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__)
  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
  89 void MyCanvas::OnEraseBackground(wxEraseEvent& event)
  90 {
  91     if (wxGetApp().GetBackgroundBitmap().Ok())
  92     {
  93         wxSize sz = GetClientSize();
  94         wxRect rect(0, 0, sz.x, sz.y);
  95
  96         if (event.GetDC())
  97         {
  98             wxGetApp().TileBitmap(rect, *(event.GetDC()), wxGetApp().GetBackgroundBitmap());
  99         }
 100         else
 101         {
 102             wxClientDC dc(this);
 103             wxGetApp().TileBitmap(rect, dc, wxGetApp().GetBackgroundBitmap());
 104         }
 105     }
 106     else
 107         event.Skip(); // The official way of doing it
 108 }
 109
 110 void MyCanvas::OnMouseEvent(wxMouseEvent& event)
 111 {
 112     if (event.LeftDown())
 113     {
 114         DragShape* shape = FindShape(event.GetPosition());
 115         if (shape)
 116         {
 117             // We tentatively start dragging, but wait for
 118             // mouse movement before dragging properly.
 119
 120             m_dragMode = TEST_DRAG_START;
 121             m_dragStartPos = event.GetPosition();
 122             m_draggedShape = shape;
 123         }
 124     }
 125     else if (event.LeftUp() && m_dragMode != TEST_DRAG_NONE)
 126     {
 127         // Finish dragging
 128
 129         m_dragMode = TEST_DRAG_NONE;
 130
 131         if (!m_draggedShape || !m_dragImage)
 132             return;
 133
 134         wxPoint newPos(m_draggedShape->GetPosition().x + (event.GetPosition().x - m_dragStartPos.x),
 135                            m_draggedShape->GetPosition().y + (event.GetPosition().y - m_dragStartPos.y));
 136
 137         m_draggedShape->SetPosition(newPos);
 138
 139         m_dragImage->Hide();
 140         m_dragImage->EndDrag();
 141         delete m_dragImage;
 142         m_dragImage = NULL;
 143
 144         wxClientDC dc(this);
 145         if (m_currentlyHighlighted)
 146         {
 147             m_currentlyHighlighted->Draw(dc);
 148         }
 149         m_draggedShape->SetShow(TRUE);
 150         m_draggedShape->Draw(dc);
 151
 152         m_currentlyHighlighted = (DragShape*) NULL;
 153
 154         m_draggedShape = (DragShape*) NULL;
 155     }
 156     else if (event.Dragging() && m_dragMode != TEST_DRAG_NONE)
 157     {
 158         if (m_dragMode == TEST_DRAG_START)
 159         {
 160             // We will start dragging if we've moved beyond a couple of pixels
 161
 162             int tolerance = 2;
 163             int dx = abs(event.GetPosition().x - m_dragStartPos.x);
 164             int dy = abs(event.GetPosition().y - m_dragStartPos.y);
 165             if (dx <= tolerance && dy <= tolerance)
 166                 return;
 167
 168             wxPoint newPos(m_draggedShape->GetPosition().x + (event.GetPosition().x - m_dragStartPos.x),
 169                            m_draggedShape->GetPosition().y + (event.GetPosition().y - m_dragStartPos.y));
 170
 171             // Start the drag.
 172             m_dragMode = TEST_DRAG_DRAGGING;
 173
 174             if (m_dragImage)
 175                 delete m_dragImage;
 176
 177             // Erase the dragged shape from the canvas
 178             m_draggedShape->SetShow(FALSE);
 179             wxClientDC dc(this);
 180             EraseShape(m_draggedShape, dc);
 181             DrawShapes(dc);
 182
 183             switch (m_draggedShape->GetDragMethod())
 184             {
 185                 case SHAPE_DRAG_BITMAP:
 186                 {
 187                     wxPoint hotSpot(event.GetPosition().x - newPos.x, event.GetPosition().y - newPos.y);
 188                     m_dragImage = new wxDragImage(m_draggedShape->GetBitmap(), wxCursor(wxCURSOR_HAND), hotSpot);
 189                     break;
 190                 }
 191                 case SHAPE_DRAG_TEXT:
 192                 {
 193                     wxPoint hotSpot(event.GetPosition().x - newPos.x, event.GetPosition().y - newPos.y);
 194                     m_dragImage = new wxDragImage("Dragging some test text", wxCursor(wxCURSOR_HAND), hotSpot);
 195                     break;
 196                 }
 197                 case SHAPE_DRAG_ICON:
 198                 {
 199                     wxPoint hotSpot(event.GetPosition().x - newPos.x, event.GetPosition().y - newPos.y);
 200
 201                     // Can anyone explain why this test is necessary,
 202                     // to prevent a gcc error?
