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
实际上解决方案是在谷歌的DialogTitle类…虽然它不如公认的方法有效，但它更简单，也更容易适应。
public class SingleLineTextView extends TextView {
public SingleLineTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
setSingleLine();
setEllipsize(TruncateAt.END);
}
public SingleLineTextView(Context context, AttributeSet attrs) {
super(context, attrs);
setSingleLine();
setEllipsize(TruncateAt.END);
}
public SingleLineTextView(Context context) {
super(context);
setSingleLine();
setEllipsize(TruncateAt.END);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
final Layout layout = getLayout();
if (layout != null) {
final int lineCount = layout.getLineCount();
if (lineCount > 0) {
final int ellipsisCount = layout.getEllipsisCount(lineCount - 1);
if (ellipsisCount > 0) {
final float textSize = getTextSize();
// textSize is already expressed in pixels
setTextSize(TypedValue.COMPLEX_UNIT_PX, (textSize - 1));
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
}
}
}
其他回答
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;
}
}
}
感谢Chase和onoelle，对于懒惰的程序员，让我在这里发布一个他们神奇的合并代码的工作版本，在一个按钮上改编，而不是一个TextView。
用AutoResizeTextButtons替换所有的按钮(不是ImageButtons)，同样无聊的问题也得到了解决。
这是代码。我只是删除了导入。
/**
* DO WHAT THE FUCK 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 THE FUCK YOU WANT TO PUBLIC LICENSE
* TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
*
* 0. You just DO WHAT THE FUCK YOU WANT TO.
* made better by onoelle
* adapted for button by beppi
*/
/**
* Text Button 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.
*
* @author Chase Colburn
* @since Apr 4, 2011
*/
public class AutoResizeTextButton extends Button {
// Minimum text size for this text view
public static final float MIN_TEXT_SIZE = 20;
// Interface for resize notifications
public interface OnTextResizeListener {
public void onTextResize(Button textView, float oldSize, float newSize);
}
// Our ellipse string
private static final String mEllipsis = "...";
// Registered resize listener
private OnTextResizeListener mTextResizeListener;
// Flag for text and/or size changes to force a resize
private boolean mNeedsResize = false;
// Text size that is set from code. This acts as a starting point for resizing
private float mTextSize;
// Temporary upper bounds on the starting text size
private float mMaxTextSize = 0;
// Lower bounds for text size
private float mMinTextSize = MIN_TEXT_SIZE;
// Text view line spacing multiplier
private float mSpacingMult = 1.0f;
// Text view additional line spacing
private float mSpacingAdd = 0.0f;
// Add ellipsis to text that overflows at the smallest text size
private boolean mAddEllipsis = true;
// Default constructor override
public AutoResizeTextButton(Context context) {
this(context, null);
}
// Default constructor when inflating from XML file
public AutoResizeTextButton(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
// Default constructor override
public AutoResizeTextButton(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
mTextSize = getTextSize();
}
/**
* When text changes, set the force resize flag to true and reset the text size.
*/
@Override
protected void onTextChanged(final CharSequence text, final int start, final int before, final int after) {
mNeedsResize = true;
// Since this view may be reused, it is good to reset the text size
resetTextSize();
}
/**
* If the text view size changed, set the force resize flag to true
*/
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
if (w != oldw || h != oldh) {
mNeedsResize = true;
}
}
/**
* Register listener to receive resize notifications
* @param listener
*/
public void setOnResizeListener(OnTextResizeListener listener) {
mTextResizeListener = listener;
}
/**
* Override the set text size to update our internal reference values
*/
@Override
public void setTextSize(float size) {
super.setTextSize(size);
mTextSize = getTextSize();
}
/**
* Override the set text size to update our internal reference values
*/
@Override
public void setTextSize(int unit, float size) {
super.setTextSize(unit, size);
mTextSize = getTextSize();
}
/**
* Override the set line spacing to update our internal reference values
*/
@Override
public void setLineSpacing(float add, float mult) {
super.setLineSpacing(add, mult);
mSpacingMult = mult;
mSpacingAdd = add;
}
/**
* Set the upper text size limit and invalidate the view
* @param maxTextSize
*/
public void setMaxTextSize(float maxTextSize) {
mMaxTextSize = maxTextSize;
requestLayout();
invalidate();
}
/**
* Return upper text size limit
* @return
*/
public float getMaxTextSize() {
return mMaxTextSize;
}
/**
* Set the lower text size limit and invalidate the view
* @param minTextSize
*/
public void setMinTextSize(float minTextSize) {
mMinTextSize = minTextSize;
requestLayout();
invalidate();
}
/**
* Return lower text size limit
* @return
*/
public float getMinTextSize() {
