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
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();
}
}
其他回答
这里还有另一个解决方案，只是为了好玩。它可能不是很有效，但它确实处理了文本的高度和宽度，以及有标记的文本。
@Override
protected void onMeasure(final int widthMeasureSpec, final int heightMeasureSpec)
{
if ((MeasureSpec.getMode(widthMeasureSpec) != MeasureSpec.UNSPECIFIED)
&& (MeasureSpec.getMode(heightMeasureSpec) != MeasureSpec.UNSPECIFIED)) {
final float desiredWidth = MeasureSpec.getSize(widthMeasureSpec);
final float desiredHeight = MeasureSpec.getSize(heightMeasureSpec);
float textSize = getTextSize();
float lastScale = Float.NEGATIVE_INFINITY;
while (textSize > MINIMUM_AUTO_TEXT_SIZE_PX) {
// Measure how big the textview would like to be with the current text size.
super.onMeasure(MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED);
// Calculate how much we'd need to scale it to fit the desired size, and
// apply that scaling to the text size as an estimate of what we need.
final float widthScale = desiredWidth / getMeasuredWidth();
final float heightScale = desiredHeight / getMeasuredHeight();
final float scale = Math.min(widthScale, heightScale);
// If we don't need to shrink the text, or we don't seem to be converging, we're done.
if ((scale >= 1f) || (scale <= lastScale)) {
break;
}
// Shrink the text size and keep trying.
textSize = Math.max((float) Math.floor(scale * textSize), MINIMUM_AUTO_TEXT_SIZE_PX);
setTextSize(TypedValue.COMPLEX_UNIT_PX, textSize);
lastScale = scale;
}
}
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
作为一名手机开发者，我很遗憾地发现没有任何原生的支持自动调整大小的功能。我的搜索没有找到任何对我有用的东西，最后，我花了大半个周末的时间创建了我自己的自动调整文本视图。我将在这里发布代码，希望它对其他人有用。
这个类使用带有原始文本视图的文本绘制的静态布局来测量高度。从那里，我后退2个字体像素，重新测量，直到我有一个合适的大小。在最后，如果文本仍然不合适，我附加一个省略号。我需要动画文本和重用视图，这似乎在我拥有的设备上工作得很好，似乎运行得足够快。
/**
* 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.
*/
import android.content.Context;
import android.text.Layout.Alignment;
import android.text.StaticLayout;
import android.text.TextPaint;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.widget.TextView;
/**
* 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.
*
* @author Chase Colburn
* @since Apr 4, 2011
*/
public class AutoResizeTextView extends TextView {
// 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(TextView 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 AutoResizeTextView(Context context) {
this(context, null);
}
// Default constructor when inflating from XML file
public AutoResizeTextView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
// Default constructor override
public AutoResizeTextView(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;
}
if (getTransformationMethod() != null) {
text = getTransformationMethod().getTransformation(text, this);
}
// 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);
// Draw using a static layout
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
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 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)
TextPaint paintCopy = new TextPaint(paint);
// Update the text paint object
paintCopy.setTextSize(textSize);
// Measure using a static layout
StaticLayout layout = new StaticLayout(source, paintCopy, width, Alignment.ALIGN_NORMAL, mSpacingMult, mSpacingAdd, true);
return layout.getHeight();
}
}
警告。有一个影响Android 3.1 - 4.04的重要修复错误，导致所有AutoResizingTextView小部件无法工作。请阅读:https://stackoverflow.com/a/21851157/2075875
AppcompatTextView现在支持从支持库26.0开始自动调整大小。TextView在Android O也以同样的方式工作。更多信息可以在这里找到。一个简单的演示程序可以在这里找到。
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:autoSizeTextType="uniform"
app:autoSizeMinTextSize="12sp"
app:autoSizeMaxTextSize="100sp"
app:autoSizeStepGranularity="2sp"
/>
</LinearLayout>
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();
}
}
}
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();
