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September 21, 2015 07:06
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Android TextView not support ellipsize if your text fills more than i line. This implementation solved this problem and allow you to use Instagram style end of line mark "[...]"
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/* | |
* Copyright (C) 2011 Micah Hainline | |
* Copyright (C) 2012 Triposo | |
* Copyright (C) 2013 Paul Imhoff | |
* Copyright (C) 2014 Shahin Yousefi | |
* Copyright (C) 2015 Stepan Goncharov | |
* | |
* 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 com.bandlab.bandlab.views; | |
import android.content.Context; | |
import android.content.res.TypedArray; | |
import android.graphics.Canvas; | |
import android.graphics.Color; | |
import android.support.annotation.NonNull; | |
import android.support.v7.widget.AppCompatTextView; | |
import android.text.Layout; | |
import android.text.Layout.Alignment; | |
import android.text.Spannable; | |
import android.text.SpannableString; | |
import android.text.SpannableStringBuilder; | |
import android.text.Spanned; | |
import android.text.StaticLayout; | |
import android.text.TextUtils; | |
import android.text.TextUtils.TruncateAt; | |
import android.text.style.ForegroundColorSpan; | |
import android.util.AttributeSet; | |
import java.util.ArrayList; | |
import java.util.List; | |
import java.util.regex.Pattern; | |
/** | |
* A {@link android.widget.TextView} that ellipsizes more intelligently. | |
* This class supports ellipsizing multiline text through setting {@code android:ellipsize} | |
* and {@code android:maxLines}. | |
* <p/> | |
* Note: {@link android.text.TextUtils.TruncateAt#MARQUEE} ellipsizing type is not supported. | |
*/ | |
public class EllipsizingTextView extends AppCompatTextView { | |
public static final int ELLIPSIZE_ALPHA = 0x88; | |
private SpannableString ELLIPSIS = new SpannableString("[\u2026]"); | |
private static final Pattern DEFAULT_END_PUNCTUATION | |
= Pattern.compile("[\\.!?,;:\u2026]*$", Pattern.DOTALL); | |
private final List<EllipsizeListener> mEllipsizeListeners = new ArrayList<>(); | |
private EllipsizeStrategy mEllipsizeStrategy; | |
private boolean isEllipsized; | |
private boolean isStale; | |
private boolean programmaticChange; | |
private CharSequence mFullText; | |
private int mMaxLines; | |
private float mLineSpacingMult = 1.0f; | |
private float mLineAddVertPad = 0.0f; | |
/** | |
* The end punctuation which will be removed when appending {@link #ELLIPSIS}. | |
*/ | |
private Pattern mEndPunctPattern; | |
public EllipsizingTextView(Context context) { | |
this(context, null); | |
} | |
public EllipsizingTextView(Context context, AttributeSet attrs) { | |
this(context, attrs, android.R.attr.textViewStyle); | |
} | |
public EllipsizingTextView(Context context, AttributeSet attrs, int defStyle) { | |
super(context, attrs, defStyle); | |
TypedArray a = context.obtainStyledAttributes(attrs, | |
new int[]{android.R.attr.maxLines, android.R.attr.ellipsize}, defStyle, 0); | |
setMaxLines(a.getInt(0, Integer.MAX_VALUE)); | |
a.recycle(); | |
setEndPunctuationPattern(DEFAULT_END_PUNCTUATION); | |
final int currentTextColor = getCurrentTextColor(); | |
final int ellipsizeColor = Color.argb(ELLIPSIZE_ALPHA, Color.red(currentTextColor), Color.green(currentTextColor), Color.blue(currentTextColor)); | |
ELLIPSIS.setSpan(new ForegroundColorSpan(ellipsizeColor), 0, ELLIPSIS.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE); | |
} | |
public void setEndPunctuationPattern(Pattern pattern) { | |
mEndPunctPattern = pattern; | |
} | |
@SuppressWarnings("unused") | |
