[SOLVED] How do I change the screen mouse pointer to a busy pointer?

[AMJF]

My project has parts where it taking seconds to achieve a task, but the mouse doesn't change during that time so it looks like the program has frozen.

I used to use busy mouse pointers in Delphi back in the day, but I'm not sure how to change the mouse pointer image in Lazarus.

Can anyone help me on this matter, please?

[wp]

The correct instruction, beginning with Laz 2.0, is the Screen.BeginWaitCursor/EndWaitCursor pair

Code: Pascal  [Select][+][-]

1. procedure TForm1.Button2Click(Sender: TObject);
2. var
3.   i,j: Integer;
4. begin
5.   Screen.BeginWaitCursor;
6.   try
7.     // Execute the time-consuming task here, e.g.
8.     for i := 1 to 1000*1000*1000 do
9.       j := Random(1000);
10.   finally
11.     Screen.EndWaitCursor;
12.   end;
13. end;

In older versions you simply set/reset the Screen.Cursor

Code: Pascal  [Select][+][-]

1. procedure TForm1.Button1Click(Sender: TObject);
2. var
3.   i,j: Integer;
4. begin
5.   Screen.Cursor := crHourglass;
6.   try
7.     // Execute the time-consuming task here, e.g.
8.     for i := 1 to 1000*1000*1000 do
9.       j := Random(1000);
10.   finally
11.     Screen.Cursor := crDefault;
12.   end;
13. end;

The former solution (BeginWaitCursor/EndWaitCursor) has the advantage that it stores the previously used cursor internally so that successive calls always return to the previous state.

[AMJF]

Thanks, wp!

I remember now, that was the old Delphi method, the crHourglass and crDefault.

What about clicks made on controls when in the "BeginWaitCursor" setting? I found that on my old Delphi project, I had to put in extra commands to disable the code that would run otherwise, is that still the case now, or will it ignore clicks?

[wp]

This has nothing to do with the cursor. It depends on whether your code in the tight loop is allowed to handle the message queue. If it is, clicks on other controls are executed as usual. This is not a disadvantage because you could cancel the operation this way:

Code: Pascal  [Select][+][-]

1. var
2.   ClickCounter: Integer = 0;
3.   OperationStopped: Boolean = false;
4.  
5. procedure TForm1.Button1Click(Sender: TObject);
6. var
7.   i,j: Integer;
8. begin
9.   Screen.BeginWaitCursor;
10.   try
11.     OperationStopped := false;
12.     for i := 1 to 1000*1000*1000 do
13.     begin
14.       // Process message loop
15.       if i mod 1000 = 0 then
16.         Application.ProcessMessages;
17.       // Break if stop has been requested by click on other button
18.       if OperationStopped then
19.         break;
20.       // Operation
21.       j := Random(1000);
22.     end;
23.   finally
24.     Screen.EndWaitCursor;
25.   end;
26. end;
27.  
28. procedure TForm1.Button2Click(Sender: TObject);
29. begin
30.   inc(ClickCounter);
31.   Caption := 'Click #' + IntToStr(ClickCounter);
32.   OperationStopped := true;
33. end;