BlackBerry - Animated Managers

package mypackage;

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.XYEdges;
import net.rim.device.api.ui.component.ButtonField;
import net.rim.device.api.ui.component.LabelField;
import net.rim.device.api.ui.container.HorizontalFieldManager;
import net.rim.device.api.ui.container.MainScreen;
import net.rim.device.api.ui.container.VerticalFieldManager;

public final class MyScreen extends MainScreen
{
	// flag which tells when to animate
	private boolean animating = false;

	// dynamic index for the manager you want to animate
	private int animatePanelNumber = 0;

	// change as you please... top value for moving managers
	private int topForInnerChilds = 10;

    public MyScreen()
    {
        // Set the displayed title of the screen
        setTitle("Moving Managers");


        // get the master central manager. the big deal!
        HorizontalFieldManager masterManager = getMasterManager( 0, 150 );
        add( masterManager );

        // this is a moving manager
        VerticalFieldManager one = getMovingManager( Color.GREEN, 280, 100 );
        masterManager.add( one );

        // this is another moving manager
        VerticalFieldManager two = getMovingManager( Color.RED, 300, 100 );
        masterManager.add( two );

        // add some components inside "one"
        one.add( getDummyChild("I'm a LabelField", Color.GREEN, 0 ) );
        one.add( getDummyChild("Focused LabelField", Color.GRAY, Field.FOCUSABLE ) );

        // place some buttons for moving manager
        add( getButtonsForMovingManagers() );

    }



    /* manager for moving from side to side*/
    private VerticalFieldManager getMovingManager(
    		final int backgroundColor, final int width, final int height )
    {
        VerticalFieldManager manager = new VerticalFieldManager()
        {
        	protected void sublayout(int maxWidth, int maxHeight)
        	{
        		maxWidth = width;
        		maxHeight = height;
        		super.sublayout(maxWidth, maxHeight);
        		setExtent(maxWidth, maxHeight);
        	}
        	protected void paintBackground(Graphics g)
        	{
        		g.setBackgroundColor( backgroundColor );
        		g.clear();
        		super.paintBackground(g);
        	}
        };

        return manager;
    }

    /* change as you please...
     * builds a dummy LabelField fopr showing inside the moving manager */
    private LabelField getDummyChild(
    		String text, final int backgroundColor, long style )
    {
        LabelField child = new LabelField( text, style )
        {
        	protected void paintBackground(Graphics g)
        	{
        		g.setBackgroundColor( backgroundColor );
        		g.clear();
        		super.paintBackground(g);
        	}
        };
        child.setMargin( new XYEdges( 3, 3, 3, 3 ) );

        return child;
    }

    /* change as you please...
     * these are button for selecting different managers */
    private HorizontalFieldManager getButtonsForMovingManagers()
    {
        HorizontalFieldManager managerButtons = new HorizontalFieldManager(
        		USE_ALL_WIDTH | FIELD_HCENTER );

        // activates manager 1
        ButtonField button = new ButtonField(" 1 ")
        {
        	protected boolean navigationUnclick(int status, int time)
        	{
        		animatePanelNumber = 0;
        		animating = true;
        		return true;
        	}
        };
        managerButtons.add( button );

        // activates manager 2
        button = new ButtonField(" 2 ")
        {
        	protected boolean navigationUnclick(int status, int time)
        	{
        		animatePanelNumber = 1;
        		animating = true;
        		return true;
        	}
        };
        managerButtons.add( button );

        return managerButtons;
    }


    /* this is the manager which will do all the work - add this to your screen */
    private HorizontalFieldManager getMasterManager( long style, final int height )
    {
        HorizontalFieldManager manager = new HorizontalFieldManager(
        		Manager.USE_ALL_WIDTH | Manager.FOCUSABLE | Manager.FIELD_HCENTER | style )
        {
        	protected void sublayout(int maxWidth, int maxHeight)
        	{
        		// padding between inner managers
        		int padding = 5;

        		// define manager height
        		maxHeight = height;
        		super.sublayout(maxWidth, maxHeight);
        		setExtent(maxWidth, maxHeight);

        		// move all the childs outside this window
        		int startingHidingLeft = Display.getWidth();
        		for ( int i=0; i < getFieldCount(); i++ )
        		{
        			Field field = getField( i );
        			setPositionChild( field,
        					startingHidingLeft, topForInnerChilds);
        			startingHidingLeft += ( field.getWidth() + padding );
        		}

        		// this is the moving animation thread
        		Thread t = new Thread( new Runnable()
				{
					public void run()
					{
						while ( true )
						{
							if ( animating )
							{
								Field fieldDeseado = getField( animatePanelNumber );

								for ( int i=0; i < getFieldCount(); i++ )
				        		{
									int leftDeseado = ( Display.getWidth() / 2 )
									- ( fieldDeseado.getWidth() / 2 );

			        				Field field = getField( i );

			        				int left = field.getLeft();
			        				int leftDelFieldDeseado = fieldDeseado.getLeft();

			        				if ( leftDelFieldDeseado > leftDeseado )
			        				{
			        					leftDelFieldDeseado --;
			        					left --;

			        				}
			        				else
			        				{
			        					leftDelFieldDeseado ++;
			        					left ++;
			        				}

			        				// animate!
									setPositionChild( field,
											left, topForInnerChilds );

									if ( leftDelFieldDeseado == leftDeseado )
										animating = false;

									// wait...
									try { Thread.sleep( 5 ); } catch (
											Exception e ) {}

									// update screen
									invalidate();
								}

							}
						}

					}
				});
        		t.start();
        	}

        };
        return manager;

    }

}