{
   Double Commander
   -------------------------------------------------------------------------
   Quick Look thumbnail provider

   Copyright (C) 2015-2019 Alexander Koblov (alexx2000@mail.ru)

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
}

unit uQuickLook;

{$mode objfpc}{$H+}
{$modeswitch objectivec1}

interface

uses
  Classes, SysUtils;

implementation

uses
  DynLibs, FileUtil, Types, Graphics, MacOSAll, uThumbnails, uDebug,
  uClassesEx, uGraphics;

const
  libQuickLook = '/System/Library/Frameworks/QuickLook.framework/Versions/Current/QuickLook';

var
  QuickLook: TLibHandle = NilHandle;

var
  QLThumbnailImageCreate: function(allocator: CFAllocatorRef; url: CFURLRef; maxThumbnailSize: CGSize; options: CFDictionaryRef): CGImageRef; cdecl;

function GetThumbnail(const aFileName: String; aSize: TSize): Graphics.TBitmap;
var
  ImageRef: CGImageRef;
  WorkStream: TBlobStream;
  maxThumbnailSize: CGSize;
  ImageData: CFMutableDataRef;
  theFileNameUrlRef: CFURLRef;
  theFileNameCFRef: CFStringRef;
  Bitmap: TPortableNetworkGraphic;
  ImageDest: CGImageDestinationRef;
begin
  theFileNameCFRef:= CFStringCreateWithFileSystemRepresentation(nil, PAnsiChar(aFileName));
  theFileNameUrlRef:= CFURLCreateWithFileSystemPath(nil, theFileNameCFRef, kCFURLPOSIXPathStyle, False);
  try
    maxThumbnailSize.width:= aSize.cx; maxThumbnailSize.height:= aSize.cy;
    ImageRef:= QLThumbnailImageCreate(kCFAllocatorDefault, theFileNameUrlRef, maxThumbnailSize, nil);
    if ImageRef = nil then Exit(nil);

    ImageData:= CFDataCreateMutable(nil, 0);
    // Get image data in PNG format
    ImageDest:= CGImageDestinationCreateWithData(ImageData, kUTTypePNG, 1, nil);
    CGImageDestinationAddImage(ImageDest, ImageRef, nil);

    if (CGImageDestinationFinalize(ImageDest) = 0) then
      Result:= nil
    else begin
      Bitmap:= TPortableNetworkGraphic.Create;
      WorkStream:= TBlobStream.Create(CFDataGetBytePtr(ImageData), CFDataGetLength(ImageData));
      try
        Result:= TBitmap.Create;
        try
          Bitmap.LoadFromStream(WorkStream);
          BitmapAssign(Result, Bitmap);
        except
          FreeAndNil(Result);
        end;
      finally
        Bitmap.Free;
        WorkStream.Free;
      end;
    end;
    CFRelease(ImageRef);
    CFRelease(ImageData);
    CFRelease(ImageDest);
  finally
    CFRelease(theFileNameCFRef);
    CFRelease(theFileNameUrlRef);
  end;
end;

procedure Initialize;
begin
  QuickLook:= LoadLibrary(libQuickLook);

  if (QuickLook <> NilHandle) then
  begin
    Pointer(QLThumbnailImageCreate):= GetProcAddress(QuickLook, 'QLThumbnailImageCreate');

    if Assigned(QLThumbnailImageCreate) then
    begin
      // Register thumbnail provider
      TThumbnailManager.RegisterProvider(@GetThumbnail);
      DCDebug('Initialize QuickLook: Success');
    end;
  end;
end;

procedure Finalize;
begin
  if (QuickLook <> NilHandle) then FreeLibrary(QuickLook);
end;

initialization
  Initialize;

finalization
  Finalize;

end.

