我正在寻找一种最佳的方法来调整包装文本在一个TextView，使它将适合它的getHeight和getWidth界限。我不是简单地寻找一种方法来包装文本-我想确保它既包装，又足够小，完全适合在屏幕上。
我在StackOverflow上看到了一些需要自动调整大小的情况，但它们要么是非常特殊的情况下的hack解决方案，没有解决方案，或涉及重新绘制TextView递归直到它足够小(这是内存紧张，迫使用户观看文本收缩一步一步与每次递归)。
但我相信有人已经找到了一个很好的解决方案，它不涉及我正在做的事情:编写几个繁重的例程来解析和测量文本，调整文本的大小，然后重复，直到找到一个合适的小尺寸。
TextView使用什么例程来包装文本?难道这些不能用来预测文本是否足够小吗?
是否有一个最佳实践的方法来自动调整TextView的大小，以适应，包装，在它的getHeight和getWidth边界?
当前回答
更新:下面的代码也满足了一个理想的AutoScaleTextView的要求，如这里所述:自动适合Android的TextView，并被标记为赢家。
更新2:增加了对maxlines的支持，现在在API级别16之前工作正常。
更新3:支持android: drawablleft, android:drawableRight, android:drawableTop和android:drawableBottom标签添加，感谢MartinH在这里的简单修复。
我的要求有点不同。我需要一种有效的方法来调整大小，因为我是动画一个整数从，可能是0 ~4000在TextView在2秒内，我想相应地调整大小。我的解决方法有点不同。这是最终的结果:
以及产生它的代码:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="16dp" >
<com.vj.widgets.AutoResizeTextView
android:layout_width="match_parent"
android:layout_height="100dp"
android:ellipsize="none"
android:maxLines="2"
android:text="Auto Resized Text, max 2 lines"
android:textSize="100sp" /> <!-- maximum size -->
<com.vj.widgets.AutoResizeTextView
android:layout_width="match_parent"
android:layout_height="100dp"
android:ellipsize="none"
android:gravity="center"
android:maxLines="1"
android:text="Auto Resized Text, max 1 line"
android:textSize="100sp" /> <!-- maximum size -->
<com.vj.widgets.AutoResizeTextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Auto Resized Text"
android:textSize="500sp" /> <!-- maximum size -->
</LinearLayout>
最后是java代码:
import android.annotation.TargetApi;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.RectF;
import android.os.Build;
import android.text.Layout.Alignment;
import android.text.StaticLayout;
import android.text.TextPaint;
import android.util.AttributeSet;
import android.util.SparseIntArray;
import android.util.TypedValue;
import android.widget.TextView;
public class AutoResizeTextView extends TextView {
private interface SizeTester {
/**
*
* @param suggestedSize
* Size of text to be tested
* @param availableSpace
* available space in which text must fit
* @return an integer < 0 if after applying {@code suggestedSize} to
* text, it takes less space than {@code availableSpace}, > 0
* otherwise
*/
public int onTestSize(int suggestedSize, RectF availableSpace);
}
private RectF mTextRect = new RectF();
private RectF mAvailableSpaceRect;
private SparseIntArray mTextCachedSizes;
private TextPaint mPaint;
private float mMaxTextSize;
private float mSpacingMult = 1.0f;
private float mSpacingAdd = 0.0f;
private float mMinTextSize = 20;
private int mWidthLimit;
private static final int NO_LINE_LIMIT = -1;
private int mMaxLines;
private boolean mEnableSizeCache = true;
private boolean mInitiallized;
public AutoResizeTextView(Context context) {
super(context);
initialize();
}
public AutoResizeTextView(Context context, AttributeSet attrs) {
super(context, attrs);
initialize();
}
public AutoResizeTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
initialize();
}
private void initialize() {
mPaint = new TextPaint(getPaint());
mMaxTextSize = getTextSize();
mAvailableSpaceRect = new RectF();
mTextCachedSizes = new SparseIntArray();
if (mMaxLines == 0) {
// no value was assigned during construction
mMaxLines = NO_LINE_LIMIT;
}
mInitiallized = true;
}
@Override
public void setText(final CharSequence text, BufferType type) {
