1/*
2 * Copyright (C) 2013 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.colorpicker;
18
19import android.graphics.Color;
20import android.graphics.PorterDuff;
21import android.graphics.drawable.Drawable;
22import android.graphics.drawable.LayerDrawable;
23
24/**
25 * A drawable which sets its color filter to a color specified by the user, and changes to a
26 * slightly darker color when pressed or focused.
27 */
28public class ColorStateDrawable extends LayerDrawable {
29
30    private static final float PRESSED_STATE_MULTIPLIER = 0.70f;
31
32    private int mColor;
33
34    public ColorStateDrawable(Drawable[] layers, int color) {
35        super(layers);
36        mColor = color;
37    }
38
39    @Override
40    protected boolean onStateChange(int[] states) {
41        boolean pressedOrFocused = false;
42        for (int state : states) {
43            if (state == android.R.attr.state_pressed || state == android.R.attr.state_focused) {
44                pressedOrFocused = true;
45                break;
46            }
47        }
48
49        if (pressedOrFocused) {
50            super.setColorFilter(getPressedColor(mColor), PorterDuff.Mode.SRC_ATOP);
51        } else {
52            super.setColorFilter(mColor, PorterDuff.Mode.SRC_ATOP);
53        }
54
55        return super.onStateChange(states);
56    }
57
58    /**
59     * Given a particular color, adjusts its value by a multiplier.
60     */
61    private static int getPressedColor(int color) {
62        float[] hsv = new float[3];
63        Color.colorToHSV(color, hsv);
64        hsv[2] = hsv[2] * PRESSED_STATE_MULTIPLIER;
65        return Color.HSVToColor(hsv);
66    }
67
68    @Override
69    public boolean isStateful() {
70        return true;
71    }
72}
73