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      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 package com.android.settings.widget;
     17 
     18 import android.content.Context;
     19 import android.content.res.Resources;
     20 import android.graphics.Canvas;
     21 import android.graphics.ColorFilter;
     22 import android.graphics.Paint;
     23 import android.graphics.PorterDuff;
     24 import android.graphics.PorterDuffColorFilter;
     25 import android.text.TextPaint;
     26 import android.util.AttributeSet;
     27 import android.view.View;
     28 
     29 import com.android.settings.R;
     30 import com.android.settings.Utils;
     31 
     32 /**
     33  * DonutView represents a donut graph. It visualizes a certain percentage of fullness with a
     34  * corresponding label with the fullness on the inside (i.e. "50%" inside of the donut).
     35  */
     36 public class DonutView extends View {
     37     private static final int TOP = -90;
     38     // From manual testing, this is the longest we can go without visual errors.
     39     private static final int LINE_CHARACTER_LIMIT = 10;
     40     private float mStrokeWidth;
     41     private float mDeviceDensity;
     42     private int mPercent;
     43     private Paint mBackgroundCircle;
     44     private Paint mFilledArc;
     45     private TextPaint mTextPaint;
     46     private TextPaint mBigNumberPaint;
     47     private String mPercentString;
     48     private String mFullString;
     49 
     50     public DonutView(Context context) {
     51         super(context);
     52     }
     53 
     54     public DonutView(Context context, AttributeSet attrs) {
     55         super(context, attrs);
     56         mDeviceDensity = getResources().getDisplayMetrics().density;
     57         mStrokeWidth = 6f * mDeviceDensity;
     58         final ColorFilter mAccentColorFilter =
     59                 new PorterDuffColorFilter(
     60                         Utils.getColorAttr(context, android.R.attr.colorAccent),
     61                         PorterDuff.Mode.SRC_IN);
     62 
     63         mBackgroundCircle = new Paint();
     64         mBackgroundCircle.setAntiAlias(true);
     65         mBackgroundCircle.setStrokeCap(Paint.Cap.BUTT);
     66         mBackgroundCircle.setStyle(Paint.Style.STROKE);
     67         mBackgroundCircle.setStrokeWidth(mStrokeWidth);
     68         mBackgroundCircle.setColorFilter(mAccentColorFilter);
     69         mBackgroundCircle.setColor(context.getColor(R.color.meter_background_color));
     70 
     71         mFilledArc = new Paint();
     72         mFilledArc.setAntiAlias(true);
     73         mFilledArc.setStrokeCap(Paint.Cap.BUTT);
     74         mFilledArc.setStyle(Paint.Style.STROKE);
     75         mFilledArc.setStrokeWidth(mStrokeWidth);
     76         mFilledArc.setColor(Utils.getDefaultColor(mContext, R.color.meter_consumed_color));
     77         mFilledArc.setColorFilter(mAccentColorFilter);
     78 
     79         Resources resources = context.getResources();
     80         mTextPaint = new TextPaint();
     81         mTextPaint.setColor(Utils.getColorAccent(getContext()));
     82         mTextPaint.setAntiAlias(true);
     83         mTextPaint.setTextSize(
     84                 resources.getDimension(R.dimen.storage_donut_view_label_text_size));
     85         mTextPaint.setTextAlign(Paint.Align.CENTER);
     86 
     87         mBigNumberPaint = new TextPaint();
     88         mBigNumberPaint.setColor(Utils.getColorAccent(getContext()));
     89         mBigNumberPaint.setAntiAlias(true);
     90         mBigNumberPaint.setTextSize(
     91                 resources.getDimension(R.dimen.storage_donut_view_percent_text_size));
     92         mBigNumberPaint.setTextAlign(Paint.Align.CENTER);
     93     }
     94 
     95     @Override
     96     protected void onDraw(Canvas canvas) {
     97         super.onDraw(canvas);
     98         drawDonut(canvas);
     99         drawInnerText(canvas);
    100     }
    101 
    102     private void drawDonut(Canvas canvas) {
    103         canvas.drawArc(
    104                 0 + mStrokeWidth,
    105                 0 + mStrokeWidth,
    106                 getWidth() - mStrokeWidth,
    107                 getHeight() - mStrokeWidth,
    108                 TOP,
    109                 360,
    110                 false,
    111                 mBackgroundCircle);
    112 
    113         canvas.drawArc(
    114                 0 + mStrokeWidth,
    115                 0 + mStrokeWidth,
    116                 getWidth() - mStrokeWidth,
    117                 getHeight() - mStrokeWidth,
    118                 TOP,
    119                 (360 * mPercent / 100),
    120                 false,
    121                 mFilledArc);
    122     }
    123 
    124     private void drawInnerText(Canvas canvas) {
    125         final float centerX = getWidth() / 2;
    126         final float centerY = getHeight() / 2;
    127         final float totalHeight = getTextHeight(mTextPaint) + getTextHeight(mBigNumberPaint);
    128         final float startY = centerY + totalHeight / 2;
    129 
    130         // The first line is the height of the bottom text + its descender above the bottom line.
    131         canvas.drawText(mPercentString, centerX,
    132                 startY - getTextHeight(mTextPaint) - mBigNumberPaint.descent(),
    133                 mBigNumberPaint);
    134         // The second line starts at the bottom + room for the descender.
    135         canvas.drawText(mFullString, centerX, startY - mTextPaint.descent(), mTextPaint);
    136     }
    137 
    138     /**
    139      * Set a percentage full to have the donut graph.
    140      */
    141     public void setPercentage(int percent) {
    142         mPercent = percent;
    143         mPercentString = Utils.formatPercentage(mPercent);
    144         mFullString = getContext().getString(R.string.storage_percent_full);
    145         if (mFullString.length() > LINE_CHARACTER_LIMIT) {
    146             mTextPaint.setTextSize(
    147                     getContext()
    148                             .getResources()
    149                             .getDimension(
    150                                     R.dimen.storage_donut_view_shrunken_label_text_size));
    151         }
    152         invalidate();
    153     }
    154 
    155     private float getTextHeight(TextPaint paint) {
    156         // Technically, this should be the cap height, but I can live with the descent - ascent.
    157         return paint.descent() - paint.ascent();
    158     }
    159 }
    160