BlackBerry Tooltips

import net.rim.device.api.system.Bitmap;
import net.rim.device.api.system.Display;
import net.rim.device.api.ui.Color;
import net.rim.device.api.ui.Field;
import net.rim.device.api.ui.Graphics;
import net.rim.device.api.ui.Manager;
import net.rim.device.api.ui.UiApplication;
import net.rim.device.api.ui.XYEdges;
import net.rim.device.api.ui.component.*;
import net.rim.device.api.ui.container.*;

public class StartApp extends UiApplication
{
    public StartApp()
    {
        pushScreen( new ScreenTest() );
    }
    public static void main(String[] args) {
        StartApp fanwards = new StartApp();
        fanwards.enterEventDispatcher();
    }

}

class ScreenTest extends MainScreen
{
    // ** need to access these from everywhere
    VerticalFieldManager scroll;
    Bitmap bitmapTooltip1 = Bitmap.getBitmapResource("tooltip1.png");
    Bitmap bitmapTooltip2 = Bitmap.getBitmapResource("tooltip2.png");
    boolean paintTooltip1 = false;
    boolean paintTooltip2 = false;

    public ScreenTest()
    {
        // ** this is the container manager
        VerticalFieldManager container = new VerticalFieldManager(
                Manager.NO_VERTICAL_SCROLL )
        {
            protected void sublayout(int maxWidth, int maxHeight) {
                maxHeight = Display.getHeight() - 10;
                super.sublayout(maxWidth, maxHeight);
                setExtent(maxWidth, maxHeight);
            }
        };
        add( container );

        // ** fixed manager for not-moving title bar
        VerticalFieldManager fixed = new VerticalFieldManager(
                Manager.NO_VERTICAL_SCROLL )
        {
            protected void paintBackground(Graphics g) {
                g.setBackgroundColor( Color.RED );
                g.clear();
                super.paintBackground(g);
            }
            protected void sublayout(int maxWidth, int maxHeight) {
                maxHeight = 40;
                super.sublayout(maxWidth, maxHeight);
                setExtent(maxWidth, maxHeight);
            }
        };
        container.add( fixed );

        // ** this manager will hold some menu buttons
        HorizontalFieldManager hButtons= new HorizontalFieldManager();
        fixed.add( hButtons );

        // ** buttons on the fixed manager
        ButtonField button1 = new ButtonField("Menu 1", Field.FOCUSABLE )
        {
            protected void onFocus(int direction) {
                paintTooltip1 = true;
                scroll.invalidate();
                super.onFocus(direction);
            }
            protected void onUnfocus() {
                paintTooltip1 = false;
                scroll.invalidate();
                super.onUnfocus();
            }
        };
        button1.setPadding( new XYEdges(5, 5, 5, 5) );
        hButtons.add( button1 );

        ButtonField button2 = new ButtonField("Menu 2", Field.FOCUSABLE )
        {
            protected void onFocus(int direction) {
                paintTooltip2 = true;
                scroll.invalidate();
                super.onFocus(direction);
            }
            protected void onUnfocus() {
                paintTooltip2 = false;
                scroll.invalidate();
                super.onUnfocus();
            }
        };
        button2.setPadding( new XYEdges(5, 5, 5, 5) );
        hButtons.add( button2 );

        ButtonField button3 = new ButtonField("No menu", Field.FOCUSABLE )
        {
            protected void onFocus(int direction) {
                paintTooltip1 = false;
                paintTooltip2 = false;
                scroll.invalidate();
                super.onFocus(direction);
            }
        };
        hButtons.add( button3 );


        // ** scroll manager (with anything inside) and some negative top margin
        scroll = new VerticalFieldManager(
                Manager.USE_ALL_WIDTH | Manager.VERTICAL_SCROLL )
        {
            protected void paint(Graphics g) {

                super.paint(g);

                if ( paintTooltip1 )
                    g.drawBitmap(5, 5, bitmapTooltip1.getWidth(),
                        bitmapTooltip1.getHeight(), bitmapTooltip1, 0, 0);

                if ( paintTooltip2 )
                    g.drawBitmap(90, 5, bitmapTooltip2.getWidth(),
                        bitmapTooltip2.getHeight(), bitmapTooltip2, 0, 0);
            }
        };
        container.add( scroll );

        // ** add some buttons just for showing something
        for ( int i=0; i<10; i++ ) {
            ButtonField button = new ButtonField("Button: " + i );
            scroll.add( button );
        }


    }
}