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rafaelneiva/AutoFitTextView.java

Created April 1, 2016 14:29
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AutoFit TextView
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AutoFitTextView.java
import android.annotation.TargetApi;
import android.content.Context;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.graphics.RectF;
import android.os.Build;
import android.text.Layout;
import android.text.StaticLayout;
import android.text.TextPaint;
import android.util.AttributeSet;
import android.util.SparseIntArray;
import android.util.TypedValue;
import android.widget.TextView;
import br.com.zup.naturasemprepresente.R;
import br.com.zup.naturasemprepresente.util.Utils;
/**
* Created by rafaelneiva on 09/12/15.
*/
public class AutoFitTextView extends TextView {
private static final int NO_LINE_LIMIT = -1;
private final RectF _availableSpaceRect = new RectF();
private final SparseIntArray _textCachedSizes = new SparseIntArray();
private SizeTester _sizeTester;
private float _maxTextSize;
private float _spacingMult = 1.0f;
private float _spacingAdd = 0.0f;
private float _minTextSize;
private int _widthLimit;
private int _maxLines;
private boolean _enableSizeCache = true;
private boolean _initiallized = false;
private TextPaint paint;
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);
}
public AutoFitTextView(Context context) {
this(context, null, 0);
}
public AutoFitTextView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public AutoFitTextView(final Context context, final AttributeSet attrs, final int defStyleAttr) {
super(context, attrs, defStyleAttr);
if (paint == null)
paint = new TextPaint(getPaint());
paint.setTypeface(this.getTypeface());
adjustTextSize();
// using the minimal recommended font size
_minTextSize = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, 12, getResources().getDisplayMetrics());
_maxTextSize = getTextSize();
if (_maxLines == 0)
// no value was assigned during construction
_maxLines = NO_LINE_LIMIT;
// prepare size tester:
_sizeTester = new SizeTester() {
final RectF textRect = new RectF();
@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
@Override
public int onTestSize(final int suggestedSize, final RectF availableSPace) {
paint.setTextSize(suggestedSize);
final String text = getText().toString();
final boolean singleLine = getMaxLines() == 1;
if (singleLine) {
textRect.bottom = paint.getFontSpacing();
textRect.right = paint.measureText(text);
} else {
final StaticLayout layout = new StaticLayout(text, paint, _widthLimit, Layout.Alignment.ALIGN_NORMAL, _spacingMult, _spacingAdd, true);
// return early if we have more lines
if (getMaxLines() != NO_LINE_LIMIT && layout.getLineCount() > getMaxLines())
return 1;
textRect.bottom = layout.getHeight();
int maxWidth = -1;
for (int i = 0; i < layout.getLineCount(); i++)
if (maxWidth < layout.getLineRight(i) - layout.getLineLeft(i))
maxWidth = (int) layout.getLineRight(i) - (int) layout.getLineLeft(i);
textRect.right = maxWidth;
}
textRect.offsetTo(0, 0);
if (availableSPace.contains(textRect))
// may be too small, don't worry we will find the best match
return -1;
// else, too big
return 1;
}
};
_initiallized = true;
}
@Override
public void setTextSize(final float size) {
_maxTextSize = size;
_textCachedSizes.clear();
adjustTextSize();
}
@Override
public void setMaxLines(final int maxlines) {
super.setMaxLines(maxlines);
_maxLines = maxlines;
reAdjust();
}
@Override
public int getMaxLines() {
return _maxLines;
}
@Override
public void setSingleLine() {
super.setSingleLine();
_maxLines = 1;
reAdjust();
}
@Override
public void setSingleLine(final boolean singleLine) {
super.setSingleLine(singleLine);
if (singleLine)
_maxLines = 1;
else _maxLines = NO_LINE_LIMIT;
reAdjust();
}
@Override
public void setLines(final int lines) {
super.setLines(lines);
_maxLines = lines;
reAdjust();
}
@Override
public void setTextSize(final int unit, final float size) {
final Context c = getContext();
Resources r;
if (c == null)
r = Resources.getSystem();
else r = c.getResources();
_maxTextSize = TypedValue.applyDimension(unit, size, r.getDisplayMetrics());
_textCachedSizes.clear();
adjustTextSize();
}
@Override
public void setLineSpacing(final float add, final float mult) {
super.setLineSpacing(add, mult);
_spacingMult = mult;
_spacingAdd = add;
}
/**
* Set the lower text size limit and invalidate the view
*
* @param minTextSize
*/
public void setMinTextSize(final float minTextSize) {
_minTextSize = minTextSize;
reAdjust();
}
public void reAdjust() {
adjustTextSize();
}
private void adjustTextSize() {
if (!_initiallized)
return;
final int startSize = (int) _minTextSize;
final int heightLimit = getMeasuredHeight() - getCompoundPaddingBottom() - getCompoundPaddingTop();
_widthLimit = getMeasuredWidth() - getCompoundPaddingLeft() - getCompoundPaddingRight();
if (_widthLimit <= 0)
return;
_availableSpaceRect.right = _widthLimit;
_availableSpaceRect.bottom = heightLimit;
superSetTextSize(startSize);
}
private void superSetTextSize(int startSize) {
super.setTextSize(TypedValue.COMPLEX_UNIT_PX, efficientTextSizeSearch(startSize, (int) _maxTextSize, _sizeTester, _availableSpaceRect));
}
/**
* 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 setEnableSizeCache(final boolean enable) {
_enableSizeCache = enable;
_textCachedSizes.clear();
adjustTextSize();
}
private int efficientTextSizeSearch(final int start, final int end, final SizeTester sizeTester, final RectF availableSpace) {
if (!_enableSizeCache)
return binarySearch(start, end, sizeTester, availableSpace);
final String text = getText().toString();
final int key = text == null ? 0 : text.length();
int size = _textCachedSizes.get(key);
if (size != 0)
return size;
size = binarySearch(start, end, sizeTester, availableSpace);
_textCachedSizes.put(key, size);
return size;
}
private int binarySearch(final int start, final int end, final SizeTester sizeTester, final RectF availableSpace) {
int lastBest = start;
int lo = start;
int hi = end - 1;
int mid = 0;
while (lo <= hi) {
mid = lo + hi >>> 1;
final 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(final int width, final int height, final int oldwidth, final int oldheight) {
_textCachedSizes.clear();
super.onSizeChanged(width, height, oldwidth, oldheight);
if (width != oldwidth || height != oldheight)
reAdjust();
}
}
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