylePaint,
Erase_Menu_Exit = wxID_EXIT,
Erase_Menu_About = wxID_ABOUT
};
bool MyApp::OnInit()
{
+ if ( !wxApp::OnInit() )
+ return false;
+
MyFrame *frame = new MyFrame;
frame->Show(true);
// ----------------------------------------------------------------------------
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)
+
EVT_MENU(Erase_Menu_Exit, MyFrame::OnQuit)
EVT_MENU(Erase_Menu_About, MyFrame::OnAbout)
+
+ EVT_UPDATE_UI(Erase_Menu_UseBuffer, MyFrame::OnUpdateUIUseBuffer)
+ EVT_UPDATE_UI_RANGE(Erase_Menu_BgStyleErase, Erase_Menu_BgStylePaint,
+ MyFrame::OnUpdateUIChangeBgStyle)
END_EVENT_TABLE()
// frame constructor
MyFrame::MyFrame()
- : wxFrame(NULL, wxID_ANY, _T("Erase sample"),
+ : wxFrame(NULL, wxID_ANY, "Erase sample",
wxPoint(50, 50), wxSize(450, 340))
{
SetIcon(wxICON(mondrian));
- wxMenu *menuFile = new wxMenu(_T(""), wxMENU_TEAROFF);
- menuFile->AppendCheckItem(Erase_Menu_UseBuffer, _T("&Use memory DC\tCtrl-M"));
+ 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");
+ menuFile->AppendRadioItem(Erase_Menu_BgStyleSystem,
+ "Use wxBG_STYLE_&SYSTEM\tCtrl-S");
+ menuFile->AppendRadioItem(Erase_Menu_BgStylePaint,
+ "Use wxBG_STYLE_&PAINT\tCtrl-P");
menuFile->AppendSeparator();
- menuFile->Append(Erase_Menu_Exit, _T("E&xit\tAlt-X"), _T("Quit this program"));
+ menuFile->Append(Erase_Menu_Exit, "E&xit\tAlt-X", "Quit this program");
wxMenu *helpMenu = new wxMenu;
- helpMenu->Append(Erase_Menu_About, _T("&About...\tCtrl-A"), _T("Show about dialog"));
+ helpMenu->Append(Erase_Menu_About, "&About...\tCtrl-A", "Show about dialog");
wxMenuBar *menuBar = new wxMenuBar();
- menuBar->Append(menuFile, _T("&File"));
- menuBar->Append(helpMenu, _T("&Help"));
+ menuBar->Append(menuFile, "&File");
+ menuBar->Append(helpMenu, "&Help");
SetMenuBar(menuBar);
-#if wxUSE_STATUSBAR
- // create a status bar just for fun (by default with 1 pane only)
- CreateStatusBar(2);
- SetStatusText(_T("Welcome to wxWidgets erase sample!"));
-#endif // wxUSE_STATUSBAR
-
m_canvas = new MyCanvas( this );
}
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;
+ m_canvas->SetBackgroundStyle(static_cast<wxBackgroundStyle>(style));
+
+ m_canvas->Refresh();
+}
+
void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event))
{
Close(true);
void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
{
- wxMessageBox(_T("This sample shows how you can draw custom background."),
- _T("About Erase Sample"), wxOK | wxICON_INFORMATION, this);
+ wxMessageBox
+ (
+ "This sample shows differences between different background styles "
+ "and how you may draw custom background.\n"
+ "\n"
+ "(c) 1998 Robert Roebling\n"
+ "(c) 2009 Vadim Zeitlin\n",
+ "About Erase Sample",
+ wxOK | wxICON_INFORMATION,
+ this
+ );
}
BEGIN_EVENT_TABLE(MyCanvas, wxScrolledWindow)
- EVT_PAINT( MyCanvas::OnPaint)
- EVT_CHAR( MyCanvas::OnChar)
- EVT_ERASE_BACKGROUND( MyCanvas::OnEraseBackground)
+ EVT_PAINT(MyCanvas::OnPaint)
+ EVT_CHAR(MyCanvas::OnChar)
+ EVT_ERASE_BACKGROUND(MyCanvas::OnEraseBackground)
END_EVENT_TABLE()
-MyCanvas::MyCanvas( wxFrame *parent )
- : wxScrolledWindow( parent, wxID_ANY, wxDefaultPosition, wxDefaultSize,