 203 #ifdef __WXMOTIF__
 204                     wxIcon icon(dragicon_xpm);
 205 #else
 206                     wxIcon icon(wxICON(dragicon));
 207 #endif
 208
 209                     m_dragImage = new wxDragImage(icon, wxCursor(wxCURSOR_HAND), hotSpot);
 210                     break;
 211                 }
 212             }
 213
 214             bool fullScreen = FALSE;
 215             if (wxGetApp().GetUseScreen())
 216             {
 217                 newPos = ClientToScreen(newPos);
 218                 fullScreen = TRUE;
 219             }
 220
 221             bool retValue;
 222
 223             if (fullScreen)
 224                 // This line uses the whole screen...
 225                 retValue = m_dragImage->BeginDrag(wxPoint(0, 0), this, TRUE);
 226                 // while this line restricts dragging to the parent frame.
 227                 // retValue = m_dragImage->BeginDrag(wxPoint(0, 0), this, GetParent());
 228             else
 229                 retValue = m_dragImage->BeginDrag(wxPoint(0, 0), this);
 230
 231             if (!retValue)
 232             {
 233                 delete m_dragImage;
 234                 m_dragImage = (wxDragImage*) NULL;
 235                 m_dragMode = TEST_DRAG_NONE;
 236             }
 237             m_dragImage->Move(newPos);
 238             m_dragImage->Show();
 239         }
 240         else if (m_dragMode == TEST_DRAG_DRAGGING)
 241         {
 242             // We're currently dragging. See if we're over another shape.
 243             DragShape* onShape = FindShape(event.GetPosition());
 244
 245             bool mustUnhighlightOld = FALSE;
 246             bool mustHighlightNew = FALSE;
 247
 248             if (m_currentlyHighlighted)
 249             {
 250                 if ((onShape == (DragShape*) NULL) || (m_currentlyHighlighted != onShape))
 251                     mustUnhighlightOld = TRUE;
 252             }
 253
 254             if (onShape && (onShape != m_currentlyHighlighted) && onShape->IsShown())
 255                 mustHighlightNew = TRUE;
 256
 257             if (mustUnhighlightOld || mustHighlightNew)
 258                 m_dragImage->Hide();
 259
 260             // Now with the drag image switched off, we can change the window contents.
