Hi guys, I've been making a MigLayout for Fantom and I've ran into some difficulties.

Here is my problem. I'm trying to debug my MigPane and in order to do so I need to have comparable data (I'm comparing existing SWT implementation with my fwt implementation). So I did a little test.

This is size and computeSize in SWT:

//some operations
Composite parent ...
Label label1 = new Label(parent, SWT.NONE)
label.setText("First Name")
//more operations 
System.out.println(label1.getSize());
System.out.println(label1.computeSize(-1,-1));

//////////////////////////////////////////
// Output
//////////////////////////////////////////
(57,15)
(57,15)

This is size and prefSize in fwt:

//some operations
label2 := Label{text="First Name"}
w := Window {label2,}.open
//more operations 
echo(label2.size)
echo(label2.prefSize)
//////////////////////////////////////////
// Output
//////////////////////////////////////////
(116,21)
(0,0)

So the discrepancy between these two don't worry me, however what does worry me is the fact that prefSize returns just (0,0). Could you guys look into this issue?

PS. I tried to replace some instances of prefSize with size, but the problem is that when I call my computeSize method from the MigLayout's source file, the size is 0,0 as well.

PSS. Also the behavior between Widget varies (for example TextField has default pref for 230,0) in SWT I think all Widgets have both dimensions pre-assigned.

SWT Widget routes prefSize to SWT computeSize (look in WidgetPeer.java). Although keep in mind that a Fantom widgets isn't always bound to its Control (as a work around to SWT requiring the parent during construction).

Still, it seems to be Label never gets any prefSize (even after being displayed on a Window), while others get only a dimension. Couldn't Label and other calculate their size based on number of letters or something? I'll have to see with Mikael, if this is the real culprit.

What happens to the prefSize when the widget has been added to a visible window? This may be caused by the SWT widget not being created yet.

What happens to the prefSize when the widget has been added to a visible window? This may be caused by the SWT widget not being created yet.

If a widget isn't mounted in the SWT then prefSize will be 0,0. So it is really only meaningful during the layout cycle handled by relayout (which Fantom controls separately from SWT). Often things like Labels need to mounted anyhow to figure out their font metrics, etc.

Ok, brian got a question. How can I delay layout until my components prefSize is something usable (both h and w are different than 0 )? If I feed the MiGLayout engine something with zeroes in it, it will just display it weirdly.

Hi Daniel,

If you want it work inside FWT work, you have to follow FWT layout model which requires you to subclass from fwt::Pane and do your layout inside the onLayout callback. See:

• docs
• InsetPane code
• EdgePane code

If a widget isn't mounted in the SWT then prefSize will be 0,0.

This doesn't apply to all widgets. For instance.

fansh> t:=Text{}
fan.fwt.Text@641e9a
fansh> t.prefSize
230,0

If you want it work inside FWT work, you have to follow FWT layout model which requires you to subclass from fwt::Pane and do your layout inside the onLayout callback.

I did do my layout in onLayout and my MigPane had Widget[] constrainsWidget. I'll try to add few more checks.

BTW is there a way to make a map that has a mutable keys? I need a Widget:Obj? map but there isn't a way to make it.

Ok, I managed to make to "fix" it. I have no clue why this works as it does. But I'd like Fantom's community help in testing out and discovering bugs.

Here is the link https://bitbucket.org/DanielFath/migpane to repository.

Few more questions:

• When making it serializable do I need to have my own each method if I added some new additions?
• Is it possible to compile it into JavaScript using @JS annotations even if it contains code in a /java folder?

Is it possible to compile it into JavaScript using @JS annotations even if it contains code in a /java folder

If your code requires peer implementations - then yes you will need to provide appropriate JS versions. If you have pure Fantom code, then those classes will work just fine without them.

Also - looks like your repo might not be public?

Ah, ok tnx. Does that still stand in case my code uses Java FFI (I call MiGLayout from my code)?

Also sorry about that. It's open now.

Cool - took a quick look at your code - looks like you depend on the Java impl of some of the Mig stuff. If you were interested in getting MigPane to work in JS (which I assume thats what you were asking?) - you would really need to write the complete implementation in Fantom.

There is no way to serialize the MigPane send it to MiGLayout for calculations and then deserialize it to JavaScript?

You could do that if you wanted - but relayout gets called alot (remember this is all built and run client-side) - so practically speaking you wouldn't want to block on network requests each time you needed to relayout.