samples/png/pngdemo.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        pngdemo.cpp
   3 // Purpose:     Demos PNG reading
   4 // Author:      Julian Smart
   5 // Modified by:
   6 // Created:     04/01/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Julian Smart
   9 // Licence:     wxWindows license
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // For compilers that support precompilation, includes "wx.h".
  13 #include "wx/wxprec.h"
  14
  15 #ifdef __BORLANDC__
  16 #pragma hdrstop
  17 #endif
  18
  19 #include "wx/image.h"
  20
  21 #include "pngdemo.h"
  22
  23 MyFrame   *frame = (MyFrame *) NULL;
  24 wxBitmap  *g_TestBitmap = (wxBitmap *) NULL;
  25
  26 IMPLEMENT_APP(MyApp)
  27
  28 bool MyApp::OnInit(void)
  29 {
  30   if ( !wxApp::OnInit() )
  31     return false;
  32
  33   wxImage::AddHandler(new wxPNGHandler);
  34
  35   // Create the main frame window
  36   frame = new MyFrame((wxFrame *) NULL, _T("wxPNGBitmap Demo"), wxPoint(0, 0), wxSize(300, 300));
  37
  38 #if wxUSE_STATUSBAR
  39   // Give it a status line
  40   frame->CreateStatusBar(2);
  41 #endif // wxUSE_STATUSBAR
  42
  43   // Make a menubar
  44   wxMenu *file_menu = new wxMenu;
  45   wxMenu *help_menu = new wxMenu;
  46
  47   file_menu->Append(PNGDEMO_LOAD_FILE, _T("&Load file"),                _T("Load file"));
  48   file_menu->Append(PNGDEMO_SAVE_FILE, _T("&Save file"),                _T("Save file"));
  49   file_menu->Append(PNGDEMO_QUIT, _T("E&xit"),                _T("Quit program"));
  50   help_menu->Append(PNGDEMO_ABOUT, _T("&About"),              _T("About PNG demo"));
  51
  52   wxMenuBar *menu_bar = new wxMenuBar;
  53
  54   menu_bar->Append(file_menu, _T("&File"));
  55   menu_bar->Append(help_menu, _T("&Help"));
  56
  57   // Associate the menu bar with the frame
  58   frame->SetMenuBar(menu_bar);
  59
  60   MyCanvas *canvas = new MyCanvas(frame, wxPoint(0, 0), wxSize(100, 100));
  61
  62   // Give it scrollbars: the virtual canvas is 20 * 50 = 1000 pixels in each direction
  63 //  canvas->SetScrollbars(20, 20, 50, 50, 4, 4);
  64   frame->canvas = canvas;
  65
  66   frame->Show(true);
  67
  68 #if wxUSE_STATUSBAR
  69   frame->SetStatusText(_T("Hello, wxWidgets"));
  70 #endif // wxUSE_STATUSBAR
  71
  72   return true;
  73 }
  74
  75 BEGIN_EVENT_TABLE(MyFrame, wxFrame)
  76     EVT_MENU(PNGDEMO_QUIT,      MyFrame::OnQuit)
  77     EVT_MENU(PNGDEMO_ABOUT,     MyFrame::OnAbout)
  78     EVT_MENU(PNGDEMO_LOAD_FILE, MyFrame::OnLoadFile)
  79     EVT_MENU(PNGDEMO_SAVE_FILE, MyFrame::OnSaveFile)
  80 END_EVENT_TABLE()
  81
  82 // Define my frame constructor
  83 MyFrame::MyFrame(wxFrame *frame, const wxString& title, const wxPoint& pos, const wxSize& size):
  84   wxFrame(frame, wxID_ANY, title, pos, size)
  85 {
  86   canvas = (MyCanvas *) NULL;
  87 }
  88
  89 // frame destructor
  90 MyFrame::~MyFrame()
  91 {
  92     if (g_TestBitmap)
  93     {
  94         delete g_TestBitmap;
  95         g_TestBitmap = (wxBitmap *) NULL;
  96     }
  97 }
  98
  99 void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event))
 100 {
 101     Close(true);
 102 }
 103
 104 void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
 105 {
 106     (void)wxMessageBox(_T("PNG demo\nJulian Smart (c) 1998"),
 107             _T("About PNG Demo"), wxOK);
 108 }
 109
