Cross platform DirectoryWatcher

[constructor]

when building, it's saying that OnFileEvent needs more parameters. On the demo app, the problem doesn't occur.
Any clue?

Hi,
I got Error: Wrong number of parameters specified for call to "OnFileEvent" when using

Code: Pascal  [Select][+][-]

1. {$mode objfpc}{$H+}

and replacing it with

Code: Pascal  [Select][+][-]

1. {$mode Delphi}{$H+}

fixed it.

[marcov]

Assignment of procedure/method types requires an @ in objfpc and fpc modes.

If you change to tp or delphi mode, you have to remove or ifdef them

[r.lukasiak]

@marcov
this did the trick! thank you!

[eny]

Warning for anyone who ends up here: there are quite some problems with the way it's implemented.
The most problematic one (on Windows 10): the dw cannot be stopped/destroyed.
Trying to do so will trigger an Access Violation error.

[LemonParty]

I have Windows 11, and using trunk compiler (version 3.3.1). And I tryied to use this library.
My attempt was with this code:

Code: Pascal  [Select][+][-]

1. program CacheDirectory;
2.  
3. {$mode objfpc}{$H+}
4.  
5. uses
6.   {$IFDEF UNIX}
7.   cthreads,
8.   {$ENDIF}
9.   Classes, DirectoryWatcherBuilder, DirectoryWatcherAPI
10.   { you can add units after this };
11.  
12. {$R *.res}
13. type
14.  
15.   { TTempObj }
16.  
17.   TTempObj = object
18.   public
19.     procedure OnFileEvent(const FilePath: String; const EventType: TDirectoryEventType);
20.   end;
21.  
22. const
23.   CTargetDirectory = 'X:\tmp\Test';
24. var
25.   DW: IDirectoryWatcher;
26.   T: TTempObj;
27.  
28. { TTempObj }
29.  
30. procedure TTempObj.OnFileEvent(const FilePath: String;
31.   const EventType: TDirectoryEventType);
32. var
33.   EventTypeString: String;
34. begin
35.   WriteLn('File: ' + FilePath);
36.  
37.   case EventType of
38.   detAdded: EventTypeString := 'ADDED';
39.   detRemoved: EventTypeString := 'REMOVED';
40.   detModified: EventTypeString := 'MODIFIED';
41.   end;
42.  
43.   WriteLn('Type: ' + EventTypeString);
44. end;
45.  
46. begin
47.   DW:= TDirectoryWatcherBuilder
48.     .New
49.     .WatchDirectory(CTargetDirectory)
50.     .Recursively(True)
51.     .OnChangeTrigger(@T.OnFileEvent)
52.     .Build;
53.   DW.Start;
54.  
55.   WriteLn(
56.     'Watching directory ', CTargetDirectory, LineEnding,
57.     'Press ENTER to stop'
58.   );
59.   Readln;
60.   DW:= nil;
61. end.

When I run this program in debug mode I am getting 'External: SIGSEGV' error on line 129 in file DirectoryWatcherThread.Windows. This line:

Code: Pascal  [Select][+][-]

1.   EventArray[1] := Integer(TermEvent.Handle^);

from first sight it is strange that we dereferencing a handle but maybe I mistake.

Has anybody a fix to this library or maybe another code that can watch directories?

[LemonParty]

I was right. This code has a mistake. Original code is:

Code: Pascal  [Select][+][-]

1.   EventArray[0] := FileEvent;
2.   EventArray[1] := Integer(TermEvent.Handle^);
3.   EventArray[2] := Integer(SuspEvent.Handle^);

The code that work for me in 64-bit application is:

Code: Pascal  [Select][+][-]

1.   EventArray[0] := FileEvent;
2.   EventArray[1] := PtrUInt(TermEvent.Handle);
3.   EventArray[2] := PtrUInt(SuspEvent.Handle);

I will report this to issues on github.

[LemonParty]

It seems the same problem on line 52 of file DirectoryWatcher.Windows. The correct code is:

Code: Pascal  [Select][+][-]

1.   PulseEvent(PtrUInt(StopEvent.Handle));