///////////////////////////////////////////////////////////////////////////// // Name: pngdemo.cpp // Purpose: Demos PNG reading // Author: Julian Smart // Modified by: // Created: 04/01/98 // RCS-ID: $Id$ // Copyright: (c) Julian Smart // Licence: wxWindows license ///////////////////////////////////////////////////////////////////////////// // For compilers that support precompilation, includes "wx.h". #include "wx/wxprec.h" #ifdef __BORLANDC__ #pragma hdrstop #endif #include "wx/image.h" #include "pngdemo.h" MyFrame *frame = (MyFrame *) NULL; wxBitmap *g_TestBitmap = (wxBitmap *) NULL; IMPLEMENT_APP(MyApp) bool MyApp::OnInit(void) { wxImage::AddHandler(new wxPNGHandler); // Create the main frame window frame = new MyFrame((wxFrame *) NULL, _T("wxPNGBitmap Demo"), wxPoint(0, 0), wxSize(300, 300)); #if wxUSE_STATUSBAR // Give it a status line frame->CreateStatusBar(2); #endif // wxUSE_STATUSBAR // Make a menubar wxMenu *file_menu = new wxMenu; wxMenu *help_menu = new wxMenu; file_menu->Append(PNGDEMO_LOAD_FILE, _T("&Load file"), _T("Load file")); file_menu->Append(PNGDEMO_SAVE_FILE, _T("&Save file"), _T("Save file")); file_menu->Append(PNGDEMO_QUIT, _T("E&xit"), _T("Quit program")); help_menu->Append(PNGDEMO_ABOUT, _T("&About"), _T("About PNG demo")); wxMenuBar *menu_bar = new wxMenuBar; menu_bar->Append(file_menu, _T("&File")); menu_bar->Append(help_menu, _T("&Help")); // Associate the menu bar with the frame frame->SetMenuBar(menu_bar); MyCanvas *canvas = new MyCanvas(frame, wxPoint(0, 0), wxSize(100, 100)); // Give it scrollbars: the virtual canvas is 20 * 50 = 1000 pixels in each direction // canvas->SetScrollbars(20, 20, 50, 50, 4, 4); frame->canvas = canvas; frame->Show(true); #if wxUSE_STATUSBAR frame->SetStatusText(_T("Hello, wxWidgets")); #endif // wxUSE_STATUSBAR return true; } BEGIN_EVENT_TABLE(MyFrame, wxFrame) EVT_MENU(PNGDEMO_QUIT, MyFrame::OnQuit) EVT_MENU(PNGDEMO_ABOUT, MyFrame::OnAbout) EVT_MENU(PNGDEMO_LOAD_FILE, MyFrame::OnLoadFile) EVT_MENU(PNGDEMO_SAVE_FILE, MyFrame::OnSaveFile) END_EVENT_TABLE() // Define my frame constructor MyFrame::MyFrame(wxFrame *frame, const wxString& title, const wxPoint& pos, const wxSize& size): wxFrame(frame, wxID_ANY, title, pos, size) { canvas = (MyCanvas *) NULL; } // frame destructor MyFrame::~MyFrame() { if (g_TestBitmap) { delete g_TestBitmap; g_TestBitmap = (wxBitmap *) NULL; } } void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event)) { Close(true); } void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event)) { (void)wxMessageBox(_T("PNG demo\nJulian Smart (c) 1998"), _T("About PNG Demo"), wxOK); } void MyFrame::OnSaveFile(wxCommandEvent& WXUNUSED(event)) { #if wxUSE_FILEDLG wxString f = wxFileSelector( wxT("Save Image"), (const wxChar *)NULL, (const wxChar *)NULL, wxT("png"), wxT("PNG files (*.png)|*.png") ); if (f.empty()) return; wxBitmap *backstore = new wxBitmap( 150, 150 ); wxMemoryDC memDC; memDC.SelectObject( *backstore ); memDC.Clear(); memDC.SetBrush( *wxBLACK_BRUSH ); memDC.SetPen( *wxWHITE_PEN ); memDC.DrawRectangle( 0, 0, 150, 150 ); memDC.SetPen( *wxBLACK_PEN ); memDC.DrawLine( 0, 0, 0, 10 ); memDC.SetTextForeground( *wxWHITE ); memDC.DrawText( _T("This is a memory dc."), 10, 10 ); memDC.SelectObject( wxNullBitmap ); backstore->SaveFile( f, wxBITMAP_TYPE_PNG, (wxPalette*)NULL ); delete backstore; #endif // wxUSE_FILEDLG } void MyFrame::OnLoadFile(wxCommandEvent& WXUNUSED(event)) { #if wxUSE_FILEDLG // Show file selector. wxString f = wxFileSelector(wxT("Open Image"), (const wxChar *) NULL, (const wxChar *) NULL, wxT("png"), wxT("PNG files (*.png)|*.png")); if (f.empty()) return; if ( g_TestBitmap ) delete g_TestBitmap; g_TestBitmap = new wxBitmap(f, wxBITMAP_TYPE_PNG); if (!g_TestBitmap->Ok()) { delete g_TestBitmap; g_TestBitmap = (wxBitmap *) NULL; } canvas->Refresh(); #endif // wxUSE_FILEDLG } BEGIN_EVENT_TABLE(MyCanvas, wxScrolledWindow) EVT_PAINT(MyCanvas::OnPaint) END_EVENT_TABLE() // Define a constructor for my canvas MyCanvas::MyCanvas(wxWindow *parent, const wxPoint& pos, const wxSize& size): wxScrolledWindow(parent, wxID_ANY, pos, size) { } // Define the repainting behaviour void MyCanvas::OnPaint(wxPaintEvent& WXUNUSED(event)) { wxPaintDC dc(this); dc.SetPen(* wxRED_PEN); int i; for ( i = 0; i < 500; i += 10) { dc.DrawLine(0, i, 800, i); } if ( g_TestBitmap && g_TestBitmap->Ok() ) { wxMemoryDC memDC; if ( g_TestBitmap->GetPalette() ) { memDC.SetPalette(* g_TestBitmap->GetPalette()); dc.SetPalette(* g_TestBitmap->GetPalette()); } memDC.SelectObject(* g_TestBitmap); // Normal, non-transparent blitting dc.Blit(20, 20, g_TestBitmap->GetWidth(), g_TestBitmap->GetHeight(), & memDC, 0, 0, wxCOPY, false); memDC.SelectObject(wxNullBitmap); } if ( g_TestBitmap && g_TestBitmap->Ok() ) { wxMemoryDC memDC; memDC.SelectObject(* g_TestBitmap); // Transparent blitting if there's a mask in the bitmap dc.Blit(20 + g_TestBitmap->GetWidth() + 20, 20, g_TestBitmap->GetWidth(), g_TestBitmap->GetHeight(), & memDC, 0, 0, wxCOPY, true); memDC.SelectObject(wxNullBitmap); } }