return mMinTextSize;
}
/**
* Set flag to add ellipsis to text that overflows at the smallest text size
* @param addEllipsis
*/
public void setAddEllipsis(boolean addEllipsis) {
mAddEllipsis = addEllipsis;
}
/**
* Return flag to add ellipsis to text that overflows at the smallest text size
* @return
*/
public boolean getAddEllipsis() {
return mAddEllipsis;
}
/**
* Reset the text to the original size
*/
public void resetTextSize() {
if(mTextSize > 0) {
super.setTextSize(TypedValue.COMPLEX_UNIT_PX, mTextSize);
mMaxTextSize = mTextSize;
}
}
/**
* Resize text after measuring
*/
@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
if(changed || mNeedsResize) {
int widthLimit = (right - left) - getCompoundPaddingLeft() - getCompoundPaddingRight();
int heightLimit = (bottom - top) - getCompoundPaddingBottom() - getCompoundPaddingTop();
resizeText(widthLimit, heightLimit);
}
super.onLayout(changed, left, top, right, bottom);
}
/**
* Resize the text size with default width and height
*/
public void resizeText() {
int heightLimit = getHeight() - getPaddingBottom() - getPaddingTop();
int widthLimit = getWidth() - getPaddingLeft() - getPaddingRight();
resizeText(widthLimit, heightLimit);
}
/**
* Resize the text size with specified width and height
* @param width
* @param height
*/
public void resizeText(int width, int height) {
CharSequence text = getText();
// 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 || mTextSize == 0) {
return;
}
// Get the text view's paint object
TextPaint textPaint = getPaint();
// Store the current text size
float oldTextSize = textPaint.getTextSize();
// If there is a max text size set, use the lesser of that and the default text size
float targetTextSize = mMaxTextSize > 0 ? Math.min(mTextSize, mMaxTextSize) : mTextSize;
// Get the required text height
int 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 = 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(mAddEllipsis && targetTextSize == mMinTextSize && textHeight > height) {
// Draw using a static layout
// modified: use a copy of TextPaint for measuring
TextPaint paint = new TextPaint(textPaint);
StaticLayout layout = new StaticLayout(text, paint, width, Alignment.ALIGN_NORMAL, mSpacingMult, mSpacingAdd, false);
// Check that we have a least one line of rendered text
if(layout.getLineCount() > 0) {
// Since the line at the specific vertical position would be cut off,
// we must trim up to the previous line
int lastLine = layout.getLineForVertical(height) - 1;
// If the text would not even fit on a single line, clear it
if(lastLine < 0) {
setText("");
}
// Otherwise, trim to the previous line and add an ellipsis
else {
int start = layout.getLineStart(lastLine);
int end = layout.getLineEnd(lastLine);
float lineWidth = layout.getLineWidth(lastLine);
float ellipseWidth = textPaint.measureText(mEllipsis);
// Trim characters off until we have enough room to draw the ellipsis
while(width < lineWidth + ellipseWidth) {
lineWidth = textPaint.measureText(text.subSequence(start, --end + 1).toString());
}
setText(text.subSequence(0, end) + mEllipsis);
}
}
}
// Some devices try to auto adjust line spacing, so force default line spacing
// and invalidate the layout as a side effect
// textPaint.setTextSize(targetTextSize);
// modified: setting text size via this.setTextSize (instead of textPaint.setTextSize(targetTextSize))
setTextSize(TypedValue.COMPLEX_UNIT_PX, targetTextSize);
setLineSpacing(mSpacingAdd, mSpacingMult);
// Notify the listener if registered
if(mTextResizeListener != null) {
mTextResizeListener.onTextResize(this, oldTextSize, targetTextSize);
}
// Reset force resize flag
mNeedsResize = false;
}
// Set the text size of the text paint object and use a static layout to render text off screen before measuring
private int getTextHeight(CharSequence source, TextPaint originalPaint, 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
TextPaint paint = new TextPaint(originalPaint);
paint.setTextSize(textSize);
// Measure using a static layout
StaticLayout layout = new StaticLayout(source, paint, width, Alignment.ALIGN_NORMAL, mSpacingMult, mSpacingAdd, true);
return layout.getHeight();
}
}
用法:
把一个AutoResizeTextButton在你的xml中代替一个正常的按钮，没有改变 一切。 在onCreate()中放置(例如):
myButton = (AutoResizeTextButton)getView().findViewById(id.myButton);
myButton.setMinTextSize(8f);
myButton.resizeText();
I needed a specific solution. I have got an edittext and textview in my layout. The textview is fixed height and width. When the user starts to type in the edittext, the text should immediately appear in the textview. The text in the textfield should auto - resize to fit the textview. So I updated Chase's solution to work for me. So when the text changes in the textview, resizing starts. The difference between mine and Chase's soluton: resizing is done even if the user DELETE some chars. I hope it can help someone.
