package com.sf.DarkCalculator;
import android.content.Context;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.os.Build;
import android.text.Editable;
import android.text.Layout;
import android.text.StaticLayout;
import android.text.TextPaint;
import android.text.TextWatcher;
import android.text.method.SingleLineTransformationMethod;
import android.text.method.TransformationMethod;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.util.Log;
import android.util.TypedValue;
import android.view.View;
import android.widget.TextView;
import java.util.ArrayList;
/**
* A helper class to enable automatically resizing {@link TextView}`s {@code textSize} to fit
* within its bounds.
*
* @attr ref R.styleable.AutofitTextView_sizeToFit
* @attr ref R.styleable.AutofitTextView_minTextSize
* @attr ref R.styleable.AutofitTextView_precision
*/
public class AutofitHelper {
private static final String TAG = "AutoFitTextHelper";
private static final boolean SPEW = false;
// Minimum size of the text in pixels
private static final int DEFAULT_MIN_TEXT_SIZE = 8; //sp
// How precise we want to be when reaching the target textWidth size
private static final float DEFAULT_PRECISION = 0.5f;
/**
* Creates a new instance of {@code AutofitHelper} that wraps a {@link TextView} and enables
* automatically sizing the text to fit.
*/
public static AutofitHelper create(TextView view) {
return create(view, null, 0);
}
/**
* Creates a new instance of {@code AutofitHelper} that wraps a {@link TextView} and enables
* automatically sizing the text to fit.
*/
public static AutofitHelper create(TextView view, AttributeSet attrs) {
return create(view, attrs, 0);
}
/**
* Creates a new instance of {@code AutofitHelper} that wraps a {@link TextView} and enables
* automatically sizing the text to fit.
*/
public static AutofitHelper create(TextView view, AttributeSet attrs, int defStyle) {
AutofitHelper helper = new AutofitHelper(view);
boolean sizeToFit = true;
if (attrs != null) {
Context context = view.getContext();
int minTextSize = (int) helper.getMinTextSize();
float precision = helper.getPrecision();
TypedArray ta = context.obtainStyledAttributes(
attrs,
R.styleable.AutofitTextView,
defStyle,
0);
sizeToFit = ta.getBoolean(R.styleable.AutofitTextView_sizeToFit, sizeToFit);
minTextSize = ta.getDimensionPixelSize(R.styleable.AutofitTextView_minTextSize,
minTextSize);
precision = ta.getFloat(R.styleable.AutofitTextView_precision, precision);
ta.recycle();
helper.setMinTextSize(TypedValue.COMPLEX_UNIT_PX, minTextSize)
.setPrecision(precision);
}
helper.setEnabled(sizeToFit);
return helper;
}
/**
* Re-sizes the textSize of the TextView so that the text fits within the bounds of the View.
*/
private static void autofit(TextView view, TextPaint paint, float minTextSize, float maxTextSize,
int maxLines, float precision) {
if (maxLines <= 0 || maxLines == Integer.MAX_VALUE) {
// Don't auto-size since there's no limit on lines.
return;
}
int targetWidth = view.getWidth() - view.getPaddingLeft() - view.getPaddingRight();
if (targetWidth <= 0) {
return;
}
CharSequence text = view.getText();
TransformationMethod method = view.getTransformationMethod();
if (method != null) {
text = method.getTransformation(text, view);
}
Context context = view.getContext();
Resources r = Resources.getSystem();
DisplayMetrics displayMetrics;
float size = maxTextSize;
float high = size;
float low = 0;
if (context != null) {
r = context.getResources();
}
displayMetrics = r.getDisplayMetrics();
paint.set(view.getPaint());
paint.setTextSize(size);
if ((maxLines == 1 && paint.measureText(text, 0, text.length()) > targetWidth)
|| getLineCount(text, paint, size, targetWidth, displayMetrics) > maxLines) {
size = getAutofitTextSize(text, paint, targetWidth, maxLines, low, high, precision,
displayMetrics);
}
if (size < minTextSize) {
size = minTextSize;
}
view.setTextSize(TypedValue.COMPLEX_UNIT_PX, size);
}
/**
* Recursive binary search to find the best size for the text.
*/
private static float getAutofitTextSize(CharSequence text, TextPaint paint,
float targetWidth, int maxLines, float low, float high, float precision,
DisplayMetrics displayMetrics) {
float mid = (low + high) / 2.0f;
int lineCount = 1;
StaticLayout layout = null;
paint.setTextSize(TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_PX, mid,
displayMetrics));
if (maxLines != 1) {
layout = new StaticLayout(text, paint, (int) targetWidth, Layout.Alignment.ALIGN_NORMAL,
1.0f, 0.0f, true);
lineCount = layout.getLineCount();
}
if (SPEW) Log.d(TAG, "low=" + low + " high=" + high + " mid=" + mid +
" target=" + targetWidth + " maxLines=" + maxLines + " lineCount=" + lineCount);
if (lineCount > maxLines) {
// For the case that `text` has more newline characters than `maxLines`.
