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Diffstat (limited to 'libraries/HtmlTextView/src/org/sufficientlysecure/htmltextview/JellyBeanSpanFixTextView.java')
| -rw-r--r-- | libraries/HtmlTextView/src/org/sufficientlysecure/htmltextview/JellyBeanSpanFixTextView.java | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/libraries/HtmlTextView/src/org/sufficientlysecure/htmltextview/JellyBeanSpanFixTextView.java b/libraries/HtmlTextView/src/org/sufficientlysecure/htmltextview/JellyBeanSpanFixTextView.java new file mode 100644 index 000000000..94bf45849 --- /dev/null +++ b/libraries/HtmlTextView/src/org/sufficientlysecure/htmltextview/JellyBeanSpanFixTextView.java @@ -0,0 +1,212 @@ +/* + * Copyright (C) 2013 Dominik Schürmann <dominik@dominikschuermann.de> + * Copyright (C) 2012 Pierre-Yves Ricau <py.ricau@gmail.com> + * + * 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 org.sufficientlysecure.htmltextview; + +import java.util.ArrayList; +import java.util.List; + +import android.content.Context; +import android.text.SpannableStringBuilder; +import android.text.Spanned; +import android.util.AttributeSet; +import android.util.Log; +import android.widget.TextView; + +/** + * <p> + * A {@link android.widget.TextView} that insert spaces around its text spans where needed to prevent + * {@link IndexOutOfBoundsException} in {@link #onMeasure(int, int)} on Jelly Bean. + * <p> + * When {@link #onMeasure(int, int)} throws an exception, we try to fix the text by adding spaces + * around spans, until it works again. We then try removing some of the added spans, to minimize the + * insertions. + * <p> + * The fix is time consuming (a few ms, it depends on the size of your text), but it should only + * happen once per text change. + * <p> + * See http://code.google.com/p/android/issues/detail?id=35466 + * + */ +public class JellyBeanSpanFixTextView extends TextView { + + private static class FixingResult { + public final boolean fixed; + public final List<Object> spansWithSpacesBefore; + public final List<Object> spansWithSpacesAfter; + + public static FixingResult fixed(List<Object> spansWithSpacesBefore, + List<Object> spansWithSpacesAfter) { + return new FixingResult(true, spansWithSpacesBefore, spansWithSpacesAfter); + } + + public static FixingResult notFixed() { + return new FixingResult(false, null, null); + } + + private FixingResult(boolean fixed, List<Object> spansWithSpacesBefore, + List<Object> spansWithSpacesAfter) { + this.fixed = fixed; + this.spansWithSpacesBefore = spansWithSpacesBefore; + this.spansWithSpacesAfter = spansWithSpacesAfter; + } + } + + public JellyBeanSpanFixTextView(Context context, AttributeSet attrs, int defStyle) { + super(context, attrs, defStyle); + } + + public JellyBeanSpanFixTextView(Context context, AttributeSet attrs) { + super(context, attrs); + } + + public JellyBeanSpanFixTextView(Context context) { + super(context); + } + + @Override + protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { + try { + super.onMeasure(widthMeasureSpec, heightMeasureSpec); + } catch (IndexOutOfBoundsException e) { + fixOnMeasure(widthMeasureSpec, heightMeasureSpec); + } + } + + /** + * If possible, fixes the Spanned text by adding spaces around spans when needed. + */ + private void fixOnMeasure(int widthMeasureSpec, int heightMeasureSpec) { + CharSequence text = getText(); + if (text instanceof Spanned) { + SpannableStringBuilder builder = new SpannableStringBuilder(text); + fixSpannedWithSpaces(builder, widthMeasureSpec, heightMeasureSpec); + } else { + if (BuildConfig.DEBUG) { + Log.d(HtmlTextView.TAG, "The text isn't a Spanned"); + } + fallbackToString(widthMeasureSpec, heightMeasureSpec); + } + } + + /** + * Add spaces around spans until the text is fixed, and then removes the unneeded spaces + */ + private void fixSpannedWithSpaces(SpannableStringBuilder builder, int widthMeasureSpec, + int heightMeasureSpec) { + long startFix = System.currentTimeMillis(); + + FixingResult result = addSpacesAroundSpansUntilFixed(builder, widthMeasureSpec, + heightMeasureSpec); + + if (result.fixed) { + removeUnneededSpaces(widthMeasureSpec, heightMeasureSpec, builder, result); + } else { + fallbackToString(widthMeasureSpec, heightMeasureSpec); + } + + if (BuildConfig.DEBUG) { + long fixDuration = System.currentTimeMillis() - startFix; + Log.d(HtmlTextView.TAG, "fixSpannedWithSpaces() duration in ms: " + fixDuration); + } + } + + private FixingResult addSpacesAroundSpansUntilFixed(SpannableStringBuilder builder, + int widthMeasureSpec, int heightMeasureSpec) { + + Object[] spans = builder.getSpans(0, builder.length(), Object.class); + List<Object> spansWithSpacesBefore = new ArrayList<Object>(spans.length); + List<Object> spansWithSpacesAfter = new ArrayList<Object>(spans.length); + + for (Object span : spans) { + int spanStart = builder.getSpanStart(span); + if (isNotSpace(builder, spanStart - 1)) { + builder.insert(spanStart, " "); + spansWithSpacesBefore.add(span); + } + + int spanEnd = builder.getSpanEnd(span); + if (isNotSpace(builder, spanEnd)) { + builder.insert(spanEnd, " "); + spansWithSpacesAfter.add(span); + } + + try { + setTextAndMeasure(builder, widthMeasureSpec, heightMeasureSpec); + return FixingResult.fixed(spansWithSpacesBefore, spansWithSpacesAfter); + } catch (IndexOutOfBoundsException notFixed) { + } + } + if (BuildConfig.DEBUG) { + Log.d(HtmlTextView.TAG, "Could not fix the Spanned by adding spaces around spans"); + } + return FixingResult.notFixed(); + } + + private boolean isNotSpace(CharSequence text, int where) { + if (where < 0) + return true; + return text.charAt(where) != ' '; + } + + private void setTextAndMeasure(CharSequence text, int widthMeasureSpec, int heightMeasureSpec) { + setText(text); + super.onMeasure(widthMeasureSpec, heightMeasureSpec); + } + + private void removeUnneededSpaces(int widthMeasureSpec, int heightMeasureSpec, + SpannableStringBuilder builder, FixingResult result) { + + for (Object span : result.spansWithSpacesAfter) { + int spanEnd = builder.getSpanEnd(span); + builder.delete(spanEnd, spanEnd + 1); + try { + setTextAndMeasure(builder, widthMeasureSpec, heightMeasureSpec); + } catch (IndexOutOfBoundsException ignored) { + builder.insert(spanEnd, " "); + } + } + + boolean needReset = true; + for (Object span : result.spansWithSpacesBefore) { + int spanStart = builder.getSpanStart(span); + builder.delete(spanStart - 1, spanStart); + try { + setTextAndMeasure(builder, widthMeasureSpec, heightMeasureSpec); + needReset = false; + } catch (IndexOutOfBoundsException ignored) { + needReset = true; + int newSpanStart = spanStart - 1; + builder.insert(newSpanStart, " "); + } + } + + if (needReset) { + setText(builder); + super.onMeasure(widthMeasureSpec, heightMeasureSpec); + } + } + + private void fallbackToString(int widthMeasureSpec, int heightMeasureSpec) { + if (BuildConfig.DEBUG) { + Log.d(HtmlTextView.TAG, "Fallback to unspanned text"); + } + String fallbackText = getText().toString(); + setTextAndMeasure(fallbackText, widthMeasureSpec, heightMeasureSpec); + } + +}
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