super.setText(text, type);
adjustTextSize(text.toString());
}
@Override
public void setTextSize(float size) {
mMaxTextSize = size;
mTextCachedSizes.clear();
adjustTextSize(getText().toString());
}
@Override
public void setMaxLines(int maxlines) {
super.setMaxLines(maxlines);
mMaxLines = maxlines;
reAdjust();
}
public int getMaxLines() {
return mMaxLines;
}
@Override
public void setSingleLine() {
super.setSingleLine();
mMaxLines = 1;
reAdjust();
}
@Override
public void setSingleLine(boolean singleLine) {
super.setSingleLine(singleLine);
if (singleLine) {
mMaxLines = 1;
} else {
mMaxLines = NO_LINE_LIMIT;
}
reAdjust();
}
@Override
public void setLines(int lines) {
super.setLines(lines);
mMaxLines = lines;
reAdjust();
}
@Override
public void setTextSize(int unit, float size) {
Context c = getContext();
Resources r;
if (c == null)
r = Resources.getSystem();
else
r = c.getResources();
mMaxTextSize = TypedValue.applyDimension(unit, size,
r.getDisplayMetrics());
mTextCachedSizes.clear();
adjustTextSize(getText().toString());
}
@Override
public void setLineSpacing(float add, float mult) {
super.setLineSpacing(add, mult);
mSpacingMult = mult;
mSpacingAdd = add;
}
/**
* Set the lower text size limit and invalidate the view
*
* @param minTextSize
*/
public void setMinTextSize(float minTextSize) {
mMinTextSize = minTextSize;
reAdjust();
}
private void reAdjust() {
adjustTextSize(getText().toString());
}
private void adjustTextSize(String string) {
if (!mInitiallized) {
return;
}
int startSize = (int) mMinTextSize;
int heightLimit = getMeasuredHeight() - getCompoundPaddingBottom()
- getCompoundPaddingTop();
mWidthLimit = getMeasuredWidth() - getCompoundPaddingLeft()
- getCompoundPaddingRight();
mAvailableSpaceRect.right = mWidthLimit;
mAvailableSpaceRect.bottom = heightLimit;
super.setTextSize(
TypedValue.COMPLEX_UNIT_PX,
efficientTextSizeSearch(startSize, (int) mMaxTextSize,
mSizeTester, mAvailableSpaceRect));
}
private final SizeTester mSizeTester = new SizeTester() {
@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
@Override
public int onTestSize(int suggestedSize, RectF availableSPace) {
mPaint.setTextSize(suggestedSize);
String text = getText().toString();
boolean singleline = getMaxLines() == 1;
if (singleline) {
mTextRect.bottom = mPaint.getFontSpacing();
mTextRect.right = mPaint.measureText(text);
} else {
StaticLayout layout = new StaticLayout(text, mPaint,
mWidthLimit, Alignment.ALIGN_NORMAL, mSpacingMult,
mSpacingAdd, true);
// return early if we have more lines
if (getMaxLines() != NO_LINE_LIMIT
&& layout.getLineCount() > getMaxLines()) {
return 1;
}
mTextRect.bottom = layout.getHeight();
int maxWidth = -1;
for (int i = 0; i < layout.getLineCount(); i++) {
if (maxWidth < layout.getLineWidth(i)) {
maxWidth = (int) layout.getLineWidth(i);
}
}
mTextRect.right = maxWidth;
}
mTextRect.offsetTo(0, 0);
if (availableSPace.contains(mTextRect)) {
// may be too small, don't worry we will find the best match
return -1;
} else {
// too big
return 1;
}
}
};
/**
* Enables or disables size caching, enabling it will improve performance
* where you are animating a value inside TextView. This stores the font
* size against getText().length() Be careful though while enabling it as 0
* takes more space than 1 on some fonts and so on.
