Java tutorial
/* * 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.text.InputType; import android.text.Spannable; import android.view.KeyCharacterMap.KeyData; import android.view.KeyEvent; /** * For dialing-only text entry * <p></p> * As for all implementations of {@link KeyListener}, this class is only concerned * with hardware keyboards. Software input methods have no obligation to trigger * the methods in this class. */ 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, event); 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 & (MetaKeyKeyListener.META_ALT_ON | MetaKeyKeyListener.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; }