public void addEllipsizeListener(@NonNull EllipsizeListener listener) { | |
mEllipsizeListeners.add(listener); | |
} | |
@SuppressWarnings("unused") | |
public void removeEllipsizeListener(@NonNull EllipsizeListener listener) { | |
mEllipsizeListeners.remove(listener); | |
} | |
@SuppressWarnings("unused") | |
public boolean isEllipsized() { | |
return isEllipsized; | |
} | |
/** | |
* @return The maximum number of lines displayed in this {@link android.widget.TextView}. | |
*/ | |
public int getMaxLines() { | |
return mMaxLines; | |
} | |
@Override | |
public void setMaxLines(int maxLines) { | |
super.setMaxLines(maxLines); | |
mMaxLines = maxLines; | |
isStale = true; | |
} | |
/** | |
* Determines if the last fully visible line is being ellipsized. | |
* | |
* @return {@code true} if the last fully visible line is being ellipsized; | |
* otherwise, returns {@code false}. | |
*/ | |
public boolean ellipsizingLastFullyVisibleLine() { | |
return mMaxLines == Integer.MAX_VALUE; | |
} | |
@Override | |
public void setLineSpacing(float add, float mult) { | |
mLineAddVertPad = add; | |
mLineSpacingMult = mult; | |
super.setLineSpacing(add, mult); | |
} | |
@Override | |
public void setText(CharSequence text, BufferType type) { | |
if (!programmaticChange) { | |
mFullText = text instanceof Spanned ? (Spanned) text : text; | |
isStale = true; | |
} | |
super.setText(text, type); | |
} | |
@Override | |
protected void onSizeChanged(int w, int h, int oldw, int oldh) { | |
super.onSizeChanged(w, h, oldw, oldh); | |
if (ellipsizingLastFullyVisibleLine()) { | |
isStale = true; | |
} | |
} | |
@Override | |
public void setPadding(int left, int top, int right, int bottom) { | |
super.setPadding(left, top, right, bottom); | |
if (ellipsizingLastFullyVisibleLine()) { | |
isStale = true; | |
} | |
} | |
@Override | |
protected void onDraw(@NonNull Canvas canvas) { | |
if (isStale) { | |
resetText(); | |
} | |
super.onDraw(canvas); | |
} | |
/** | |
* Sets the ellipsized text if appropriate. | |
*/ | |
private void resetText() { | |
int maxLines = getMaxLines(); | |
CharSequence workingText = mFullText; | |
boolean ellipsized = false; | |
if (maxLines != -1) { | |
if (mEllipsizeStrategy == null) setEllipsize(null); | |
workingText = mEllipsizeStrategy.processText(mFullText); | |
ellipsized = !mEllipsizeStrategy.isInLayout(mFullText); | |
} | |
if (!workingText.equals(getText())) { | |
programmaticChange = true; | |
try { | |
setText(workingText); | |
} finally { | |
programmaticChange = false; | |
} | |
} | |
isStale = false; | |
if (ellipsized != isEllipsized) { | |
isEllipsized = ellipsized; | |
for (EllipsizeListener listener : mEllipsizeListeners) { | |
listener.ellipsizeStateChanged(ellipsized); | |
} | |
} | |
} | |
/** | |
* Causes words in the text that are longer than the view is wide to be ellipsized | |
* instead of broken in the middle. Use {@code null} to turn off ellipsizing. | |
* <p/> | |
* Note: Method does nothing for {@link android.text.TextUtils.TruncateAt#MARQUEE} | |
* ellipsizing type. | |
* | |
* @param where part of text to ellipsize | |
*/ | |
@Override | |
public void setEllipsize(TruncateAt where) { | |
if (where == null) { | |
mEllipsizeStrategy = new EllipsizeNoneStrategy(); | |
return; | |
} | |
switch (where) { | |
case END: | |
mEllipsizeStrategy = new EllipsizeEndStrategy(); | |
break; | |
case START: | |
mEllipsizeStrategy = new EllipsizeStartStrategy(); | |
break; | |
case MIDDLE: | |
mEllipsizeStrategy = new EllipsizeMiddleStrategy(); | |
break; | |
case MARQUEE: | |
default: | |
mEllipsizeStrategy = new EllipsizeNoneStrategy(); | |
break; | |
} | |
} | |
/** | |
* A listener that notifies when the ellipsize state has changed. | |
