defaultinputmethodhandler.java

有关j2me的很好的例子可以研究一下

/*
 * @(#)DefaultInputMethodHandler.java	1.46 01/08/12
 *
 * 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 java.util.TimerTask;
import java.util.Timer;

import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.TextBox;
import javax.microedition.lcdui.TextField;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Font;

/**
 * A Default implementation of the InputMethodHandler interface.
 */
public class DefaultInputMethodHandler extends InputMethodHandler {
    /**
     * InputMethodClient client that is implemented by TextBox.
     */
    protected InputMethodClient imc;
    /**
     * Text buffer.
     */
    protected char buf[] = new char[2];
    /**
     * Number of characters in the buffer.
     */
    protected int bufLen;
    /**
     * Committed length of editted buffer.
     */
    protected int committedLen;
    /**
     * Max length to fit the client's max length.
     */
    protected int maxLen;
    /**
     * Depository for an event.
     */
    protected int savedEvent;
    /*
     * IDs for supported input modes
     */
    /** The 'none' input mode. */
    protected static final int IM_NONE        = 0;
    /** The 'roman caps' input mode. */
    protected static final int IM_ROMAN_CAPS  = 1;
    /** The 'lowercase roman' input mode. */
    protected static final int IM_ROMAN_SMALL = 2;
    /** The 'numeric' input mode. */
    protected static final int IM_NUMERIC     = 3;
    /** The 'symbol' input mode. */
    protected static final int IM_SYMBOL      = 4;

    /**
     * Default input mode.
     */
    protected int defaultMode;
    /**
     * The number of allowed input modes.
     */
    protected int allowedModesNum;
    /**
     * The set of allowed input modes.
     */
    protected int allowedModes[] = new int[5];
    /**
     * Currrent input mode.
     */
    protected int inputMode;
    /**
     * Next input mode.
     */
    protected int nextInputMode;
    /**
     * InputMode values for supported input modes.
     */
    protected String supportedInputModes[] = {
        "LATIN",
        "LATIN_DIGITS",
    };

    /**
     * Conversion table between this input modes and InputMode's input modes.
     */
    protected Object inputModeConvTable[][] = {
        {"LATIN",              new Integer(IM_ROMAN_CAPS)},
        {"LATIN",              new Integer(IM_ROMAN_SMALL)},
        {"LATIN_DIGITS",       new Integer(IM_NUMERIC)},
        {"LATIN",              new Integer(IM_SYMBOL)},
    };

    /**
     * Current constraint.
     */
    protected int constraint;

    // Key definition for key maps

    /** A special no-op key. */
    protected static final int KEY_NONE   = -1;
    /** The '0' key. */
    protected static final int KEY_NUM0   = 0;
    /** The '1' key. */
    protected static final int KEY_NUM1   = 1;
    /** The '2' key. */
    protected static final int KEY_NUM2   = 2;
    /** The '3' key. */
    protected static final int KEY_NUM3   = 3;
    /** The '4' key. */
    protected static final int KEY_NUM4   = 4;
    /** The '5' key. */
    protected static final int KEY_NUM5   = 5;
    /** The '6' key. */
    protected static final int KEY_NUM6   = 6;
    /** The '7' key. */
    protected static final int KEY_NUM7   = 7;
    /** The '8' key. */
    protected static final int KEY_NUM8   = 8;
    /** The '9' key. */
    protected static final int KEY_NUM9   = 9;
    /** The '*' key. */
    protected static final int KEY_STAR   = 10;
    /** The '#' key. */
    protected static final int KEY_POUND  = 11;
    /** The 'CLR' key. */
    protected static final int KEY_CLEAR  = 100;

    /**
     * Current input table that can be one of the following.
     */
    protected char keyMap[][];

    /**
     * The uppercase roman key map.
     */
    protected char upperRomanKeyMap[][] = {
	{'0'},
	{'1'},
	{'A', 'B', 'C', '2'},
	{'D', 'E', 'F', '3'},
	{'G', 'H', 'I', '4'},
	{'J', 'K', 'L', '5'},
	{'M', 'N', 'O', '6'},
	{'P', 'Q', 'R', 'S', '7'},
	{'T', 'U', 'V', '8'},
	{'W', 'X', 'Y', 'Z', '9'},
	{'\0'},
	{' '}
    };

    /**
     * The lowercase roman key map.
     */
    protected char lowerRomanKeyMap[][] = {
	{'0'},
	{'1'},
	{'a', 'b', 'c', '2'},
	{'d', 'e', 'f', '3'},
	{'g', 'h', 'i', '4'},
	{'j', 'k', 'l', '5'},
	{'m', 'n', 'o', '6'},
	{'p', 'q', 'r', 's', '7'},
	{'t', 'u', 'v', '8'},
	{'w', 'x', 'y', 'z', '9'},
	{'\0'},
	{' '}
    };

