Mac OS X平台下QuickLook开发教程

OSStatus GenerateThumbnailForURL(void *thisInterface, QLThumbnailRequestRef thumbnail, CFURLRef url, CFStringRef contentTypeUTI, CFDictionaryRef options, CGSize maxSize)
{
@autoreleasepool
{
// Get the UTI properties
NSDictionary* uti_declarations = (__bridge_transfer NSDictionary*)UTTypeCopyDeclaration(contentTypeUTI); // Get the extensions corresponding to the image UTI, for some UTI there can be more than 1 extension (ex image.jpeg = jpeg, jpg...)
// If it fails for whatever reason fallback to the filename extension
id extensions = uti_declarations[(__bridge NSString*)kUTTypeTagSpecificationKey][(__bridge NSString*)kUTTagClassFilenameExtension];
NSString* extension = ([extensions isKindOfClass:[NSArray class]]) ? extensions[0] : extensions;
if (nil == extension)
extension = ([(__bridge NSURL*)url pathExtension] != nil) ? [(__bridge NSURL*)url pathExtension] : @"";
extension = [extension lowercaseString]; // Create the properties dic
CFTypeRef keys[1] = {kQLThumbnailPropertyExtensionKey};
CFTypeRef values[1] = {(__bridge CFStringRef)extension};
CFDictionaryRef properties = CFDictionaryCreate(kCFAllocatorDefault, (const void**)keys, (const void**)values, 1, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks); // Check by extension because it's highly unprobable that an UTI for these formats is declared
// the simplest way to declare one is creating a dummy automator app and adding imported/exported UTI conforming to public.image
CGImageRef img_ref = NULL;
CFStringRef filepath = CFURLCopyPath(url);
if ([extension isEqualToString:@"insp"])
{
if (!QLThumbnailRequestIsCancelled(thumbnail))
{
// 1. decode the image
img_ref = decode_insp_at_path(filepath, NULL);
if (filepath != NULL)
CFRelease(filepath); // 2. render it
if (img_ref != NULL)
{
QLThumbnailRequestSetImage(thumbnail, img_ref, properties);
CGImageRelease(img_ref);
}
else
QLThumbnailRequestSetImageAtURL(thumbnail, url, properties);
}
else
QLThumbnailRequestSetImageAtURL(thumbnail, url, properties);
}
else if ([extension isEqualToString:@"insv"])
{
if (!QLThumbnailRequestIsCancelled(thumbnail))
{
// 1. decode the image
img_ref = decode_insv_at_path(filepath, NULL);
if (filepath != NULL)
CFRelease(filepath); // 2. render it
if (img_ref != NULL)
{
QLThumbnailRequestSetImage(thumbnail, img_ref, properties);
CGImageRelease(img_ref);
}
else
QLThumbnailRequestSetImageAtURL(thumbnail, url, properties);
}
else
QLThumbnailRequestSetImageAtURL(thumbnail, url, properties);
}
else
QLThumbnailRequestSetImageAtURL(thumbnail, url, properties); if (properties != NULL)
CFRelease(properties);
}
return noErr;
}

OSStatus GeneratePreviewForURL(void *thisInterface, QLPreviewRequestRef preview, CFURLRef url, CFStringRef contentTypeUTI, CFDictionaryRef options)
{
@autoreleasepool
{
NSString* extension = [[(__bridge NSURL*)url pathExtension] lowercaseString];
image_infos infos;
memset(&infos, 0, sizeof(image_infos));
CGImageRef img_ref = NULL;
CFStringRef filepath = CFURLCopyPath(url);
if ([extension isEqualToString:@"insp"])
{
// 1. decode the image
if (!QLPreviewRequestIsCancelled(preview))
{
img_ref = decode_insp_at_path(filepath, &infos);
if (filepath != NULL)
CFRelease(filepath); // 2. render it
CFDictionaryRef properties = create_properties(url, infos.filesize, infos.width, infos.height, true);
if (img_ref != NULL)
{
// Have to draw the image ourselves
CGContextRef ctx = QLPreviewRequestCreateContext(preview, (CGSize){.width = OUT_WIDTH, .height = OUT_HEIGHT+LOGO_HEIGHT}, YES, properties);
CGContextDrawImage(ctx, (CGRect){.origin = CGPointZero, .size.width = OUT_WIDTH, .size.height = OUT_HEIGHT+LOGO_HEIGHT}, img_ref);
QLPreviewRequestFlushContext(preview, ctx);
CGContextRelease(ctx);
CGImageRelease(img_ref);
}
else
QLPreviewRequestSetURLRepresentation(preview, url, contentTypeUTI, properties);
if (properties != NULL)
CFRelease(properties);
}
}
else if([extension isEqualToString:@"insv"])
{
// 1. decode the image
if (!QLPreviewRequestIsCancelled(preview))
{
img_ref = decode_insv_at_path(filepath, &infos);
if (filepath != NULL)
CFRelease(filepath); // 2. render it
CFDictionaryRef properties = create_properties(url, infos.filesize, infos.width, infos.height, true);
if (img_ref != NULL)
{
// Have to draw the image ourselves
CGContextRef ctx = QLPreviewRequestCreateContext(preview, (CGSize){.width = OUT_WIDTH, .height = OUT_HEIGHT+LOGO_HEIGHT}, YES, properties);
CGContextDrawImage(ctx, (CGRect){.origin = CGPointZero, .size.width = OUT_WIDTH, .size.height = OUT_HEIGHT+LOGO_HEIGHT}, img_ref);
QLPreviewRequestFlushContext(preview, ctx);
CGContextRelease(ctx);
CGImageRelease(img_ref);
}
else
QLPreviewRequestSetURLRepresentation(preview, url, contentTypeUTI, properties);
if (properties != NULL)
CFRelease(properties);
} }
else
{
// Standard images (supported by the OS by default)
size_t width = 0, height = 0, file_size = 0;
properties_for_file(url, &width, &height, &file_size); // Request preview with updated titlebar
CFDictionaryRef properties = create_properties(url, file_size, width, height, false);
QLPreviewRequestSetURLRepresentation(preview, url, contentTypeUTI, properties); if (properties != NULL)
CFRelease(properties);
}
}
return kQLReturnNoError;
}