60 lines
2.7 KiB
Java
60 lines
2.7 KiB
Java
/*
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* Copyright (C) 2023 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package android.graphics.text;
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/** @hide */
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public class GraphemeBreak {
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private GraphemeBreak() { }
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/**
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* Util method that checks if the offsets in given range are grapheme break.
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*
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* @param advances the advances of characters in the given text. It contains the font
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* information used by the algorithm to determine the grapheme break. It's useful
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* when some character is missing in the font. For example, if the smile emoji
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* "0xD83D 0xDE0A" is not found in the font and is displayed as 2 characters.
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* We can't treat it as a single grapheme cluster.
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* @param text the text to be processed.
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* @param start the start offset of the queried range, inclusive.
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* @param end the end offset of the queried range, exclusive.
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* @param isGraphemeBreak the array to receive the result. The i-th element of the
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* array will be set to true if the offset (start + i) is a grapheme
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* break; otherwise, it will be set to false.
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*/
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public static void isGraphemeBreak(float[] advances, char[] text, int start, int end,
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boolean[] isGraphemeBreak) {
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if (start > end) {
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throw new IllegalArgumentException("start is greater than end: start = " + start
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+ " end = " + end);
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}
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if (advances.length < end) {
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throw new IllegalArgumentException("the length of advances is less than end"
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+ "advances.length = " + advances.length
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+ " end = " + end);
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}
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if (isGraphemeBreak.length < end - start) {
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throw new IndexOutOfBoundsException("isGraphemeBreak doesn't have enough space to "
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+ "receive the result, isGraphemeBreak.length: " + isGraphemeBreak.length
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+ " needed space: " + (end - start));
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}
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nIsGraphemeBreak(advances, text, start, end, isGraphemeBreak);
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}
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private static native void nIsGraphemeBreak(float[] advances, char[] text, int start, int end,
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boolean[] isGraphemeBreak);
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}
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