    /**
     * The numeric key map.
     * Includes 0-9,*, and space.
     */
    protected char numericKeyMap[][] = {
	{'0'}, 
        {'1'}, 
        {'2'}, 
        {'3'}, 
        {'4'}, 
        {'5'},
	{'6'}, 
        {'7'}, 
        {'8'}, 
        {'9'},
	{'*'},
	{' '}
    };

    /**
     * The phone numeric key map.
     * Includes 0-9,*,#,+.
     */
    protected char phoneNumericKeyMap[][] = {
	{'0'}, 
        {'1'}, 
        {'2'}, 
        {'3'}, 
        {'4'}, 
        {'5'},
	{'6'}, 
        {'7'}, 
        {'8'}, 
        {'9'},
	{'*'},
	{'#', '+'}
    };


    /**
     * Symbol table.
     */
    protected SymbolTable st = new SymbolTable();

    /**
     * The number of symbol_table is designed to be 25 for 5x5 matrix,
     * starting the selection at 12.  But if you have more, the total
     * must be under 36 for 6x6 matrix.  
     */
    protected char symbolTableChars[] = {
        '_',	'$',	'(',	')',	'\\',

        '~',	'"',	'\'',	'/',	'&',

        '*',	'@',	'.',	'?',	'!',

        '#',	'-',	',',	':',	';',

        '%',	'=',	'+',	'<',	'>'};

    /**
     * Default cursor position for the Symbol table.
     */
    protected int defaultSymbolCursorPos = 12;

    /**
     * Boolean indicating whether the current client is returned from
     * the Symbol table or not.
     */
    protected boolean hasSymbolTable = false;

    /**
     * Set the focus of this handler.
     * Overrides InputMethodHandler.setFocus
     *
     * @param focus If True, this handler should take focus
     */
    public void setFocus(boolean focus) {
        /*
         * Note that setFocus() is always called when Display is
         * changed.  
         */
        if (imc == null) {
            return;
        }
        if (focus) {
            if (hasSymbolTable) {
                int mode = nextInputMode();
                if (bufLen > 0) {
                    handleCharInput();
                }
                setInputMode(mode);
		hasSymbolTable = false;
            } else {
                setInputMode(defaultMode);
            }
        } else {
            if (!hasSymbolTable) {
                setInputMode(IM_NONE);
            }
        }
    }

    /**
     * Establish the input method client for this handler.
     * Overrides InputMethodHandler.setInputMethodClient
     *
     * @param imc The input method client
     */
    public void setInputMethodClient(InputMethodClient imc) {
        /*
         * return if the same imc.  this is called when the Symbol
         * table returns.  
         */
        if (this.imc == imc) {
            return;
        }

        // initialize variables
        lastKey = -1;
        lastPos = 0;
        incomposing = false;

        // set the imc specific stuff
        this.imc = imc;

        constraint = imc.getConstraints() & TextField.CONSTRAINT_MASK;

        setConstraint();

        // initialize inputMode and keyMap in case TextBox is
        // invoked from TextField.
        inputMode = defaultMode;

	switch (inputMode) {
	case IM_ROMAN_CAPS:
	    keyMap = upperRomanKeyMap;
	    break;
	case IM_ROMAN_SMALL:
	    keyMap = lowerRomanKeyMap;
	    break;
	case IM_NUMERIC:
	    keyMap = (constraint == TextField.PHONENUMBER) ?
                phoneNumericKeyMap : numericKeyMap;
	    break;
        }
    }

    /**
     * Clear the input method client.
     * Overrides InputMethodHandler.clearInputMethodClient.
     *
     * @param imcToBeCleared The input method client to be cleared
     */
    public void clearInputMethodClient(InputMethodClient imcToBeCleared) {
        if (!hasSymbolTable && imc == imcToBeCleared) {
            imc = null;
        }
    }

    /**
     * Translate the given key code to its index in the key map.
     *
     * @param keyCode The key code of the key pressed
     * @return int The index of the given key code in the key map
     */
    protected int toKeyMapIndex(int keyCode) {
	switch (keyCode) {
        case Canvas.KEY_NUM0:
            return KEY_NUM0;
        case Canvas.KEY_NUM1:
            return KEY_NUM1;
        case Canvas.KEY_NUM2:
            return KEY_NUM2;
        case Canvas.KEY_NUM3:
            return KEY_NUM3;
        case Canvas.KEY_NUM4:
            return KEY_NUM4;
        case Canvas.KEY_NUM5:
            return KEY_NUM5;
        case Canvas.KEY_NUM6:
            return KEY_NUM6;
        case Canvas.KEY_NUM7:
            return KEY_NUM7;
        case Canvas.KEY_NUM8:
            return KEY_NUM8;
        case Canvas.KEY_NUM9:
            return KEY_NUM9;
        case Canvas.KEY_STAR:
            return KEY_STAR;
        case Canvas.KEY_POUND:
            return KEY_POUND;
        case -8:
            return KEY_CLEAR;
	default:
	    return KEY_NONE;
	}
    }

    /**
     * Handle a key pressed event.
     * Overrides InputMethodHandler.keyPressed.
     *