我在寻找，以调整在的TextView 将连续文本，使其适合其的getHeight和的getWidth范围内的最佳方式。我不只是在寻找一种方式来包装我想，以确保它两个包裹和足够小，以适应整个屏幕上的文本的。
I'm looking for an optimal way to resize wrapping text in a TextView so that it will fit within its getHeight and getWidth bounds. I'm not simply looking for a way to wrap the text- I want to make sure it both wraps and is small enough to fit entirely on the screen.
我已经看到了一些案件计算器，其中需要自动调整大小，但他们要么是非常特殊的情况下，与黑客的解决方案，有没有办法解决，或者涉及重新绘制的TextView 递归，直到它足够小（这是内存激烈，迫使用户观看文字收缩一步一步的每递归）。
I've seen a few cases on StackOverflow where auto resizing was needed, but they are either very special cases with hack solutions, have no solution, or involve re-drawing the TextView recursively until it is small enough (which is memory intense and forces the user to watch the text shrink step-by-step with every recursion).
但我敢肯定有人在那里发现，不涉及我在做什么很好的解决方案：编写分析和测量的文本，调整文本几个重程序，并重复直到适当规模较小，被发现。
But I'm sure somebody out there has found a good solution that doesn't involve what I'm doing: writing several heavy routines that parse and measure the text, resize the text, and repeat until a suitably small size has been found.
确实的TextView 用什么程序来自动换行？难道不是那些以某种方式使用predict文本是否足够小？
What routines does TextView use to wrap the text? Couldn't those be somehow used to predict whether text will be small enough?
TL;博士：是否有一个最佳实践的方法来自动调整大小的的TextView 来适应，包装，在其的getHeight和的getWidth界限？
tl;dr: is there a best-practice way to auto-resize a TextView to fit, wrapped, in its getHeight and getWidth bounds?
推荐答案
作为一名移动开发者，我很悲哀地发现，支持自动调整大小没什么当地人。我的搜索也没有发现任何为我工作的，到最后，我花了较好的一半，我的周末，并创建了自己的自动调整文本视图。我将在这里发布的code和希望这将是为别人有用。
As a mobile developer, I was sad to find nothing native that supports auto resizing. My searches did not turn up anything that worked for me and in the end, I spent the better half of my weekend and created my own auto resize text view. I will post the code here and hopefully it will be useful for someone else.
本类使用与原来的文本视图来衡量高度的文本油漆静态布局。从那里，我下台了2字体像素，并重新测量，直到我有一个适合的尺寸。最后，如果文本还是放不下，我追加省略号。我不得不要求进行动画处理的文本和重用的意见，这似乎对我有设备运行良好，似乎跑得快够我。
This class uses a static layout with the text paint of the original text view to measure the height. From there, I step down by 2 font pixels and remeasure until I have a size that fits. At the end, if the text still does not fit, I append an ellipsis. I had requirements to animate the text and reuse views and this seems to work well on the devices I have and seems to run fast enough for me.
/**
* 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();
}
}
警告还有一个重要修正了影响的Android 3.1 - 4.04导致所有AutoResizingTextView小工具无法正常工作。请阅读：http://stackoverflow.com/a/21851157/2075875
Warning. There is an important fixed bug affecting Android 3.1 - 4.04 causing all AutoResizingTextView widgets not to work. Please read: http://stackoverflow.com/a/21851157/2075875
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