Cannot change Cursor to crHourGlass at run-time
lazarus / 8-Other

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Stefano · 2006-05-08 13:25

Hello, I cannot change at run-time che Cursor, either using
Self.Cursor property, either using Screen.Cursor property.

Here there is my code:

var
  MyCursor: TCursor;
begin
  MyCursor := Self.Cursor;
  Self.Cursor := crHourGlass;
  {MyCode}
  Self.Cursor := MyCursor;
end; 

I don't receive any error message, but the cursor doesn't change.

If I set the Form Cursor Property at design time, it's ok.

Could you help me?

I use Lazarus 9.1.13 on Windows 2000 Professional.

Best regards,

Stefano

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Anonymous · 2006-05-19 14:58

I cannot solve my problem yet.

A great thanks if someone can help me.

Best regards,

Stefano

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RudieD · 2006-05-19 16:39

Have you tried a Application.ProcessMessages after you set the cursor
?

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Anonymous · 2006-05-19 20:05

Thanks for your reply, I've tried now, but unfortunately it doesn't
work yet.

The same code, on Delphi, worked without problems (even without
ProcessMessages).

Have you any other idea to solve this problem on Lazarus?

Thank you very much.

Best regards,

Stefano

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g-r-g · 2006-05-20 05:52

Quote from: "Stefano"var
  MyCursor: TCursor;
begin
  MyCursor := Self.Cursor;
  Self.Cursor := crHourGlass;
  {MyCode}
  Self.Cursor := MyCursor;
end; 


WinXP, Lazarus 0.9.14 - it's working (sorry for this "code" :oops:):
Code: [Select]
var
  lA: TLabel;
  i,j: Integer;
begin
  MyCursor:=Self.Cursor;
  Self.Cursor:=crHourGlass;
  for i:=0 to 10 do begin
    Application.ProcessMessages;
    for j:=0 to 1000000 do begin
      Application.ProcessMessages;
    end;
    lA.Caption:=lA.Caption+'lA ';
  end;
  Self.Cursor:=MyCursor;
end;


I think there is a problem with your "{MyCode}".

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felipemdc · 2006-05-21 01:20

Self.Cursor := crHourGlass;
{MyCode}
Self.Cursor := MyCursor;

Did you consider the possibility that {MyCode} is executed so fast
that you really have no time to see the new cursor?

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Anonymous · 2006-05-23 22:26

Thanks for your reply, yes, I've considered this case, I have also
tried to delete the last line: Self.Cursor := MyCursor, in this case
the cursor would had stay = crHourGlass for all the time, but the
cursor hasn't changed even this time.

{MyCode} is very simple, I load a form (that require a bit of time for
charging), in any case here there is all my code:

*************************************
procedure TfrmPrincipale.mnuLiqIVAClick(Sender: TObject);
var
  MyQueryIVA: TfrmQueryIVA;
  MyItem: TMenuItem;
  N: SmallInt;
  MyCursor: TCursor;
begin
  if Ditta = '' then begin
    StartLogIn;
    if Ditta = '' then exit; //Wrong login
  end;
  MyCursor := Self.Cursor;
  Self.Cursor := crHourGlass;
  N := RetFreeNumber;
  MyItem := TMenuItem.Create(nil);
  MyItem.Name := 'mnuWin' + IntToStr(N);
  MyItem.Caption := IntToStr(N) + ' MyCaption';
  MyItem.GroupIndex := 1;
  MyItem.OnClick := mnuWindow.OnClick;
  mnuWindow.Insert((N+nWinItems-1), MyItem);

  MyQueryIVA := TfrmQueryIVA.Create(nil);
  MyQueryIVA.Caption := MyItem.Caption;
  MyQueryIVA.Position := poDefault;
  MyQueryIVA.Top := Self.Top + 48;
  MyQueryIVA.Left := Self.Left;
  MyQueryIVA.Width := Self.Width;
  MyQueryIVA.Show;

  Self.Cursor := MyCursor;

end;
************************************
Thank you very much if you can help me, excuse me for my delay to
reply but in this days I had found problems to connect me to the
forum.

Best regards,

Stefano

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felipemdc · 2006-05-24 01:48

I noticed you are using Lazarus 0.9.13 and someone said this works
with 0.9.14

Did you try to upgrade to 0.9.14?

Also you should try changing your code for this very simple one to
have a more clear test:

procedure TfrmPrincipale.mnuLiqIVAClick(Sender: TObject);
begin
Self.Cursor := crHourGlass;
end;

If this doesn't work, then there are problems.

After this you can slowly add your code until it stops working.

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Anonymous · 2006-05-24 09:28

Thanks for your fast reply, I've tried with a very simple code and it
works, so I think it isn't a problem of version 9.13 but other.
However, I undestrand the problem is in changing the cursor while the
new form is charged from the main form.

What I want to do is showing the crHourGlass cursor from the moment
the user click the item in the main menu, until the selected form is
really showed.

Aftere a lot of trial, I can say that:

1) If I use the Self.Cursor property (Self is the main form of the
program), the Cursor starts changing only when the the secondary form
is showed (but not from the main form menu's user click);
Application.ProcessMessages unfortunately doesn't solve this problem;

2) If I use the SecondaryForm.Cursor property, nothing happens, I
don't know why;

3) If I use the Screen.Cursor property, nothing happens and this is
very strange.

I have no idea for solve this problem. Have you some advice to help
me?

Thank you very very much.

Best regards,

Stefano

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Anonymous · 2006-05-24 14:41

Quote from: "Anonymous"
3) If I use the Screen.Cursor property, nothing happens and this is
very strange.

same for me. Windows 98, Lazarus 0.9.14

Regards, Bernd.

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Anonymous · 2006-05-26 21:01

I've looked at the Lazarus Bugtracker and, for the Screen.Cursor
problem, I've found it:
http://www.freepascal.org/mantis/view.php?id=1666

However, I've found no Bugtracker for my Form.Cursor problem.

If someone has an idea for changing the cursor during the time
necessary for showing the form, I will be grateful. Else I wait the
Screen.Cursor bug will be resolved.

In any case a great thanks to all who have replied to this topic, and
to all the Lazarus's staff, I appreciate Lazarus very much and I'm
satisfaied to have leave Delphi for Lazarus.

Best regards and sorry for my bad English,

Stefano

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g-r-g · 2006-05-27 11:09

Quote from: "Anonymous"2) If I use the SecondaryForm.Cursor property,
nothing happens, I don't know why;

Try something like this:
Code: [Select]procedure TfrmMain.MenuItemFrmSecondaryClick(Sender:
TObject);
var
  i: Integer;
begin
  FrmSecondary.Cursor:=crHourGlass;
  for i:=0 to FrmSecondary.ControlCount-1 do
    FrmSecondary.Controls[i].Cursor:=crHourGlass;
  FrmSecondary.ShowModal;
end;