How get widget width, after it's drawed ?

[Michał Zakrzewski]

Hi,

I need take VLayout width, but first I must know that it's drawed. How I can check this and get width value after ?

[Jens]

The safest thing to do is to use Scheduler.get().scheduleDeferred() inside Widget.onLoad() or Widget.addAttachHandler(). This will schedule a command that is slightly delayed so that the browser has enough time to render everything. Then you can read height/width values.

Widget.isAttached() is also available but it only tells you that the widget is attached to the DOM and not if its correctly rendered yet.

-- J.

[Michał Zakrzewski]

I have that code in my app

Scheduler.get().scheduleDeferred(new Scheduler.ScheduledCommand() {

@Override

public void execute() {

try {

answerPanelHeight = display.getAnswerPanel().getOffsetHeight();

display.getNextButtonPanel().setHeight(answerPanelHeight);

display.getNextButtonPanel().redraw();

} catch (Exception e) {

}

}

});

What argument I must add in Widget.addAttachHandler() ? Because I use SmartGwt and i dont have method onLoad();

[Jens]

panel.addAttachHandler(new AttachEvent.Handler() {

  public void onAttachOrDetach(AttachEvent event) {

    if(event.isAttached()) {

       //scheduler here

    }

  }

});

Widget.onLoad() is protected so you need to override it in sub classes or implement it anonymously.

-- J.

[Michał Zakrzewski]

Thanks for your help, but my problem is still not resolved. Sometimes I have good value, sometimes not...

[Paul Stockley]

Try this method that uses ComputedStyle. I couldn't be bothered to optimize it with deferred binding so it does some runtime checks.

static public native String getComputedStyleProperty(Element el, String property) /*-{

        if (window['getComputedStyle']) { // W3C DOM method

    if (property === 'float')

    property = 'cssFloat';

            var value = el.style[property], computed;

            if (!value) {

                computed = el['ownerDocument']['defaultView']['getComputedStyle'](el, null);

                if (computed) { // test computed before touching for safari

                    value = computed[property];

                }

            }

            return value;

        } else if (el['currentStyle']) {

            var value;

            switch(property) {

                case 'opacity' :// IE opacity uses filter

                    value = 100;

                    try { // will error if no DXImageTransform

                        value = el.filters['DXImageTransform.Microsoft.Alpha'].opacity;

                    } catch(e) {

                        try { // make sure its in the document

                            value = el.filters('alpha').opacity;

                        } catch(err) {

                        }

                    }

                    return value / 100;

                case 'float': // fix reserved word

                    property = 'styleFloat'; // fall through

                default:

                    value = el['currentStyle'] ? el['currentStyle'][property] : null;

                    return ( el.style[property] || value );

            }

        }

        return "";

}-*/;

[Sanjiv Jivan]

Since you're using SmartGWT, use addDrawHandler(..). The callback gets invoked after the widget is rendered.

vLayout.addDrawHandler(new DrawHandler() {

    @Override

    public void onDraw(DrawEvent drawEvent) {

        ..

    }

})

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