src/com/android/camera/settings/CameraPictureSizesCacher.java

   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.ex.camera2.portability.Size;
  26
  27 import java.util.List;
  28
  29 /**
  30  * Facilitates caching of camera supported picture sizes, which is slow
  31  * to query.  Will update cache if Build ID changes.
  32  */
  33 public class CameraPictureSizesCacher {
  34     public static final String PICTURE_SIZES_BUILD_KEY = "CachedSupportedPictureSizes_Build_Camera";
  35     public static final String PICTURE_SIZES_SIZES_KEY = "CachedSupportedPictureSizes_Sizes_Camera";
  36
  37     /**
  38      * Opportunistically update the picture sizes cache, if needed.
  39      *
  40      * @param cameraId cameraID we have sizes for.
  41      * @param sizes List of valid sizes.
  42      */
  43     public static void updateSizesForCamera(Context context, int cameraId, List<Size> sizes) {
  44         String key_build = PICTURE_SIZES_BUILD_KEY + cameraId;
  45         SharedPreferences defaultPrefs = PreferenceManager.getDefaultSharedPreferences(context);
  46         String thisCameraCachedBuild = defaultPrefs.getString(key_build, null);
  47         // Write to cache.
  48         if (thisCameraCachedBuild == null) {
  49             String key_sizes = PICTURE_SIZES_SIZES_KEY + cameraId;
  50             SharedPreferences.Editor editor = defaultPrefs.edit();
  51             editor.putString(key_build, Build.DISPLAY);
  52             editor.putString(key_sizes, Size.listToString(sizes));
  53             editor.apply();
  54         }
  55     }
  56
  57     /**
  58      * Return list of Sizes for provided cameraId.  Check first to see if we
  59      * have it in the cache for the current android.os.Build.
  60      * Note: This method calls Camera.open(), so the camera must be closed
  61      * before calling or null will be returned if sizes were not previously
  62      * cached.
  63      *
  64      * @param cameraId cameraID we would like sizes for.
  65      * @return List of valid sizes, or null if the Camera can not be opened.
  66      */
  67     public static List<Size> getSizesForCamera(int cameraId, Context context) {
  68         String key_build = PICTURE_SIZES_BUILD_KEY + cameraId;
  69         String key_sizes = PICTURE_SIZES_SIZES_KEY + cameraId;
  70         SharedPreferences defaultPrefs = PreferenceManager.getDefaultSharedPreferences(context);
  71         // Return cached value for cameraId and current build, if available.
  72         String thisCameraCachedBuild = defaultPrefs.getString(key_build, null);
  73         if (thisCameraCachedBuild != null && thisCameraCachedBuild.equals(Build.DISPLAY)) {
  74             String thisCameraCachedSizeList = defaultPrefs.getString(key_sizes, null);
  75             if (thisCameraCachedSizeList != null) {
  76                 return Size.stringToList(thisCameraCachedSizeList);
  77             }
  78         }
  79         // No cached value, so need to query Camera API.
  80         Camera thisCamera;
  81         try {
  82             thisCamera = Camera.open(cameraId);
  83         } catch (RuntimeException e) {
  84             // Camera open will fail if already open.
  85             return null;
  86         }
  87         if (thisCamera != null) {
  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 }