| /* |
| * Copyright (C) 2012 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.view; |
| |
| import android.annotation.UnsupportedAppUsage; |
| import android.content.res.Configuration; |
| |
| import java.text.BreakIterator; |
| import java.util.Locale; |
| |
| /** |
| * This class contains the implementation of text segment iterators |
| * for accessibility support. |
| * |
| * Note: Such iterators are needed in the view package since we want |
| * to be able to iterator over content description of any view. |
| * |
| * @hide |
| */ |
| public final class AccessibilityIterators { |
| |
| /** |
| * @hide |
| */ |
| public static interface TextSegmentIterator { |
| public int[] following(int current); |
| public int[] preceding(int current); |
| } |
| |
| /** |
| * @hide |
| */ |
| public static abstract class AbstractTextSegmentIterator implements TextSegmentIterator { |
| |
| @UnsupportedAppUsage |
| protected String mText; |
| |
| private final int[] mSegment = new int[2]; |
| |
| public void initialize(String text) { |
| mText = text; |
| } |
| |
| protected int[] getRange(int start, int end) { |
| if (start < 0 || end < 0 || start == end) { |
| return null; |
| } |
| mSegment[0] = start; |
| mSegment[1] = end; |
| return mSegment; |
| } |
| } |
| |
| static class CharacterTextSegmentIterator extends AbstractTextSegmentIterator |
| implements ViewRootImpl.ConfigChangedCallback { |
| private static CharacterTextSegmentIterator sInstance; |
| |
| private Locale mLocale; |
| |
| protected BreakIterator mImpl; |
| |
| public static CharacterTextSegmentIterator getInstance(Locale locale) { |
| if (sInstance == null) { |
| sInstance = new CharacterTextSegmentIterator(locale); |
| } |
| return sInstance; |
| } |
| |
| private CharacterTextSegmentIterator(Locale locale) { |
| mLocale = locale; |
| onLocaleChanged(locale); |
| ViewRootImpl.addConfigCallback(this); |
| } |
| |
| @Override |
| public void initialize(String text) { |
| super.initialize(text); |
| mImpl.setText(text); |
| } |
| |
| @Override |
| public int[] following(int offset) { |
| final int textLegth = mText.length(); |
| if (textLegth <= 0) { |
| return null; |
| } |
| if (offset >= textLegth) { |
| return null; |
| } |
| int start = offset; |
| if (start < 0) { |
| start = 0; |
| } |
| while (!mImpl.isBoundary(start)) { |
| start = mImpl.following(start); |
| if (start == BreakIterator.DONE) { |
| return null; |
| } |
| } |
| final int end = mImpl.following(start); |
| if (end == BreakIterator.DONE) { |
| return null; |
| } |
| return getRange(start, end); |
| } |
| |
| @Override |
| public int[] preceding(int offset) { |
| final int textLegth = mText.length(); |
| if (textLegth <= 0) { |
| return null; |
| } |
| if (offset <= 0) { |
| return null; |
| } |
| int end = offset; |
| if (end > textLegth) { |
| end = textLegth; |
| } |
| while (!mImpl.isBoundary(end)) { |
| end = mImpl.preceding(end); |
| if (end == BreakIterator.DONE) { |
| return null; |
| } |
| } |
| final int start = mImpl.preceding(end); |
| if (start == BreakIterator.DONE) { |
| return null; |
| } |
| return getRange(start, end); |
| } |
| |
| @Override |
| public void onConfigurationChanged(Configuration globalConfig) { |
| final Locale locale = globalConfig.getLocales().get(0); |
| if (locale == null) { |
| return; |
| } |
| if (!mLocale.equals(locale)) { |
| mLocale = locale; |
| onLocaleChanged(locale); |
| } |
| } |
| |
| protected void onLocaleChanged(Locale locale) { |
| mImpl = BreakIterator.getCharacterInstance(locale); |
| } |
| } |
| |
| static class WordTextSegmentIterator extends CharacterTextSegmentIterator { |
| private static WordTextSegmentIterator sInstance; |
| |
| public static WordTextSegmentIterator getInstance(Locale locale) { |
| if (sInstance == null) { |
| sInstance = new WordTextSegmentIterator(locale); |
