1 /*
2  * Copyright (C) 2017 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 
17 package com.android.launcher3.discovery;
18 
19 import android.content.Context;
20 import android.graphics.Canvas;
21 import android.graphics.drawable.ClipDrawable;
22 import android.graphics.drawable.Drawable;
23 import android.util.AttributeSet;
24 import android.view.Gravity;
25 import android.view.View;
26 
27 import com.android.launcher3.R;
28 
29 /**
30  * A simple rating view that shows stars with a rating from 0-5.
31  */
32 public class RatingView extends View {
33 
34     private static final float WIDTH_FACTOR = 0.9f;
35     private static final int MAX_LEVEL = 10000;
36     private static final int MAX_STARS = 5;
37 
38     private final Drawable mStarDrawable;
39     private final int mColorGray;
40     private final int mColorHighlight;
41 
42     private float rating;
43 
RatingView(Context context)44     public RatingView(Context context) {
45         this(context, null);
46     }
47 
RatingView(Context context, AttributeSet attrs)48     public RatingView(Context context, AttributeSet attrs) {
49         this(context, attrs, 0);
50     }
51 
RatingView(Context context, AttributeSet attrs, int defStyle)52     public RatingView(Context context, AttributeSet attrs, int defStyle) {
53         super(context, attrs, defStyle);
54         mStarDrawable = getResources().getDrawable(R.drawable.ic_star_rating, null);
55         mColorGray = 0x1E000000;
56         mColorHighlight = 0x8A000000;
57     }
58 
setRating(float rating)59     public void setRating(float rating) {
60         this.rating = Math.min(Math.max(rating, 0), MAX_STARS);
61     }
62 
63     @Override
onDraw(Canvas canvas)64     protected void onDraw(Canvas canvas) {
65         drawStars(canvas, MAX_STARS, mColorGray);
66         drawStars(canvas, rating, mColorHighlight);
67     }
68 
drawStars(Canvas canvas, float stars, int color)69     private void drawStars(Canvas canvas, float stars, int color) {
70         int fullWidth = getLayoutParams().width;
71         int cellWidth = fullWidth / MAX_STARS;
72         int starWidth = (int) (cellWidth * WIDTH_FACTOR);
73         int padding = cellWidth - starWidth;
74         int fullStars = (int) stars;
75         float partialStarFactor = stars - fullStars;
76 
77         for (int i = 0; i < fullStars; i++) {
78             int x = i * cellWidth + padding;
79             Drawable star = mStarDrawable.getConstantState().newDrawable().mutate();
80             star.setTint(color);
81             star.setBounds(x, padding, x + starWidth, padding + starWidth);
82             star.draw(canvas);
83         }
84         if (partialStarFactor > 0f) {
85             int x = fullStars * cellWidth + padding;
86             ClipDrawable star = new ClipDrawable(mStarDrawable,
87                     Gravity.LEFT, ClipDrawable.HORIZONTAL);
88             star.setTint(color);
89             star.setLevel((int) (MAX_LEVEL * partialStarFactor));
90             star.setBounds(x, padding, x + starWidth, padding + starWidth);
91             star.draw(canvas);
92         }
93     }
94 }
95