/* * Copyright (C) 2007 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 com.android.internal.util;/** * {@link CharSequence} utility methods. */public class CharSequences {    /**     * Adapts {@link CharSequence} to an array of ASCII (7-bits per character)     * bytes.     *      * @param bytes ASCII bytes     */    public static CharSequence forAsciiBytes(final byte[] bytes) {        return new CharSequence() {            public char charAt(int index) {                return (char) bytes[index];            }            public int length() {                return bytes.length;            }            public CharSequence subSequence(int start, int end) {                return forAsciiBytes(bytes, start, end);            }            public String toString() {                return new String(bytes);            }        };    }    /**     * Adapts {@link CharSequence} to an array of ASCII (7-bits per character)     * bytes.     *     * @param bytes ASCII bytes     * @param start index, inclusive     * @param end index, exclusive     *     * @throws IndexOutOfBoundsException if start or end are negative, if end     *  is greater than length(), or if start is greater than end     */    public static CharSequence forAsciiBytes(final byte[] bytes,            final int start, final int end) {        validate(start, end, bytes.length);        return new CharSequence() {            public char charAt(int index) {                return (char) bytes[index + start];            }            public int length() {                return end - start;            }            public CharSequence subSequence(int newStart, int newEnd) {                newStart -= start;                newEnd -= start;                validate(newStart, newEnd, length());                return forAsciiBytes(bytes, newStart, newEnd);            }            public String toString() {                return new String(bytes, start, length());            }        };    }    static void validate(int start, int end, int length) {        if (start < 0) throw new IndexOutOfBoundsException();        if (end < 0) throw new IndexOutOfBoundsException();        if (end > length) throw new IndexOutOfBoundsException();        if (start > end) throw new IndexOutOfBoundsException();    }    /**     * Compares two character sequences for equality.     */    public static boolean equals(CharSequence a, CharSequence b) {        if (a.length() != b.length()) {            return false;        }        int length = a.length();        for (int i = 0; i < length; i++) {            if (a.charAt(i) != b.charAt(i)) {                return false;            }        }        return true;    }        /**     * Compares two character sequences with API like {@link Comparable#compareTo}.     *      * @param me The CharSequence that receives the compareTo call.     * @param another The other CharSequence.     * @return See {@link Comparable#compareTo}.     */    public static int compareToIgnoreCase(CharSequence me, CharSequence another) {        // Code adapted from String#compareTo        int myLen = me.length(), anotherLen = another.length();        int myPos = 0, anotherPos = 0, result;        int end = (myLen < anotherLen) ? myLen : anotherLen;        while (myPos < end) {            if ((result = Character.toLowerCase(me.charAt(myPos++))                    - Character.toLowerCase(another.charAt(anotherPos++))) != 0) {                return result;            }        }        return myLen - anotherLen;    }}