| } |
| return sInstance; |
| } |
| |
| private WordTextSegmentIterator(Locale locale) { |
| super(locale); |
| } |
| |
| @Override |
| protected void onLocaleChanged(Locale locale) { |
| mImpl = BreakIterator.getWordInstance(locale); |
| } |
| |
| @Override |
| public int[] following(int offset) { |
| final int textLegth = mText.length(); |
| if (textLegth <= 0) { |
| return null; |
| } |
| if (offset >= mText.length()) { |
| return null; |
| } |
| int start = offset; |
| if (start < 0) { |
| start = 0; |
| } |
| while (!isLetterOrDigit(start) && !isStartBoundary(start)) { |
| start = mImpl.following(start); |
| if (start == BreakIterator.DONE) { |
| return null; |
| } |
| } |
| final int end = mImpl.following(start); |
| if (end == BreakIterator.DONE || !isEndBoundary(end)) { |
| return null; |
| } |
| return getRange(start, end); |
| } |
| |
| @Override |
| public int[] preceding(int offset) { |
| final int textLegth = mText.length(); |
| if (textLegth <= 0) { |
| return null; |
| } |
| if (offset <= 0) { |
| return null; |
| } |
| int end = offset; |
| if (end > textLegth) { |
| end = textLegth; |
| } |
| while (end > 0 && !isLetterOrDigit(end - 1) && !isEndBoundary(end)) { |
| end = mImpl.preceding(end); |
| if (end == BreakIterator.DONE) { |
| return null; |
| } |
| } |
| final int start = mImpl.preceding(end); |
| if (start == BreakIterator.DONE || !isStartBoundary(start)) { |
| return null; |
| } |
| return getRange(start, end); |
| } |
| |
| private boolean isStartBoundary(int index) { |
| return isLetterOrDigit(index) |
| && (index == 0 || !isLetterOrDigit(index - 1)); |
| } |
| |
| private boolean isEndBoundary(int index) { |
| return (index > 0 && isLetterOrDigit(index - 1)) |
| && (index == mText.length() || !isLetterOrDigit(index)); |
| } |
| |
| private boolean isLetterOrDigit(int index) { |
| if (index >= 0 && index < mText.length()) { |
| final int codePoint = mText.codePointAt(index); |
| return Character.isLetterOrDigit(codePoint); |
| } |
| return false; |
| } |
| } |
| |
| static class ParagraphTextSegmentIterator extends AbstractTextSegmentIterator { |
| private static ParagraphTextSegmentIterator sInstance; |
| |
| public static ParagraphTextSegmentIterator getInstance() { |
| if (sInstance == null) { |
| sInstance = new ParagraphTextSegmentIterator(); |
| } |
| return sInstance; |
| } |
| |
| @Override |
| public int[] following(int offset) { |
| final int textLength = mText.length(); |
| if (textLength <= 0) { |
| return null; |
| } |
| if (offset >= textLength) { |
| return null; |
| } |
| int start = offset; |
| if (start < 0) { |
| start = 0; |
| } |
| while (start < textLength && mText.charAt(start) == '\n' |
| && !isStartBoundary(start)) { |
| start++; |
| } |
| if (start >= textLength) { |
| return null; |
| } |
| int end = start + 1; |
| while (end < textLength && !isEndBoundary(end)) { |
| end++; |
| } |
| return getRange(start, end); |
| } |
| |
| @Override |
| public int[] preceding(int offset) { |
| final int textLength = mText.length(); |
| if (textLength <= 0) { |
| return null; |
| } |
| if (offset <= 0) { |
| return null; |
| } |
| int end = offset; |
| if (end > textLength) { |
| end = textLength; |
| } |
| while(end > 0 && mText.charAt(end - 1) == '\n' && !isEndBoundary(end)) { |
| end--; |
| } |
| if (end <= 0) { |
| return null; |
| } |
| int start = end - 1; |
| while (start > 0 && !isStartBoundary(start)) { |
| start--; |
| } |
| return getRange(start, end); |
| } |
| |
| private boolean isStartBoundary(int index) { |
| return (mText.charAt(index) != '\n' |
| && (index == 0 || mText.charAt(index - 1) == '\n')); |
| } |
| |
| private boolean isEndBoundary(int index) { |
| return (index > 0 && mText.charAt(index - 1) != '\n' |
| && (index == mText.length() || mText.charAt(index) == '\n')); |
| } |
| } |
| } |