 261
 262             if (mustUnhighlightOld)
 263             {
 264                 wxClientDC clientDC(this);
 265                 m_currentlyHighlighted->Draw(clientDC);
 266                 m_currentlyHighlighted = (DragShape*) NULL;
 267             }
 268             if (mustHighlightNew)
 269             {
 270                 wxClientDC clientDC(this);
 271                 m_currentlyHighlighted = onShape;
 272                 m_currentlyHighlighted->Draw(clientDC, wxINVERT);
 273             }
 274
 275             wxPoint newPos(m_draggedShape->GetPosition().x + (event.GetPosition().x - m_dragStartPos.x),
 276                            m_draggedShape->GetPosition().y + (event.GetPosition().y - m_dragStartPos.y));
 277
 278             if (wxGetApp().GetUseScreen())
 279             {
 280                 newPos = ClientToScreen(newPos);
 281             }
 282
 283             // Move and show the image again
 284             m_dragImage->Move(newPos);
 285
 286             if (mustUnhighlightOld || mustHighlightNew)
 287                  m_dragImage->Show();
 288         }
 289     }
 290 }
 291
 292 void MyCanvas::DrawShapes(wxDC& dc)
 293 {
 294     wxNode* node = m_displayList.First();
 295     while (node)
 296     {
 297         DragShape* shape = (DragShape*) node->Data();
 298         if (shape->IsShown())
 299           shape->Draw(dc);
 300         node = node->Next();
 301     }
 302 }
 303
 304 void MyCanvas::EraseShape(DragShape* shape, wxDC& dc)
 305 {
 306     wxSize sz = GetClientSize();
 307     wxRect rect(0, 0, sz.x, sz.y);
 308
 309     wxRect rect2(shape->GetRect());
 310     dc.SetClippingRegion(rect2.x, rect2.y, rect2.width, rect2.height);
 311
 312     wxGetApp().TileBitmap(rect, dc, wxGetApp().GetBackgroundBitmap());
 313
 314     dc.DestroyClippingRegion();
 315 }
 316
 317 void MyCanvas::ClearShapes()
 318 {
 319     wxNode* node = m_displayList.First();
 320     while (node)
 321     {
 322         DragShape* shape = (DragShape*) node->Data();
 323         delete shape;
 324         node = node->Next();
 325     }
 326     m_displayList.Clear();
 327 }
 328
 329 DragShape* MyCanvas::FindShape(const wxPoint& pt) const
 330 {
 331     wxNode* node = m_displayList.First();
 332     while (node)
 333     {
 334         DragShape* shape = (DragShape*) node->Data();
 335         if (shape->HitTest(pt))
 336             return shape;
 337         node = node->Next();
 338     }
 339     return (DragShape*) NULL;
 340 }
 341
 342 // MyFrame
 343
 344 IMPLEMENT_DYNAMIC_CLASS( MyFrame, wxFrame )
 345
 346 BEGIN_EVENT_TABLE(MyFrame,wxFrame)
 347   EVT_MENU    (wxID_ABOUT, MyFrame::OnAbout)
 348   EVT_MENU    (wxID_EXIT,  MyFrame::OnQuit)
 349 END_EVENT_TABLE()
 350
 351 MyFrame::MyFrame()
 352        : wxFrame( (wxFrame *)NULL, -1, "wxDragImage sample",
 353                   wxPoint(20,20), wxSize(470,360) )
 354 {
 355   wxMenu *file_menu = new wxMenu();
 356   file_menu->Append( wxID_ABOUT, "&About...");
 357   file_menu->Append( TEST_USE_SCREEN, "&Use whole screen for dragging", "Use whole screen", TRUE);
 358   file_menu->Append( wxID_EXIT, "E&xit");
 359
 360   wxMenuBar *menu_bar = new wxMenuBar();
 361   menu_bar->Append(file_menu, "&File");
 362
 363   SetMenuBar( menu_bar );
 364
 365   CreateStatusBar(2);
 366   int widths[] = { -1, 100 };
 367   SetStatusWidths( 2, widths );
 368
 369   m_canvas = new MyCanvas( this, -1, wxPoint(0,0), wxSize(10,10) );
 370 }
 371
 372 void MyFrame::OnQuit( wxCommandEvent &WXUNUSED(event) )
 373 {
 374   Close( TRUE );
 375 }
 376
 377 void MyFrame::OnAbout( wxCommandEvent &WXUNUSED(event) )
 378 {
 379   (void)wxMessageBox( "wxDragImage demo\n"
