1/*
2 * Copyright (C) 2014 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.systemui.recents.misc;
18
19import android.animation.Animator;
20import android.graphics.Color;
21import android.graphics.Matrix;
22import android.graphics.Rect;
23import android.view.View;
24
25import java.util.ArrayList;
26
27/* Common code */
28public class Utilities {
29
30    /** Scales a rect about its centroid */
31    public static void scaleRectAboutCenter(Rect r, float scale) {
32        if (scale != 1.0f) {
33            int cx = r.centerX();
34            int cy = r.centerY();
35            r.offset(-cx, -cy);
36            r.left = (int) (r.left * scale + 0.5f);
37            r.top = (int) (r.top * scale + 0.5f);
38            r.right = (int) (r.right * scale + 0.5f);
39            r.bottom = (int) (r.bottom * scale + 0.5f);
40            r.offset(cx, cy);
41        }
42    }
43
44    /** Maps a coorindate in a descendant view into the parent. */
45    public static float mapCoordInDescendentToSelf(View descendant, View root,
46            float[] coord, boolean includeRootScroll) {
47        ArrayList<View> ancestorChain = new ArrayList<View>();
48
49        float[] pt = {coord[0], coord[1]};
50
51        View v = descendant;
52        while(v != root && v != null) {
53            ancestorChain.add(v);
54            v = (View) v.getParent();
55        }
56        ancestorChain.add(root);
57
58        float scale = 1.0f;
59        int count = ancestorChain.size();
60        for (int i = 0; i < count; i++) {
61            View v0 = ancestorChain.get(i);
62            // For TextViews, scroll has a meaning which relates to the text position
63            // which is very strange... ignore the scroll.
64            if (v0 != descendant || includeRootScroll) {
65                pt[0] -= v0.getScrollX();
66                pt[1] -= v0.getScrollY();
67            }
68
69            v0.getMatrix().mapPoints(pt);
70            pt[0] += v0.getLeft();
71            pt[1] += v0.getTop();
72            scale *= v0.getScaleX();
73        }
74
75        coord[0] = pt[0];
76        coord[1] = pt[1];
77        return scale;
78    }
79
80    /** Maps a coordinate in the root to a descendent. */
81    public static float mapCoordInSelfToDescendent(View descendant, View root,
82            float[] coord, Matrix tmpInverseMatrix) {
83        ArrayList<View> ancestorChain = new ArrayList<View>();
84
85        float[] pt = {coord[0], coord[1]};
86
87        View v = descendant;
88        while(v != root) {
89            ancestorChain.add(v);
90            v = (View) v.getParent();
91        }
92        ancestorChain.add(root);
93
94        float scale = 1.0f;
95        int count = ancestorChain.size();
96        tmpInverseMatrix.set(Matrix.IDENTITY_MATRIX);
97        for (int i = count - 1; i >= 0; i--) {
98            View ancestor = ancestorChain.get(i);
99            View next = i > 0 ? ancestorChain.get(i-1) : null;
100
101            pt[0] += ancestor.getScrollX();
102            pt[1] += ancestor.getScrollY();
103
104            if (next != null) {
105                pt[0] -= next.getLeft();
106                pt[1] -= next.getTop();
107                next.getMatrix().invert(tmpInverseMatrix);
108                tmpInverseMatrix.mapPoints(pt);
109                scale *= next.getScaleX();
110            }
111        }
112
113        coord[0] = pt[0];
114        coord[1] = pt[1];
115        return scale;
116    }
117
118    /** Calculates the constrast between two colors, using the algorithm provided by the WCAG v2. */
119    public static float computeContrastBetweenColors(int bg, int fg) {
120        float bgR = Color.red(bg) / 255f;
121        float bgG = Color.green(bg) / 255f;
122        float bgB = Color.blue(bg) / 255f;
123        bgR = (bgR < 0.03928f) ? bgR / 12.92f : (float) Math.pow((bgR + 0.055f) / 1.055f, 2.4f);
124        bgG = (bgG < 0.03928f) ? bgG / 12.92f : (float) Math.pow((bgG + 0.055f) / 1.055f, 2.4f);
125        bgB = (bgB < 0.03928f) ? bgB / 12.92f : (float) Math.pow((bgB + 0.055f) / 1.055f, 2.4f);
126        float bgL = 0.2126f * bgR + 0.7152f * bgG + 0.0722f * bgB;
127
128        float fgR = Color.red(fg) / 255f;
129        float fgG = Color.green(fg) / 255f;
130        float fgB = Color.blue(fg) / 255f;
131        fgR = (fgR < 0.03928f) ? fgR / 12.92f : (float) Math.pow((fgR + 0.055f) / 1.055f, 2.4f);
132        fgG = (fgG < 0.03928f) ? fgG / 12.92f : (float) Math.pow((fgG + 0.055f) / 1.055f, 2.4f);
133        fgB = (fgB < 0.03928f) ? fgB / 12.92f : (float) Math.pow((fgB + 0.055f) / 1.055f, 2.4f);
134        float fgL = 0.2126f * fgR + 0.7152f * fgG + 0.0722f * fgB;
135
136        return Math.abs((fgL + 0.05f) / (bgL + 0.05f));
137    }
138
139    /** Returns the base color overlaid with another overlay color with a specified alpha. */
140    public static int getColorWithOverlay(int baseColor, int overlayColor, float overlayAlpha) {
141        return Color.rgb(
142            (int) (overlayAlpha * Color.red(baseColor) +
143                    (1f - overlayAlpha) * Color.red(overlayColor)),
144            (int) (overlayAlpha * Color.green(baseColor) +
145                    (1f - overlayAlpha) * Color.green(overlayColor)),
146            (int) (overlayAlpha * Color.blue(baseColor) +
147                    (1f - overlayAlpha) * Color.blue(overlayColor)));
148    }
149
150    /**
151     * Cancels an animation ensuring that if it has listeners, onCancel and onEnd
152     * are not called.
153     */
154    public static void cancelAnimationWithoutCallbacks(Animator animator) {
155        if (animator != null) {
156            animator.removeAllListeners();
157            animator.cancel();
158        }
159    }
160}
161