if ((high - low) < precision) {
return low;
}
return getAutofitTextSize(text, paint, targetWidth, maxLines, low, mid, precision,
displayMetrics);
} else if (lineCount < maxLines) {
return getAutofitTextSize(text, paint, targetWidth, maxLines, mid, high, precision,
displayMetrics);
} else {
float maxLineWidth = 0;
if (maxLines == 1) {
maxLineWidth = paint.measureText(text, 0, text.length());
} else {
for (int i = 0; i < lineCount; i++) {
if (layout.getLineWidth(i) > maxLineWidth) {
maxLineWidth = layout.getLineWidth(i);
}
}
}
if ((high - low) < precision) {
return low;
} else if (maxLineWidth > targetWidth) {
return getAutofitTextSize(text, paint, targetWidth, maxLines, low, mid, precision,
displayMetrics);
} else if (maxLineWidth < targetWidth) {
return getAutofitTextSize(text, paint, targetWidth, maxLines, mid, high, precision,
displayMetrics);
} else {
return mid;
}
}
}
private static int getLineCount(CharSequence text, TextPaint paint, float size, float width,
DisplayMetrics displayMetrics) {
paint.setTextSize(TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_PX, size,
displayMetrics));
StaticLayout layout = new StaticLayout(text, paint, (int) width,
Layout.Alignment.ALIGN_NORMAL, 1.0f, 0.0f, true);
return layout.getLineCount();
}
private static int getMaxLines(TextView view) {
int maxLines = -1; // No limit (Integer.MAX_VALUE also means no limit)
TransformationMethod method = view.getTransformationMethod();
if (method != null && method instanceof SingleLineTransformationMethod) {
maxLines = 1;
} else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
// setMaxLines() and getMaxLines() are only available on android-16+
maxLines = view.getMaxLines();
}
return maxLines;
}
// Attributes
private TextView mTextView;
private TextPaint mPaint;
/**
* Original textSize of the TextView.
*/
private float mTextSize;
private int mMaxLines;
private float mMinTextSize;
private float mMaxTextSize;
private float mPrecision;
private boolean mEnabled;
private boolean mIsAutofitting;
private ArrayList<OnTextSizeChangeListener> mListeners;
private TextWatcher mTextWatcher = new AutofitTextWatcher();
private View.OnLayoutChangeListener mOnLayoutChangeListener =
new AutofitOnLayoutChangeListener();
private AutofitHelper(TextView view) {
final Context context = view.getContext();
float scaledDensity = context.getResources().getDisplayMetrics().scaledDensity;
mTextView = view;
mPaint = new TextPaint();
setRawTextSize(view.getTextSize());
mMaxLines = getMaxLines(view);
mMinTextSize = scaledDensity * DEFAULT_MIN_TEXT_SIZE;
mMaxTextSize = mTextSize;
mPrecision = DEFAULT_PRECISION;
}
/**
* Adds an {@link OnTextSizeChangeListener} to the list of those whose methods are called
* whenever the {@link TextView}'s {@code textSize} changes.
*/
public AutofitHelper addOnTextSizeChangeListener(OnTextSizeChangeListener listener) {
if (mListeners == null) {
mListeners = new ArrayList<OnTextSizeChangeListener>();
}
mListeners.add(listener);
return this;
}
/**
* Removes the specified {@link OnTextSizeChangeListener} from the list of those whose methods
* are called whenever the {@link TextView}'s {@code textSize} changes.
*/
public AutofitHelper removeOnTextSizeChangeListener(OnTextSizeChangeListener listener) {
if (mListeners != null) {
mListeners.remove(listener);
}
return this;
}
/**
* Returns the amount of precision used to calculate the correct text size to fit within its
* bounds.
*/
public float getPrecision() {
return mPrecision;
}
/**
* Set the amount of precision used to calculate the correct text size to fit within its
* bounds. Lower precision is more precise and takes more time.
*
* @param precision The amount of precision.
*/
public AutofitHelper setPrecision(float precision) {
if (mPrecision != precision) {
mPrecision = precision;
autofit();
}
return this;
}
/**
* Returns the minimum size (in pixels) of the text.
*/
public float getMinTextSize() {
return mMinTextSize;
}
/**
* Set the minimum text size to the given value, interpreted as "scaled pixel" units. This size
* is adjusted based on the current density and user font size preference.
*
* @param size The scaled pixel size.
* @attr ref me.grantland.R.styleable#AutofitTextView_minTextSize
*/
public AutofitHelper setMinTextSize(float size) {
return setMinTextSize(TypedValue.COMPLEX_UNIT_SP, size);
}
/**
* Set the minimum text size to a given unit and value. See TypedValue for the possible
* dimension units.
*
* @param unit The desired dimension unit.
* @param size The desired size in the given units.
* @attr ref me.grantland.R.styleable#AutofitTextView_minTextSize
*/
public AutofitHelper setMinTextSize(int unit, float size) {
Context context = mTextView.getContext();
Resources r = Resources.getSystem();
if (context != null) {
r = context.getResources();
}
setRawMinTextSize(TypedValue.applyDimension(unit, size, r.getDisplayMetrics()));
return this;
}
private void setRawMinTextSize(float size) {
if (size != mMinTextSize) {
mMinTextSize = size;
autofit();
}
}
/**
* Returns the maximum size (in pixels) of the text.
