src/MacAppBundle/QuickLook/GenerateThumbnailForURL.m

// SPDX-License-Identifier: LGPL-2.1-or-later

#include <CoreFoundation/CoreFoundation.h>
#include <CoreServices/CoreServices.h>
#include <QuickLook/QuickLook.h>
#include <Foundation/Foundation.h>
#include <AppKit/AppKit.h>

/* -----------------------------------------------------------------------------
    Generate a thumbnail for file

   This function's job is to create thumbnail for designated file as fast as possible
   ----------------------------------------------------------------------------- */

OSStatus GenerateThumbnailForURL(void *thisInterface, QLThumbnailRequestRef thumbnail, CFURLRef url, CFStringRef contentTypeUTI, CFDictionaryRef options, CGSize maxSize)
{
  OSStatus ret = coreFoundationUnknownErr;

  @autoreleasepool {

    // unzip -qq -o -j -d /tmp ~/test.FCStd thumbnails/Thumbnail.png
    //  -qq : be really quiet
    //  -o : overwrite without prompt
    //  -j : don't create archive paths
    //  -d : destination path (create this path)
    // extracts thumbnails/Thumbnail.png to /tmp/Thumbnail.png .
    // We add a UUID and use a system temp directory here.

    NSUUID *uuid = [NSUUID UUID];
    NSString *uuidPath = [uuid UUIDString];
    NSString *unzipDstPath = [NSString stringWithFormat:@"%@/%@/", NSTemporaryDirectory(), uuidPath];
    NSString *unzipDstFile = [NSString stringWithFormat:@"%@%@", unzipDstPath, @"Thumbnail.png"];
    NSURL *zipFile = (__bridge NSURL *)url;
    NSTask *task = [NSTask launchedTaskWithLaunchPath:@"/usr/bin/unzip"
                                            arguments:@[@"-qq", @"-o", @"-j", @"-d", unzipDstPath, [zipFile path], @"thumbnails/Thumbnail.png"]];
    [task waitUntilExit];
    //        NSLog(@"%@", unzipDstPath);
    //        NSLog(@"%@", unzipDstFile);

    if ( [[NSFileManager defaultManager] fileExistsAtPath:unzipDstFile] )
    {
      CGSize canvasSize = CGSizeMake(128, 128);
      CGContextRef cgContext = QLThumbnailRequestCreateContext(thumbnail, /*maxSize*/canvasSize, true, NULL);
      if(cgContext)
      {
        CGDataProviderRef pngDP = CGDataProviderCreateWithFilename([unzipDstFile fileSystemRepresentation]);
        CGImageRef image = CGImageCreateWithPNGDataProvider(pngDP, NULL, true, kCGRenderingIntentDefault);
        CGDataProviderRelease(pngDP);

        CGContextDrawImage(cgContext,CGRectMake(0, 0, 128, 128), image);

        QLThumbnailRequestFlushContext(thumbnail, cgContext);
        ret = noErr;

        CFRelease(cgContext);
        CFRelease(image);
      }
    }

    if ( [[NSFileManager defaultManager] isDeletableFileAtPath:unzipDstFile] )
      [[NSFileManager defaultManager] removeItemAtPath:unzipDstFile error:nil];

    if ( [[NSFileManager defaultManager] isDeletableFileAtPath:unzipDstPath] )
      [[NSFileManager defaultManager] removeItemAtPath:unzipDstPath error:nil];
  }

  return ret;
}


void CancelThumbnailGeneration(void* thisInterface, QLThumbnailRequestRef thumbnail)
{
    // implement only if supported
}