Java Development

[rampelotti]

Hello Experts!

I have some problems when i try to change my background.

Well the problem is the performance, i have a menu that i likely to change my background image when i set focus on any button, for example when i focus the button settings i likely to show a picture with shafts,,, when i focused the button called start i like to change the background some landscape.

Well, i do it when my button receive the focus, to update layout to change the background, but it's so unperformed

Somebody can help me?

Regards, Ronaldo. 

[chengbang69]

perhaps post a few line of codes so we can see how you are doing it

[laliux]

How you are creating the background? BackgroundFactory ?

[rampelotti]

Hello chengbang69!

here some lines of my code:

...
// Auxiliar class to load images to memory
public class Utils {
         public static final Background backs[] = new Background[] {
		BackgroundFactory.createBitmapBackground(Bitmap.getBitmapResource("about.gif"))
	 };
}
...

At Main Screen:
...
        link = new ButtonField("About", _caret) {
	        protected void onFocus(int direction) {
	        background = Utils.backs[0];
                UiApplication.getUiApplication().invokeLater(new Runnable(){
	          public void run() {
		          updateLayout();
		  }
	         });
	        super.onFocus(direction);
	     }
	};
	link.setChangeListener(new FieldChangeListener() {
		public void fieldChanged(Field field, int context) {
			UiApplication.getUiApplication().pushScreen(new AboutScreen());
		}
	});

...
protected void sublayout(int width, int height) {
		super.sublayout(width, height);
		getMainManager().setBackground(background);

	}
...

 Well, i hope that helps.

 Regards, Rampelotti

[rampelotti]

Hello laliux!

Thank for reply, so i´m use BackgroundFactory, you can see how i use it on the last reply.

I´m waiting for some help..

Regards, Rampelotti.

[geeneeus]

You will need to lock the event thread (temporarily) when invoking a method from a different thread.

(EDIT: This only applies to when updating the GUI, you do not need to lock the event thread when you do other operations.)

REMEMBER: Only lock the event thread for a very short time as it can lock up the application.

Here is the sample:

synchronized(Application.getEventLock()){
	updateLayout();
}

Hope this helps!

[rampelotti]

Hello geeneeus!

Thanks for reply.

I will test this tip and post my results later.

Regards, Rampelotti.

[ekke]

in my NavigatorScreen I'm doing something similar using some focusable bitmaps.

and if a bitmap gets focus I simply do

getMainManager().setBackground(xxx)

works great - no performance problem

ekke

[laliux]

I'm using the following code to replace a background,

FocusChangeListener focusChangeListener = new FocusChangeListener(){
   public void focusChanged(Field field, int eventType) {
     if(eventType == FocusChangeListener.FOCUS_GAINED){
        ClipartButtonField bgButton = (ClipartButtonField) field;
					
        Bitmap bitmapBackground = Bitmap.getBitmapResource(bgButton.getClipartName());
					
        Background background =  BackgroundFactory.createBitmapBackground(bitmapBackground, 0, 0, Background.REPEAT_BOTH);
					

//Custom method for getting the Manager to apply new Bg
getMainManager().setBackground(background);
getMainManager().invalidate();

				}
			}
			
		};

I'm not using invokeLater() or sublayout() methods. I hope this help.

Greetings

[rampelotti]

Hi geeneeus...

So, i have done what you said but doesn´t  increased my performance, then it´s not the solution for me yet.

Do you have more suggestion.

Regards, Rampelotti