TEdit.Text already changed when KeyPress is triggered

[daniel_sap]

Hi,
I observe different behaviour on Windows and MacOS when OnKeyPress event is triggered.

On Mac when the event is triggered the Text value is already changed and contains the Key which is pressed.
For example if I see in the edit the text 'Edit1' and then press the 'A' in the OnKeyPress event handler the 'A' is appended to the text. In Windows it is still the old text.

Is there any way to have the old value when key is pressed.

Code: Pascal  [Select][+][-]

1. unit Unit1;
2.  
3. {$mode objfpc}{$H+}
4.  
5. interface
6.  
7. uses
8.   Classes, SysUtils, Forms, Controls, Graphics, Dialogs, StdCtrls;
9.  
10. type
11.  
12.   { TForm1 }
13.  
14.   TForm1 = class(TForm)
15.     Edit1: TEdit;
16.     procedure Edit1KeyPress(Sender: TObject; var Key: char);
17.   private
18.  
19.   public
20.  
21.   end;
22.  
23. var
24.   Form1: TForm1;
25.  
26. implementation
27.  
28. {$R *.lfm}
29.  
30. { TForm1 }
31.  
32. procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: char);
33. begin
34.   ShowMessage(Edit1.Text);
35. end;
36.  
37. end.
38.        

(I'm writing a custom control, so I want to handle it in the TCustomEdit descendant.)
Thanks

Lazarus 4.99 (rev main_4_99-369-g86db8d9f83) FPC 3.2.2 aarch64-darwin-cocoa
I built Lazarus for arm64 by myself. Not sure if this is related to that behaviour

[jamie]

that event requires both the KeyDown and KeyUp so yes, it will be changed already.,.

Use the KeyDown even to make alterations

[Bart]

It's perfectly lega to use OnKeyPress to make changes (e.g. block certain keys).
Only after OnKeyPressed is processed the Text should be updated (e.g. the control should only then receive the key).

This should work as expected:

Code: Pascal  [Select][+][-]

1. procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: char);
2. begin
3.   if not (Key in ['0'..'9'] then
4.     Key := #0
5.   else
6.     //just mess with the user's input for fun
7.     Key := '9';
8. end;

The result should be that whatever you type, it's either rejected, or converted to a '9'.
This can only happen because it's the altered Key that is received by the control, not the original Key.

If this sample code does not work on Cocoa, then that is a bug.

Bart

[jamie]

It's perfectly lega to use OnKeyPress to make changes (e.g. block certain keys).
Only after OnKeyPressed is processed the Text should be updated (e.g. the control should only then receive the key).

This should work as expected:

Code: Pascal  [Select][+][-]

1. procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: char);
2. begin
3.   if not (Key in ['0'..'9'] then
4.     Key := #0
5.   else
6.     //just mess with the user's input for fun
7.     Key := '9';
8. end;

The result should be that whatever you type, it's either rejected, or converted to a '9'.
This can only happen because it's the altered Key that is received by the control, not the original Key.

If this sample code does not work on Cocoa, then that is a bug.

Bart

You are correct, Sorry.
Jamie

[daniel_sap]

It's perfectly lega to use OnKeyPress to make changes (e.g. block certain keys).
Only after OnKeyPressed is processed the Text should be updated (e.g. the control should only then receive the key).

This should work as expected:
Code: Pascal  [Select]

procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: char);
begin
  if not (Key in ['0'..'9'] then
    Key := #0
  else
    //just mess with the user's input for fun
    Key := '9';
end;

The result should be that whatever you type, it's either rejected, or converted to a '9'.
This can only happen because it's the altered Key that is received by the control, not the original Key.

If this sample code does not work on Cocoa, then that is a bug.

Bart

This is not working on MacOS. The text is changed prior to KeyPress execution and the Key is not used after that for updating the Text.
Even SelStart and SelLength are already updated

Code: Pascal  [Select][+][-]

1. unit MainForm;
2.  
3. {$mode objfpc}{$H+}
4.  
5. interface
6.  
7. uses
8.   Classes, SysUtils, Forms, Controls, Graphics, Dialogs, StdCtrls;
9.  
10. type
11.  
12.   { TForm1 }
13.  
14.   TForm1 = class(TForm)
15.     Edit1: TEdit;
16.     Memo1: TMemo;
17.     procedure Edit1KeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);
18.     procedure Edit1KeyPress(Sender: TObject; var Key: char);
19.     procedure Edit1KeyUp(Sender: TObject; var Key: Word; Shift: TShiftState);
20.   private
21.  
22.   public
23.  
24.   end;
25.  
26. var
27.   Form1: TForm1;
28.  
29. implementation
30.  
31. {$R *.lfm}
32.  
33. { TForm1 }
34.  
35. procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: char);
36. begin
37.   Memo1.Lines.Add('Key press: ' + Edit1.Text);
38.   if not (Key in ['0'..'9']) then
39.     Key := #0
40.   else
41.     //just mess with the user's input for fun
42.     Key := '9';
43.   Memo1.Lines.Add(Format('Selection SelStart: %d, SelCount: %d', [Edit1.SelStart, Edit1.SelLength]));
44. end;
45.  
46. procedure TForm1.Edit1KeyUp(Sender: TObject; var Key: Word; Shift: TShiftState);
47. begin
48.   Memo1.Lines.Add('Key Up: ' + Edit1.Text);
49. end;
50.  
51. procedure TForm1.Edit1KeyDown(Sender: TObject; var Key: Word; Shift: TShiftState
52.   );
53. begin
54.   Memo1.Lines.Add('Key down: ' + Edit1.Text);
55. end;
56.  
57. end.
58.  

[Bart]

@daniel_sap: Which version of Lazarus are you using?

If you are not using Lazarus main (4.99) could you try that?
If the issue is present on Lazarus main, then you should file a bugreport.

Since I don't have access to a Mac, I cannot reporduce this issue myself.

Bart

[daniel_sap]

@daniel_sap: Which version of Lazarus are you using?

If you are not using Lazarus main (4.99) could you try that?
If the issue is present on Lazarus main, then you should file a bugreport.

Since I don't have access to a Mac, I cannot reporduce this issue myself.

Bart

I'm with Lazarus 4.99 (rev main_4_99-369-g86db8d9f83) FPC 3.2.2 aarch64-darwin-cocoa (I built Lazarus for arm64)
Not latest commit. ASAP will try to pull latest changes and try again