samples/dragimag/dragimag.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        dragimag.cpp
   3 // Purpose:     wxDragImage sample
   4 // Author:      Julian Smart
   5 // Modified by:
   6 // Created:     28/2/2000
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Julian Smart
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // For compilers that support precompilation, includes "wx/wx.h".
  13 #include "wx/wxprec.h"
  14
  15 #ifdef __BORLANDC__
  16 #pragma hdrstop
  17 #endif
  18
  19 #ifndef WX_PRECOMP
  20 #include "wx/wx.h"
  21 #endif
  22
  23 #include "wx/image.h"
  24
  25 // Under Windows, change this to 1
  26 // to use wxGenericDragImage
  27
  28 #define wxUSE_GENERIC_DRAGIMAGE 1
  29
  30 #if wxUSE_GENERIC_DRAGIMAGE
  31 #include "wx/generic/dragimgg.h"
  32 #define wxDragImage wxGenericDragImage
  33 #else
  34 #include "wx/dragimag.h"
  35 #endif
  36
  37 #include "dragimag.h"
  38
  39 #if defined(__WXGTK__) || defined(__WXMOTIF__) || defined(__WXMAC__) || defined(__WXMGL__) || defined(__WXX11__)
  40 #include "mondrian.xpm"
  41 #include "dragicon.xpm"
  42 #endif
  43
  44 // main program
  45
  46 IMPLEMENT_APP(MyApp)
  47
  48 // MyCanvas
  49
  50 IMPLEMENT_CLASS(MyCanvas, wxScrolledWindow)
  51
  52 BEGIN_EVENT_TABLE(MyCanvas, wxScrolledWindow)
  53   EVT_PAINT(MyCanvas::OnPaint)
  54   EVT_ERASE_BACKGROUND(MyCanvas::OnEraseBackground)
  55   EVT_MOUSE_EVENTS(MyCanvas::OnMouseEvent)
  56 END_EVENT_TABLE()
  57
  58 MyCanvas::MyCanvas( wxWindow *parent, wxWindowID id,
  59                     const wxPoint &pos, const wxSize &size )
  60         : wxScrolledWindow( parent, id, pos, size, wxSUNKEN_BORDER )
  61 {
  62     SetBackgroundColour(* wxWHITE);
  63
  64     SetCursor(wxCursor(wxCURSOR_ARROW));
  65
  66     m_dragMode = TEST_DRAG_NONE;
  67     m_draggedShape = (DragShape*) NULL;
  68     m_dragImage = (wxDragImage*) NULL;
  69     m_currentlyHighlighted = (DragShape*) NULL;
  70 }
  71
  72 MyCanvas::~MyCanvas()
  73 {
  74     ClearShapes();
  75
  76     if (m_dragImage)
  77         delete m_dragImage;
  78 }
  79
  80 void MyCanvas::OnPaint( wxPaintEvent &WXUNUSED(event) )
  81 {
  82     wxPaintDC dc( this );
  83     PrepareDC( dc );
  84
  85     DrawShapes(dc);
  86 }
  87
  88 void MyCanvas::OnEraseBackground(wxEraseEvent& event)
  89 {
  90     if (wxGetApp().GetBackgroundBitmap().Ok())
  91     {
  92         wxSize sz = GetClientSize();
  93         wxRect rect(0, 0, sz.x, sz.y);
  94
  95         if (event.GetDC())
  96         {
  97             wxGetApp().TileBitmap(rect, *(event.GetDC()), wxGetApp().GetBackgroundBitmap());
  98         }
  99         else
 100         {
 101             wxClientDC dc(this);
 102             wxGetApp().TileBitmap(rect, dc, wxGetApp().GetBackgroundBitmap());
 103         }
 104     }
 105     else
 106         event.Skip(); // The official way of doing it
 107 }
 108
 109 void MyCanvas::OnMouseEvent(wxMouseEvent& event)
 110 {
 111     if (event.LeftDown())
 112     {
 113         DragShape* shape = FindShape(event.GetPosition());
 114         if (shape)
 115         {
 116             // We tentatively start dragging, but wait for
 117             // mouse movement before dragging properly.
