[news.eclipse.platform.swt] Re: Composite update problem

["Veronika Irvine" <veronika_irvine@xxxxxxx>]

If you are using 3.1, the following should work for you:

shell.layout(composite_child.getChildren());

If you know exactly which children have changed to can also do:

shell.layout(new Control[] {child1, child2, child5});

If you are not in 3.1, you need to know a bit about the parents between the 
shell and composite_mother.  If there is a parent that does not change size, 
then the chain of layouts trigerred by shell.layout() will stop at the first 
parent that does not resize.  For example, if you have a parent that is in a 
FillLayout, the only time that parent will change size is when its parent 
gets bigger - it will not resize just because one of its children changed 
its preferred size.  If you have identified any parents like that in the 
parent heirarchy of composite_child, then you must call layout() on that 
parent.

For example:


public static void main (String [] args) {
        Display display = new Display ();
        final Shell shell = new Shell (display);
        FillLayout layout = new FillLayout();
        layout.marginWidth = layout.marginHeight = 5;
        shell.setLayout(layout);

        final Composite c1 = new Composite(shell, SWT.BORDER);
        c1.setBackground(display.getSystemColor(SWT.COLOR_GREEN));
        layout = new FillLayout();
        layout.marginWidth = layout.marginHeight = 5;
        c1.setLayout(layout);

        final Composite c2 = new Composite(c1, SWT.BORDER);
        c2.setBackground(display.getSystemColor(SWT.COLOR_BLUE));
        c2.setLayout(new GridLayout(2, false));

        Composite c3 = new Composite(c2, SWT.BORDER);
        c3.setBackground(display.getSystemColor(SWT.COLOR_CYAN));
        c3.setLayout(new GridLayout(2, false));
        for (int i = 0; i < 10; i++) {
                Button b = new Button(c3, SWT.PUSH);
                b.setText("c3 "+i);
        }

        final Composite c4 = new Composite(c2, SWT.BORDER);
        c4.setBackground(display.getSystemColor(SWT.COLOR_RED));
        c4.setLayout(new GridLayout(5, false));
        Button b = new Button(c4, SWT.PUSH);
        b.setText("CLICK HERE");
        b.addListener(SWT.Selection, new Listener() {
                int index = 0;
                public void handleEvent(Event e) {
                        Button b = new Button(c4, SWT.PUSH);
                        b.setText("c4 "+index++);
                        // In 3.1, you can do:
                        //shell.layout(new Control[] {b});

                        // In 3.0 you must do the following (also works in 
3.1)
                        c2.layout();
                        c4.layout();
                        // both are needed
                        // c2.layout is required if red area needs to grow.
                        // c4.layout is needed because sometimes c4 does not 
change size
                        // (add buttons to existing row) but the new button 
still need to
                        // be displayed

                        // Note: calling shell.layout() or c1.layout() has 
no effect
                        // here because the children in the FillLayout do 
not change size.

                }
        });
        shell.setSize(400, 400);
        shell.open ();
        while (!shell.isDisposed ()) {
                if (!display.readAndDispatch ()) display.sleep ();
        }
        display.dispose ();
}



"Marco Kohns" <mek@xxxxxxxxxxxx> wrote in message 
news:d4qn8p$5n2$1@xxxxxxxxxxxxxxxxxxx
> Hello everybody,
>
> i have a composite_mother and inside that a toolbar (with two toolitems) 
> and another composite_child. When I press one of the toolitems, the 
> composite_child changes its content. But I can only see that when I resize 
> the window of the application.
>
> What I've tried so far:
>
> composite_child.layout()
> composite_mother.layout()
> shell.layout
> shell.update
> composite_mother.pack()
> composite_child.pack()
>
> But without success...
>
> Thanks for any help!
>