Lazarus

Programming => General => Topic started by: Ramses on March 05, 2021, 02:46:20 pm

Title: How to prevent text to be selected in tedit?
Post by: Ramses on March 05, 2021, 02:46:20 pm

Hi!

I have a tedit that i use to show information, and i dont want the user to be able to select/copy text in it, is there an easy way to do that without disabled it (because the disable function gray out the text)?

Or maybe its more easier to replace the tedit by a label?

Thanks

Title: Re: How to prevent text to be selected in tedit?
Post by: ASerge on March 05, 2021, 02:48:54 pm

Quote from: Ramses on March 05, 2021, 02:46:20 pm

Or maybe its more easier to replace the tedit by a label?

Yes

Title: Re: How to prevent text to be selected in tedit?
Post by: Ramses on March 05, 2021, 03:13:02 pm

alright, i was thinking that there was an option somewhere to do that, but if there is no easy way to do that i will replace every tedit with labels..

thanks for yiour answer

Title: Re: How to prevent text to be selected in tedit?
Post by: winni on March 05, 2021, 05:11:34 pm

Hi!

If you prefer TEdit:

It has a property ReadOnly.
Setting this to true is disabling any changes.

Winni

Title: Re: How to prevent text to be selected in tedit?
Post by: Ramses on March 05, 2021, 05:54:12 pm

Quote from: winni on March 05, 2021, 05:11:34 pm

Hi!

If you prefer TEdit:

It has a property ReadOnly.
Setting this to true is disabling any changes.

Winni

read only prevent any change but dont prevent from select/copy text, so i used the label instead

Title: Re: How to prevent text to be selected in tedit?
Post by: Warfley on March 05, 2021, 06:09:36 pm

Also possible, disable the edit, this will "gray it out"

Code: Pascal  [Select][+][-]

1. MyEdit.Enabled := False;

But it will also disable all events and possibly (I don't know right now) also disable updating the control, so you might need to temporary enable it to write stuff into it

Title: Re: How to prevent text to be selected in tedit?
Post by: winni on March 05, 2021, 06:24:42 pm

Quote from: Warfley on March 05, 2021, 06:09:36 pm

Also possible, disable the edit, this will "gray it out"

Code: Pascal  [Select][+][-]

1. MyEdit.Enabled := False;

But it will also disable all events and possibly (I don't know right now) also disable updating the control, so you might need to temporary enable it to write stuff into it

He does not want that!

Try to read again!

Title: Re: How to prevent text to be selected in tedit?
Post by: wp on March 05, 2021, 07:19:08 pm

Could not yet find a way to prevent selecting by a double-click, but when you catch the keyboard events, at least OnKeyDown, and disable it (Key := 0) then the user cannot enter anything any more. Also pasting from the clipboard by pressing CTRL+V is disable this way.  You could also disable selecting by dragging the mouse when you call Abort in the OnMouseMove event:

Code: Pascal  [Select][+][-]

1. procedure TForm1.Edit1KeyDown(Sender: TObject; var Key: Word; Shift: TShiftState
2.   );
3. begin
4.   Key := 0;
5. end;
6.  
7. procedure TForm1.Edit1Click(Sender: TObject);
8. begin
9.   Abort;
10. end;
11.  
12. procedure TForm1.Edit1MouseMove(Sender: TObject; Shift: TShiftState; X,
13.   Y: Integer);
14. begin
15.   Abort;
16. end;

Title: Re: How to prevent text to be selected in tedit?
Post by: Bart on March 05, 2021, 08:13:33 pm

Quote from: wp on March 05, 2021, 07:19:08 pm

Could not yet find a way to prevent selecting by a double-click,

On double click set SelLength to zero?

All this of course is a hack.

Bart

Title: Re: How to prevent text to be selected in tedit?
Post by: wp on March 05, 2021, 09:58:00 pm

Yes, I thought if that. But the selection goes away and comes back again. Strange...

Title: Re: How to prevent text to be selected in tedit?
Post by: jamie on March 05, 2021, 11:46:48 pm

This may work cross platform wise, I can't say but anyways, this will reject a copy paste operation. It may look and feel like its taking place but it gets rejected..

 Also you can replace the popup menu for the edit with a dummy one, that way the system's menu does not come up either..

I can't say if this works well in Lazarus across the board but it something I've done in Delphi...

You need to set the variable to TRUE to reject the operation... otherwise it behaves normally..

This only works per unit/Form page.. of course..

Code: Pascal  [Select][+][-]

1. unit Unit1;
2.  
3. {$mode objfpc}{$H+}
4.  
5. interface
6.  
7. uses
8.   Windows,Classes, SysUtils, Forms, Controls, Graphics, Dialogs, StdCtrls;
9.  
10. type
11.  
12.   { TForm1 }
13. TEDIT = Class(stdCtrls.TEDIT)
14.   procedure HandlePaste(Var Msg:TMessage); Message WM_Paste;
15.   procedure HandleCopy(Var Msg:TMessage); Message WM_Copy;
16.   Public
17.    RejectClipBoardOperations:Boolean;
18. end;
19.  
20.   TForm1 = class(TForm)
21.     Edit1: TEdit;
22.   private
23.  
24.   public
25.   end;
26.  
27. var
28.   Form1: TForm1;
29.  
30. implementation
31.  
32. {$R *.lfm}
33.  
34. { TForm1 }
35. Procedure TEdit.HandleCopy(Var msg:TMessage);
36. Begin
37.   if rejectClipBoardOperations Then
38.      Msg.Result := 1 else Inherited;
39. end;
40.  
41. Procedure TEdit.HandlePaste(Var Msg:TMessage);
42. Begin
43.   If rejectClipboardOperations Then
44.             Msg.Result := 1 Else Inherited;
45. end;
46.  
47. end.
48.  
49.  

Don't forget to set the variable at runtime somewhere on the EDITS you want this behavior..