 118
 119             m_dragMode = TEST_DRAG_START;
 120             m_dragStartPos = event.GetPosition();
 121             m_draggedShape = shape;
 122         }
 123     }
 124     else if (event.LeftUp() && m_dragMode != TEST_DRAG_NONE)
 125     {
 126         // Finish dragging
 127
 128         m_dragMode = TEST_DRAG_NONE;
 129
 130         if (!m_draggedShape || !m_dragImage)
 131             return;
 132
 133         m_draggedShape->SetPosition(m_draggedShape->GetPosition()
 134                                     + event.GetPosition() - m_dragStartPos);
 135
 136         m_dragImage->Hide();
 137         m_dragImage->EndDrag();
 138         delete m_dragImage;
 139         m_dragImage = NULL;
 140
 141         m_draggedShape->SetShow(true);
 142
 143         m_currentlyHighlighted = (DragShape*) NULL;
 144
 145         m_draggedShape = (DragShape*) NULL;
 146
 147         Refresh(true);
 148     }
 149     else if (event.Dragging() && m_dragMode != TEST_DRAG_NONE)
 150     {
 151         if (m_dragMode == TEST_DRAG_START)
 152         {
 153             // We will start dragging if we've moved beyond a couple of pixels
 154
 155             int tolerance = 2;
 156             int dx = abs(event.GetPosition().x - m_dragStartPos.x);
 157             int dy = abs(event.GetPosition().y - m_dragStartPos.y);
 158             if (dx <= tolerance && dy <= tolerance)
 159                 return;
 160
 161             // Start the drag.
 162             m_dragMode = TEST_DRAG_DRAGGING;
 163
 164             if (m_dragImage)
 165                 delete m_dragImage;
 166
 167             // Erase the dragged shape from the canvas
 168             m_draggedShape->SetShow(false);
 169
 170             // redraw immediately
 171             Refresh(true);
 172             Update();
 173
 174             switch (m_draggedShape->GetDragMethod())
 175             {
 176                 case SHAPE_DRAG_BITMAP:
 177                 {
 178                     m_dragImage = new MyDragImage(this, m_draggedShape->GetBitmap(), wxCursor(wxCURSOR_HAND));
 179                     break;
 180                 }
 181                 case SHAPE_DRAG_TEXT:
 182                 {
 183                     m_dragImage = new MyDragImage(this, wxString(_T("Dragging some test text")), wxCursor(wxCURSOR_HAND));
 184                     break;
 185                 }
 186                 case SHAPE_DRAG_ICON:
 187                 {
 188                     m_dragImage = new MyDragImage(this, wxICON(dragicon), wxCursor(wxCURSOR_HAND));
 189                     break;
 190                 }
 191             }
 192
 193             bool fullScreen = wxGetApp().GetUseScreen();
 194
 195             // The offset between the top-left of the shape image and the current shape position
 196             wxPoint beginDragHotSpot = m_dragStartPos - m_draggedShape->GetPosition();
 197
 198             // Now we do this inside the implementation: always assume
 199             // coordinates relative to the capture window (client coordinates)
 200
 201             //if (fullScreen)
 202             //    beginDragHotSpot -= ClientToScreen(wxPoint(0, 0));
 203
 204             if (!m_dragImage->BeginDrag(beginDragHotSpot, this, fullScreen))
 205             {
 206                 delete m_dragImage;
 207                 m_dragImage = (wxDragImage*) NULL;
 208                 m_dragMode = TEST_DRAG_NONE;
 209
 210             } else
 211             {
 212                 m_dragImage->Move(event.GetPosition());
 213                 m_dragImage->Show();
 214             }
 215         }
 216         else if (m_dragMode == TEST_DRAG_DRAGGING)
 217         {
 218             // We're currently dragging. See if we're over another shape.
 219             DragShape* onShape = FindShape(event.GetPosition());
 220
 221             bool mustUnhighlightOld = false;
 222             bool mustHighlightNew = false;
 223
 224             if (m_currentlyHighlighted)
 225             {
 226                 if ((onShape == (DragShape*) NULL) || (m_currentlyHighlighted != onShape))
 227                     mustUnhighlightOld = true;
 228             }
 229
 230             if (onShape && (onShape != m_currentlyHighlighted) && onShape->IsShown())
 231                 mustHighlightNew = true;
 232
 233             if (mustUnhighlightOld || mustHighlightNew)
 234                 m_dragImage->Hide();
 235
 236             // Now with the drag image switched off, we can change the window contents.
