inputmethodhandler.java

有关j2me的很好的例子可以研究一下

/*
 * @(#)InputMethodHandler.java	1.12 01/08/21
 *
 * Copyright (c) 2000-2001 Sun Microsystems, Inc., 901 San Antonio Road,
 * Palo Alto, CA 94303, U.S.A.  All Rights Reserved.
 *
 * Sun Microsystems, Inc. has intellectual property rights relating
 * to the technology embodied in this software.  In particular, and
 * without limitation, these intellectual property rights may include
 * one or more U.S. patents, foreign patents, or pending
 * applications.  Sun, Sun Microsystems, the Sun logo, Java, KJava,
 * and all Sun-based and Java-based marks are trademarks or
 * registered trademarks of Sun Microsystems, Inc.  in the United
 * States and other countries.
 *
 * This software is distributed under licenses restricting its use,
 * copying, distribution, and decompilation.  No part of this
 * software may be reproduced in any form by any means without prior
 * written authorization of Sun and its licensors, if any.
 *
 * FEDERAL ACQUISITIONS:  Commercial Software -- Government Users
 * Subject to Standard License Terms and Conditions
 */
package com.sun.midp.lcdui;

import javax.microedition.lcdui.TextBox;
import javax.microedition.lcdui.TextField;
import com.sun.midp.Configuration;

/**
 * The InputMethod handler.
 */
abstract public class InputMethodHandler {
    /** handle for the current input method handler. */
    private static InputMethodHandler thisIM;
    /**
     * get the input method handler.
     * @return the current input method handler.
     */
    public static InputMethodHandler getInputMethodHandler() {
        if (thisIM != null) {
            return thisIM;
        }
        thisIM = getInputMethodHandlerImpl();
        return thisIM;
    }
    /**
     * get the input handler class.
     * @return handle to input method handlet.
     */
    private static InputMethodHandler getInputMethodHandlerImpl() {
        try {
            String n =
		Configuration.getProperty("com.sun.lcdui.inputMethodHandler");
            if (n != null) {
                Class c = Class.forName(n);
                return (InputMethodHandler) c.newInstance();
            }
            String loc = Configuration.getProperty("microedition.locale");
            if (loc != null) {
                String cls
                    = "com.sun.midp.lcdui.i18n.DefaultInputMethodHandler_";
                while (true) {
                    try {
                        Class c = Class.forName(cls + loc);
                        return (InputMethodHandler) c.newInstance();
                    } catch (Throwable t) {}
                    int pos = loc.lastIndexOf('_');
                    if (pos == -1) {
                        break;
                    } else {
                        loc = loc.substring(0, pos);
                    }
                }
            }
            Class c = 
                Class.forName("com.sun.midp.lcdui.DefaultInputMethodHandler");
            return (InputMethodHandler) c.newInstance();
        } catch (Throwable t) {            
            System.out.println(t);          
	    throw new Error("Textbox input method was not initialized.");
        }
    }

    /**
     * Set the focus on the InputMethod.
     * @param focus true, if now in focus.
     */
    public abstract void setFocus(boolean focus);

    /**
     * Set the InputMethodClient object to the InputMethod.
     * @param imc save the current input method client.
     */
    public abstract void setInputMethodClient(InputMethodClient imc);

    /**
     * Clear the given InputMethodClient object, so it can be garbage
     * collected. Do nothing if the given client is not the one set.
     * @param  imcToBeCleared input method client to be cleared.
     */
    public abstract void clearInputMethodClient(InputMethodClient 
                                                imcToBeCleared);

    /**
     * Called when a key is pressed.
     * @param keyCode The key code of the key that was pressed
     * @return true if the InputMethod consumed the
     * key code.  
     */
    public abstract boolean keyPressed(int keyCode);

    /**
     * Called when a key is released.
     * @param keyCode The key code of the key that was released
     * @return true if the InputMethod consumed the
     * key code.  
     */
    public abstract boolean keyReleased(int keyCode);

    /**
     * Called when a key is repeated.
     * @param keyCode The key code of the key that was repeated
     * @return true if the InputMethod consumed the
     * key code.  
     */
    public abstract boolean keyRepeated(int keyCode);

    /**
     * End the on-going composition.
     */
    public abstract void endComposition();

    /**
     * Return the supported input modes.
     * @return array of strings of supported input modes.
     */
    public abstract String[] supportedInputModes();
}