src/cocoa/dcmemory.mm

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/cocoa/dcmemory.mm
   3 // Purpose:     wxMemoryDCImpl 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 #endif //WX_PRECOMP
  17
  18 #include "wx/cocoa/dcmemory.h"
  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 // wxMemoryDCImpl
  29 //-----------------------------------------------------------------------------
  30
  31 IMPLEMENT_ABSTRACT_CLASS(wxMemoryDCImpl,wxCocoaDCImpl)
  32
  33 void wxMemoryDCImpl::Init()
  34 {
  35     m_cocoaNSImage = NULL;
  36     m_ok = false;
  37 }
  38
  39 wxMemoryDCImpl::wxMemoryDCImpl(wxMemoryDC *owner, wxDC *WXUNUSED(dc))
  40 :   wxCocoaDCImpl(owner)
  41 {
  42     Init();
  43 }
  44
  45 wxMemoryDCImpl::~wxMemoryDCImpl(void)
  46 {
  47     CocoaUnwindStackAndLoseFocus();
  48     [m_cocoaNSImage release];
  49 }
  50
  51 bool wxMemoryDCImpl::CocoaLockFocus()
  52 {
  53     if(m_cocoaNSImage)
  54     {
  55         [m_cocoaNSImage lockFocus];
  56         sm_cocoaDCStack.Insert(this);
  57         NSAffineTransform *newTransform = CocoaGetWxToBoundsTransform([m_cocoaNSImage isFlipped], [m_cocoaNSImage size].height);
  58         [newTransform retain];
  59         [m_cocoaWxToBoundsTransform release];
  60         m_cocoaWxToBoundsTransform = newTransform;
  61         CocoaApplyTransformations();
  62         return true;
  63     }
  64     return false;
  65 }
  66
  67 bool wxMemoryDCImpl::CocoaUnlockFocus()
  68 {
  69     [m_cocoaNSImage unlockFocus];
  70     return true;
  71 }
  72
  73 // NOTE: The AppKit is unable to draw onto an NSBitmapImageRep so we must
  74 // instead copy the data to an offscreen window, then copy it back
  75 void wxMemoryDCImpl::DoSelect( const wxBitmap& bitmap )
  76 {
  77     wxAutoNSAutoreleasePool pool;
  78     if(m_selectedBitmap.Ok())
  79     {
  80         CocoaTakeFocus();
  81         wxASSERT(m_cocoaNSImage);
  82         // Replace the bitmap's native data with a newly created one based on the
  83         // NSImage that has been (potentially) drawn upon.  Note that this may and
  84         // probably will in many cases change the bitmap's format.
  85         // There is nothing we can do about this using pure Cocoa code.  Even using
  86         // CGBitmapContext is not an option because it only supports a limited
  87         // number of bitmap formats.  Specifically, 24-bpp is not supported.
  88         m_selectedBitmap.SetNSBitmapImageRep(
  89             [[NSBitmapImageRep alloc]
  90                 initWithFocusedViewRect:NSMakeRect(0.0,0.0,
  91                     m_selectedBitmap.GetWidth(),
  92                     m_selectedBitmap.GetHeight())]);
  93     }
  94     CocoaUnwindStackAndLoseFocus();
  95     [m_cocoaNSImage release];
  96     m_cocoaNSImage = nil;
  97     m_selectedBitmap = bitmap;
  98     if(m_selectedBitmap.Ok())
  99     {
 100         // Create an offscreen window of the same size
 101         m_cocoaNSImage = [[NSImage alloc]
 102                 initWithSize:NSMakeSize(m_selectedBitmap.GetWidth(),
 103                     m_selectedBitmap.GetHeight())];
 104
 105         // Now copy the data
 106         // Pass false to GetNSImage so the mask is not applied as an alpha channel.
 107         // Cocoa uses premultiplied alpha so applying the mask would cause all
 108         // color information masked out to be turned black which is undesirable.
 109         // FIXME: Currently, the mask will not be updated if any drawing occurs.
 110         // My only suggestion is for wxCocoa users to eschew the mask in favor
 111         // of an alpha channel or to recreate the mask after drawing.
 112         // The only way to fix this is to draw twice, once as normal and again
 113         // onto the mask to update it.  That would require overriding every
 114         // single drawing primitive (e.g. DoDrawLine, DoDrawRectangle, etc.)
 115         // and would be a major undertaking.