 380                       "Julian Smart (c) 2000",
 381                       "About wxDragImage Demo", wxICON_INFORMATION | wxOK );
 382 }
 383
 384 //-----------------------------------------------------------------------------
 385 // MyApp
 386 //-----------------------------------------------------------------------------
 387
 388 BEGIN_EVENT_TABLE(MyApp, wxApp)
 389     EVT_MENU(TEST_USE_SCREEN, MyApp::OnUseScreen)
 390 END_EVENT_TABLE()
 391
 392 MyApp::MyApp()
 393 {
 394     // Drag across whole screen
 395     m_useScreen = FALSE;
 396 }
 397
 398 bool MyApp::OnInit()
 399 {
 400 #if wxUSE_LIBPNG
 401     wxImage::AddHandler( new wxPNGHandler );
 402 #endif
 403
 404     wxImage image;
 405     if (image.LoadFile("backgrnd.png", wxBITMAP_TYPE_PNG))
 406     {
 407         m_background = image.ConvertToBitmap();
 408     }
 409
 410
 411     MyFrame *frame = new MyFrame();
 412
 413     wxString rootName("shape0");
 414
 415     int i;
 416     for (i = 1; i < 4; i++)
 417     {
 418         wxString filename;
 419         filename.Printf("%s%d.png", (const char*) rootName, i);
 420         if (image.LoadFile(filename, wxBITMAP_TYPE_PNG))
 421         {
 422             DragShape* newShape = new DragShape(image.ConvertToBitmap());
 423             newShape->SetPosition(wxPoint(i*50, i*50));
 424
 425             if (i == 2)
 426                 newShape->SetDragMethod(SHAPE_DRAG_TEXT);
 427             else if (i == 3)
 428                 newShape->SetDragMethod(SHAPE_DRAG_ICON);
 429             else
 430                 newShape->SetDragMethod(SHAPE_DRAG_BITMAP);
 431             frame->GetCanvas()->GetDisplayList().Append(newShape);
 432         }
 433     }
 434
 435 #if 0
 436     // Under Motif or GTK, this demonstrates that
 437     // wxScreenDC only gets the root window content.
 438     // We need to be able to copy the overall content
 439     // for full-screen dragging to work.
 440     int w, h;
 441     wxDisplaySize(& w, & h);
 442     wxBitmap bitmap(w, h);
 443
 444     wxScreenDC dc;
 445     wxMemoryDC memDC;
 446     memDC.SelectObject(bitmap);
 447     memDC.Blit(0, 0, w, h, & dc, 0, 0);
 448     memDC.SelectObject(wxNullBitmap);
 449     m_background = bitmap;
 450 #endif
 451
 452     frame->Show( TRUE );
 453
 454     return TRUE;
 455 }
 456
 457 bool MyApp::TileBitmap(const wxRect& rect, wxDC& dc, wxBitmap& bitmap)
 458 {
 459     int w = bitmap.GetWidth();
 460     int h = bitmap.GetHeight();
 461
 462     int i, j;
 463     for (i = rect.x; i < rect.x + rect.width; i += w)
 464     {
 465         for (j = rect.y; j < rect.y + rect.height; j+= h)
 466             dc.DrawBitmap(bitmap, i, j);
 467     }
 468     return TRUE;
 469 }
 470
 471 void MyApp::OnUseScreen(wxCommandEvent& event)
 472 {
 473     m_useScreen = !m_useScreen;
 474 }
 475
 476 // DragShape
 477
 478 DragShape::DragShape(const wxBitmap& bitmap)
 479 {
 480     m_bitmap = bitmap;
 481     m_pos.x = 0;
 482     m_pos.y = 0;
 483     m_dragMethod = SHAPE_DRAG_BITMAP;
 484     m_show = TRUE;
 485 }
 486
 487 DragShape::~DragShape()
 488 {
 489 }
 490
 491 bool DragShape::HitTest(const wxPoint& pt) const
 492 {
 493     wxRect rect(GetRect());
 494     return rect.Inside(pt.x, pt.y);
 495 }
 496
 497 bool DragShape::Draw(wxDC& dc, int op)
 498 {
 499     if (m_bitmap.Ok())
 500     {
 501         wxMemoryDC memDC;
 502         memDC.SelectObject(m_bitmap);
 503
 504         dc.Blit(m_pos.x, m_pos.y, m_bitmap.GetWidth(), m_bitmap.GetHeight(),
 505             & memDC, 0, 0, op, TRUE);
 506
 507         return TRUE;
 508     }
 509     else
 510         return FALSE;
 511 }
 512