handler EventKit can't get it to work

[BVale]

hi everyone,

here is my code, its just a simple form with a button.
I tried already several things but it just dont work out. The way I want to.
The following code works kinda. the system asks me if I want to access the calendar. But I can't handle the event. 

Code: Pascal  [Select][+][-]

1. unit Unit1;
2.  
3. {$mode delphi}{$H+}
4. {$modeswitch objectivec1}
5. {$modeswitch cblocks}
6. {$linkframework EventKit}
7. interface
8.  
9. uses
10.   Classes, SysUtils, Forms, Controls, Graphics, Dialogs, StdCtrls,
11.   CocoaAll, MacOSAll, EventKit;
12.  
13. type
14.  
15.   { TForm1 }
16.  
17.   TForm1 = class(TForm)
18.     Button1: TButton;
19.     procedure Button1Click(Sender: TObject);
20.   private
21.  
22.  
23.   public
24.  
25.  
26.   end;
27.  
28. var
29.   Form1: TForm1;
30.  
31. implementation
32.  
33. {$R *.lfm}
34.  
35. { TForm1 }
36. //
37. //procedure CompletionHandler(granted: boolean; error: NSError)cdecl;
38. //begin
39. //  if granted then
40. //    ShowMessage('Zugriff gewährt')
41. //  else
42. //    ShowMessage('Zugriff verweigert oder Fehler aufgetreten: ' +
43. //      error.localizedDescription.utf8string);
44. //end;
45.  
46. procedure TForm1.Button1Click(Sender: TObject);
47. var
48.   handler: EKEventStoreRequestAccessCompletionHandler;
49.   store: EKEventStore;
50. begin
51.   store := EKEventStore.alloc.init;
52.   store.requestAccessToEntityType_completion(EKEntityTypeEvent, handler);
53.  
54. end;
55.  
56. end.
57.  

this one crashes
when I press the button

Code: Pascal  [Select][+][-]

1. unit Unit1;
2.  
3. {$mode delphi}{$H+}
4. {$modeswitch objectivec1}
5. {$modeswitch cblocks}
6. {$linkframework EventKit}
7. interface
8.  
9. uses
10.   Classes, SysUtils, Forms, Controls, Graphics, Dialogs, StdCtrls,
11.   CocoaAll, MacOSAll, EventKit;
12.  
13. type
14.  
15.   { TForm1 }
16.  
17.   TForm1 = class(TForm)
18.     Button1: TButton;
19.     procedure Button1Click(Sender: TObject);
20.   private
21.  
22.  
23.   public
24.  
25.  
26.   end;
27.  
28. var
29.   Form1: TForm1;
30.  
31. implementation
32.  
33. {$R *.lfm}
34.  
35. { TForm1 }
36.  
37. procedure CompletionHandler(granted: boolean; error: NSError)cdecl;
38. begin
39.   if granted then
40.     ShowMessage('Zugriff gewährt')
41.   else
42.     ShowMessage('Zugriff verweigert oder Fehler aufgetreten: ' +
43.       error.localizedDescription.utf8string);
44. end;
45.  
46. procedure TForm1.Button1Click(Sender: TObject);
47. var
48.  // handler: EKEventStoreRequestAccessCompletionHandler;
49.   store: EKEventStore;
50. begin
51.   store := EKEventStore.alloc.init;
52.   store.requestAccessToEntityType_completion(EKEntityTypeEvent, @CompletionHandler);
53.  
54. end;
55.  
56. end.
57.  
58.  

does anyone knows how "to handle" this?

[Jonas Maebe]

The first example doesn't make any sense. You're not assigning anything handler, so you're passing a random pointer value there. Additionally, the "boolean" parameter of the completion handler needs to be "ObjCBOOL".

The second one won't work because the Cocoa header parser has not been adjusted since FPC got support for C-blocks, so it defines all "block" parameters as a plain pointer.

If you fix the completion handler's booleanm parameter and assign its address to "handler", then I think the first example will work.

[BVale]

thank you for the answer.

Code: Pascal  [Select][+][-]

1.  
2. unit Unit1;
3.  
4. {$mode delphi}{$H+}
5. {$modeswitch objectivec1}
6. {$modeswitch cblocks}
7. {$linkframework EventKit}
8. interface
9.  
10. uses
11.   Classes, SysUtils, Forms, Controls, Graphics, Dialogs, StdCtrls,
12.   CocoaAll, MacOSAll, EventKit;
13.  
14. type
15.  
16.   { TForm1 }
17.  
18.   TForm1 = class(TForm)
19.     Button1: TButton;
20.     procedure Button1Click(Sender: TObject);
21.   private
22.  
23.  
24.   public
25.  
26.  
27.   end;
28.  
29. var
30.   Form1: TForm1;
31.  
32.  
33. implementation
34.  
35. {$R *.lfm}
36.  
37. { TForm1 }
38.  
39. procedure CompletionHandler(granted: ObjCBOOL; error: NSError);
40. begin
41.   if granted then
42.     ShowMessage('Zugriff gewährt')
43.   else
44.     ShowMessage('Zugriff verweigert oder Fehler aufgetreten: ' +
45.       error.localizedDescription.utf8string);
46. end;
47.  
48. procedure TForm1.Button1Click(Sender: TObject);
49. var
50.   store: EKEventStore;
51.   myAccessHandler: EKEventStoreRequestAccessCompletionHandler;
52. begin
53.    myAccessHandler:=@CompletionHandler;
54.   store := EKEventStore.alloc.init;
55.   store.requestAccessToEntityType_completion(EKEntityTypeEvent, myAccessHandler);
56.  
57. end;
58.  
59. end.
60.  

probably u mean something like this. it won't work either.

all I get is allways this error. like in the picture

its so frustrating... u have no idea how I long I am already trying to get this to work the only chance for me to get no crash is to send the handler to nirvana. maybe u have or someone else has an other idea, or maybe is trying for a second to get this to work too... dont know. 

