Sizing a TRadioGroup at runtime
lazarus / 10-Designer

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Bart · 2007-03-12 13:48

Hi,

For a new component I'm designing, I create a TRadioGroup at runtime
and place it on a panel.
Now the radiogroup holds two items in two columns.
The item "captions"  are resource strings as is the RadioGroup's
caption. These then may be altered by translations.

Now I want to "sculpt" the RadioGroup so that is is as small as
possible (widht, height), whilst ensuring that all captions are still
readable.

So, I thougth: I need to know the width and height of each item,
including the radiobutton, the height of the radiogroup.caption etc,
all OS independent.
This is where I get stuck.
TRadioGroup AFAIK provides no info about that.

Anybody got some suggestions as on how to approach this?

Bart

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antonio · 2007-03-30 01:06

Your idea is interesting... You have Canvas.TextHeight and
Canvas.TextWidth to measure the strings.

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Bart · 2007-04-15 15:35

But TRadioGroup has no canvas...
I decided to use 2 radiobuttons and a bevel instead. This works fine
for me right now.

Bart

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antonio · 2007-04-22 12:09

Maybe the ancestor has Canvas property protected.

  type
    trg = class(tcustomradiogroup)
  end;

var
  rg:trg;

implementation

procedure TForm1.FormCreate(Sender: TObject);
var
  i :integer;
begin
  rg := trg.create(self);
  rg.align := alleft;
  rg.parent := form1;
  rg.caption := 'custom_radio_group';
  rg.items.add('one');
  rg.items.add('two');
  rg.items.add('threeeeeeeeeeeeeeeeeee');
  rg.items.add('four');
  rg.items.add('five');
  rg.items.add('six');
  rg.items.add('seven');
  rg.width := 40 + rg.canvas.textwidth(rg.items[0]);
  for i := 1 to rg.items.count -1 do
      if (40 + rg.canvas.textwidth(rg.items) > rg.width) then
         rg.width := 40 + rg.canvas.textwidth(rg.items);
end;

procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  rg.free;
end;