1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/mobile/android/base/LightweightThemeDrawable.java Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,128 @@
1.4 +/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
1.5 + * This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +package org.mozilla.gecko;
1.10 +
1.11 +import android.content.res.Resources;
1.12 +import android.graphics.Bitmap;
1.13 +import android.graphics.BitmapShader;
1.14 +import android.graphics.Canvas;
1.15 +import android.graphics.ColorFilter;
1.16 +import android.graphics.ComposeShader;
1.17 +import android.graphics.LinearGradient;
1.18 +import android.graphics.Paint;
1.19 +import android.graphics.PixelFormat;
1.20 +import android.graphics.PorterDuff;
1.21 +import android.graphics.PorterDuffColorFilter;
1.22 +import android.graphics.Rect;
1.23 +import android.graphics.Shader;
1.24 +import android.graphics.drawable.Drawable;
1.25 +
1.26 +/**
1.27 + * A special drawable used with lightweight themes. This draws a color
1.28 + * (with an optional color-filter) and a bitmap (with a linear gradient
1.29 + * to specify the alpha) in order.
1.30 + */
1.31 +public class LightweightThemeDrawable extends Drawable {
1.32 + private Paint mPaint;
1.33 + private Paint mColorPaint;
1.34 +
1.35 + private Bitmap mBitmap;
1.36 + private Resources mResources;
1.37 +
1.38 + private int mStartColor;
1.39 + private int mEndColor;
1.40 +
1.41 + public LightweightThemeDrawable(Resources resources, Bitmap bitmap) {
1.42 + mBitmap = bitmap;
1.43 + mResources = resources;
1.44 +
1.45 + mPaint = new Paint();
1.46 + mPaint.setAntiAlias(true);
1.47 + mPaint.setStrokeWidth(0.0f);
1.48 + }
1.49 +
1.50 + @Override
1.51 + protected void onBoundsChange(Rect bounds) {
1.52 + super.onBoundsChange(bounds);
1.53 + initializeBitmapShader();
1.54 + }
1.55 +
1.56 + @Override
1.57 + public void draw(Canvas canvas) {
1.58 + // Draw the colors, if available.
1.59 + if (mColorPaint != null)
1.60 + canvas.drawPaint(mColorPaint);
1.61 +
1.62 + // Draw the bitmap.
1.63 + canvas.drawPaint(mPaint);
1.64 + }
1.65 +
1.66 + @Override
1.67 + public int getOpacity() {
1.68 + return PixelFormat.TRANSLUCENT;
1.69 + }
1.70 +
1.71 + @Override
1.72 + public void setAlpha(int alpha) {
1.73 + // A StateListDrawable will reset the alpha value with 255.
1.74 + // We cannot use to be the bitmap alpha.
1.75 + mPaint.setAlpha(alpha);
1.76 + }
1.77 +
1.78 + @Override
1.79 + public void setColorFilter(ColorFilter filter) {
1.80 + mPaint.setColorFilter(filter);
1.81 + }
1.82 +
1.83 + /**
1.84 + * Creates a paint that paint a particular color.
1.85 + *
1.86 + * @param color The color to be painted.
1.87 + */
1.88 + public void setColor(int color) {
1.89 + mColorPaint = new Paint(mPaint);
1.90 + mColorPaint.setColor(color);
1.91 + }
1.92 +
1.93 + /**
1.94 + * Creates a paint that paint a particular color, and a filter for the color.
1.95 + *
1.96 + * @param color The color to be painted.
1.97 + * @param filter The filter color to be applied using SRC_OVER mode.
1.98 + */
1.99 + public void setColorWithFilter(int color, int filter) {
1.100 + mColorPaint = new Paint(mPaint);
1.101 + mColorPaint.setColor(color);
1.102 + mColorPaint.setColorFilter(new PorterDuffColorFilter(filter, PorterDuff.Mode.SRC_OVER));
1.103 + }
1.104 +
1.105 + /**
1.106 + * Set the alpha for the linear gradient used with the bitmap's shader.
1.107 + *
1.108 + * @param startAlpha The starting alpha (0..255) value to be applied to the LinearGradient.
1.109 + * @param startAlpha The ending alpha (0..255) value to be applied to the LinearGradient.
1.110 + */
1.111 + public void setAlpha(int startAlpha, int endAlpha) {
1.112 + mStartColor = startAlpha << 24;
1.113 + mEndColor = endAlpha << 24;
1.114 + initializeBitmapShader();
1.115 + }
1.116 +
1.117 + private void initializeBitmapShader() {
1.118 + // A bitmap-shader to draw the bitmap.
1.119 + // Clamp mode will repeat the last row of pixels.
1.120 + // Hence its better to have an endAlpha of 0 for the linear-gradient.
1.121 + BitmapShader bitmapShader = new BitmapShader(mBitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
1.122 +
1.123 + // A linear-gradient to specify the opacity of the bitmap.
1.124 + LinearGradient gradient = new LinearGradient(0, 0, 0, mBitmap.getHeight(), mStartColor, mEndColor, Shader.TileMode.CLAMP);
1.125 +
1.126 + // Make a combined shader -- a performance win.
1.127 + // The linear-gradient is the 'SRC' and the bitmap-shader is the 'DST'.
1.128 + // Drawing the DST in the SRC will provide the opacity.
1.129 + mPaint.setShader(new ComposeShader(bitmapShader, gradient, PorterDuff.Mode.DST_IN));
1.130 + }
1.131 +}
