src/cocoa/dcmemory.mm

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/cocoa/dcmemory.mm
   3 // Purpose:     wxMemoryDC class
   4 // Author:      David Elliott
   5 // Modified by:
   6 // Created:     2003/03/16
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 2002 David Elliott
   9 // Licence:     wxWidgets licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #include "wx/wxprec.h"
  13
  14 #ifndef WX_PRECOMP
  15     #include "wx/log.h"
  16     #include "wx/dcmemory.h"
  17 #endif //WX_PRECOMP
  18
  19 #include "wx/cocoa/autorelease.h"
  20
  21 #import <AppKit/NSImage.h>
  22 #import <AppKit/NSAffineTransform.h>
  23 #import <AppKit/NSGraphicsContext.h>
  24 #import <AppKit/NSColor.h>
  25 #import <AppKit/NSBezierPath.h>
  26
  27 //-----------------------------------------------------------------------------
  28 // wxMemoryDC
  29 //-----------------------------------------------------------------------------
  30
  31 IMPLEMENT_DYNAMIC_CLASS(wxMemoryDC,wxDC)
  32
  33 void wxMemoryDC::Init()
  34 {
  35     m_cocoaNSImage = NULL;
  36     m_ok = false;
  37 }
  38
  39 wxMemoryDC::wxMemoryDC( wxDC *WXUNUSED(dc) )
  40 {
  41     Init();
  42 }
  43
  44 wxMemoryDC::~wxMemoryDC(void)
  45 {
  46     CocoaUnwindStackAndLoseFocus();
  47     [m_cocoaNSImage release];
  48 }
  49
  50 bool wxMemoryDC::CocoaLockFocus()
  51 {
  52     if(m_cocoaNSImage)
  53     {
  54         [m_cocoaNSImage lockFocus];
  55         sm_cocoaDCStack.Insert(this);
  56         NSAffineTransform *newTransform = CocoaGetWxToBoundsTransform([m_cocoaNSImage isFlipped], [m_cocoaNSImage size].height);
  57         [newTransform retain];
  58         [m_cocoaWxToBoundsTransform release];
  59         m_cocoaWxToBoundsTransform = newTransform;
  60         CocoaApplyTransformations();
  61         return true;
  62     }
  63     return false;
  64 }
  65
  66 bool wxMemoryDC::CocoaUnlockFocus()
  67 {
  68     [m_cocoaNSImage unlockFocus];
  69     return true;
  70 }
  71
  72 // NOTE: The AppKit is unable to draw onto an NSBitmapImageRep so we must
  73 // instead copy the data to an offscreen window, then copy it back
  74 void wxMemoryDC::DoSelect( const wxBitmap& bitmap )
  75 {
  76     wxAutoNSAutoreleasePool pool;
  77     if(m_selectedBitmap.Ok())
  78     {
  79         CocoaTakeFocus();
  80         wxASSERT(m_cocoaNSImage);
  81         // Replace the bitmap's native data with a newly created one based on the
  82         // NSImage that has been (potentially) drawn upon.  Note that this may and
  83         // probably will in many cases change the bitmap's format.
  84         // There is nothing we can do about this using pure Cocoa code.  Even using
  85         // CGBitmapContext is not an option because it only supports a limited
  86         // number of bitmap formats.  Specifically, 24-bpp is not supported.
  87         m_selectedBitmap.SetNSBitmapImageRep(
  88             [[NSBitmapImageRep alloc]
  89                 initWithFocusedViewRect:NSMakeRect(0.0,0.0,
  90                     m_selectedBitmap.GetWidth(),
  91                     m_selectedBitmap.GetHeight())]);
  92     }
  93     CocoaUnwindStackAndLoseFocus();
  94     [m_cocoaNSImage release];
  95     m_cocoaNSImage = nil;
  96     m_selectedBitmap = bitmap;
  97     if(m_selectedBitmap.Ok())
  98     {
  99         // Create an offscreen window of the same size
 100         m_cocoaNSImage = [[NSImage alloc]
 101                 initWithSize:NSMakeSize(m_selectedBitmap.GetWidth(),
 102                     m_selectedBitmap.GetHeight())];
 103
 104         // Now copy the data
 105         // Pass false to GetNSImage so the mask is not applied as an alpha channel.
 106         // Cocoa uses premultiplied alpha so applying the mask would cause all
 107         // color information masked out to be turned black which is undesirable.
 108         // FIXME: Currently, the mask will not be updated if any drawing occurs.
 109         // My only suggestion is for wxCocoa users to eschew the mask in favor
 110         // of an alpha channel or to recreate the mask after drawing.
