Auto Fix TextView

/** *               DO WHAT YOU WANT TO PUBLIC LICENSE *                    Version 2, December 2004 *  * Copyright (C) 2004 Sam Hocevar <[e-mail]> *  * 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();    }}