 110 void MyFrame::OnSaveFile(wxCommandEvent& WXUNUSED(event))
 111 {
 112 #if wxUSE_FILEDLG
 113     wxString f = wxFileSelector( wxT("Save Image"), (const wxChar *)NULL,
 114                                  (const wxChar *)NULL,
 115                                  wxT("png"), wxT("PNG files (*.png)|*.png") );
 116
 117     if (f.empty())  return;
 118
 119     wxBitmap *backstore = new wxBitmap( 150, 150 );
 120
 121     wxMemoryDC memDC;
 122     memDC.SelectObject( *backstore );
 123     memDC.Clear();
 124     memDC.SetBrush( *wxBLACK_BRUSH );
 125     memDC.SetPen( *wxWHITE_PEN );
 126     memDC.DrawRectangle( 0, 0, 150, 150 );
 127     memDC.SetPen( *wxBLACK_PEN );
 128     memDC.DrawLine( 0, 0, 0, 10 );
 129     memDC.SetTextForeground( *wxWHITE );
 130     memDC.DrawText( _T("This is a memory dc."), 10, 10 );
 131
 132     memDC.SelectObject( wxNullBitmap );
 133
 134     backstore->SaveFile( f, wxBITMAP_TYPE_PNG, (wxPalette*)NULL );
 135
 136     delete backstore;
 137 #endif // wxUSE_FILEDLG
 138 }
 139
 140 void MyFrame::OnLoadFile(wxCommandEvent& WXUNUSED(event))
 141 {
 142 #if wxUSE_FILEDLG
 143     // Show file selector.
 144     wxString f = wxFileSelector(wxT("Open Image"), (const wxChar *) NULL,
 145                                     (const wxChar *) NULL, wxT("png"),
 146                                     wxT("PNG files (*.png)|*.png"));
 147
 148     if (f.empty())
 149         return;
 150
 151     if ( g_TestBitmap )
 152         delete g_TestBitmap;
 153
 154     g_TestBitmap = new wxBitmap(f, wxBITMAP_TYPE_PNG);
 155     if (!g_TestBitmap->Ok())
 156     {
 157         delete g_TestBitmap;
 158         g_TestBitmap = (wxBitmap *) NULL;
 159     }
 160
 161     canvas->Refresh();
 162 #endif // wxUSE_FILEDLG
 163 }
 164
 165 BEGIN_EVENT_TABLE(MyCanvas, wxScrolledWindow)
 166     EVT_PAINT(MyCanvas::OnPaint)
 167 END_EVENT_TABLE()
 168
 169 // Define a constructor for my canvas
 170 MyCanvas::MyCanvas(wxWindow *parent, const wxPoint& pos, const wxSize& size):
 171  wxScrolledWindow(parent, wxID_ANY, pos, size)
 172 {
 173 }
 174
 175 // Define the repainting behaviour
 176 void MyCanvas::OnPaint(wxPaintEvent& WXUNUSED(event))
 177 {
 178     wxPaintDC dc(this);
 179     dc.SetPen(* wxRED_PEN);
 180
 181     int i;
 182     for ( i = 0; i < 500; i += 10)
 183     {
 184         dc.DrawLine(0, i, 800, i);
 185     }
 186     if ( g_TestBitmap && g_TestBitmap->Ok() )
 187     {
 188         wxMemoryDC memDC;
 189         if ( g_TestBitmap->GetPalette() )
 190         {
 191             memDC.SetPalette(* g_TestBitmap->GetPalette());
 192             dc.SetPalette(* g_TestBitmap->GetPalette());
 193         }
 194         memDC.SelectObject(* g_TestBitmap);
 195
 196         // Normal, non-transparent blitting
 197         dc.Blit(20, 20, g_TestBitmap->GetWidth(), g_TestBitmap->GetHeight(), & memDC, 0, 0, wxCOPY, false);
 198
 199         memDC.SelectObject(wxNullBitmap);
 200     }
 201
 202     if ( g_TestBitmap && g_TestBitmap->Ok() )
 203     {
 204         wxMemoryDC memDC;
 205         memDC.SelectObject(* g_TestBitmap);
 206
 207         // Transparent blitting if there's a mask in the bitmap
 208         dc.Blit(20 + g_TestBitmap->GetWidth() + 20, 20, g_TestBitmap->GetWidth(), g_TestBitmap->GetHeight(), & memDC,
 209             0, 0, wxCOPY, true);
 210
 211         memDC.SelectObject(wxNullBitmap);
 212     }
 213 }