[KodeZwerg]

I have no MacOS but from my Windows experience Handlers or Callbacks must be outside of methods that need them, so I would modify your code into this:
(added OnCreate() event for Form1)

Code: Pascal  [Select][+][-]

1. unit Unit1;
2.  
3. {$mode delphi}{$H+}
4. {$modeswitch objectivec1}
5. {$modeswitch cblocks}
6. {$linkframework EventKit}
7. interface
8.  
9. uses
10.   Classes, SysUtils, Forms, Controls, Graphics, Dialogs, StdCtrls,
11.   CocoaAll, MacOSAll, EventKit;
12.  
13. type
14.  
15.   { TForm1 }
16.  
17.   TForm1 = class(TForm)
18.     Button1: TButton;
19.     procedure FormCreate(Sender: TObject);  
20.     procedure Button1Click(Sender: TObject);
21.   strict private
22.     FHandler: EKEventStoreRequestAccessCompletionHandler;
23.     FStore: EKEventStore;
24.   protected
25.     procedure CompletionHandler(granted: ObjCBOOL; error: NSError);
26.   private
27.   public
28.   end;
29.  
30. var
31.   Form1: TForm1;
32.  
33.  
34. implementation
35.  
36. {$R *.lfm}
37.  
38. { TForm1 }
39.  
40. procedure TForm1.CompletionHandler(granted: ObjCBOOL; error: NSError);
41. begin
42.   if granted then
43.     ShowMessage('Zugriff gewährt')
44.   else
45.     ShowMessage('Zugriff verweigert oder Fehler aufgetreten: ' +
46.       error.localizedDescription.utf8string);
47. end;
48.  
49. procedure TForm1.Button1Click(Sender: TObject);
50. begin
51.   if FHandler = nil then
52.     FHandler := @CompletionHandler;
53.   if FStore = nil then
54.     FStore := EKEventStore.alloc.init;
55.   FStore.requestAccessToEntityType_completion(EKEntityTypeEvent, FHandler);
56. end;
57.  
58. procedure TForm1.FormCreate(Sender: TObject);  
59. begin
60.   FHandler := nil;
61.   FStore := nil;
62. end;
63.  
64. end.

Additional, set in line "if granted then" a breakpoint, run app, do something that the event has a chance to get fired, will it stop in the CompletionHandler?

[BVale]

hi kodezwerg, that don't work either.

[Jonas Maebe]

The issue is that the type definition for all of the C-block types in the CocoaInt headers is wrong. It's defined as Pointer, but it should be a C-block procvar type. These are records, and are passed by value rather than by reference (so just passing @cblockvar won't work).

To fix this for individual cases, you'll need to redefine the relevant methods using correct parameter types. You can do so by creating a category for the relevant class with a method that has the correct signature. I.e., in this case, something like this (untested):

Code: [Select]

type
  EKEventStoreRequestAccessCompletionHandler_Fixed = reference to Procedure(granted: ObjCBOOL; error: NSError); cdecl; cblock;

  EKEventStore_FixedMethods = objccategory(EKEventStore)
    procedure requestAccessToEntityType_completion_fixed (entityType: EKEntityType; completion: EKEventStoreRequestAccessCompletionHandler_Fixed); message 'requestAccessToEntityType:completion:';
  end;

And then call requestAccessToEntityType_completion_fixed instead of requestAccessToEntityType_completion.

It would be very nice if someone could take responsibility to fixing and maintaining the Cocoa headers, because the original creator hasn't done so for quite a while and never added support for blocks after the compiler got support for it. You can find the converter used to create the header translations at https://github.com/genericptr/Framework-Parser

[BVale]

jonas maebe, thank you for the answer, I have tried that also... it will just rise an error as well.

my knowledge of development is not that advance... the framework-parser dont work here couse it needs php7... and  I just get php8 installed and forcing it to run on 8 doesn't work that well.

[BVale]

found the solution

Code: Pascal  [Select][+][-]

1. type
2.  
3.   EKEventStoreRequestAccessCompletionHandler = procedure(granted: Boolean; error: NSError) of object; cblock; cdecl;
4.  
5.    EKEventStore = objcclass external (NSObject)
6.      procedure requestFullAccessToEventsWithCompletion(completion: EKEventStoreRequestAccessCompletionHandler); message 'requestFullAccessToEventsWithCompletion:'; // Beachten Sie die Verwendung der message-Direktive
7.      function calendarsForEntityType(entityType: EKEntityType): NSArray; message 'calendarsForEntityType:';      
8.  
9.  
10.  

Code: Pascal  [Select][+][-]

1. procedure TForm1.RequestAccessHandler(granted: Boolean; error: NSError);
2. begin
3.   if granted then
4.     //FMessage := 'Zugriff gewährt'
5.   else if Assigned(error) then
6.     //FMessage := 'Fehler: ' + error.localizedDescription.UTF8String
7.   else
8.     //FMessage := 'Zugriff verweigert';
9.  
10. end;
11.  
12.  
13. procedure TForm1.Button1Click(Sender: TObject);
14. var
15.   store: EKEventStore;
16. begin
17.   store := EKEventStore.alloc.init;
18.   store.requestFullAccessToEventsWithCompletion(RequestAccessHandler);
19.  
20. end;  
21.  

[Jonas Maebe]

You really should use ObjCBool instead of boolean, otherwise it's guaranteed to break on some platforms.

[BVale]

@Jonas maebe oh yeah u are right!
thanks for the reminder.

do u have an idea how to integrate that into the eventstore.inc? so I have not to include everything from there to my working unit?...