 111         // The only way to fix this is to draw twice, once as normal and again
 112         // onto the mask to update it.  That would require overriding every
 113         // single drawing primitive (e.g. DoDrawLine, DoDrawRectangle, etc.)
 114         // and would be a major undertaking.
 115         NSImage *nsimage = [m_selectedBitmap.GetNSImage(false) retain];
 116         [m_cocoaNSImage lockFocus];
 117         [nsimage drawAtPoint: NSMakePoint(0,0)
 118             fromRect: NSMakeRect(0.0,0.0,m_selectedBitmap.GetWidth(),m_selectedBitmap.GetHeight())
 119             operation: NSCompositeCopy
 120             fraction: 1.0];
 121         [m_cocoaNSImage unlockFocus];
 122
 123         [nsimage release];
 124     }
 125 }
 126
 127 void wxMemoryDC::DoGetSize( int *width, int *height ) const
 128 {
 129     if(width)
 130         *width = m_selectedBitmap.GetWidth();
 131     if(height)
 132         *height = m_selectedBitmap.GetHeight();
 133 }
 134
 135 bool wxMemoryDC::CocoaDoBlitOnFocusedDC(wxCoord xdest, wxCoord ydest,
 136     wxCoord width, wxCoord height, wxCoord xsrc, wxCoord ysrc,
 137     int logicalFunc, bool useMask, wxCoord xsrcMask, wxCoord ysrcMask)
 138 {
 139     if(!m_selectedBitmap.Ok())
 140         return false;
 141
 142     NSAffineTransform *transform = [NSAffineTransform transform];
 143     [transform translateXBy:xdest yBy:ydest];
 144
 145     NSAffineTransform *flipTransform = [NSAffineTransform transform];
 146     /*  x' = 1x + 0y + 0
 147         y' = 0x + -1y + window's height
 148     */
 149     NSAffineTransformStruct matrix = {
 150         1,  0
 151     ,   0, -1
 152     ,   0, height
 153     };
 154     [flipTransform setTransformStruct: matrix];
 155
 156     NSGraphicsContext *context = [NSGraphicsContext currentContext];
 157     [context saveGraphicsState];
 158     [transform concat];
 159     [flipTransform concat];
 160
 161     NSImage *sourceImage;
 162     if(useMask)
 163     {
 164         sourceImage = [m_cocoaNSImage copy];
 165         // Apply the mask to the copied image
 166         NSBitmapImageRep *maskRep = m_selectedBitmap.GetMask()->GetNSBitmapImageRep();
 167         NSImage *maskImage = [[NSImage alloc] initWithSize:[maskRep size]];
 168         [maskImage addRepresentation:maskRep];
 169         [sourceImage lockFocus];
 170         [maskImage compositeToPoint:NSZeroPoint operation:NSCompositeDestinationIn];
 171         [sourceImage unlockFocus];
 172         [maskImage release];
 173     }
 174     else
 175     {   // retain the m_cocoaNSImage so it has the same ownership as the copy done in the other case.
 176         sourceImage = [m_cocoaNSImage retain];
 177     }
 178     NSCompositingOperation drawingOp;
 179     switch(logicalFunc)
 180     {
 181     case wxCOPY:
 182         // Even if not using the mask, the image might have an alpha channel
 183         // so always use NSCompositeSourceOver.  If the image is fully opaque
 184         // it works out the same as NSCompositeCopy.
 185         drawingOp = NSCompositeSourceOver;
 186         break;
 187     // FIXME: implement more raster ops
 188     default:
 189         wxLogDebug(wxT("wxCocoa does not support blitting with raster operation %d."), logicalFunc);
 190         // Just use the default operation.
 191         drawingOp = NSCompositeCopy;
 192     }
 193
 194     wxLogTrace(wxTRACE_COCOA,wxT("[m_cocoaNSImage isFlipped]=%d"), [m_cocoaNSImage isFlipped]);
 195     [sourceImage drawAtPoint: NSMakePoint(0,0)
 196         fromRect: NSMakeRect(xsrc,
 197             m_selectedBitmap.GetHeight()-height-ysrc,
 198             width, height)
 199         operation: drawingOp
 200         fraction: 1.0];
 201
 202     [sourceImage release]; // It was either retained, copied, or allocated.
 203     [context restoreGraphicsState];
 204     return false;
 205 }
 206
 207 bool wxMemoryDC::CocoaGetBounds(void *rectData)
 208 {
 209     if(!rectData)
 210         return false;
 211     if(!m_cocoaNSImage)
 212         return false;
 213     NSRect *pRect = (NSRect*)rectData;
 214     pRect->origin.x = 0.0;
 215     pRect->origin.y = 0.0;
 216     pRect->size = [m_cocoaNSImage size];
 217     return true;
 218 }
 219