自动缩放TextView文本以适应范围

作为一名移动开发人员，我很难过没有发现任何支持自动调整大小的本地产品。我的搜索没有找到任何对我有用的东西，最后，我花了更多的时间在我的周末，并创建了我自己的自动调整文本视图。我将在这里张贴代码，并希望它将对其他人有用。该类使用静态布局和原始文本视图的文本绘制来度量高度。从那里，我放下了2个字体像素，并重新测量，直到我有一个适合的大小。最后，如果文本仍然不适合，我附加一个省略号。我有动画文本和重用视图的要求，这在我所拥有的设备上似乎运行得很好，并且对我来说运行得足够快。/** * 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。影响Android3.1-4.04的一个重要的修复错误导致所有AutoResizingTextView小部件无法工作。

自动缩放TextView文本以适应范围

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