xref: /frameworks/base/core/java/android/text/AndroidCharacter.java

/*
 * 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;

/**
 * AndroidCharacter exposes some character properties that are not
 * easily accessed from java.lang.Character.
 */
public class AndroidCharacter
{
    public static final int EAST_ASIAN_WIDTH_NEUTRAL = 0;
    public static final int EAST_ASIAN_WIDTH_AMBIGUOUS = 1;
    public static final int EAST_ASIAN_WIDTH_HALF_WIDTH = 2;
    public static final int EAST_ASIAN_WIDTH_FULL_WIDTH = 3;
    public static final int EAST_ASIAN_WIDTH_NARROW = 4;
    public static final int EAST_ASIAN_WIDTH_WIDE = 5;

    /**
     * Fill in the first <code>count</code> bytes of <code>dest</code> with the
     * directionalities from the first <code>count</code> chars of <code>src</code>.
     * This is just like Character.getDirectionality() except it is a
     * batch operation.
     */
    public native static void getDirectionalities(char[] src, byte[] dest,
                                                  int count);

    /**
     * Calculate the East Asian Width of a character according to
     * <a href="http://unicode.org/reports/tr11/">Unicode TR#11</a>. The return
     * will be one of {@link #EAST_ASIAN_WIDTH_NEUTRAL},
     * {@link #EAST_ASIAN_WIDTH_AMBIGUOUS}, {@link #EAST_ASIAN_WIDTH_HALF_WIDTH},
     * {@link #EAST_ASIAN_WIDTH_FULL_WIDTH}, {@link #EAST_ASIAN_WIDTH_NARROW},
     * or {@link #EAST_ASIAN_WIDTH_WIDE}.
     *
     * @param input the character to measure
     * @return the East Asian Width for input
     */
    public native static int getEastAsianWidth(char input);

    /**
     * Fill the first <code>count</code> bytes of <code>dest</code> with the
     * East Asian Width from <code>count</code> chars of <code>src</code>
     * starting at <code>start</code>. East Asian Width is calculated based on
     * <a href="http://unicode.org/reports/tr11/">Unicode TR#11</a>. Each entry
     * in <code>dest</code> will be one of {@link #EAST_ASIAN_WIDTH_NEUTRAL},
     * {@link #EAST_ASIAN_WIDTH_AMBIGUOUS}, {@link #EAST_ASIAN_WIDTH_HALF_WIDTH},
     * {@link #EAST_ASIAN_WIDTH_FULL_WIDTH}, {@link #EAST_ASIAN_WIDTH_NARROW},
     * or {@link #EAST_ASIAN_WIDTH_WIDE}.
     *
     * @param src character array of input to measure
     * @param start first character in array to measure
     * @param count maximum number of characters to measure
     * @param dest byte array of results for each character in src
     */
    public native static void getEastAsianWidths(char[] src, int start,
                                                 int count, byte[] dest);

    /**
     * Replace the specified slice of <code>text</code> with the chars'
     * right-to-left mirrors (if any), returning true if any
     * replacements were made.
     *
     * @param text array of characters to apply mirror operation
     * @param start first character in array to mirror
     * @param count maximum number of characters to mirror
     * @return true if replacements were made
     */
    public native static boolean mirror(char[] text, int start, int count);

    /**
     * Return the right-to-left mirror (or the original char if none)
     * of the specified char.
     */
    public native static char getMirror(char ch);
}