Android example source code file (DialerKeyListener.java)

This example Android source code file (DialerKeyListener.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

android, characters, dialerkeylistener, keydata, n, numberkeylistener, override, spannable, text, ui, view

The DialerKeyListener.java Android example source code

/*
 * Copyright (C) 2006 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.text.method;

import android.view.KeyEvent;
import android.view.KeyCharacterMap.KeyData;
import android.text.InputType;
import android.text.Spannable;

/**
 * For dialing-only text entry
 */
public class DialerKeyListener extends NumberKeyListener
{
    @Override
    protected char[] getAcceptedChars()
    {
        return CHARACTERS;
    }

    public static DialerKeyListener getInstance() {
        if (sInstance != null)
            return sInstance;

        sInstance = new DialerKeyListener();
        return sInstance;
    }

    public int getInputType() {
        return InputType.TYPE_CLASS_PHONE;
    }
    
    /**
     * Overrides the superclass's lookup method to prefer the number field
     * from the KeyEvent.
     */
    protected int lookup(KeyEvent event, Spannable content) {
        int meta = getMetaState(content);
        int number = event.getNumber();

        /*
         * Prefer number if no meta key is active, or if it produces something
         * valid and the meta lookup does not.
         */
        if ((meta & (KeyEvent.META_ALT_ON | KeyEvent.META_SHIFT_ON)) == 0) {
            if (number != 0) {
                return number;
            }
        }

        int match = super.lookup(event, content);

        if (match != 0) {
            return match;
        } else {
            /*
             * If a meta key is active but the lookup with the meta key
             * did not produce anything, try some other meta keys, because
             * the user might have pressed SHIFT when they meant ALT,
             * or vice versa.
             */

            if (meta != 0) {
                KeyData kd = new KeyData();
                char[] accepted = getAcceptedChars();

                if (event.getKeyData(kd)) {
                    for (int i = 1; i < kd.meta.length; i++) {
                        if (ok(accepted, kd.meta[i])) {
                            return kd.meta[i];
                        }
                    }
                }
            }

            /*
             * Otherwise, use the number associated with the key, since
             * whatever they wanted to do with the meta key does not
             * seem to be valid here.
             */

            return number;
        }
    }


    /**
     * The characters that are used.
     *
     * @see KeyEvent#getMatch
     * @see #getAcceptedChars
     */
    public static final char[] CHARACTERS = new char[] {
            '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '#', '*',
            '+', '-', '(', ')', ',', '/', 'N', '.', ' ', ';'
        };

    private static DialerKeyListener sInstance;
}