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 
17 package com.android.camera.settings;
18 
19 import android.content.Context;
20 import android.content.SharedPreferences;
21 import android.hardware.Camera;
22 import android.os.Build;
23 import android.preference.PreferenceManager;
24 
25 import com.android.camera.util.Size;
26 import com.google.common.base.Optional;
27 
28 import java.util.List;
29 
30 /**
31  * Facilitates caching of camera supported picture sizes, which is slow
32  * to query.  Will update cache if Build ID changes.
33  */
34 public class CameraPictureSizesCacher {
35     private static final String PICTURE_SIZES_BUILD_KEY = "CachedSupportedPictureSizes_Build_Camera";
36     private static final String PICTURE_SIZES_SIZES_KEY = "CachedSupportedPictureSizes_Sizes_Camera";
37 
38     /**
39      * Opportunistically update the picture sizes cache, if needed.
40      *
41      * @param cameraId cameraID we have sizes for.
42      * @param sizes List of valid sizes.
43      */
updateSizesForCamera(Context context, int cameraId, List<Size> sizes)44     public static void updateSizesForCamera(Context context, int cameraId, List<Size> sizes) {
45         String key_build = PICTURE_SIZES_BUILD_KEY + cameraId;
46         SharedPreferences defaultPrefs = PreferenceManager.getDefaultSharedPreferences(context);
47         String thisCameraCachedBuild = defaultPrefs.getString(key_build, null);
48         // Write to cache.
49         if (thisCameraCachedBuild == null) {
50             String key_sizes = PICTURE_SIZES_SIZES_KEY + cameraId;
51             SharedPreferences.Editor editor = defaultPrefs.edit();
52             editor.putString(key_build, Build.DISPLAY);
53             editor.putString(key_sizes, Size.listToString(sizes));
54             editor.apply();
55         }
56     }
57 
58     /**
59      * Return list of Sizes for provided cameraId.  Check first to see if we
60      * have it in the cache for the current android.os.Build.
61      * Note: This method calls Camera.open(), so the camera must be closed
62      * before calling or null will be returned if sizes were not previously
63      * cached.
64      *
65      * @param cameraId cameraID we would like sizes for.
66      * @param context valid android application context.
67      * @return List of valid sizes, or null if the Camera can not be opened.
68      */
getSizesForCamera(int cameraId, Context context)69     public static List<Size> getSizesForCamera(int cameraId, Context context) {
70         Optional<List<Size>> cachedSizes = getCachedSizesForCamera(cameraId, context);
71         if (cachedSizes.isPresent()) {
72             return cachedSizes.get();
73         }
74 
75         // No cached value, so need to query Camera API.
76         Camera thisCamera;
77         try {
78             thisCamera = Camera.open(cameraId);
79         } catch (RuntimeException e) {
80             // Camera open will fail if already open.
81             return null;
82         }
83         if (thisCamera != null) {
84             String key_build = PICTURE_SIZES_BUILD_KEY + cameraId;
85             String key_sizes = PICTURE_SIZES_SIZES_KEY + cameraId;
86             SharedPreferences defaultPrefs = PreferenceManager.getDefaultSharedPreferences(context);
87 
88             List<Size> sizes = Size.buildListFromCameraSizes(thisCamera.getParameters()
89                     .getSupportedPictureSizes());
90             thisCamera.release();
91             SharedPreferences.Editor editor = defaultPrefs.edit();
92             editor.putString(key_build, Build.DISPLAY);
93             editor.putString(key_sizes, Size.listToString(sizes));
94             editor.apply();
95             return sizes;
96         }
97         return null;
98     }
99 
100     /**
101      * Returns the cached sizes for the current camera. See
102      * {@link #getSizesForCamera} for details.
103      *
104      * @param cameraId cameraID we would like sizes for.
105      * @param context valid android application context.
106      * @return Optional ist of valid sizes. Not present if the sizes for the
107      *         given camera were not cached.
108      */
getCachedSizesForCamera(int cameraId, Context context)109     public static Optional<List<Size>> getCachedSizesForCamera(int cameraId, Context context) {
110         String key_build = PICTURE_SIZES_BUILD_KEY + cameraId;
111         String key_sizes = PICTURE_SIZES_SIZES_KEY + cameraId;
112         SharedPreferences defaultPrefs = PreferenceManager.getDefaultSharedPreferences(context);
113         // Return cached value for cameraId and current build, if available.
114         String thisCameraCachedBuild = defaultPrefs.getString(key_build, null);
115         if (thisCameraCachedBuild != null && thisCameraCachedBuild.equals(Build.DISPLAY)) {
116             String thisCameraCachedSizeList = defaultPrefs.getString(key_sizes, null);
117             if (thisCameraCachedSizeList != null) {
118                 return Optional.of(Size.stringToList(thisCameraCachedSizeList));
119             }
120         }
121         return Optional.absent();
122     }
123 }
124