How to react on user's click on minimize button?
lazarus / 10-Designer

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Zoran · 2009-10-15 17:54

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?

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zeljko · 2009-10-15 18:25

Why you cannot use message under lazarus ?

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Zoran · 2009-10-15 19:16

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

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v-t-l · 2009-10-16 11:19

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;

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Zoran · 2009-10-16 13:54

Quote from: v-t-l on October 16, 2009, 01:19:16 pmCode:
[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?

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Marc · 2009-10-19 09:11

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

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Zoran · 2009-10-19 09:31

Quote from: Marc on October 19, 2009, 11:11:00 aminstead 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?

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Marc · 2009-10-19 09:37

Quote from: zoran on October 19, 2009, 11:31:38 amThank 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)

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zeljko · 2009-10-19 11:32

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

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Zoran · 2009-10-19 12:33

Quote from: zeljko on October 19, 2009, 01:32:52 pmThink that
TApplication.OnEvent() could help here (CLX have such thing , don't
know VCL)

No. There is no such thing.

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cdbc · 2009-11-02 18:06

Hello...

How about TApplication.OnUserInput ?!?

Regards Benny

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Zoran · 2009-11-04 17:48

Quote from: cdbc on November 02, 2009, 07:06:58 pmHello...

How about TApplication.OnUserInput ?!?

Regards Benny

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

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cdbc · 2009-11-04 19:02

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

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Zoran · 2009-11-05 18:29

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.