*/ | |
public interface EllipsizeListener { | |
void ellipsizeStateChanged(boolean ellipsized); | |
} | |
/** | |
* A base class for an ellipsize strategy. | |
*/ | |
private abstract class EllipsizeStrategy { | |
/** | |
* Returns ellipsized text if the text does not fit inside of the layout; | |
* otherwise, returns the full text. | |
* | |
* @param text text to process | |
* @return Ellipsized text if the text does not fit inside of the layout; | |
* otherwise, returns the full text. | |
*/ | |
public CharSequence processText(CharSequence text) { | |
return !isInLayout(text) ? createEllipsizedText(text) : text; | |
} | |
/** | |
* Determines if the text fits inside of the layout. | |
* | |
* @param text text to fit | |
* @return {@code true} if the text fits inside of the layout; | |
* otherwise, returns {@code false}. | |
*/ | |
public boolean isInLayout(CharSequence text) { | |
Layout layout = createWorkingLayout(text); | |
return layout.getLineCount() <= getLinesCount(); | |
} | |
/** | |
* Creates a working layout with the given text. | |
* | |
* @param workingText text to create layout with | |
* @return {@link android.text.Layout} with the given text. | |
*/ | |
protected Layout createWorkingLayout(CharSequence workingText) { | |
return new StaticLayout(workingText, getPaint(), | |
getWidth() - getCompoundPaddingLeft() - getCompoundPaddingRight(), | |
Alignment.ALIGN_NORMAL, mLineSpacingMult, | |
mLineAddVertPad, false /* includepad */); | |
} | |
/** | |
* Get how many lines of text we are allowed to display. | |
*/ | |
protected int getLinesCount() { | |
if (ellipsizingLastFullyVisibleLine()) { | |
int fullyVisibleLinesCount = getFullyVisibleLinesCount(); | |
return fullyVisibleLinesCount == -1 ? 1 : fullyVisibleLinesCount; | |
} else { | |
return mMaxLines; | |
} | |
} | |
/** | |
* Get how many lines of text we can display so their full height is visible. | |
*/ | |
protected int getFullyVisibleLinesCount() { | |
Layout layout = createWorkingLayout(""); | |
int height = getHeight() - getCompoundPaddingTop() - getCompoundPaddingBottom(); | |
int lineHeight = layout.getLineBottom(0); | |
return height / lineHeight; | |
} | |
/** | |
* Creates ellipsized text from the given text. | |
* | |
* @param fullText text to ellipsize | |
* @return Ellipsized text | |
*/ | |
protected abstract CharSequence createEllipsizedText(CharSequence fullText); | |
} | |
/** | |
* An {@link EllipsizingTextView.EllipsizeStrategy} that | |
* does not ellipsize text. | |
*/ | |
private class EllipsizeNoneStrategy extends EllipsizeStrategy { | |
@Override | |
protected CharSequence createEllipsizedText(CharSequence fullText) { | |
return fullText; | |
} | |
} | |
/** | |
* An {@link EllipsizingTextView.EllipsizeStrategy} that | |
* ellipsizes text at the end. | |
*/ | |
private class EllipsizeEndStrategy extends EllipsizeStrategy { | |
@Override | |
protected CharSequence createEllipsizedText(CharSequence fullText) { | |
Layout layout = createWorkingLayout(fullText); | |
int cutOffIndex = layout.getLineEnd(mMaxLines - 1); | |
int textLength = fullText.length(); | |
int cutOffLength = textLength - cutOffIndex; | |
if (cutOffLength < ELLIPSIS.length()) cutOffLength = ELLIPSIS.length(); | |
CharSequence workingText = TextUtils.substring(fullText, 0, textLength - cutOffLength).trim(); | |
while (!isInLayout(TextUtils.concat(stripEndPunctuation(workingText), ELLIPSIS))) { | |
int lastSpace = TextUtils.lastIndexOf(workingText, ' '); | |
if (lastSpace == -1) { | |
break; | |
} | |
workingText = TextUtils.substring(workingText, 0, lastSpace).trim(); | |
} | |
workingText = TextUtils.concat(stripEndPunctuation(workingText), ELLIPSIS); | |