 237             if (mustUnhighlightOld)
 238                 m_currentlyHighlighted = (DragShape*) NULL;
 239
 240             if (mustHighlightNew)
 241                 m_currentlyHighlighted = onShape;
 242
 243             if (mustUnhighlightOld || mustHighlightNew)
 244             {
 245                 Refresh(mustUnhighlightOld);
 246                 Update();
 247             }
 248
 249             // Move and show the image again
 250             m_dragImage->Move(event.GetPosition());
 251
 252             if (mustUnhighlightOld || mustHighlightNew)
 253                  m_dragImage->Show();
 254         }
 255     }
 256 }
 257
 258 void MyCanvas::DrawShapes(wxDC& dc)
 259 {
 260     wxList::compatibility_iterator node = m_displayList.GetFirst();
 261     while (node)
 262     {
 263         DragShape* shape = (DragShape*) node->GetData();
 264         if (shape->IsShown() && m_draggedShape != shape)
 265         {
 266             shape->Draw(dc, (m_currentlyHighlighted == shape));
 267         }
 268         node = node->GetNext();
 269     }
 270 }
 271
 272 void MyCanvas::EraseShape(DragShape* shape, wxDC& dc)
 273 {
 274     wxSize sz = GetClientSize();
 275     wxRect rect(0, 0, sz.x, sz.y);
 276
 277     wxRect rect2(shape->GetRect());
 278     dc.SetClippingRegion(rect2.x, rect2.y, rect2.width, rect2.height);
 279
 280     wxGetApp().TileBitmap(rect, dc, wxGetApp().GetBackgroundBitmap());
 281
 282     dc.DestroyClippingRegion();
 283 }
 284
 285 void MyCanvas::ClearShapes()
 286 {
 287     wxList::compatibility_iterator node = m_displayList.GetFirst();
 288     while (node)
 289     {
 290         DragShape* shape = (DragShape*) node->GetData();
 291         delete shape;
 292         node = node->GetNext();
 293     }
 294     m_displayList.Clear();
 295 }
 296
 297 DragShape* MyCanvas::FindShape(const wxPoint& pt) const
 298 {
 299     wxList::compatibility_iterator node = m_displayList.GetFirst();
 300     while (node)
 301     {
 302         DragShape* shape = (DragShape*) node->GetData();
 303         if (shape->HitTest(pt))
 304             return shape;
 305         node = node->GetNext();
 306     }
 307     return (DragShape*) NULL;
 308 }
 309
 310 // MyFrame
 311 IMPLEMENT_DYNAMIC_CLASS( MyFrame, wxFrame )
 312
 313 BEGIN_EVENT_TABLE(MyFrame,wxFrame)
 314   EVT_MENU    (wxID_ABOUT, MyFrame::OnAbout)
 315   EVT_MENU    (wxID_EXIT,  MyFrame::OnQuit)
 316 END_EVENT_TABLE()
 317
 318 MyFrame::MyFrame()
 319 : wxFrame( (wxFrame *)NULL, wxID_ANY, _T("wxDragImage sample"),
 320           wxPoint(20,20), wxSize(470,360) )
 321 {
 322     wxMenu *file_menu = new wxMenu();
 323     file_menu->Append( wxID_ABOUT, _T("&About..."));
 324     file_menu->AppendCheckItem( TEST_USE_SCREEN, _T("&Use whole screen for dragging"), _T("Use whole screen"));
 325     file_menu->Append( wxID_EXIT, _T("E&xit"));
 326
 327     wxMenuBar *menu_bar = new wxMenuBar();
 328     menu_bar->Append(file_menu, _T("&File"));
 329
 330     SetIcon(wxICON(mondrian));
 331     SetMenuBar( menu_bar );
 332
 333 #if wxUSE_STATUSBAR
 334     CreateStatusBar(2);
 335     int widths[] = { -1, 100 };
 336     SetStatusWidths( 2, widths );
 337 #endif // wxUSE_STATUSBAR
 338
 339     m_canvas = new MyCanvas( this, wxID_ANY, wxPoint(0,0), wxSize(10,10) );
 340 }
 341
 342 void MyFrame::OnQuit( wxCommandEvent &WXUNUSED(event) )
 343 {
 344     Close( true );
 345 }
 346
 347 void MyFrame::OnAbout( wxCommandEvent &WXUNUSED(event) )
 348 {
 349     (void)wxMessageBox( _T("wxDragImage demo\n")
 350         _T("Julian Smart (c) 2000"),
 351         _T("About wxDragImage Demo"),
 352         wxICON_INFORMATION | wxOK );
 353 }
 354
 355 //-----------------------------------------------------------------------------
 356 // MyApp
 357 //-----------------------------------------------------------------------------
 358
 359 BEGIN_EVENT_TABLE(MyApp, wxApp)
 360     EVT_MENU(TEST_USE_SCREEN, MyApp::OnUseScreen)
 361 END_EVENT_TABLE()
 362
 363 MyApp::MyApp()
 364 {
 365     // Drag across whole screen
 366     m_useScreen = false;
 367 }
 368
 369 bool MyApp::OnInit()
 370 {
 371     if ( !wxApp::OnInit() )
 372         return false;
 373
 374 #if wxUSE_LIBPNG
 375     wxImage::AddHandler( new wxPNGHandler );
 376 #endif
 377
 378     wxImage image;
 379     if (image.LoadFile(_T("backgrnd.png"), wxBITMAP_TYPE_PNG))
 380     {
 381         m_background = wxBitmap(image);
 382     }
 383
 384     MyFrame *frame = new MyFrame();
 385
 386     wxString rootName(_T("shape0"));
 387
 388     for (int i = 1; i < 4; i++)
 389     {
 390     /* For some reason under wxX11, the 2nd LoadFile in this loop fails, with
 391        a BadMatch inside CreateFromImage (inside ConvertToBitmap). This happens even if you copy
 392        the first file over the second file. */
 393         if (image.LoadFile(wxString::Format("%s%d.png", rootName, i), wxBITMAP_TYPE_PNG))
 394         {
 395             DragShape* newShape = new DragShape(wxBitmap(image));
 396             newShape->SetPosition(wxPoint(i*50, i*50));
 397
 398             if (i == 2)
 399                 newShape->SetDragMethod(SHAPE_DRAG_TEXT);
 400             else if (i == 3)
 401                 newShape->SetDragMethod(SHAPE_DRAG_ICON);
 402             else
 403                 newShape->SetDragMethod(SHAPE_DRAG_BITMAP);
 404             frame->GetCanvas()->GetDisplayList().Append(newShape);
 405         }
 406     }
 407
 408 #if 0
 409     // Under Motif or GTK, this demonstrates that
 410     // wxScreenDC only gets the root window content.
