| /* |
| * Copyright (c) 2000, 2003, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * (C) Copyright IBM Corp. 1999-2000 - All Rights Reserved |
| * |
| * The original version of this source code and documentation is |
| * copyrighted and owned by IBM. These materials are provided |
| * under terms of a License Agreement between IBM and Sun. |
| * This technology is protected by multiple US and International |
| * patents. This notice and attribution to IBM may not be removed. |
| */ |
| |
| package sun.font; |
| |
| import java.text.Bidi; |
| |
| public final class BidiUtils { |
| |
| |
| |
| /** |
| * Return the level of each character into the levels array starting at start. |
| * This is a convenience method for clients who prefer to use an explicit levels |
| * array instead of iterating over the runs. |
| * |
| * @param levels the array to receive the character levels |
| * @param start the starting offset into the the array |
| * @throws IndexOutOfBoundsException if <code>start</code> is less than 0 or |
| * <code>start + getLength()</code> is greater than <code>levels.length</code>. |
| */ |
| public static void getLevels(Bidi bidi, byte[] levels, int start) { |
| int limit = start + bidi.getLength(); |
| |
| if (start < 0 || limit > levels.length) { |
| throw new IndexOutOfBoundsException("levels.length = " + levels.length + |
| " start: " + start + " limit: " + limit); |
| } |
| |
| int runCount = bidi.getRunCount(); |
| int p = start; |
| for (int i = 0; i < runCount; ++i) { |
| int rlimit = start + bidi.getRunLimit(i); |
| byte rlevel = (byte)bidi.getRunLevel(i); |
| |
| while (p < rlimit) { |
| levels[p++] = rlevel; |
| } |
| } |
| } |
| |
| /** |
| * Return an array containing the resolved bidi level of each character, in logical order. |
| * @return an array containing the level of each character, in logical order. |
| */ |
| public static byte[] getLevels(Bidi bidi) { |
| byte[] levels = new byte[bidi.getLength()]; |
| getLevels(bidi, levels, 0); |
| return levels; |
| } |
| |
| static final char NUMLEVELS = 62; |
| |
| /** |
| * Given level data, compute a a visual to logical mapping. |
| * The leftmost (or topmost) character is at visual index zero. The |
| * logical index of the character is derived from the visual index |
| * by the expression <code>li = map[vi];</code>. |
| * @param levels the levels array |
| * @return the mapping array from visual to logical |
| */ |
| public static int[] createVisualToLogicalMap(byte[] levels) { |
| int len = levels.length; |
| int[] mapping = new int[len]; |
| |
| byte lowestOddLevel = (byte)(NUMLEVELS + 1); |
| byte highestLevel = 0; |
| |
| // initialize mapping and levels |
| |
| for (int i = 0; i < len; i++) { |
| mapping[i] = i; |
| |
| byte level = levels[i]; |
| if (level > highestLevel) { |
| highestLevel = level; |
| } |
| |
| if ((level & 0x01) != 0 && level < lowestOddLevel) { |
| lowestOddLevel = level; |
| } |
| } |
| |
| while (highestLevel >= lowestOddLevel) { |
| int i = 0; |
| for (;;) { |
| while (i < len && levels[i] < highestLevel) { |
| i++; |
| } |
| int begin = i++; |
| |
| if (begin == levels.length) { |
| break; // no more runs at this level |
| } |
| |
| while (i < len && levels[i] >= highestLevel) { |
| i++; |
| } |
| int end = i - 1; |
| |
| while (begin < end) { |
| int temp = mapping[begin]; |
| mapping[begin] = mapping[end]; |
| mapping[end] = temp; |
| ++begin; |
| --end; |
| } |
| } |
| |
| --highestLevel; |
| } |
| |
| return mapping; |
| } |
| |
| /** |
| * Return the inverse position map. The source array must map one-to-one (each value |
| * is distinct and the values run from zero to the length of the array minus one). |
| * For example, if <code>values[i] = j</code>, then <code>inverse[j] = i</code>. |
| * @param values the source ordering array |
| * @return the inverse array |
| */ |
| public static int[] createInverseMap(int[] values) { |
| if (values == null) { |
| return null; |
| } |
| |
| int[] result = new int[values.length]; |
| for (int i = 0; i < values.length; i++) { |
| result[values[i]] = i; |
| } |
| |
| return result; |
| } |
| |
| |
| /** |
| * Return an array containing contiguous values from 0 to length |
| * having the same ordering as the source array. If this would be |
| * a canonical ltr ordering, return null. The data in values[] is NOT |
| * required to be a permutation, but elements in values are required |
| * to be distinct. |
| * @param values an array containing the discontiguous values |
| * @return the contiguous values |
| */ |
| public static int[] createContiguousOrder(int[] values) { |
| if (values != null) { |
| return computeContiguousOrder(values, 0, values.length); |
| } |
| |
| return null; |
| } |
| |
| /** |
| * Compute a contiguous order for the range start, limit. |
| */ |
| private static int[] computeContiguousOrder(int[] values, int start, |
| int limit) { |
| |