*
* @param enable
* enable font size caching
*/
public void enableSizeCache(boolean enable) {
mEnableSizeCache = enable;
mTextCachedSizes.clear();
adjustTextSize(getText().toString());
}
private int efficientTextSizeSearch(int start, int end,
SizeTester sizeTester, RectF availableSpace) {
if (!mEnableSizeCache) {
return binarySearch(start, end, sizeTester, availableSpace);
}
String text = getText().toString();
int key = text == null ? 0 : text.length();
int size = mTextCachedSizes.get(key);
if (size != 0) {
return size;
}
size = binarySearch(start, end, sizeTester, availableSpace);
mTextCachedSizes.put(key, size);
return size;
}
private static int binarySearch(int start, int end, SizeTester sizeTester,
RectF availableSpace) {
int lastBest = start;
int lo = start;
int hi = end - 1;
int mid = 0;
while (lo <= hi) {
mid = (lo + hi) >>> 1;
int midValCmp = sizeTester.onTestSize(mid, availableSpace);
if (midValCmp < 0) {
lastBest = lo;
lo = mid + 1;
} else if (midValCmp > 0) {
hi = mid - 1;
lastBest = hi;
} else {
return mid;
}
}
// make sure to return last best
// this is what should always be returned
return lastBest;
}
@Override
protected void onTextChanged(final CharSequence text, final int start,
final int before, final int after) {
super.onTextChanged(text, start, before, after);
reAdjust();
}
@Override
protected void onSizeChanged(int width, int height, int oldwidth,
int oldheight) {
mTextCachedSizes.clear();
super.onSizeChanged(width, height, oldwidth, oldheight);
if (width != oldwidth || height != oldheight) {
reAdjust();
}
}
}
其他回答
Android 4.x的一个变通方案:
我找到了AutoResizeTextView，它在我的Android 2.1模拟器上工作得很好。我非常喜欢它。但不幸的是，它在我自己的4.0.4手机和4.1模拟器上失败了。经过尝试，我发现它可以通过在xml中的AutoResizeTextView类中添加以下属性轻松解决:
android：ellipsize=“none” android：singleLine=“true”
有了上面的两行，现在AutoResizeTextView在我的2.1和4.1模拟器和我自己的4.0.4手机上完美地工作。
希望这对你有所帮助。: -)
我刚刚创建了以下方法(基于Chase的想法)，如果你想在任何画布上绘制文本，它可能会帮助你:
private static void drawText(Canvas canvas, int xStart, int yStart,
int xWidth, int yHeigth, String textToDisplay,
TextPaint paintToUse, float startTextSizeInPixels,
float stepSizeForTextSizeSteps) {
// Text view line spacing multiplier
float mSpacingMult = 1.0f;
// Text view additional line spacing
float mSpacingAdd = 0.0f;
StaticLayout l = null;
do {
paintToUse.setTextSize(startTextSizeInPixels);
startTextSizeInPixels -= stepSizeForTextSizeSteps;
l = new StaticLayout(textToDisplay, paintToUse, xWidth,
Alignment.ALIGN_NORMAL, mSpacingMult, mSpacingAdd, true);
} while (l.getHeight() > yHeigth);
int textCenterX = xStart + (xWidth / 2);
int textCenterY = (yHeigth - l.getHeight()) / 2;
canvas.save();
canvas.translate(textCenterX, textCenterY);
l.draw(canvas);
canvas.restore();
}
这可以在任何自定义视图的任何onDraw()方法中使用。
你可以使用android.text.StaticLayout类。这就是TextView内部使用的。
为那些在Xamarin.Android上编码的人提供了这个用c#重写的顶级答案版本。对我来说很管用。
/**
* DO WHAT YOU WANT TO PUBLIC LICENSE
* Version 2, December 2004
*
* Copyright (C) 2004 Sam Hocevar <sam@hocevar.net>
*
* Everyone is permitted to copy and distribute verbatim or modified
* copies of this license document, and changing it is allowed as long
* as the name is changed.
