1 /* 2 * Copyright (C) 2023 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package android.graphics.text; 18 19 /** @hide */ 20 @android.ravenwood.annotation.RavenwoodKeepWholeClass 21 public class GraphemeBreak { GraphemeBreak()22 private GraphemeBreak() { } 23 24 /** 25 * Util method that checks if the offsets in given range are grapheme break. 26 * 27 * @param advances the advances of characters in the given text. It contains the font 28 * information used by the algorithm to determine the grapheme break. It's useful 29 * when some character is missing in the font. For example, if the smile emoji 30 * "0xD83D 0xDE0A" is not found in the font and is displayed as 2 characters. 31 * We can't treat it as a single grapheme cluster. 32 * @param text the text to be processed. 33 * @param start the start offset of the queried range, inclusive. 34 * @param end the end offset of the queried range, exclusive. 35 * @param isGraphemeBreak the array to receive the result. The i-th element of the 36 * array will be set to true if the offset (start + i) is a grapheme 37 * break; otherwise, it will be set to false. 38 */ isGraphemeBreak(float[] advances, char[] text, int start, int end, boolean[] isGraphemeBreak)39 public static void isGraphemeBreak(float[] advances, char[] text, int start, int end, 40 boolean[] isGraphemeBreak) { 41 if (start > end) { 42 throw new IllegalArgumentException("start is greater than end: start = " + start 43 + " end = " + end); 44 } 45 if (advances.length < end) { 46 throw new IllegalArgumentException("the length of advances is less than end" 47 + "advances.length = " + advances.length 48 + " end = " + end); 49 } 50 if (isGraphemeBreak.length < end - start) { 51 throw new IndexOutOfBoundsException("isGraphemeBreak doesn't have enough space to " 52 + "receive the result, isGraphemeBreak.length: " + isGraphemeBreak.length 53 + " needed space: " + (end - start)); 54 } 55 nIsGraphemeBreak(advances, text, start, end, isGraphemeBreak); 56 } 57 nIsGraphemeBreak(float[] advances, char[] text, int start, int end, boolean[] isGraphemeBreak)58 private static native void nIsGraphemeBreak(float[] advances, char[] text, int start, int end, 59 boolean[] isGraphemeBreak); 60 } 61