public class TextFitTextView extends TextView {
// Minimum text size for this text view
public static final float MIN_TEXT_SIZE = 10;
// Maximum text size for this text view - if it is 0, then the text acts
// like match_parent
public static final float MAX_TEXT_SIZE = 0;
// Our ellipse string
private static final String mEllipsis = "...";
// Text size that is set from code. This acts as a starting point for
// resizing
private float mTextSize;
// Lower bounds for text size
private float mMinTextSize = MIN_TEXT_SIZE;
// Max bounds for text size
private float mMaxTextSize = MAX_TEXT_SIZE;
// Text view line spacing multiplier
private float mSpacingMult = 1.0f;
// Text view additional line spacing
private float mSpacingAdd = 0.0f;
// Add ellipsis to text that overflows at the smallest text size
private boolean mAddEllipsis = true;
// Add ellipsis to text that overflows at the smallest text size
private int heightLimit;
private int widthLimit;
// Default constructor override
public TextFitTextView(Context context) {
this(context, null);
}
// Default constructor when inflating from XML file
public TextFitTextView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
// Default constructor override
public TextFitTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
mTextSize = getTextSize();
}
/**
* When text changes resize the text size.
*/
@Override
protected void onTextChanged(final CharSequence text, final int start, final int before, final int after) {
// if we are adding new chars to text
if (before <= after && after != 1) {
resizeText(true);
// now we are deleting chars
} else {
resizeText(false);
}
}
/**
* Override the set text size to update our internal reference values
*/
@Override
public void setTextSize(float size) {
super.setTextSize(size);
mTextSize = getTextSize();
}
/**
* Override the set text size to update our internal reference values
*/
@Override
public void setTextSize(int unit, float size) {
super.setTextSize(unit, size);
mTextSize = getTextSize();
}
/**
* Override the set line spacing to update our internal reference values
*/
@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;
requestLayout();
invalidate();
}
/**
* Return lower text size limit
*
* @return
*/
public float getMinTextSize() {
return mMinTextSize;
}
/**
* Set flag to add ellipsis to text that overflows at the smallest text size
*
* @param addEllipsis
*/
public void setAddEllipsis(boolean addEllipsis) {
mAddEllipsis = addEllipsis;
}
/**
* Return flag to add ellipsis to text that overflows at the smallest text
* size
*
* @return
*/
public boolean getAddEllipsis() {
return mAddEllipsis;
}
/**
* Get width and height limits
*/
@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
if (widthLimit == 0 && heightLimit == 0) {
widthLimit = (right - left) - getCompoundPaddingLeft() - getCompoundPaddingRight();
heightLimit = (bottom - top) - getCompoundPaddingBottom() - getCompoundPaddingTop();
}
super.onLayout(changed, left, top, right, bottom);
}
/**
* Resize the text size with specified width and height
*
* @param width
* @param height
*/
public void resizeText(boolean increase) {
CharSequence text = getText();
// Do not resize if the view does not have dimensions or there is no
// text
if (text == null || text.length() == 0 || heightLimit <= 0 || widthLimit <= 0 || mTextSize == 0) {
return;
}
// Get the text view's paint object
TextPaint textPaint = getPaint();
// Get the required text height
int textHeight = getTextHeight(text, textPaint, widthLimit, mTextSize);
// If the text length is increased
// Until we either fit within our text view or we had reached our min
// text size, incrementally try smaller sizes
if (increase) {
while (textHeight > heightLimit && mTextSize > mMinTextSize) {
mTextSize = Math.max(mTextSize - 2, mMinTextSize);
textHeight = getTextHeight(text, textPaint, widthLimit, mTextSize);
}
}
// text length has been decreased
else {
// if max test size is set then add it to while condition
if (mMaxTextSize != 0) {
while (textHeight < heightLimit && mTextSize <= mMaxTextSize) {
mTextSize = mTextSize + 2;
textHeight = getTextHeight(text, textPaint, widthLimit, mTextSize);
}
} else {
while (textHeight < heightLimit) {
mTextSize = mTextSize + 2;
textHeight = getTextHeight(text, textPaint, widthLimit, mTextSize);
}
}
mTextSize = textHeight > heightLimit ? mTextSize - 2 : mTextSize;
}
