Re: Creating a jpeg and or gif for drag and drop.

FROM : Andrew Zamler-Carhart
DATE : Thu Nov 21 10:22:01 2002

Folks,

I would only comment that you might want to specify the compression
factor when creating a JPEG image. Rather than passing nil for the
second argument of representationUsingType:properties:, you can pass in
a dictionary where the NSImageCompressionFactor is an NSNumber with a
float value ranging from 0.0 to 1.0, where 0.0 yields a small,
low-quality image and 1.0 a large, high-quality image. I've found that
0.9 works well for my purposes. The default setting creates rather poor
quality images.

NSDictionary *properties = [NSDictionary dictionaryWithObject:
    [NSNumber numberWithFloat: 0.9] forKey: NSImageCompressionFactor];
NSData *jpgData = [imageRep representationUsingType: NSJPEGFileType
    properties: properties];

Hope this helps,
Andrew

On Thursday, November 21, 2002, at 07:14  AM, Fabio Lossotti wrote:

> You've got almost everything you need, just pull a JPEG or GIF instead
> of a TIFF.  Here are some code snippets that should help.
>
> To get the JPEG image:
>    NSBitmapImageRep    *imageRep = [NSBitmapImageRep
> imageRepWithData:[image TIFFRepresentationUsingCompression:
> NSTIFFCompressionLZW factor: 15.0]];
>    NSData *jpgData = [imageRep representationUsingType:NSJPEGFileType
> properties:nil];
>    (then write the data to the pasteboard)
>
> And for GIFs:
>      NSBitmapImageRep    *imageRep = [NSBitmapImageRep
> imageRepWithData:[image TIFFRepresentationUsingCompression:
> NSTIFFCompressionLZW factor: 15.0]];
>      NSData *gifData = [imageRep
>        representationUsingType:NSGIFFileType properties:nil];
>    (then write the data to the pasteboard)
>
> -FL
>
>
>
> --- Timothy Paustian <<email_removed>> wrote:

>> 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

>
>
> __________________________________________________
> Do you Yahoo!?
> Yahoo! Mail Plus ñ Powerful. Affordable. Sign up now.
> http://mailplus.yahoo.com
> _______________________________________________
> MacOSX-dev mailing list
> <email_removed>
> http://www.omnigroup.com/mailman/listinfo/macosx-dev
>