Parent & Child Node with different images & Clickable Event - Treeview Blackberry

Parent & Child Node with different images & Clickable Event - Treeview
Blackberry

I am using tree view in app to show the client server data in blackberry.
Same thing i chieved in android app by using expanable listview items. But
here i facing two issues
One is:
I want to add parent node icone like a folder icon & Child node must have
different icone For example if Parent item is images then child nodes must
have Images icon, if parent item is video Then child have video icons.
Second:
When i click on any child node(Like image child node), This node open in
new screen & show the clickable item wether i click on image, video.
Here is my code that i used to Get the desired result:
package mypackage;
import net.rim.device.api.system.Bitmap;
import net.rim.device.api.ui.Font;
import net.rim.device.api.ui.FontFamily;
import net.rim.device.api.ui.Graphics;
import net.rim.device.api.ui.component.TreeField;
import net.rim.device.api.ui.component.TreeFieldCallback;
class CustomTreeFieldCallback implements TreeFieldCallback {
public void drawTreeItem(TreeField _tree, Graphics g, int node,
int y,
int width, int indent) {
// FontFamily
FontFamily fontFamily[] = FontFamily.getFontFamilies();
Font font = fontFamily[1].getFont(FontFamily.CBTF_FONT, 18);
g.setFont(font);
String text = (String) _tree.getCookie(node);
Bitmap b = Bitmap.getBitmapResource("images.png");
g.drawText(text, indent + b.getWidth(), y);
g.drawBitmap(indent, y - 15, b.getWidth(), b.getHeight(), b,
0, 0);
}
}
package mypackage;
import net.rim.device.api.system.Bitmap;
import net.rim.device.api.ui.Field;
import net.rim.device.api.ui.component.TreeField;
import net.rim.device.api.ui.container.MainScreen;
import net.rim.device.api.ui.decor.Background;
import net.rim.device.api.ui.decor.BackgroundFactory;
public class FilesManager extends MainScreen {
public FilesManager() {
// Set the linear background.
Bitmap background = Bitmap.getBitmapResource("background.png");
Background bg =
BackgroundFactory.createBitmapBackground(background);
this.getMainManager().setBackground(bg);
String parentNode = new String("Images");
String firstChild = new String("first child");
String secondChild = new String("second child");
String thirdChild = new String("third child");
CustomTreeFieldCallback myCallback = new
CustomTreeFieldCallback();
myTree = new TreeField(myCallback, Field.FOCUSABLE);
int node2 = myTree.addChildNode(0, parentNode);
myTree.addChildNode(node2, firstChild);
myTree.addChildNode(node2, secondChild);
myTree.addChildNode(node2, thirdChild);
add(myTree);
}
}
I also attached the screenShot that i make in android. Any one give me
guideline to achieve this thing in bb.
Attached Image: http://postimg.org/image/m3owjfl8h/