// If we had reached our minimum text size and still don't fit, append
// an ellipsis
if (mAddEllipsis && mTextSize == mMinTextSize && textHeight > heightLimit) {
// Draw using a static layout
TextPaint paint = new TextPaint(textPaint);
StaticLayout layout = new StaticLayout(text, paint, widthLimit, Alignment.ALIGN_NORMAL, mSpacingMult,
mSpacingAdd, false);
// Check that we have a least one line of rendered text
if (layout.getLineCount() > 0) {
// Since the line at the specific vertical position would be cut
// off,
// we must trim up to the previous line
int lastLine = layout.getLineForVertical(heightLimit) - 1;
// If the text would not even fit on a single line, clear it
if (lastLine < 0) {
setText("");
}
// Otherwise, trim to the previous line and add an ellipsis
else {
int start = layout.getLineStart(lastLine);
int end = layout.getLineEnd(lastLine);
float lineWidth = layout.getLineWidth(lastLine);
float ellipseWidth = paint.measureText(mEllipsis);
// Trim characters off until we have enough room to draw the
// ellipsis
while (widthLimit < lineWidth + ellipseWidth) {
lineWidth = paint.measureText(text.subSequence(start, --end + 1).toString());
}
setText(text.subSequence(0, end) + mEllipsis);
}
}
}
// Some devices try to auto adjust line spacing, so force default line
// spacing
// and invalidate the layout as a side effect
setTextSize(TypedValue.COMPLEX_UNIT_PX, mTextSize);
setLineSpacing(mSpacingAdd, mSpacingMult);
}
// Set the text size of the text paint object and use a static layout to
// render text off screen before measuring
private int getTextHeight(CharSequence source, TextPaint originalPaint, int width, float textSize) {
// Update the text paint object
TextPaint paint = new TextPaint(originalPaint);
paint.setTextSize(textSize);
// Measure using a static layout
StaticLayout layout = new StaticLayout(source, paint, width, Alignment.ALIGN_NORMAL, mSpacingMult, mSpacingAdd,
true);
return layout.getHeight();
}
}
适合边界的文本(1行)
让文本缩小到适合一行的边界:
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:autoSizeTextType="uniform"
android:lines:"1"
/>
我只是借用了一些其他人的想法，并在下面写了一些代码，可能会有帮助。
import android.content.Context;
import android.graphics.Canvas;
import android.text.Layout.Alignment;
import android.text.StaticLayout;
import android.text.TextPaint;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.widget.TextView;
public class AutoResizeTextView extends TextView {
private static final int MAX_SIZE = 1000;
private static final int MIN_SIZE = 5;
private TextPaint mTextPaint;
private float mSpacingMult = 1.0f;
private float mSpacingAdd = 0.0f;
private boolean needAdapt = false;
private boolean adapting = false;
public AutoResizeTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init();
}
public AutoResizeTextView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public AutoResizeTextView(Context context) {
super(context);
init();
}
private void init() {
mTextPaint = new TextPaint();
}
@Override
protected void onDraw(Canvas canvas) {
if (adapting) {
return;
}
if (needAdapt) {
adaptTextSize();
} else {
super.onDraw(canvas);
}
}
private void adaptTextSize() {
CharSequence text = getText();
int viewWidth = getMeasuredWidth();
int viewHeight = getMeasuredHeight();
if (viewWidth==0 || viewHeight==0
|| TextUtils.isEmpty(text)) {
return;
}
adapting = true;
/* binary search */
int bottom=MIN_SIZE, top=MAX_SIZE, mid = 0;
while (bottom <= top) {
mid = (bottom + top)/2;
mTextPaint.setTextSize(mid);
int textWidth = (int) mTextPaint.measureText(text, 0, text.length());
int textHeight = getTextHeight(text, viewWidth);
if (textWidth<viewWidth && textHeight<viewHeight) {
bottom = mid+1;
} else {
top = mid-1;
}
}
int newSize = mid-1;
setTextSize(TypedValue.COMPLEX_UNIT_PX, newSize);
adapting=false;
needAdapt = false;
invalidate();
}
private int getTextHeight(CharSequence text, int targetWidth) {
StaticLayout layout = new StaticLayout(text, mTextPaint, targetWidth,
Alignment.ALIGN_NORMAL, mSpacingMult, mSpacingAdd, true);
return layout.getHeight();
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
needAdapt = true;
}
@Override
protected void onTextChanged(CharSequence text, int start,
int lengthBefore, int lengthAfter) {
super.onTextChanged(text, start, lengthBefore, lengthAfter);
needAdapt = true;
}
@Override
public void setLineSpacing(float add, float mult) {
super.setLineSpacing(add, mult);
mSpacingMult = mult;
mSpacingAdd = add;
}
}
