Java Development

[mreed]

We have a ListField inside of a scrollable Manager, and on OS 7 we are not able to scroll through the ListField using touch events or the trackpad. The selected row changes, however the Manager does not scroll vertically when a row off the screen becomes selected.

The ScrollChangeListener is not even being called.

Any ideas?

I'm seeing this on the OS 7.0.0.218 9930 simulator.

[tommy20]

Can you post the code here?

[mreed]

I cannot. I'm just looking to see if anyone else has had similiar issues on OS 7. It is fine on earlier version.

[tommy20]

You may want to use SimpleList, RichList, or TableView instead.

[nag]

did u tried with

super(VERTICAL_SCROLL);

Thank u

[tommy20]

This simple code just works perfectly on the 9930 simulator (OS 7.0.0.218). So, this confirm that your problem is from your code, not from the OS or simulator.

import java.util.Vector;

import net.rim.device.api.system.Display;
import net.rim.device.api.ui.Graphics;
import net.rim.device.api.ui.component.ListField;
import net.rim.device.api.ui.component.ListFieldCallback;
import net.rim.device.api.ui.container.MainScreen;

public final class MyScreen extends MainScreen implements ListFieldCallback {
	Vector v = new Vector();
	public MyScreen() {
		for(int i = 1; i <= 50; i++){
			v.addElement("Item " + i);
		}
		
		ListField l = new ListField();
		l.setCallback(this);
		l.setSize(v.size());
		add(l);
	}

	public void drawListRow(ListField listField, Graphics g, int index, int y, int width) {
		if (index > -1 && index < v.size()) {
			g.drawText((String)v.elementAt(index), 4, y + 2, 0, width);
		}
	}

	public Object get(ListField listField, int index) {
		if (index > -1 && index < v.size()) {
			return v.elementAt(index);
		}
		return null;
	}

	public int getPreferredWidth(ListField listField) {
		return (Display.getWidth());
	}

	public int indexOfList(ListField listField, String prefix, int start) {
		return (-1);
	}
}

[dnepr]

If your scrollable manager overrides sublayout I would look in there. Make sure virtual extent is set to a proper value.

I have the same concept as you do, list field inside a scrollable manager and it works fine on all OS7 sims/devices.

Hope that helps.

[mreed]

Thanks. It is a large custom Manager/List, so I guess I'll just start commenting out sections to see what is affected.

[hendrik]

---

dnepr wrote:
If your scrollable manager overrides sublayout I would look in there. Make sure virtual extent is set to a proper value.

---

Good advice! Just tried and changed this in a manager of my own: In the sublayout method I first set the extent to the minimum of the available height and my used height, which might exceed the available height, then I set the virtual extent to my used height. Works perfectly!

[mreed]

The virtual height is fine:  height[386], virtualHeight[170462]