Hotkey problem
lazarus / 13-General

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Cz-David · 2008-02-05 11:47

I'am trying to make windows wide hotkey using register hot key... but
declaration in private
Code: [Select]Procedure WMHotkey( Var msg: TWMHotkey );
    message WM_HOTKEY;
gives this
Code: [Select]main.pas(41,44) Error: Identifier not found "TWMHotkey"
so i've checked the messages.inc and there is no hotkey what so ever.
then i tried using google... nothing useful for lazarus... in this
forum i've found usage of "TMessage" instead of twmhotkey... it does
not show any error message but it doesn't work either...
Code: [Select]procedure Tmain_form.FormCreate(Sender: TObject);
begin
  registerhotkey(handle, 1, mod_control or mod_shift, vk_f2);
end;

Code: [Select]procedure Tmain_form.wmhotkey(var msg:TMessage);
//TWMHotkey
  begin
    showmessage('Byla stisknuta klávesová zkratka');
    msg.Result:=0;
  end;

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Phil · 2008-02-05 18:45

Quote from: "Cz-David"Code: [Select]main.pas(41,44) Error: Identifier
not found "TWMHotkey"

Take a look at this:

http://www.bitwisemag.com/copy/delphi/delphi3.html

TWMHotKey does not appear to be declared in any FPC or LCL unit, but
you should be able to use TMessage. The hotkey is passed in the WParam
field of the TMesage record.

Thanks.

-Phil

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Cz-David · 2008-02-05 20:59

OK. I've read it... but it doesnt help... I have tried
Code: [Select]procedure Tmain_form.wmhotkey(var msg:TMessage);
begin
  if msg.wparam = 1 then
  begin
    showmessage('Byla stisknuta klávesová zkratka');
    msg.Result:=0;
  end;
end;
but it still does not work... I think I need more "step by step"
help... but thanks anyway

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Leledumbo · 2008-02-06 06:25

Maybe LCL has its cross-platform alternative named as TLMHotKey.
Remember, in Lazarus all messages are prefixed with LM not WM. Maybe
you can find it in LCLType or LCLIntf.

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Cz-David · 2008-02-06 09:03

Still same error. I found this
Code: [Select]  ICC_HOTKEY_CLASS       = $00000040;
in LCLType but this is not very helpful... Are you trying to tell me
that no one has ever actually made a working hotkey?

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Leledumbo · 2008-02-11 10:02

I've checked LMessages as in Delphi TWMHotKey is defined there. It
looks like currently LCL doesn't have such a thing. Your code:
Code: [Select]
procedure Tmain_form.FormCreate(Sender: TObject);
begin
  registerhotkey(handle, 1, mod_control or mod_shift, vk_f2);
end;

Seems to work fine. Have you checked the result of registerhotkey?

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Cz-David · 2008-02-11 14:38

Code: [Select] if not registerhotkey(handle, 1, mod_control or
mod_shift, vk_f2) then showmessage('hotkey error');
work fine

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Cz-David · 2008-02-18 10:28

User mishob gave me an answer. Working answer. It is kinda bypass for
the message function but it works... The virtual hotkey number can be
find very easily.
Code: [Select]

type
  TForm1 = class(TForm)
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  private
    procedure Hook;
    procedure Unhook;
  public
    procedure ProcessHotKey(HK: LongInt);
  end;

var
  Form1: TForm1;

type
  TMWndProc = Windows.WNDPROC;

var
  OldProc: TMWndProc;

function MsgProc(Handle: HWnd; Msg: UInt; WParam: Windows.WParam;
                 LParam: Windows.LParam): LResult; stdcall;

implementation


procedure TForm1.FormCreate(Sender: TObject);
begin
  RegisterHotKey(Handle, 0, MOD_WIN, VK_A);
  Hook;
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  Unhook;
  UnregisterHotKey(Handle, 0);
end;  

procedure TForm1.Hook;
begin
  OldProc := TMWndProc(Windows.GetWindowLong(Handle, GWL_WNDPROC));
  Windows.SetWindowLong(Handle, GWL_WNDPROC, LongInt(@MsgProc));
end;

procedure TForm1.Unhook;
begin
  if Assigned(OldProc) then
    Windows.SetWindowLong(Handle, GWL_WNDPROC, LongInt(OldProc));
  OldProc := nil;
end;      

procedure TForm1.ProcessHotKey(HK: LongInt);
begin
  // HK is a virtual key code, process it here
end;

function MsgProc(Handle: HWnd; Msg: UInt; WParam: Windows.WParam;
    LParam: Windows.LParam): LResult; stdcall;
begin
  with Form1 do
  begin
    if Msg = WM_HOTKEY then
      ProcessHotKey(HIWORD(LParam))
    else
      Result := Windows.CallWindowProc(OldProc, Handle, Msg, WParam,
LParam);
  end;
end;