How to Make the exxtensible width panel ?

Hello all,

I want to make the extensible width panel in GWT. For example, I have a horizontalPanel that content two others VerticalPanel. I want to that, the horizontalPanel take 100% as width i.e all of the client Window width. And, I want to that, the others tow VerticalPanel takes each 50% of the last HorizontalPanel. Natutaly, I writed the following code:

public class MonPanel1 extends Composite {

private HorizontalPanel hPanel = new HorizontalPanel();

private VerticalPanel vPanel1 = new VerticalPanel();
private VerticalPanel vPanel2 = new VerticalPanel();

public MonPanel1() {
initWidget(hPanel);

setWidth("100%");
hPanel.setWidth("100%");

hPanel.add( vPanel1);
hPanel.add( vPanel2);

int w = Window.getClientWidth();

vPanel1.setWidth("50%");
vPanel2.setWidth("50%");

vPanel1.add(new Button("Panel 1 "));
vPanel2.add(new HTML("Panel 2 "));

vPanel1.addStyleName("dialloma-vPanel1");
vPanel2.addStyleName("dialloma-vPanel2");
hPanel.addStyleName("dialloma-hPanel");
}
}

result is not the one for that I waited. Please, try to execute this code in your own computer.

In the second part, I have tried the following code and the result is now fine:

public class MonPanel1 extends Composite {

private HorizontalPanel hPanel = new HorizontalPanel();

private VerticalPanel vPanel1 = new VerticalPanel();
private VerticalPanel vPanel2 = new VerticalPanel();

public MonPanel1() {
initWidget(hPanel);

setWidth("100%");
hPanel.setWidth("100%");

hPanel.add( vPanel1);
hPanel.add( vPanel2);

int w = Window.getClientWidth();

vPanel1.setWidth(w/2+"px");
vPanel2.setWidth(w/2+"px");

vPanel1.add(new Button("Panel 1 "));
vPanel2.add(new HTML("Panel 2 "));

vPanel1.addStyleName("dialloma-vPanel1");
vPanel2.addStyleName("dialloma-vPanel2");
hPanel.addStyleName("dialloma-hPanel");
}
}

My question is, what is the in the first case i.e my first example. Why I didn't use the synthaxe: vPanel1.setWidth("50%");
I think, it whil be natural if we can use it. Please help me. have a good day

dialloma