*
* DO WHAT YOU WANT TO PUBLIC LICENSE
* TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
*
* 0. You just DO WHAT YOU WANT TO.
*/
using System;
using Android.Content;
using Android.Runtime;
using Android.Text;
using Android.Util;
using Android.Widget;
using Java.Lang;
namespace App.GuestGuide.Droid.Controls
{
public class OnTextResizeEventArgs : EventArgs
{
public TextView TextView { get; set; }
public float OldSize { get; set; }
public float NewSize { get; set; }
}
/// <inheritdoc />
/// <summary>
/// Text view that auto adjusts text size to fit within the view.
/// If the text size equals the minimum text size and still does not
/// fit, append with an ellipsis.
/// </summary>
public class AutoResizeTextView : TextView
{
/// <summary>
/// Minimum text size for this text view
/// </summary>
public static float MIN_TEXT_SIZE = 10;
/// <summary>
/// Our ellipse string
/// </summary>
private const string Ellipsis = "...";
private float _mMaxTextSize;
private float _mMinTextSize = MIN_TEXT_SIZE;
/// <summary>
/// Register subscriber to receive resize notifications
/// </summary>
public event EventHandler<OnTextResizeEventArgs> OnTextResize;
/// <summary>
/// Flag for text and/or size changes to force a resize
/// </summary>
private bool _needsResize;
/// <summary>
/// Text size that is set from code. This acts as a starting point for resizing
/// </summary>
private float _textSize;
/// <summary>
/// Text view line spacing multiplier
/// </summary>
private float _spacingMult = 1.0f;
/// <summary>
/// Text view additional line spacing
/// </summary>
private float _spacingAdd;
/// <summary>
/// Add ellipsis to text that overflows at the smallest text size
/// </summary>
public bool ShouldAddEllipsis { get; set; }
/// <inheritdoc />
/// <summary>
/// Override the set text size to update our internal reference values
/// </summary>
public override float TextSize
{
get => base.TextSize;
set
{
base.TextSize = value;
_textSize = TextSize;
}
}
/// <summary>
/// Temporary upper bounds on the starting text size
/// </summary>
public float MaxTextSize
{
get => _mMaxTextSize;
// Set the upper text size limit and invalidate the view
set
{
_mMaxTextSize = value;
RequestLayout();
Invalidate();
}
}
/// <summary>
/// Lower bounds for text size
/// </summary>
public float MinTextSize
{
get => _mMinTextSize;
//Set the lower text size limit and invalidate the view
set
{
_mMinTextSize = value;
RequestLayout();
Invalidate();
}
}
public AutoResizeTextView(Context context) : this(context, null)
{
}
public AutoResizeTextView(Context context, IAttributeSet attrs) : this(context, attrs, 0)
{
}
public AutoResizeTextView(Context context, IAttributeSet attrs, int defStyleAttr) : base(context, attrs, defStyleAttr)
{
_textSize = TextSize;
}
public AutoResizeTextView(Context context, IAttributeSet attrs, int defStyleAttr, int defStyleRes) : base(context, attrs, defStyleAttr, defStyleRes)
{
_textSize = TextSize;
}
protected AutoResizeTextView(IntPtr javaReference, JniHandleOwnership transfer) : base(javaReference, transfer)
{
_textSize = TextSize;
}
/// <inheritdoc />
/// <summary>
/// When text changes, set the force resize flag to true and reset the text size.
