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/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
package org.mozilla.gecko.widget;
import org.mozilla.gecko.R;
import android.content.Context;
import android.content.res.ColorStateList;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.LinearGradient;
import android.graphics.Paint;
import android.graphics.Shader;
import android.util.AttributeSet;
/**
* Fades the end of the text by gecko:fadeWidth amount,
* if the text is too long and requires an ellipsis.
*
* This implementation is an improvement over Android's built-in fadingEdge
* but potentially slower than the {@link org.mozilla.gecko.widget.FadedSingleColorTextView}.
* It works for text of multiple colors but only one background color. It works by
* drawing a gradient rectangle with the background color over the text, fading it out.
*/
public class FadedMultiColorTextView extends FadedTextView {
private final ColorStateList fadeBackgroundColorList;
private final Paint fadePaint;
private FadedTextGradient backgroundGradient;
public FadedMultiColorTextView(Context context, AttributeSet attrs) {
super(context, attrs);
fadePaint = new Paint();
final TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.FadedMultiColorTextView);
fadeBackgroundColorList =
a.getColorStateList(R.styleable.FadedMultiColorTextView_fadeBackgroundColor);
a.recycle();
}
@Override
public void onDraw(Canvas canvas) {
super.onDraw(canvas);
final boolean needsEllipsis = needsEllipsis();
if (needsEllipsis) {
final int right = getWidth() - getCompoundPaddingRight();
final float left = right - fadeWidth;
updateGradientShader(needsEllipsis, right);
// Shrink height of gradient to prevent it overlaying parent view border.
// The shrunk size just nee to cover the text itself.
final float density = getResources().getDisplayMetrics().density;
final float h = Math.abs(fadePaint.getFontMetrics().top) + 1;
final float l = fadePaint.getFontMetrics().bottom + 1;
final float top = getBaseline() - h * density;
final float bottom = getBaseline() + l * density;
canvas.drawRect(left, top, right, bottom, fadePaint);
}
}
private void updateGradientShader(final boolean needsEllipsis, final int gradientEndRight) {
final int backgroundColor =
fadeBackgroundColorList.getColorForState(getDrawableState(), Color.RED);
final boolean needsNewGradient = (backgroundGradient == null ||
backgroundGradient.getBackgroundColor() != backgroundColor ||
backgroundGradient.getEndRight() != gradientEndRight);
if (needsEllipsis && needsNewGradient) {
backgroundGradient = new FadedTextGradient(gradientEndRight, fadeWidth, backgroundColor);
fadePaint.setShader(backgroundGradient);
}
}
private static class FadedTextGradient extends LinearGradient {
private final int endRight;
private final int backgroundColor;
public FadedTextGradient(final int gradientEndRight, final int fadeWidth,
final int backgroundColor) {
super(gradientEndRight - fadeWidth, 0, gradientEndRight, 0,
getColorWithZeroedAlpha(backgroundColor), backgroundColor, Shader.TileMode.CLAMP);
this.endRight = gradientEndRight;
this.backgroundColor = backgroundColor;
}
private static int getColorWithZeroedAlpha(final int color) {
return Color.argb(0, Color.red(color), Color.green(color), Color.blue(color));
}
public int getEndRight() {
return endRight;
}
public int getBackgroundColor() {
return backgroundColor;
}
}
}
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