pyobjc_quicklook_thumbnail_generator_async_with_quartz_export.py

1import os
2import Quartz
3import QuickLookThumbnailing
4from Foundation import NSURL, CGSize
5
6def generate_thumbnail(file_path, output_path):
7    # Create a URL for the file we want to thumbnail
8    file_url = NSURL.fileURLWithPath_(os.path.abspath(file_path))
9    
10    # Define the size and scale for the thumbnail
11    size = CGSize(256, 256)
12    scale = 1.0 # 2.0 for retina
13    
14    # Create a thumbnail request
15    request = QuickLookThumbnailing.QLThumbnailGeneratorRequest.alloc().initWithFileAtURL_size_scale_representationTypes_(
16        file_url, 
17        size, 
18        scale, 
19        QuickLookThumbnailing.QLThumbnailGenerationRequestRepresentationTypeIcon
20    )
21    
22    generator = QuickLookThumbnailing.QLThumbnailGenerator.sharedGenerator()
23    
24    # Define the completion handler
25    def completion_handler(thumbnail, error):
26        if error:
27            print(f"Error generating thumbnail: {error.localizedDescription()}")
28            return
29        
30        if thumbnail:
31            # Get the CGImage from the representation
32            cg_image = thumbnail.CGImage()
33            
34            # Save to disk using Quartz (Core Graphics)
35            dest_url = NSURL.fileURLWithPath_(output_path)
36            destination = Quartz.CGImageDestinationCreateWithURL(dest_url, "public.png", 1, None)
37            if destination:
38                Quartz.CGImageDestinationAddImage(destination, cg_image, None)
39                Quartz.CGImageDestinationFinalize(destination)
40                print(f"Thumbnail saved to: {output_path}")
41
42    # Start the request
43    generator.generateRepresentationsForRequest_updateHandler_(request, completion_handler)
44
45if __name__ == "__main__":
46    # Example usage: Replace 'test_image.jpg' with a real file path
47    target_file = "test_image.jpg"
48    if os.path.exists(target_file):
49        generate_thumbnail(target_file, "thumbnail.png")
50    else:
51        print(f"Please provide a valid file at {target_file}")