Call procedure in class function (SOLVED)

[TheLastCayen]

Hi,

I am using:
 - Windows 7 64 bit
 - Lazarus 2.0.6 64 bit
 - FPC 3.0.4 64 bit

In order to use a windows function, I had to create a class function. From that class function, I am not able to access any other procedure, function or object property from the rest of my code.  How can I use that class function to interact with my code? This is the code I have a problem with:

Code: Pascal  [Select][+][-]

1. Const
2.   WH_KEYBOARD_LL = 13;
3.  
4. type
5.   KeybdLLHookStruct = record
6.     vkCode      : cardinal;
7.     scanCode    : cardinal;
8.     flags       : cardinal;
9.     time        : cardinal;
10.     dwExtraInfo : cardinal;
11.   end;
12.  
13. procedure TForm1.FormCreate(Sender: TObject);
14. begin
15.     HookHandle := SetWindowsHookExa(WH_KEYBOARD_LL, HookPROC(@TForm1.AHookProc),HInstance, 0);
16. end;  
17.  
18. procedure TForm1.FormDestroy(Sender: TObject);
19. begin
20.     UnhookWindowsHookEx(HookHandle);
21. end;
22.  
23. procedure TForm1.SimpleAutoClick;
24. begin
25.   If TimerSimpleClick.Enabled = False then
26.     begin
27.       TimerSimpleClick.Interval:=strtoint(LabeledEdit1.Text);
28.       TimerSimpleClick.Enabled := True;
29.     end
30.   else
31.     TimerSimpleClick.Enabled := False;
32. end;
33.  
34. class Function Tform1.AHookProc(nCode:LongInt; wParam:WPARAM;Lparam:LParam):LRESULT; StdCall;
35. var
36.   keyboard : ^KeybdLLHookStruct absolute lParam;
37. begin
38.   Result :=  CallnextHookEx(HookHandle,nCode,wParam, lparam);
39.   if wParam = WM_KEYDOWN then
40.     case keyboard^.vkCode of
41.       VK_F4: TForm1.SimpleAutoClick;                 //Error: Only class methods, class properties and class variables can be accessed in class methods
42.       VK_F5: TimerSimpleClick.Enabled := True;   //Error: Only class methods, class properties and class variables can be accessed in class methods
43.       //VK_F5: PlayProfile;
44.       //VK_F7: AddToProfile;
45.       //VK_F8: DelFromProfile;
46.     end;
47. end;
48.  
49.  

In the worst-case scenario, I was thinking to use variables and a timer that checks the status of those variables but it feels like a cheap patch and a waste of resources:( So how real programmer deal with that kind of scenario?

Thank you

[jamie]

Form1. not TFORM.

You need to interact with the Instance of the form not the class of it.

 form1.SimpleAutoClose;

 Make that a normal method I guess.
etc.

[marcov]

And make it a STATIC class proc, otherwise it will go wrong. Class procs still have a reference to the class type as hidden param

For bonus points, don't use the form1 variable, but pass form via the parameter (LPARAM etc) to the class proc handler. This is useful if you have handler react to multiple classes individually

[TheLastCayen]

Thank you Jamie, it fixes my issue. I was so focused on the error I didn't notice I forgot to remove the t after I copy and past;)

sorry marcov, I am still a noob, I don't understand what you mean by making it a static class proc. Can you give me an example?

Thank you