*/
public float getMaxTextSize() {
return mMaxTextSize;
}
/**
* Set the maximum text size to the given value, interpreted as "scaled pixel" units. This size
* is adjusted based on the current density and user font size preference.
*
* @param size The scaled pixel size.
* @attr ref android.R.styleable#TextView_textSize
*/
public AutofitHelper setMaxTextSize(float size) {
return setMaxTextSize(TypedValue.COMPLEX_UNIT_SP, size);
}
/**
* Set the maximum text size to a given unit and value. See TypedValue for the possible
* dimension units.
*
* @param unit The desired dimension unit.
* @param size The desired size in the given units.
* @attr ref android.R.styleable#TextView_textSize
*/
public AutofitHelper setMaxTextSize(int unit, float size) {
Context context = mTextView.getContext();
Resources r = Resources.getSystem();
if (context != null) {
r = context.getResources();
}
setRawMaxTextSize(TypedValue.applyDimension(unit, size, r.getDisplayMetrics()));
return this;
}
private void setRawMaxTextSize(float size) {
if (size != mMaxTextSize) {
mMaxTextSize = size;
autofit();
}
}
/**
* @see TextView#getMaxLines()
*/
public int getMaxLines() {
return mMaxLines;
}
/**
* @see TextView#setMaxLines(int)
*/
public AutofitHelper setMaxLines(int lines) {
if (mMaxLines != lines) {
mMaxLines = lines;
autofit();
}
return this;
}
/**
* Returns whether or not automatically resizing text is enabled.
*/
public boolean isEnabled() {
return mEnabled;
}
/**
* Set the enabled state of automatically resizing text.
*/
public AutofitHelper setEnabled(boolean enabled) {
if (mEnabled != enabled) {
mEnabled = enabled;
if (enabled) {
mTextView.addTextChangedListener(mTextWatcher);
mTextView.addOnLayoutChangeListener(mOnLayoutChangeListener);
autofit();
} else {
mTextView.removeTextChangedListener(mTextWatcher);
mTextView.removeOnLayoutChangeListener(mOnLayoutChangeListener);
mTextView.setTextSize(TypedValue.COMPLEX_UNIT_PX, mTextSize);
}
}
return this;
}
/**
* Returns the original text size of the View.
*
* @see TextView#getTextSize()
*/
public float getTextSize() {
return mTextSize;
}
/**
* Set the original text size of the View.
*
* @see TextView#setTextSize(float)
*/
public void setTextSize(float size) {
setTextSize(TypedValue.COMPLEX_UNIT_SP, size);
}
/**
* Set the original text size of the View.
*
* @see TextView#setTextSize(int, float)
*/
public void setTextSize(int unit, float size) {
if (mIsAutofitting) {
// We don't want to update the TextView's actual textSize while we're autofitting
// since it'd get set to the autofitTextSize
return;
}
Context context = mTextView.getContext();
Resources r = Resources.getSystem();
if (context != null) {
r = context.getResources();
}
setRawTextSize(TypedValue.applyDimension(unit, size, r.getDisplayMetrics()));
}
private void setRawTextSize(float size) {
if (mTextSize != size) {
mTextSize = size;
}
}
private void autofit() {
float oldTextSize = mTextView.getTextSize();
float textSize;
mIsAutofitting = true;
autofit(mTextView, mPaint, mMinTextSize, mMaxTextSize, mMaxLines, mPrecision);
mIsAutofitting = false;
textSize = mTextView.getTextSize();
if (textSize != oldTextSize) {
sendTextSizeChange(textSize, oldTextSize);
}
}
private void sendTextSizeChange(float textSize, float oldTextSize) {
if (mListeners == null) {
return;
}
for (OnTextSizeChangeListener listener : mListeners) {
listener.onTextSizeChange(textSize, oldTextSize);
}
}
private class AutofitTextWatcher implements TextWatcher {
@Override
public void beforeTextChanged(CharSequence charSequence, int start, int count, int after) {
// do nothing
}
@Override
public void onTextChanged(CharSequence charSequence, int start, int before, int count) {
autofit();
}
@Override
public void afterTextChanged(Editable editable) {
// do nothing
}
}
private class AutofitOnLayoutChangeListener implements View.OnLayoutChangeListener {
@Override
public void onLayoutChange(View view, int left, int top, int right, int bottom,
int oldLeft, int oldTop, int oldRight, int oldBottom) {
autofit();
}
}
/**
* When an object of a type is attached to an {@code AutofitHelper}, its methods will be called
* when the {@code textSize} is changed.
*/
public interface OnTextSizeChangeListener {
/**
* This method is called to notify you that the size of the text has changed to
* {@code textSize} from {@code oldTextSize}.
*/
public void onTextSizeChange(float textSize, float oldTextSize);
}
}