SpannableStringBuilder dest = new SpannableStringBuilder(workingText); | |
if (fullText instanceof Spanned) { | |
TextUtils.copySpansFrom((Spanned) fullText, 0, workingText.length(), null, dest, 0); | |
} | |
return dest; | |
} | |
/** | |
* Strips the end punctuation from a given text according to {@link #mEndPunctPattern}. | |
* | |
* @param workingText text to strip end punctuation from | |
* @return Text without end punctuation. | |
*/ | |
public String stripEndPunctuation(CharSequence workingText) { | |
return mEndPunctPattern.matcher(workingText).replaceFirst(""); | |
} | |
} | |
/** | |
* An {@link EllipsizingTextView.EllipsizeStrategy} that | |
* ellipsizes text at the start. | |
*/ | |
private class EllipsizeStartStrategy extends EllipsizeStrategy { | |
@Override | |
protected CharSequence createEllipsizedText(CharSequence fullText) { | |
Layout layout = createWorkingLayout(fullText); | |
int cutOffIndex = layout.getLineEnd(mMaxLines - 1); | |
int textLength = fullText.length(); | |
int cutOffLength = textLength - cutOffIndex; | |
if (cutOffLength < ELLIPSIS.length()) cutOffLength = ELLIPSIS.length(); | |
CharSequence workingText = TextUtils.substring(fullText, cutOffLength, textLength).trim(); | |
while (!isInLayout(TextUtils.concat(ELLIPSIS, workingText))) { | |
int firstSpace = TextUtils.indexOf(workingText, ' '); | |
if (firstSpace == -1) { | |
break; | |
} | |
workingText = TextUtils.substring(workingText, firstSpace, workingText.length()).trim(); | |
} | |
workingText = TextUtils.concat(ELLIPSIS, workingText); | |
SpannableStringBuilder dest = new SpannableStringBuilder(workingText); | |
if (fullText instanceof Spanned) { | |
TextUtils.copySpansFrom((Spanned) fullText, textLength - workingText.length(), | |
textLength, null, dest, 0); | |
} | |
return dest; | |
} | |
} | |
/** | |
* An {@link EllipsizingTextView.EllipsizeStrategy} that | |
* ellipsizes text in the middle. | |
*/ | |
private class EllipsizeMiddleStrategy extends EllipsizeStrategy { | |
@Override | |
protected CharSequence createEllipsizedText(CharSequence fullText) { | |
Layout layout = createWorkingLayout(fullText); | |
int cutOffIndex = layout.getLineEnd(mMaxLines - 1); | |
int textLength = fullText.length(); | |
int cutOffLength = textLength - cutOffIndex; | |
if (cutOffLength < ELLIPSIS.length()) cutOffLength = ELLIPSIS.length(); | |
cutOffLength += cutOffIndex % 2; // Make it even. | |
String firstPart = TextUtils.substring( | |
fullText, 0, textLength / 2 - cutOffLength / 2).trim(); | |
String secondPart = TextUtils.substring( | |
fullText, textLength / 2 + cutOffLength / 2, textLength).trim(); | |
while (!isInLayout(TextUtils.concat(firstPart, ELLIPSIS, secondPart))) { | |
int lastSpaceFirstPart = firstPart.lastIndexOf(' '); | |
int firstSpaceSecondPart = secondPart.indexOf(' '); | |
if (lastSpaceFirstPart == -1 || firstSpaceSecondPart == -1) break; | |
firstPart = firstPart.substring(0, lastSpaceFirstPart).trim(); | |
secondPart = secondPart.substring(firstSpaceSecondPart, secondPart.length()).trim(); | |
} | |
SpannableStringBuilder firstDest = new SpannableStringBuilder(firstPart); | |
SpannableStringBuilder secondDest = new SpannableStringBuilder(secondPart); | |
if (fullText instanceof Spanned) { | |
TextUtils.copySpansFrom((Spanned) fullText, 0, firstPart.length(), | |
null, firstDest, 0); | |
TextUtils.copySpansFrom((Spanned) fullText, textLength - secondPart.length(), | |
textLength, null, secondDest, 0); | |
} | |
return TextUtils.concat(firstDest, ELLIPSIS, secondDest); | |
} | |
} | |
} |
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This is an example for different color with in a line