[SOLVED] Autosize - How to know size before show?

[Dibo]

Hi,

I have problem with autosize. I am reading documentation of this property but can't find solution. I have this situtation (this is only example, in my form is more controls with autosize):

Form1.Autosize = True;
Label1.AutoSize = True;
Label1.Align = alTop;

When I change caption in Label1, form width is "fit" to this size. This is ok, but new form width is calculated only when I make it visible. How do I know final form width before show?

Regards.

[Blaazen]

I made a few experimetns and I have no idea how to do it in convenient way. 

Only thing that work for me is this crazy method:

Code: [Select]

  Form2.Show;
  Form2.Close;
  Caption:=inttostr(Form2.Width);    //now it has final size   

Show and Close is sooooo fast .....   

[Martin_fr]

it's somewhere on the wiki.

forms autosize only ONCE.

To autosize a form a 2nd time, set Form.Autosize to False, and then back to true again.

You must do this, each time you need the autosize.
---

The reason: under Linux some Windowmanager do interfere with autosize... search the wiki, read the full story there

[Blaazen]

http://wiki.lazarus.freepascal.org/Autosize_/_Layout#AutoSize_and_Forms

But seems not work for invisible forms at least here on Qt.

[zeljko]

I don't use autosize for forms, but again,don't understand what does not work with qt ? afaik, it does not matter if form is visible or not. Open an issue about it and attach example.

[Blaazen]

OK. I opened issue http://bugs.freepascal.org/view.php?id=18775. When you say that invisible forms should be resized than it is probably bug.

[Dibo]

it's somewhere on the wiki.

forms autosize only ONCE.

To autosize a form a 2nd time, set Form.Autosize to False, and then back to true again.

You must do this, each time you need the autosize.

This doesn't work on linux (GTK). I try read more about this

[Dibo]

@Blaazen. Mattias Gaertner post nice trick in your issue. This code solve my problem and return me final form width without showing it:

Form1.HandleNeeded;
Form1.GetPreferredSize(W,H);