Creating a jpeg and or gif for drag and drop.

FROM : Timothy Paustian
DATE : Wed Nov 20 19:45:01 2002

I have a view that has several graphics in it. From this I want to be
able to allows users to drag out a jpeg and/or gif to other parts of
the application or even to other applications. I have this working
for tiffs and here is the code I use. (Note I know the command key
thing is a bit non-standard, but it works for what I am trying to do.
How can I modify this code to get me a jpeg or gif?

- (void)mouseDown:(NSEvent *)theEvent
{
    NSSize dragOffset = NSMakeSize(0.0, 0.0);
    NSPasteboard *pboard;
    unsigned int modifiers = [theEvent modifierFlags];
   
    if(modifiers & NSCommandKeyMask)
    {
   NSRect    bounds = [self bounds];
   NSImage *image = [[[NSImage alloc] initWithSize: bounds.size]
autorelease];
   NSImage *dragImage = [[[NSImage alloc] initWithSize:
bounds.size] autorelease];
   NSPoint    dragPoint = NSMakePoint(0.0, 0.0);

   pboard = [NSPasteboard pasteboardWithName:NSDragPboard];
   [pboard declareTypes:[NSArray
arrayWithObject:NSTIFFPboardType] owner:self];

   [image lockFocus];
   [self drawRect:bounds];
   [image unlockFocus];

   [pboard setData: [image TIFFRepresentationUsingCompression:
NSTIFFCompressionLZW factor: 15.0]            forType:
NSTIFFPboardType];

   [dragImage setBackgroundColor:[NSColor clearColor]];
   [dragImage lockFocus];
   [image dissolveToPoint: dragPoint fraction: 0.5];
   [dragImage unlockFocus];

   [self dragImage:dragImage
       at:bounds.origin
       offset: dragOffset
       event:theEvent
       pasteboard:pboard
       source:self slideBack:YES];
    }
    else
    {
   [super mouseDown:theEvent];
    }
    return;
}

--
Cheers,
Tim

Timothy Paustian
UW-Madison, Bacteriology