- wxScrolledWindowStyle | wxSUNKEN_BORDER )
+MyCanvas::MyCanvas(wxFrame *parent)
+ : wxScrolledWindow(parent, wxID_ANY)
{
m_useBuffer = false;
+ m_eraseBgInPaint = false;
SetScrollbars( 10, 10, 40, 100, 0, 0 );
m_bitmap = wxBitmap( wxICON(mondrian) );
new wxStaticBitmap( this, wxID_ANY, m_bitmap, wxPoint(80,20) );
-
+
SetFocusIgnoringChildren();
+ SetBackgroundColour(*wxBLUE);
}
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( 10,10,200,50 );
+ dc.DrawRectangle( 10,10,60,50 );
- dc.DrawBitmap( m_bitmap, 10, 20, true );
+ dc.DrawBitmap( m_bitmap, 20, 20, true );
- dc.SetTextForeground(*wxBLUE);
- dc.DrawText(_T("This text is drawn from OnPaint"), 65, 65);
+ dc.SetTextForeground(*wxWHITE);
+ dc.DrawText("This text is drawn from OnPaint", 65, 65);
wxString tmp;
- tmp.Printf( _T("Hit any key to display more text: %s"), m_text.c_str() );
+ tmp.Printf("Hit any key to display more text: %s", m_text);
+
int w,h;
dc.GetTextExtent( tmp, &w, &h );
- dc.SetBrush( *wxWHITE_BRUSH );
dc.DrawRectangle( 65, 85, w, h );
dc.DrawText( tmp, 65, 85 );
-
-#if 0
- wxRegionIterator upd( GetUpdateRegion() );
- while (upd)
- {
- wxLogDebug( _T("Paint: %d %d %d %d"), upd.GetX(), upd.GetY(), upd.GetWidth(), upd.GetHeight() );
- upd ++;
- }
-#endif
-
-#if 0
- wxSize size = GetSize();
- wxSize client_size = GetClientSize();
- wxLogDebug( _T("size %d %d client_size %d %d"), size.x, size.y, client_size.x, client_size.y );
-#endif
-
-#if 0
- int i;
- dc.SetPen( *wxWHITE_PEN );
- for (i = 0; i < 20; i += 2)
- dc.DrawLine( i,i, i+100,i );
-
- dc.SetPen( *wxWHITE_PEN );
- for (i = 200; i < 220; i += 2)
- dc.DrawLine( i-200,i, i-100,i );
-
- wxRegion region( 110, 110, 80, 80 );
- wxRegion hole( 130, 130, 40, 1 );
- region.Intersect( hole );
- dc.SetClippingRegion( region );
-
- dc.SetBrush( *wxRED_BRUSH );
- dc.DrawRectangle( 100, 100, 200, 200 );
-
- dc.DestroyClippingRegion();
-
- dc.SetPen( *wxTRANSPARENT_PEN );
-
- wxRegion strip( 110, 200, 30, 1 );
- wxRegionIterator it( strip );
- while (it)
- {
- dc.DrawRectangle( it.GetX(), it.GetY(), it.GetWidth(), it.GetHeight() );
- it ++;
- }
-#endif // 0
}
void MyCanvas::OnPaint( wxPaintEvent &WXUNUSED(event) )
{
- wxPaintDC dcWin(this);
- PrepareDC( dcWin );
-
if ( m_useBuffer )
{
- const wxSize size = GetClientSize();
- wxMemoryDC dc;
- wxBitmap bmp(size.x, size.y);
- dc.SelectObject(bmp);
- dc.Blit(0, 0, size.x, size.y, &dcWin, 0, 0);
- dc.DrawText(_T("(copy of background)"), 5, 120 );
+ wxAutoBufferedPaintDC dc(this);
+ PrepareDC(dc);
DoPaint(dc);
-
- dcWin.Blit(0, 0, size.x, size.y, &dc, 0, 0);
}
else
{
- DoPaint(dcWin);
+ wxPaintDC dc(this);
+ PrepareDC(dc);
+
+ DoPaint(dc);
}
}
void MyCanvas::OnEraseBackground( wxEraseEvent& event )
{
+ wxASSERT_MSG
+ (
+ GetBackgroundStyle() == wxBG_STYLE_ERASE,
+ "shouldn't be called unless background style is \"erase\""
+ );
+
wxDC& dc = *event.GetDC();
dc.SetPen(*wxGREEN_PEN);
PrepareDC( dc );
-
+
// clear any junk currently displayed
dc.Clear();
}
dc.SetTextForeground(*wxRED);
- dc.DrawText(_T("This text is drawn from OnEraseBackground"), 60, 160);
+ dc.SetBackgroundMode(wxSOLID);
+ dc.DrawText("This text is drawn from OnEraseBackground", 60, 160);
}