TEdit.NumbersOnly take two

[atlatl]

I want an edit field that only accepts numbers.

Started off with TEdit with the NumbersOnly property set...no luck; I can type anything into it.

Found a few takes on numbers-only filter statements; same result.

Read the previous thread about this topic:[https://forum.lazarus.freepascal.org/index.php/topic,51549.msg378499.html#msg378499], tried the suggested solution - TSpinEdit; again same result.

Finally found this in the wiki: LCL Key Handling [https://wiki.lazarus.freepascal.org/LCL_Key_Handling]. It sounds like it might be the solution to the issue. Has anybody translated it to working Pascal code? I haven't got clue where to begin.

Thanks,
Harv

[Zvoni]

Use OnKeyPress-Eventhandler

Code: Pascal  [Select][+][-]

1. procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: char);
2. begin
3.   If Not ((Ord(key)>=48) And (Ord(Key)<=57) Or (Ord(Key)=8)) Then Key:=Char('');
4. end;          

No decimal separators, no +/- signs. Digits Only

Note: This doesn't defend from Copy/Pasting into the Edit

[egsuh]

It's strange. I cannot type in other characters than numbers, if NumberOnly is set true. On Windows 10 (and afterwards, possibly).

Of course I can assign other text directly to TEdit control, like:

         Edit1.Text := 'abcde';

[Zvoni]

It's strange. I cannot type in other characters than numbers, if NumberOnly is set true. On Windows 10 (and afterwards, possibly).

Of course I can assign other text directly to TEdit control, like:

         Edit1.Text := 'abcde';

https://lazarus-ccr.sourceforge.io/docs/lcl/stdctrls/tcustomedit.numbersonly.html

NumbersOnly is not supported on all platform for the LCL; GTK 2 does not support the property.
....
Remark:      NumbersOnly is not supported for the GTK2 or GTK3 widgetset.

[Ally]

Have a look at this.

https://forum.lazarus.freepascal.org/index.php/topic,53352.msg394615.html#msg394615

I think this component could solve your problems.

[atlatl]

Thanks to all who responded.

I'm thinking I may not have been clear enough that the issue was with the Cocoa widgetset.

@Zvoni: Nice, concise code, but it doesn't work in my case 😞.

Remark:      NumbersOnly is not supported for the GTK2 or GTK3 widgetset.

Nor, does it seem, is it supported fo Cocoa.

@Ally: Thanks, I'll take a look at it.

[atlatl]

This is what I finally came up with:

Code: Pascal  [Select][+][-]

1. FUNCTION IsAnInteger(pIntStr: String): Boolean;
2.   VAR
3.     sInt: Integer;
4.   BEGIN
5.     Result:= True;
6.     TRY
7.       sInt:= StrToInt(pIntStr);
8.     EXCEPT
9.       Result:= False;
10.     END;
11.   END;
12.  
13. PROCEDURE TForm1.Timer1Timer(Sender: TObject);
14.   BEGIN
15.     IF Form1.SpinEdit1.Text <> '' THEN
16.       IF Not IsAnInteger(Form1.SpinEdit1.Text) THEN
17.         BEGIN
18.           Form1.SpinEdit1.Text:= '';
19.         END;
20.   END;
21.  

Perhaps not the most elegant code, but it does the job.
I set the timer to 1/10 second, so it's responsive enough.
It can be used with any edit control.
It handles pasted text.
It _should_ work with any widgetset.

[wp]

Code: Pascal  [Select][+][-]

1. FUNCTION IsAnInteger(pIntStr: String): Boolean;
2.   VAR
3.     sInt: Integer;
4.   BEGIN
5.     Result:= True;
6.     TRY
7.       sInt:= StrToInt(pIntStr);
8.     EXCEPT
9.       Result:= False;
10.     END;
11.   END;

I'd prefer to use TryStrToInt which does not raise an exception and thus does not interrupt your work in the IDE (even when caught in the "except" part):

Code: Pascal  [Select][+][-]

1. FUNCTION IsAnInteger(pIntStr: String): Boolean;
2. VAR
3.   sInt: Integer;
4. BEGIN
5.   Result := TryStrToInt(pIntStr, sInt);
6. END;

[atlatl]

Thanks wp, I'd never seen 'TryStrToInt' until now.

I'd prefer to use TryStrToInt which does not raise an exception and thus does not interrupt your work in the IDE (even when caught in the "except" part):

Code: Pascal  [Select][+][-]

1. FUNCTION IsAnInteger(pIntStr: String): Boolean;
2. VAR
3.   sInt: Integer;
4. BEGIN
5.   Result := TryStrToInt(pIntStr, sInt);
6. END;

[AlexTP]

TATSynEdit gives the TATEdit subclass (single line), which has OptInputNumberOnly property. Leading minus is allowed by OptInputNumberAllowNegative property.