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      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 
     17 package com.example.android.activityanim;
     18 
     19 import java.util.ArrayList;
     20 import java.util.HashMap;
     21 
     22 import android.content.Context;
     23 import android.content.res.Resources;
     24 import android.graphics.Bitmap;
     25 import android.graphics.BitmapFactory;
     26 import android.graphics.drawable.BitmapDrawable;
     27 import android.widget.ImageView;
     28 
     29 public class BitmapUtils {
     30 
     31     int[] mPhotos = {
     32             R.drawable.p1,
     33             R.drawable.p2,
     34             R.drawable.p3,
     35             R.drawable.p4
     36     };
     37 
     38     String[] mDescriptions = {
     39             "This picture was taken while sunbathing in a natural hot spring, which was " +
     40             "unfortunately filled with acid, which is a lasting memory from that trip, whenever I " +
     41             "I look at my own skin.",
     42             "I took this shot with a pinhole camera mounted on a tripod constructed out of " +
     43             "soda straws. I felt that that combination best captured the beauty of the landscape " +
     44             "in juxtaposition with the detritus of mankind.",
     45             "I don't remember where or when I took this picture. All I know is that I was really " +
     46             "drunk at the time, and I woke up without my left sock.",
     47             "Right before I took this picture, there was a busload of school children right " +
     48             "in my way. I knew the perfect shot was coming, so I quickly yelled 'Free candy!!!' " +
     49             "and they scattered.",
     50     };
     51 
     52     static HashMap<Integer, Bitmap> sBitmapResourceMap = new HashMap<Integer, Bitmap>();
     53 
     54     /**
     55      * Load pictures and descriptions. A real app wouldn't do it this way, but that's
     56      * not the point of this animation demo. Loading asynchronously is a better way to go
     57      * for what can be time-consuming operations.
     58      */
     59     public ArrayList<PictureData> loadPhotos(Resources resources) {
     60         ArrayList<PictureData> pictures = new ArrayList<PictureData>();
     61         for (int i = 0; i < 30; ++i) {
     62             int resourceId = mPhotos[(int) (Math.random() * mPhotos.length)];
     63             Bitmap bitmap = getBitmap(resources, resourceId);
     64             Bitmap thumbnail = getThumbnail(bitmap, 200);
     65             String description = mDescriptions[(int) (Math.random() * mDescriptions.length)];
     66             pictures.add(new PictureData(resourceId, description, thumbnail));
     67         }
     68         return pictures;
     69     }
     70 
     71     /**
     72      * Utility method to get bitmap from cache or, if not there, load it
     73      * from its resource.
     74      */
     75     static Bitmap getBitmap(Resources resources, int resourceId) {
     76         Bitmap bitmap = sBitmapResourceMap.get(resourceId);
     77         if (bitmap == null) {
     78             bitmap = BitmapFactory.decodeResource(resources, resourceId);
     79             sBitmapResourceMap.put(resourceId, bitmap);
     80         }
     81         return bitmap;
     82     }
     83 
     84     /**
     85      * Create and return a thumbnail image given the original source bitmap and a max
     86      * dimension (width or height).
     87      */
     88     private Bitmap getThumbnail(Bitmap original, int maxDimension) {
     89         int width = original.getWidth();
     90         int height = original.getHeight();
     91         int scaledWidth, scaledHeight;
     92         if (width >= height) {
     93             float scaleFactor = (float) maxDimension / width;
     94             scaledWidth = 200;
     95             scaledHeight = (int) (scaleFactor * height);
     96         } else {
     97             float scaleFactor = (float) maxDimension / height;
     98             scaledWidth = (int) (scaleFactor * width);
     99             scaledHeight = 200;
    100         }
    101         Bitmap thumbnail = Bitmap.createScaledBitmap(original, scaledWidth, scaledHeight, true);
    102 
    103         return thumbnail;
    104     }
    105 
    106 
    107 }
    108