TButton size??
lazarus / 31-LCL

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garlar27 · 2011-05-12 20:00

I'm clueless and hope someone could help me with this one:

   I Have a form which has a public method which receives a string and
an array of string. The method creates as many buttons as elements
array have. Everything works fine.
   Then I wanted have all buttons with the same width: the width of
the button with the longest caption.

   So I did this:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
{_________________________________________________________________
ButtonClick }procedure TFormMensaje.ButtonClick(Sender: TObject);var 
 Msj: string;begin   if Sender is TButton then begin      FResponse :=
(Sender as TButton).Caption; // property FResponse: string;   end;end;
{<--- ButtonClick } function TFormMessage.ShowMsg(const Mssg: string;
const BtnLst: array of string): string;var   i, TheLonger: Integer; 
 B: TButton;begin   Result := '';   TheLonger := 0; 
 SetLength(FBtnLst, High(BtnLst+1)); // property: FBtnLst Array of
TButton    for i := 0 to High(BtnLst) do begin      B :=
TButton.Create(Self);      FBtnLst[i] := B;      { Here I set
properties like parent, position, etc. }      B.OnClick :=
@ButtonClick;      B.Autosize := True;      B.Caption := BtnLst[i];  
  TheLonger := Max(TheLonger, B.With);   end;    for i := 0 to
High(FBtnLst) do begin      FBtnLst[i].AutoSize := FALSE;     
FBtnLst[i].Width := TheLongest;   end;    ShowModal;    Result :=
FResponse;end; 
   The problem with that code is that it always set the width to 75
and not the "real" button's width.

   I did a workaround by doing this
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i    //..... 
 TheLongest := Max(TheLongest, Canvas.TextExtent(B.Caption).cx); 
 //...    //...      FBtnLst[i].Width := TheLongest +
AN_ARBITRARY_MARGIN_CONSTANT;   //...  
   It works but I don't like it because different OS / Themes might
have or need different margins.

   So here comes my question: Does anybody knows a better way to do
it?

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Blaazen · 2011-05-12 21:52

I can't see TheLongest declared.
Code: [Select] for i := 0 to High(BtnLst) do begin 
      B := TButton.Create(Self); 
      FBtnLst<i> := B; 
      { Here I set properties like parent, position, etc. } 
      B.OnClick := @ButtonClick; 
      B.Autosize := True; 
      B.Caption := BtnLst<i>; 
      TheLonger := Max(TheLonger, B.With); 
   end; 
 
   for i := 0 to High(FBtnLst) do begin 
      FBtnLst<i>.AutoSize := FALSE; 
      FBtnLst<i>.Width := TheLongest; 
   end; 
  and probably you had to change [ ] to < > because of this forum.

Otherwise code seems good to me, maybe this problem is widgetset
related. I tried to make TButton with AutoSize=True and to give it
very long Caption and its size was immediately changed.

Oh, maybe I found problem now. You change buttons but the form is
invisible. You call ShowModal at the end. IMO it is the reason.

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garlar27 · 2011-05-13 12:20

Quote from: Blaazen on May 12, 2011, 11:52:18 pmI can't see TheLongest
declared.
Code: [Select] for i := 0 to High(BtnLst) do begin 
      B := TButton.Create(Self); 
      FBtnLst<i> := B; 
      { Here I set properties like parent, position, etc. } 
      B.OnClick := @ButtonClick; 
      B.Autosize := True; 
      B.Caption := BtnLst<i>; 
      TheLonger := Max(TheLonger, B.With); 
   end; 
 
   for i := 0 to High(FBtnLst) do begin 
      FBtnLst<i>.AutoSize := FALSE; 
      FBtnLst<i>.Width := TheLongest; 
   end; 
  and probably you had to change [ ] to < > because of this forum.

Yep, I have to watch my hands from typo "Longer" should be "Longest".
And I forgot about that bracket thing...

Quote from: Blaazen on May 12, 2011, 11:52:18 pmOh, maybe I found
problem now. You change buttons but the form is invisible. You call
ShowModal at the end. IMO it is the reason.

Exactly!! I realized that very quickly and placing the resizing code
in FormShow didn't help. afterwards I tried to access properties and
methods to get the size the button will have when painted tried with
almost any thing that came to my head but I couldn't make it.

If possible I would like to adjust size before showing the form.

My work around is working but it might get me in trouble when using
another theming or OS.

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Blaazen · 2011-05-13 13:48

I think I got it. You need this:
Code: [Select]procedure GetPreferredSize(var PreferredWidth,
PreferredHeight: integer;
                               Raw: boolean = false;
                               WithThemeSpace: boolean = true);
virtual;Simply:
Code: [Select]var w, h: Longint;
begin
...
Button.GetPreferredSize(w, h, false, true);
...and you will have the right width in variable "w" even if the
button is invisible and its size is not changed yet.

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garlar27 · 2011-05-16 15:21

I couldn't make it work  maybe it's due to my old (Lazarus 0.9.28.2)
or my OS (Ubuntu 9.10).

Code: [Select]...
Button := TButton.Create(Self);
Button.Parent := Self;
Button.Autosize := True;
Button.Top := 0;
Button.Left := 0;
Button.Caption  := ACaption;
Button.GetPreferredSize(w, h, false, true);
// Here "w" and "h" values are zero

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Blaazen · 2011-05-16 15:34

This works (Laz. 0.9.31 + Qt):
Code: [Select]var w, h: LongInt;
   Butt: TButton;
begin
  Butt:=TButton.Create(self);
  with Butt do
    begin
      Butt.Parent:=self;
      Butt.Visible:=False;
      Butt.AutoSize:=False;  //regardless if it is False; or True;
      Butt.Caption:='Butt++++++++++++++++++++++';
      Butt.GetPreferredSize(w, h, false, true);
      Form1.Caption:=inttostr(Butt.Width)+' '+inttostr(w);
      Free;
    end;Form title is: "75 186"
75 is the default width, 186

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garlar27 · 2011-05-16 16:44

Thank you Blaazen.

I will try to test it on 0.9.30 + gtk.

I think I won't have problems.