/// </summary>
/// <param name="text"></param>
/// <param name="start"></param>
/// <param name="lengthBefore"></param>
/// <param name="lengthAfter"></param>
protected override void OnTextChanged(ICharSequence text, int start, int lengthBefore, int lengthAfter)
{
_needsResize = true;
// Since this view may be reused, it is good to reset the text size
ResetTextSize();
}
/// <inheritdoc />
/// <summary>
/// If the text view size changed, set the force resize flag to true
/// </summary>
/// <param name="w"></param>
/// <param name="h"></param>
/// <param name="oldw"></param>
/// <param name="oldh"></param>
protected override void OnSizeChanged(int w, int h, int oldw, int oldh)
{
if (w != oldw || h != oldh)
{
_needsResize = true;
}
}
public override void SetTextSize([GeneratedEnum] ComplexUnitType unit, float size)
{
base.SetTextSize(unit, size);
_textSize = TextSize;
}
/// <inheritdoc />
/// <summary>
/// Override the set line spacing to update our internal reference values
/// </summary>
/// <param name="add"></param>
/// <param name="mult"></param>
public override void SetLineSpacing(float add, float mult)
{
base.SetLineSpacing(add, mult);
_spacingMult = mult;
_spacingAdd = add;
}
/// <summary>
/// Reset the text to the original size
/// </summary>
public void ResetTextSize()
{
if (_textSize > 0)
{
base.SetTextSize(ComplexUnitType.Px, _textSize);
_mMaxTextSize = _textSize;
}
}
/// <inheritdoc />
/// <summary>
/// Resize text after measuring
/// </summary>
/// <param name="changed"></param>
/// <param name="left"></param>
/// <param name="top"></param>
/// <param name="right"></param>
/// <param name="bottom"></param>
protected override void OnLayout(bool changed, int left, int top, int right, int bottom)
{
if (changed || _needsResize)
{
var widthLimit = (right - left) - CompoundPaddingLeft - CompoundPaddingRight;
var heightLimit = (bottom - top) - CompoundPaddingBottom - CompoundPaddingTop;
ResizeText(widthLimit, heightLimit);
}
base.OnLayout(changed, left, top, right, bottom);
}
/// <summary>
/// Resize the text size with default width and height
/// </summary>
public void ResizeText()
{
var heightLimit = Height - PaddingBottom - PaddingTop;
var widthLimit = Width - PaddingLeft - PaddingRight;
ResizeText(widthLimit, heightLimit);
}
/// <summary>
/// Resize the text size with specified width and height
/// </summary>
/// <param name="width"></param>
/// <param name="height"></param>
public void ResizeText(int width, int height)
{
ICharSequence text = null;
if (!string.IsNullOrEmpty(Text))
{
text = new Java.Lang.String(Text);
}
// Do not resize if the view does not have dimensions or there is no text
if (text == null || text.Length() == 0 || height <= 0 || width <= 0 || _textSize == 0)
{
return;
}
if (TransformationMethod != null)
{
text = TransformationMethod.GetTransformationFormatted(text, this);
}
// Get the text view's paint object
var textPaint = Paint;
// Store the current text size
var oldTextSize = textPaint.TextSize;
// If there is a max text size set, use the lesser of that and the default text size
var targetTextSize = _mMaxTextSize > 0 ? System.Math.Min(_textSize, _mMaxTextSize) : _textSize;
// Get the required text height
var textHeight = GetTextHeight(text, textPaint, width, targetTextSize);
// Until we either fit within our text view or we had reached our min text size, incrementally try smaller sizes
while (textHeight > height && targetTextSize > _mMinTextSize)
{
targetTextSize = System.Math.Max(targetTextSize - 2, _mMinTextSize);
textHeight = GetTextHeight(text, textPaint, width, targetTextSize);
}
// If we had reached our minimum text size and still don't fit, append an ellipsis
if (ShouldAddEllipsis && targetTextSize == _mMinTextSize && textHeight > height)
{
// Draw using a static layout