 116         NSImage *nsimage = [m_selectedBitmap.GetNSImage(false) retain];
 117         [m_cocoaNSImage lockFocus];
 118         [nsimage drawAtPoint: NSMakePoint(0,0)
 119             fromRect: NSMakeRect(0.0,0.0,m_selectedBitmap.GetWidth(),m_selectedBitmap.GetHeight())
 120             operation: NSCompositeCopy
 121             fraction: 1.0];
 122         [m_cocoaNSImage unlockFocus];
 123
 124         [nsimage release];
 125     }
 126 }
 127
 128 void wxMemoryDCImpl::DoGetSize( int *width, int *height ) const
 129 {
 130     if(width)
 131         *width = m_selectedBitmap.GetWidth();
 132     if(height)
 133         *height = m_selectedBitmap.GetHeight();
 134 }
 135
 136 bool wxMemoryDCImpl::CocoaDoBlitOnFocusedDC(wxCoord xdest, wxCoord ydest,
 137     wxCoord width, wxCoord height, wxCoord xsrc, wxCoord ysrc,
 138     int logicalFunc, bool useMask, wxCoord xsrcMask, wxCoord ysrcMask)
 139 {
 140     if(!m_selectedBitmap.Ok())
 141         return false;
 142
 143     NSAffineTransform *transform = [NSAffineTransform transform];
 144     [transform translateXBy:xdest yBy:ydest];
 145
 146     NSAffineTransform *flipTransform = [NSAffineTransform transform];
 147     /*  x' = 1x + 0y + 0
 148         y' = 0x + -1y + window's height
 149     */
 150     NSAffineTransformStruct matrix = {
 151         1,  0
 152     ,   0, -1
 153     ,   0, height
 154     };
 155     [flipTransform setTransformStruct: matrix];
 156
 157     NSGraphicsContext *context = [NSGraphicsContext currentContext];
 158     [context saveGraphicsState];
 159     [transform concat];
 160     [flipTransform concat];
 161
 162     NSImage *sourceImage;
 163     if(useMask)
 164     {
 165         sourceImage = [m_cocoaNSImage copy];
 166         // Apply the mask to the copied image
 167         NSBitmapImageRep *maskRep = m_selectedBitmap.GetMask()->GetNSBitmapImageRep();
 168         NSImage *maskImage = [[NSImage alloc] initWithSize:[maskRep size]];
 169         [maskImage addRepresentation:maskRep];
 170         [sourceImage lockFocus];
 171         [maskImage compositeToPoint:NSZeroPoint operation:NSCompositeDestinationIn];
 172         [sourceImage unlockFocus];
 173         [maskImage release];
 174     }
 175     else
 176     {   // retain the m_cocoaNSImage so it has the same ownership as the copy done in the other case.
 177         sourceImage = [m_cocoaNSImage retain];
 178     }
 179     NSCompositingOperation drawingOp;
 180     switch(logicalFunc)
 181     {
 182     case wxCOPY:
 183         // Even if not using the mask, the image might have an alpha channel
 184         // so always use NSCompositeSourceOver.  If the image is fully opaque
 185         // it works out the same as NSCompositeCopy.
 186         drawingOp = NSCompositeSourceOver;
 187         break;
 188     // FIXME: implement more raster ops
 189     default:
 190         wxLogDebug(wxT("wxCocoa does not support blitting with raster operation %d."), logicalFunc);
 191         // Just use the default operation.
 192         drawingOp = NSCompositeCopy;
 193     }
 194
 195     wxLogTrace(wxTRACE_COCOA,wxT("[m_cocoaNSImage isFlipped]=%d"), [m_cocoaNSImage isFlipped]);
 196     [sourceImage drawAtPoint: NSMakePoint(0,0)
 197         fromRect: NSMakeRect(xsrc,
 198             m_selectedBitmap.GetHeight()-height-ysrc,
 199             width, height)
 200         operation: drawingOp
 201         fraction: 1.0];
 202
 203     [sourceImage release]; // It was either retained, copied, or allocated.
 204     [context restoreGraphicsState];
 205     return false;
 206 }
 207
 208 bool wxMemoryDCImpl::CocoaGetBounds(void *rectData)
 209 {
 210     if(!rectData)
 211         return false;
 212     if(!m_cocoaNSImage)
 213         return false;
 214     NSRect *pRect = (NSRect*)rectData;
 215     pRect->origin.x = 0.0;
 216     pRect->origin.y = 0.0;
 217     pRect->size = [m_cocoaNSImage size];
 218     return true;
 219 }
 220