| int[] result = new int[limit-start]; |
| for (int i=0; i < result.length; i++) { |
| result[i] = i + start; |
| } |
| |
| // now we'll sort result[], with the following comparison: |
| // result[i] lessthan result[j] iff values[result[i]] < values[result[j]] |
| |
| // selection sort for now; use more elaborate sorts if desired |
| for (int i=0; i < result.length-1; i++) { |
| int minIndex = i; |
| int currentValue = values[result[minIndex]]; |
| for (int j=i; j < result.length; j++) { |
| if (values[result[j]] < currentValue) { |
| minIndex = j; |
| currentValue = values[result[minIndex]]; |
| } |
| } |
| int temp = result[i]; |
| result[i] = result[minIndex]; |
| result[minIndex] = temp; |
| } |
| |
| // shift result by start: |
| if (start != 0) { |
| for (int i=0; i < result.length; i++) { |
| result[i] -= start; |
| } |
| } |
| |
| // next, check for canonical order: |
| int k; |
| for (k=0; k < result.length; k++) { |
| if (result[k] != k) { |
| break; |
| } |
| } |
| |
| if (k == result.length) { |
| return null; |
| } |
| |
| // now return inverse of result: |
| return createInverseMap(result); |
| } |
| |
| /** |
| * Return an array containing the data in the values array from start up to limit, |
| * normalized to fall within the range from 0 up to limit - start. |
| * If this would be a canonical ltr ordering, return null. |
| * NOTE: This method assumes that values[] is a logical to visual map |
| * generated from levels[]. |
| * @param values the source mapping |
| * @param levels the levels corresponding to the values |
| * @param start the starting offset in the values and levels arrays |
| * @param limit the limiting offset in the values and levels arrays |
| * @return the normlized map |
| */ |
| public static int[] createNormalizedMap(int[] values, byte[] levels, |
| int start, int limit) { |
| |
| if (values != null) { |
| if (start != 0 || limit != values.length) { |
| // levels optimization |
| boolean copyRange, canonical; |
| byte primaryLevel; |
| |
| if (levels == null) { |
| primaryLevel = (byte) 0x0; |
| copyRange = true; |
| canonical = true; |
| } |
| else { |
| if (levels[start] == levels[limit-1]) { |
| primaryLevel = levels[start]; |
| canonical = (primaryLevel & (byte)0x1) == 0; |
| |
| // scan for levels below primary |
| int i; |
| for (i=start; i < limit; i++) { |
| if (levels[i] < primaryLevel) { |
| break; |
| } |
| if (canonical) { |
| canonical = levels[i] == primaryLevel; |
| } |
| } |
| |
| copyRange = (i == limit); |
| } |
| else { |
| copyRange = false; |
| |
| // these don't matter; but the compiler cares: |
| primaryLevel = (byte) 0x0; |
| canonical = false; |
| } |
| } |
| |
| if (copyRange) { |
| if (canonical) { |
| return null; |
| } |
| |
| int[] result = new int[limit-start]; |
| int baseValue; |
| |
| if ((primaryLevel & (byte)0x1) != 0) { |
| baseValue = values[limit-1]; |
| } else { |
| baseValue = values[start]; |
| } |
| |
| if (baseValue == 0) { |
| System.arraycopy(values, start, result, 0, limit-start); |
| } |
| else { |
| for (int j=0; j < result.length; j++) { |
| result[j] = values[j+start] - baseValue; |
| } |
| } |
| |
| return result; |
| } |
| else { |
| return computeContiguousOrder(values, start, limit); |
| } |
| } |
| else { |
| return values; |
| } |
| } |
| |
| return null; |
| } |
| |
| /** |
| * Reorder the objects in the array into visual order based on their levels. |
| * This is a utility function to use when you have a collection of objects |
| * representing runs of text in logical order, each run containing text |
| * at a single level. The elements in the objects array will be reordered |
| * into visual order assuming each run of text has the level provided |
| * by the corresponding element in the levels array. |
| * @param levels an array representing the bidi level of each object |
| * @param objects the array of objects to be reordered into visual order |
| */ |
| public static void reorderVisually(byte[] levels, Object[] objects) { |
| int len = levels.length; |
| |
| byte lowestOddLevel = (byte)(NUMLEVELS + 1); |
| byte highestLevel = 0; |
| |
| // initialize mapping and levels |
| |
| for (int i = 0; i < len; i++) { |
| byte level = levels[i]; |
| if (level > highestLevel) { |
| highestLevel = level; |
| } |
| |
| if ((level & 0x01) != 0 && level < lowestOddLevel) { |
| lowestOddLevel = level; |
| } |
| } |
| |
| while (highestLevel >= lowestOddLevel) { |
| int i = 0; |
| for (;;) { |
| while (i < len && levels[i] < highestLevel) { |
| i++; |
| } |
| int begin = i++; |
| |
| if (begin == levels.length) { |
| break; // no more runs at this level |
| } |
| |
| while (i < len && levels[i] >= highestLevel) { |
| i++; |
| } |
| int end = i - 1; |
| |
| while (begin < end) { |
| Object temp = objects[begin]; |
| objects[begin] = objects[end]; |
| objects[end] = temp; |
| ++begin; |
| --end; |
| } |
| } |
| |
| --highestLevel; |
| } |
| } |
| } |