// modified: use a copy of TextPaint for measuring
var paint = new TextPaint(textPaint);
// Draw using a static layout
var layout = new StaticLayout(text, paint, width, Layout.Alignment.AlignNormal, _spacingMult, _spacingAdd, false);
// Check that we have a least one line of rendered text
if (layout.LineCount > 0)
{
// Since the line at the specific vertical position would be cut off,
// we must trim up to the previous line
var lastLine = layout.GetLineForVertical(height) - 1;
// If the text would not even fit on a single line, clear it
if (lastLine < 0)
{
Text = string.Empty;
}
// Otherwise, trim to the previous line and add an ellipsis
else
{
var start = layout.GetLineStart(lastLine);
var end = layout.GetLineEnd(lastLine);
var lineWidth = layout.GetLineWidth(lastLine);
var ellipseWidth = textPaint.MeasureText(Ellipsis);
// Trim characters off until we have enough room to draw the ellipsis
while (width < lineWidth + ellipseWidth)
{
lineWidth = textPaint.MeasureText(text.SubSequence(start, --end + 1));
}
Text = text.SubSequence(0, end) + Ellipsis;
}
}
}
// Some devices try to auto adjust line spacing, so force default line spacing
// and invalidate the layout as a side effect
SetTextSize(ComplexUnitType.Px, targetTextSize);
SetLineSpacing(_spacingAdd, _spacingMult);
var notifyArgs = new OnTextResizeEventArgs
{
TextView = this,
NewSize = targetTextSize,
OldSize = oldTextSize
};
// Notify the listener if registered
OnTextResize?.Invoke(this, notifyArgs);
// Reset force resize flag
_needsResize = false;
}
/// <summary>
/// Set the text size of the text paint object and use a static layout to render text off screen before measuring
/// </summary>
/// <param name="source"></param>
/// <param name="paint"></param>
/// <param name="width"></param>
/// <param name="textSize"></param>
/// <returns></returns>
private int GetTextHeight(ICharSequence source, TextPaint paint, int width, float textSize)
{
// modified: make a copy of the original TextPaint object for measuring
// (apparently the object gets modified while measuring, see also the
// docs for TextView.getPaint() (which states to access it read-only)
// Update the text paint object
var paintCopy = new TextPaint(paint)
{
TextSize = textSize
};
// Measure using a static layout
var layout = new StaticLayout(source, paintCopy, width, Layout.Alignment.AlignNormal, _spacingMult, _spacingAdd, true);
return layout.Height;
}
}
}
如果有人需要它，这里是相同的代码片段，但Xamarin.Android。
/**
* DO WHAT YOU WANT TO PUBLIC LICENSE
* Version 1, December 2017
*
* Copyright (C) 2017 Nathan Westfall
*
* Everyone is permitted to copy and distribute verbatim or modified
* copies of this license document, and changing it is allowed as long
* as the name is changed.
*
* DO WHAT YOU WANT TO PUBLIC LICENSE
* TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
*
* 0. You just DO WHAT YOU WANT TO.
*/
using Android.Content;
using Android.Runtime;
using Android.Widget;
using Android.Util;
using Android.Text;
using Java.Lang;
namespace My.Text
{
public class AutoResizeTextView : TextView
{
public const float MIN_TEXT_SIZE = 20;
public interface OnTextResizeListener
{
void OnTextResize(TextView textView, float oldSize, float newSize);
}
private const string mEllipsis = "...";
private OnTextResizeListener mTextResizeListener;
private bool mNeedsResize = false;
private float mTextSize;
private float mMaxTextSize = 0;
private float mMinTextSize = MIN_TEXT_SIZE;
private float mSpacingMult = 1.0f;
private float mSpacingAdd = 0.0f;
public bool AddEllipsis { get; set; } = true;
public AutoResizeTextView(Context context) : this(context, null) { }
public AutoResizeTextView(Context context, IAttributeSet attrs) : this(context, attrs, 0) { }
public AutoResizeTextView(Context context, IAttributeSet attrs, int defStyle): base(context, attrs, defStyle)
{