 411     // We need to be able to copy the overall content
 412     // for full-screen dragging to work.
 413     int w, h;
 414     wxDisplaySize(& w, & h);
 415     wxBitmap bitmap(w, h);
 416
 417     wxScreenDC dc;
 418     wxMemoryDC memDC;
 419     memDC.SelectObject(bitmap);
 420     memDC.Blit(0, 0, w, h, & dc, 0, 0);
 421     memDC.SelectObject(wxNullBitmap);
 422     m_background = bitmap;
 423 #endif
 424
 425     frame->Show( true );
 426
 427     return true;
 428 }
 429
 430 int MyApp::OnExit()
 431 {
 432     return 0;
 433 }
 434
 435 bool MyApp::TileBitmap(const wxRect& rect, wxDC& dc, wxBitmap& bitmap)
 436 {
 437     int w = bitmap.GetWidth();
 438     int h = bitmap.GetHeight();
 439
 440     int i, j;
 441     for (i = rect.x; i < rect.x + rect.width; i += w)
 442     {
 443         for (j = rect.y; j < rect.y + rect.height; j+= h)
 444             dc.DrawBitmap(bitmap, i, j);
 445     }
 446     return true;
 447 }
 448
 449 void MyApp::OnUseScreen(wxCommandEvent& WXUNUSED(event))
 450 {
 451     m_useScreen = !m_useScreen;
 452 }
 453
 454 // DragShape
 455
 456 DragShape::DragShape(const wxBitmap& bitmap)
 457 {
 458     m_bitmap = bitmap;
 459     m_pos.x = 0;
 460     m_pos.y = 0;
 461     m_dragMethod = SHAPE_DRAG_BITMAP;
 462     m_show = true;
 463 }
 464
 465 bool DragShape::HitTest(const wxPoint& pt) const
 466 {
 467     wxRect rect(GetRect());
 468     return rect.Contains(pt.x, pt.y);
 469 }
 470
 471 bool DragShape::Draw(wxDC& dc, bool highlight)
 472 {
 473     if (m_bitmap.Ok())
 474     {
 475         wxMemoryDC memDC;
 476         memDC.SelectObject(m_bitmap);
 477
 478         dc.Blit(m_pos.x, m_pos.y, m_bitmap.GetWidth(), m_bitmap.GetHeight(),
 479             & memDC, 0, 0, wxCOPY, true);
 480
 481         if (highlight)
 482         {
 483             dc.SetPen(*wxWHITE_PEN);
 484             dc.SetBrush(*wxTRANSPARENT_BRUSH);
 485             dc.DrawRectangle(m_pos.x, m_pos.y, m_bitmap.GetWidth(), m_bitmap.GetHeight());
 486         }
 487
 488         return true;
 489     }
 490     else
 491         return false;
 492 }
 493
 494 // MyDragImage
 495
 496 // On some platforms, notably Mac OS X with Core Graphics, we can't blit from
 497 // a window, so we need to draw the background explicitly.
 498 bool MyDragImage::UpdateBackingFromWindow(wxDC& WXUNUSED(windowDC), wxMemoryDC& destDC, const wxRect& WXUNUSED(sourceRect),
 499                     const wxRect& destRect) const
 500 {
 501     destDC.SetClippingRegion(destRect);
 502
 503     if (wxGetApp().GetBackgroundBitmap().Ok())
 504         wxGetApp().TileBitmap(destRect, destDC, wxGetApp().GetBackgroundBitmap());
 505
 506     m_canvas->DrawShapes(destDC);
 507     return true;
 508 }
 509