How to programmatically set the split position of BorderLayout in GXT? - gwt

Question

I have a border layout set on a widget using Ext-GWT. Is there a way where I can set the 'split' position automatically? Reason being, if the user resizes a control on a page (not necessarily the parent of the one the split widget is in), I'd like to set the split value to a certain percentage value (like 30%). How can this be done?
Here's the existing code:
import com.extjs.gxt.ui.client.Style.LayoutRegion;
import com.extjs.gxt.ui.client.util.Margins;
import com.extjs.gxt.ui.client.widget.ContentPanel;
import com.extjs.gxt.ui.client.widget.LayoutContainer;
import com.extjs.gxt.ui.client.widget.layout.BorderLayout;
import com.extjs.gxt.ui.client.widget.layout.BorderLayoutData;
import com.google.gwt.user.client.Element;
public class BorderLayoutExample extends LayoutContainer {
setSplitPositionTo(float percentage) {
// TODO: How to do this?
}
protected void onRender(Element target, int index) {
super.onRender(target, index);
final BorderLayout layout = new BorderLayout();
setLayout(layout);
setStyleAttribute("padding", "10px");
ContentPanel west = new ContentPanel();
ContentPanel center = new ContentPanel();
//uncomment this section if you dont want to see headers
/*
* west.setHeaderVisible(false);
* center.setHeaderVisible(false);
*/
BorderLayoutData westData = new BorderLayoutData(LayoutRegion.WEST, 150);
westData.setSplit(true);
westData.setCollapsible(true);
westData.setMargins(new Margins(0,5,0,0));
BorderLayoutData centerData = new BorderLayoutData(LayoutRegion.CENTER);
centerData.setMargins(new Margins(0));
add(west, westData);
add(center, centerData);
}
}

Answer 1

This one was fairly tricky
You'll need to get access to a non center layoutdata and widget for the border layout.
(As center is calculated via remaining space).
Then make them available to the setSplitPositionTo method.
In my example I made them members on the class.
In the end my method looks as follows and a call like myBorderLayoutInstance.setPlitPositionTo(0.4f);
works like a charm using the example you provided and this amendment.
BorderLayoutData westData;
ContentPanel west;
void setSplitPositionTo(float percentage) {
westData.setSize(percentage);
Component c = west;
Map<String, Object> state = c.getState();
state.put("size", westData.getSize());
c.saveState();
layout(true);
}