mTextSize = TextSize;
}
protected override void OnTextChanged(ICharSequence text, int start, int lengthBefore, int lengthAfter)
{
base.OnTextChanged(text, start, lengthBefore, lengthAfter);
mNeedsResize = true;
ResetTextSize();
}
protected override void OnSizeChanged(int w, int h, int oldw, int oldh)
{
base.OnSizeChanged(w, h, oldw, oldh);
if (w != oldw || h != oldh)
mNeedsResize = true;
}
public void SetOnResizeListener(OnTextResizeListener listener)
{
mTextResizeListener = listener;
}
public override void SetTextSize([GeneratedEnum] ComplexUnitType unit, float size)
{
base.SetTextSize(unit, size);
mTextSize = TextSize;
}
public override void SetLineSpacing(float add, float mult)
{
base.SetLineSpacing(add, mult);
mSpacingMult = mult;
mSpacingAdd = add;
}
public void SetMaxTextSize(float maxTextSize)
{
mMaxTextSize = maxTextSize;
RequestLayout();
Invalidate();
}
public float GetMaxTextSize()
{
return mMaxTextSize;
}
public void SetMinTextSize(float minTextSize)
{
mMinTextSize = minTextSize;
RequestLayout();
Invalidate();
}
public float GetMinTextSize()
{
return mMinTextSize;
}
public void ResetTextSize()
{
if(mTextSize > 0)
{
base.SetTextSize(ComplexUnitType.Px, mTextSize);
mMaxTextSize = mTextSize;
}
}
protected override void OnLayout(bool changed, int left, int top, int right, int bottom)
{
if(changed || mNeedsResize)
{
int widthLimit = (right - left) - CompoundPaddingLeft - CompoundPaddingRight;
int heightLimit = (bottom - top) - CompoundPaddingBottom - CompoundPaddingTop;
ResizeText(widthLimit, heightLimit);
}
base.OnLayout(changed, left, top, right, bottom);
base.OnLayout(changed, left, top, right, bottom);
}
public void ResizeText()
{
int heightLimit = Height - PaddingBottom - PaddingTop;
int widthLimit = Width - PaddingLeft - PaddingRight;
ResizeText(widthLimit, heightLimit);
}
public void ResizeText(int width, int height)
{
var text = TextFormatted;
if (text == null || text.Length() == 0 || height <= 0 || width <= 0 || mTextSize == 0)
return;
if (TransformationMethod != null)
text = TransformationMethod.GetTransformationFormatted(TextFormatted, this);
TextPaint textPaint = Paint;
float oldTextSize = textPaint.TextSize;
float targetTextSize = mMaxTextSize > 0 ? System.Math.Min(mTextSize, mMaxTextSize) : mTextSize;
int textHeight = GetTextHeight(text, textPaint, width, targetTextSize);
while(textHeight > height && targetTextSize > mMinTextSize)
{
targetTextSize = System.Math.Max(targetTextSize - 2, mMinTextSize);
textHeight = GetTextHeight(text, textPaint, width, targetTextSize);
}
if(AddEllipsis && targetTextSize == mMinTextSize && textHeight > height)
{
TextPaint paint = new TextPaint(textPaint);
StaticLayout layout = new StaticLayout(text, paint, width, Layout.Alignment.AlignNormal, mSpacingMult, mSpacingAdd, false);
if(layout.LineCount > 0)
{
int lastLine = layout.GetLineForVertical(height) - 1;
if (lastLine < 0)
SetText("", BufferType.Normal);
else
{
int start = layout.GetLineStart(lastLine);
int end = layout.GetLineEnd(lastLine);
float lineWidth = layout.GetLineWidth(lastLine);
float ellipseWidth = textPaint.MeasureText(mEllipsis);
while (width < lineWidth + ellipseWidth)
lineWidth = textPaint.MeasureText(text.SubSequence(start, --end + 1).ToString());
SetText(text.SubSequence(0, end) + mEllipsis, BufferType.Normal);
}
}
}
SetTextSize(ComplexUnitType.Px, targetTextSize);
SetLineSpacing(mSpacingAdd, mSpacingMult);
mTextResizeListener?.OnTextResize(this, oldTextSize, targetTextSize);
mNeedsResize = false;
}
private int GetTextHeight(ICharSequence source, TextPaint paint, int width, float textSize)
{
TextPaint paintCopy = new TextPaint(paint);
paintCopy.TextSize = textSize;
StaticLayout layout = new StaticLayout(source, paintCopy, width, Layout.Alignment.AlignNormal, mSpacingMult, mSpacingAdd, false);
return layout.Height;
}
}
}
