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      1 /*
      2  * Copyright (C) 2015 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.deskclock;
     18 
     19 import android.animation.ObjectAnimator;
     20 import android.content.BroadcastReceiver;
     21 import android.content.Context;
     22 import android.content.Intent;
     23 import android.content.IntentFilter;
     24 import android.graphics.drawable.ColorDrawable;
     25 import android.os.Bundle;
     26 import android.support.v7.app.AppCompatActivity;
     27 
     28 /**
     29  * Base activity class that changes with window's background color dynamically based on the
     30  * current hour.
     31  */
     32 public class BaseActivity extends AppCompatActivity {
     33 
     34     /**
     35      * Key used to save/restore the current background color from the saved instance state.
     36      */
     37     private static final String KEY_BACKGROUND_COLOR = "background_color";
     38 
     39     /**
     40      * Duration in millis to animate changes to the background color.
     41      */
     42     private static final long BACKGROUND_COLOR_ANIMATION_DURATION = 3000L;
     43 
     44     /**
     45      * {@link BroadcastReceiver} to update the background color whenever the system time changes.
     46      */
     47     private BroadcastReceiver mOnTimeChangedReceiver;
     48 
     49     /**
     50      * {@link ColorDrawable} used to draw the window's background.
     51      */
     52     private ColorDrawable mBackground;
     53 
     54     @Override
     55     protected void onCreate(Bundle savedInstanceState) {
     56         super.onCreate(savedInstanceState);
     57 
     58         final int currentColor = Utils.getCurrentHourColor();
     59         final int backgroundColor = savedInstanceState == null ? currentColor
     60                 : savedInstanceState.getInt(KEY_BACKGROUND_COLOR, currentColor);
     61         setBackgroundColor(backgroundColor, false /* animate */);
     62     }
     63 
     64     @Override
     65     protected void onResume() {
     66         super.onResume();
     67 
     68         // Register mOnTimeChangedReceiver to update current background color periodically.
     69         if (mOnTimeChangedReceiver == null) {
     70             final IntentFilter filter = new IntentFilter();
     71             filter.addAction(Intent.ACTION_TIME_TICK);
     72             filter.addAction(Intent.ACTION_TIME_CHANGED);
     73             filter.addAction(Intent.ACTION_TIMEZONE_CHANGED);
     74             registerReceiver(mOnTimeChangedReceiver = new BroadcastReceiver() {
     75                 @Override
     76                 public void onReceive(Context context, Intent intent) {
     77                     setBackgroundColor(Utils.getCurrentHourColor(), true /* animate */);
     78                 }
     79             }, filter);
     80         }
     81 
     82         // Ensure the background color is up-to-date.
     83         setBackgroundColor(Utils.getCurrentHourColor(), true /* animate */);
     84     }
     85 
     86     @Override
     87     protected void onPause() {
     88         super.onPause();
     89 
     90         // Stop updating the background color when not active.
     91         if (mOnTimeChangedReceiver != null) {
     92             unregisterReceiver(mOnTimeChangedReceiver);
     93             mOnTimeChangedReceiver = null;
     94         }
     95     }
     96 
     97     @Override
     98     protected void onSaveInstanceState(Bundle outState) {
     99         super.onSaveInstanceState(outState);
    100 
    101         // Save the background color so we can animate the change when the activity is restored.
    102         if (mBackground != null) {
    103             outState.putInt(KEY_BACKGROUND_COLOR, mBackground.getColor());
    104         }
    105     }
    106 
    107     /**
    108      * Sets the current background color to the provided value and animates the change if desired.
    109      *
    110      * @param color the ARGB value to set as the current background color
    111      * @param animate {@code true} if the change should be animated
    112      */
    113     protected void setBackgroundColor(int color, boolean animate) {
    114         if (mBackground == null) {
    115             mBackground = new ColorDrawable(color);
    116             getWindow().setBackgroundDrawable(mBackground);
    117         }
    118 
    119         if (mBackground.getColor() != color) {
    120             if (animate) {
    121                 ObjectAnimator.ofObject(mBackground, "color", AnimatorUtils.ARGB_EVALUATOR, color)
    122                         .setDuration(BACKGROUND_COLOR_ANIMATION_DURATION)
    123                         .start();
    124             } else {
    125                 mBackground.setColor(color);
    126             }
    127         }
    128     }
    129 }
    130