How to react on user's click on minimize button?

[Zoran]

In an application I have a modal form, and, when user clicks on minimize button of that form, I want the whole Application, not just that form, to be minimized.

In Delphi, on Windows, I achieve this behavior this way:

Code: [Select]

...
private
  procedure WmSysCommand(var Msg: TWMSysCommand); message WM_SYSCOMMAND;

...

procedure TForm2.WmSysCommand(var Msg: TWMSysCommand);
begin
  if msg.CmdType = SC_MINIMIZE then
    Application.Minimize
  else
    inherited;
end;

In Lazarus, when I cannot use Windows message, what can I do to achieve this?

[zeljko]

Why you cannot use message under lazarus ?

[Zoran]

Well... I just assumed I couldn't... But, now I tried and... No, I can't

[v-t-l]

Code: [Select]

procedure TForm1.FormWindowStateChange(Sender: TObject);
begin
  case WindowState of
    wsNormal: Application.Title := 'Normal';
    wsMaximized: Application.Title := 'Maximized';
    wsMinimized: Application.Title := 'Minimized';
  end;
end;

[Zoran]

Code: [Select]

procedure TForm1.FormWindowStateChange(Sender: TObject);
begin
  case WindowState of
    wsNormal: Application.Title := 'Normal';
    wsMaximized: Application.Title := 'Maximized';
    wsMinimized: Application.Title := 'Minimized';
  end;
end;

Thank you, v-t-l, but OnWindowStateChange event is triggered after the form is minimized. I want to intercept the user's minimize request. I would need something like form's OnCloseQuery event, which is used to intercept closing of the form.

Is there some way to do it?

[Marc]

instead of intercepting, which leads to user confusion, disable the minimize button.
See TForm.BorderIcons property

[Zoran]

instead of intercepting, which leads to user confusion, disable the minimize button.
See TForm.BorderIcons property

Thank you, Marc, but I don't think that intercepting would confuse user, when clicking a modal form's minimize button would result in minimizing the application, instead of the modal form only. Wouldn't it be the expected behavior for the user?

For now, I leave the minimize button and in OnFormWindowStateChange event I put "if WindowState = wsMinimized then Application.Minimize;". Now the form gets down first, then followed by the whole application. I'd rather see only the application's minimization.

So, there really seems to be no way of doing it?

[Marc]

Thank you, Marc, but I don't think that intercepting would confuse user, when clicking a modal form's minimize button would result in minimizing the application, instead of the modal form only. Wouldn't it be the expected behavior for the user?

Sorry, I wasn't fully awake, I forgot about the whole topic and read only your intercept message. Indeed, minimizing all wouldn't confuse I think. (clicking and do nothing would, but that was not your intention)

[zeljko]

Think that TApplication.OnEvent() could help here (CLX have such thing , don't know VCL)

[Zoran]

Think that TApplication.OnEvent() could help here (CLX have such thing , don't know VCL)

No. There is no such thing. 

[cdbc]

Hello...

How about TApplication.OnUserInput ?!?

Regards Benny

[Zoran]

Hello...

How about TApplication.OnUserInput ?!?

Regards Benny

How? Can you help me with this? I dont know how to achieve what I intend to.

[cdbc]

Hi Zoran.
Ok... I'll try, here goes:

Code: [Select]

{ in your test unit }
uses forms,....

type
  TfrmMain = class(TForm)
    ...
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    ...
    fLog: TStrings;
    fLogMessages: boolean;
  public
    ...
    procedure User_Input_Test(Sender: TObject; Msg: Cardinal);
  end;

implementation

procedure TfrmMain.FormCreate(Sender: TObject);
begin
  fLog:= TStringlist.Create;
  Application.OnUserInput:= @User_Input_Test;
end;

procedure TfrmMain.Button1Click(Sender: TObject);
begin
  fLogMessages:= not fLogMessages; { toggle logging or not }
end;

procedure TfrmMain.User_Input_Test(Sender: TObject; Msg: Cardinal);
var S: string;
begin
  if fLogMessages then begin
    S:= DateTimeToStr(Now)+' '+Sender.ClassName+' Msg = '+IntToStr(Msg);
    fLog.Add(S);
  end;
end;

procedure TfrmMain.FormDestroy(Sender: TObject);
begin
  fLog.SaveToFile('UserInputTest.log');
  FreeThenNil(fLog);
end;
{ one could trace mousemoves too... }
{ you'll have to excuse me the quick 'n dirty style }
With these snippets, you should be able to figure out, which msg'es comes from where and goes where...
It generates a lot of msg'es, thus the button to turn of logging.

You might try clicking the 'minimize' button, a few times after another 

After a run, open your texteditor to view your results...

Anyway, that's what I would do...

HTH ;-)
Regards Benny

[Zoran]

Thank you, Benny, for trying to help.

However, now I only managed to find out that minimizing a form doesn't trigger Application.OnUserInput event.