/////////////////////////////////////////////////////////////////////////////
-// Name: erase.cpp
-// Purpose: Erase wxWindows sample
-// Author: Robert Roebling
-// Modified by:
+// Name: samples/erase/erase.cpp
+// Purpose: Erase wxWidgets sample
+// 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
// ----------------------------------------------------------------------------
-#ifdef __GNUG__
- #pragma implementation "erase.cpp"
- #pragma interface "erase.cpp"
-#endif
-
// For compilers that support precompilation, includes "wx/wx.h".
#include "wx/wxprec.h"
#endif
// for all others, include the necessary headers (this file is usually all you
-// need because it includes almost all "standard" wxWindows headers)
+// need because it includes almost all "standard" wxWidgets headers)
#ifndef WX_PRECOMP
#include "wx/wx.h"
#endif
+#include "wx/dcbuffer.h"
+
// ----------------------------------------------------------------------------
// resources
// ----------------------------------------------------------------------------
+
// the application icon
-#if defined(__WXGTK__) || defined(__WXMOTIF__) || defined(__WXMAC__)
- #include "mondrian.xpm"
+#if !defined(__WXMSW__) && !defined(__WXPM__)
+ #include "../sample.xpm"
#endif
// ----------------------------------------------------------------------------
};
-class MyFrame : public wxFrame
+class MyCanvas : public wxScrolledWindow
{
public:
- MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size);
+ MyCanvas(wxFrame *parent);
- void OnQuit(wxCommandEvent& event);
- void OnAbout(wxCommandEvent& event);
+ 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 );
+ void OnEraseBackground( wxEraseEvent &event );
+
+ void DoPaint(wxDC& dc);
+
+
+ wxBitmap m_bitmap;
+ wxString m_text;
+
+ // use wxMemoryDC in OnPaint()?
+ bool m_useBuffer;
+
+ // erase background in OnPaint()?
+ bool m_eraseBgInPaint;
+
+
DECLARE_EVENT_TABLE()
};
-
-class MyCanvas : public wxScrolledWindow
+class MyFrame : public wxFrame
{
public:
- MyCanvas( MyFrame *parent );
-
- void OnPaint( wxPaintEvent &event );
- void OnEraseBackground( wxEraseEvent &event );
+ MyFrame();
private:
+ void OnUseBuffer(wxCommandEvent& event);
+ void OnEraseBgInPaint(wxCommandEvent& event);
+ void OnChangeBgStyle(wxCommandEvent& event);
+ void OnQuit(wxCommandEvent& event);
+ void OnAbout(wxCommandEvent& event);
+
+ // 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()
};
+
// ----------------------------------------------------------------------------
// constants
// ----------------------------------------------------------------------------
enum
{
// menu items
- Minimal_Quit = 1,
- Minimal_About
+ 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()
{
- MyFrame *frame = new MyFrame("Minimal wxWindows App",
- wxPoint(50, 50), wxSize(450, 340));
+ if ( !wxApp::OnInit() )
+ return false;
- frame->Show(TRUE);
-
- return TRUE;
+ MyFrame *frame = new MyFrame;
+
+ frame->Show(true);
+
+ return true;
}
// ----------------------------------------------------------------------------
// ----------------------------------------------------------------------------
BEGIN_EVENT_TABLE(MyFrame, wxFrame)
- EVT_MENU(Minimal_Quit, MyFrame::OnQuit)
- EVT_MENU(Minimal_About, MyFrame::OnAbout)
+ 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(const wxString& title, const wxPoint& pos, const wxSize& size)
- : wxFrame((wxFrame *)NULL, -1, title, pos, size)
+MyFrame::MyFrame()
+ : wxFrame(NULL, wxID_ANY, "Erase sample",
+ wxPoint(50, 50), wxSize(450, 340))
{
-#ifdef __WXMAC__
- wxApp::s_macAboutMenuItemId = Minimal_About;
-#endif
-
- SetIcon(wxICON(mondrian));
+ SetIcon(wxICON(sample));
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, "E&xit\tAlt-X", "Quit this program");
- wxMenu *helpMenu = new wxMenu;
- helpMenu->Append(Minimal_About, "&About...\tCtrl-A", "Show about dialog");
- menuFile->Append(Minimal_Quit, "E&xit\tAlt-X", "Quit this program");
+ wxMenu *helpMenu = new wxMenu;
+ helpMenu->Append(Erase_Menu_About, "&About...\tCtrl-A", "Show about dialog");
wxMenuBar *menuBar = new wxMenuBar();
menuBar->Append(menuFile, "&File");
SetMenuBar(menuBar);
-#if wxUSE_STATUSBAR
- // create a status bar just for fun (by default with 1 pane only)
- CreateStatusBar(2);
- SetStatusText("Welcome to wxWindows!");
-#endif // wxUSE_STATUSBAR
+ m_canvas = new MyCanvas( this );
+}
- (void)new MyCanvas( this );
+
+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;
+ m_canvas->SetBackgroundStyle(static_cast<wxBackgroundStyle>(style));
+
+ m_canvas->Refresh();
+}
void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event))
{
- Close(TRUE);
+ Close(true);
}
void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
{
- wxString msg;
- msg.Printf( _T("This is the about dialog of the Erase sample.\n")
- _T("Welcome to %s"), wxVERSION_STRING);
-
- wxMessageBox(msg, "About Erase", 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_ERASE_BACKGROUND( MyCanvas::OnEraseBackground)
+ EVT_PAINT(MyCanvas::OnPaint)
+ EVT_CHAR(MyCanvas::OnChar)
+ EVT_ERASE_BACKGROUND(MyCanvas::OnEraseBackground)
END_EVENT_TABLE()
-MyCanvas::MyCanvas( MyFrame *parent )
- : wxScrolledWindow( parent, -1, wxDefaultPosition, wxDefaultSize,
- wxScrolledWindowStyle|wxNO_FULL_REPAINT_ON_RESIZE )
+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(sample) );
+
+ new wxStaticBitmap( this, wxID_ANY, m_bitmap, wxPoint(80,20) );
+
+ SetFocusIgnoringChildren();
+ SetBackgroundColour(*wxBLUE);
}
-void MyCanvas::OnPaint( wxPaintEvent &event )
+void MyCanvas::OnChar( wxKeyEvent &event )
{
- wxPaintDC dc(this);
- PrepareDC( dc );
-
- dc.SetBrush( *wxRED_BRUSH );
- dc.DrawRectangle( 100, 100, 300, 500 );
+#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::OnEraseBackground( wxEraseEvent &event )
+void MyCanvas::DoPaint(wxDC& dc)
{
- event.Skip( TRUE );
+ 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 );
+
+ dc.DrawBitmap( m_bitmap, 20, 20, true );
+
+ dc.SetTextForeground(*wxWHITE);
+ 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) )
+{
+ if ( m_useBuffer )
+ {
+ wxAutoBufferedPaintDC dc(this);
+ PrepareDC(dc);
+
+ DoPaint(dc);
+ }
+ else
+ {
+ 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();
+
+ const wxSize size = GetClientSize();
+ for ( int x = 0; x < size.x; x += 15 )
+ {
+ dc.DrawLine(x, 0, x, size.y);
+ }
+
+ for ( int y = 0; y < size.y; y += 15 )
+ {
+ dc.DrawLine(0, y, size.x, y);
+ }
+
+ dc.SetTextForeground(*wxRED);
+ dc.SetBackgroundMode(wxSOLID);
+ dc.DrawText("This text is drawn from OnEraseBackground", 60, 160);
}