プレビュー画像のサイズ情報を渡す　【QuickLook Plug-inの開発：実践的Macintoshプログラミング解説】

OSStatus GeneratePreviewForURL(
    void *thisInterface,
    QLPreviewRequestRef preview,
    CFURLRef url,
    CFStringRef contentTypeUTI,
    CFDictionaryRef options)
{
    NSAutoreleasePool   *pool = [[NSAutoreleasePool alloc] init];
    NSBezierPath        *bp;
    NSSize  imageSize = NSMakeSize(300,200);
    NSImage *image = [[[NSImage alloc] initWithSize:imageSize] autorelease];
    NSDictionary    *dict = [NSDictionary dictionaryWithObjectsAndKeys:
        [NSNumber numberWithInt:300],kQLPreviewPropertyWidthKey,
        [NSNumber numberWithInt:200],kQLPreviewPropertyHeightKey,
        nil];
    [image lockFocus];

    [[NSColor whiteColor] set];
    [NSBezierPath fillRect:NSMakeRect(0,0,300,200)];
    bp = [NSBezierPath bezierPathWithOvalInRect:NSMakeRect(90,40,120,120)];
    [[NSColor redColor] set];
    [bp fill];

    [image unlockFocus];
    CFDataRef   imageData = (CFDataRef)[image TIFFRepresentation];
    QLPreviewRequestSetDataRepresentation(
        preview,imageData,kUTTypeImage,(CFDictionaryRef)dict);
    [pool release];
    return noErr;
}