How to use ScrollPanel with relative size

Question

I\'m trying to use a ScrollPanel of GWT in a page. Since most of the contents are in the ScrollPanel, I want it to take an as-large-as-possible part of the page and resize a

Answer 1

First, ScrollPanel is something not acting as other widget for reason I don't know why. Cannot set relative size (50%), and if I give it some style, it's lost somewhere and cannot be found from page.

My solution is to use a ResizeLayoutPanel. Andrei suggested using something ProvidesResize but requires the provide / require resize chain remain unbroken, which can be very tricky. I found this ResizeLayoutPanel "ProvidesResize to its one child, but does not RequiresResize", which is the perfect candidate for the root panel of my composite. Then, I just extend the ScrollPanel to resize itself in the "onResize" method whenever it's called by the parent ResizeLayoutPanel.

Still no answer to my first question: by ScrollPanel behave like this in the first place? I tried to find answer in its source code but was not successful (though I didn't spend enough time studying the source code).

public class My100PctScrollPanel extends ScrollPanel {
    @Override
    public void onResize() {
        // Window.alert("on resize"); 
        this.setWidth(this.getParent().getOffsetWidth()+"px");
        this.setHeight(this.getParent().getOffsetHeight()+"px");
        super.onResize();
    }
}

........

compositeRoot = new ResizeLayoutPanel();  

........
scrollPanel = new My100PctScrollPanel();
compositeRoot.clear();
compositeRoot.add(scrollPanel);