Graphics and touch events in Blackberry? - events

Question

finally I got the idea how to handle touch and gestures events on Blackberry, but now I have 2 questions:
1)how to render graphics above another graphis while being able to handle touch events?
2)how to draw simple rectangle on touch event, say CLICK?
My code & screen:
package mypackage;
import net.rim.device.api.lcdui.game.BlackBerryGameCanvas;
import net.rim.device.api.system.Bitmap;
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.TouchGesture;
import net.rim.device.api.ui.VirtualKeyboard;
import net.rim.device.api.ui.component.LabelField;
import net.rim.device.api.ui.component.Menu;
import net.rim.device.api.ui.container.MainScreen;
import net.rim.device.api.ui.container.VerticalFieldManager;
import net.rim.device.api.ui.TouchEvent;
public class MyScreen extends MainScreen
{
LabelField touch_type;
public boolean onMenu(int instance) {
return instance == Menu.INSTANCE_CONTEXT ? false : super.onMenu(instance);
}
public MyScreen()
{
super(NO_SYSTEM_MENU_ITEMS);
getScreen().getVirtualKeyboard().setVisibility(VirtualKeyboard.HIDE_FORCE);
VerticalFieldManager vf = new VerticalFieldManager();
touch_type = new LabelField("SOME TEXT", FIELD_HCENTER);
vf.add(touch_type);
vf.add(new HandleTouch());
add(vf);
}
/*
* Implementing touch handler class
*/
class HandleTouch extends Field {
protected void layout(int width, int height) {
setExtent(360, 460);
}
public void paint(Graphics graphics) {
graphics.drawBitmap(0, 0, this.getWidth(), this.getHeight(), Bitmap.getBitmapResource("bg.png"), 0, 0);
}
protected void drawFocus(Graphics g, boolean on) {}
public boolean isFocusable() { return true;}
public void drawBall(int x, int y) {
}
protected boolean touchEvent(TouchEvent message) {
switch( message.getEvent() ) {
case TouchEvent.CLICK:
int x = message.getGlobalX(1);
int y = message.getGlobalY(1);
touch_type.setText("CLICK");
return true;
case TouchEvent.DOWN:
//System.out.println("----------------------------->DOWN");
touch_type.setText("DOWN");
return true;
case TouchEvent.MOVE:
//System.out.println("----------------------------->MOVE");
touch_type.setText("MOVE");
return true;
case TouchEvent.UNCLICK:
//System.out.println("----------------------------->UNCLICK");
touch_type.setText("UNCLICK");
return true;
case TouchEvent.GESTURE:
TouchGesture gesture = message.getGesture();
int gestureCode = gesture.getEvent();
switch (gestureCode) {
case TouchGesture.HOVER:
//System.out.println("----------------------------->HOVER");
touch_type.setText("HOVER");
return true;
case TouchGesture.SWIPE:
//System.out.println("----------------------------->SWIPE");
touch_type.setText("SWIPE");
return true;
case TouchGesture.TAP:
//System.out.println("----------------------------->TAP");
touch_type.setText("TAP");
return true;
case TouchGesture.CLICK_REPEAT:
//System.out.println("----------------------------->CLICK REPEAT");
touch_type.setText("CLICK REPEAT");
return true;
case TouchGesture.DOUBLE_TAP:
//System.out.println("----------------------------->DOUBLE TAP");
touch_type.setText("DOUBLE TAP");
return true;
}
}
//System.out.println("PRINT ME SOMETHING IN ANY CASE");
super.touchEvent(message);
return false;
}
public HandleTouch() {
}
}
}

Answer 1

1.) I'm not sure what the question actually is. Can you rephrase it or give an example? I'll update this answer once there's something I can figure out.
2.) Just set a flag on the DOWN event, save the touch coordinates, call invalidate(), and in your paint method check for said flag and if it exists draw the rectangle at/around your coordinates. On the UP event unset the flag, call invalidate(), and you will remove the rectangle.