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How to handle keystrokes in a J2ME GUI application

I have programmed bluetooth Television-Remote control for mobile phones in J2ME using javax.microedition.lcdui.*

(Gauge, List, ChoiseGroup) GUI-Elements.

I want the cell phone to have real-time interaction with my TV, I would like to find a way to immediately send custom inputs made with GUI-Elements (like change channel or change volume) to the TV.

Since I require real-time interaction with my TV, I would like to find a way to immediately send custom inputs made with GUI-Elements (like change channel or change volume) to the TV.

Using javax.microedition.lcdui.Command

/ CommandListner

and commandAction

won't work as they have to recognize the commands selected with the side buttons. I would like to have something that can recognize any key pressed.

I found I Javax.microedition.lcdui.Canvas.keyPressed

can handle any key pressed on a mobile, but I don't know how to get Canvas to work with MIDP GUI elements like Gauge. They cannot be added as Commands.

Should I figure out a way to create an interface for these GUI elements to make them work with Canvas?

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4 answers


I found half the solution myself, in case anyone is interested: "Javax.microedition.lcdui.ItemStateListener". This function can handle states (or state changes) of GUI elements in real time. Its not keyPress, but this will work for my application too.



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According to this FAQ, you cannot do what you ask for. This is for MIDP 1.0, but I believe this also applies to MIDP 2.0. If you only need a pressure gauge, you can easily draw one yourself.



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From what I've seen, this can only be done with Canvas .

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I highly recommend that you either draw your gauge-like object to a Canvas object or follow the guidelines outlined on Dec 19 at 15:00 "zhengtonic". I don't know any other approach to this problem, I was there but used the first options provided by me

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