1 /*
2  * Copyright (C) 2010 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.gallery3d.app;
18 
19 import com.android.gallery3d.R;
20 import com.android.gallery3d.data.MediaObject;
21 import com.android.gallery3d.data.Path;
22 
23 // This class handles filtering and clustering.
24 //
25 // We allow at most only one filter operation at a time (Currently it
26 // doesn't make sense to use more than one). Also each clustering operation
27 // can be applied at most once. In addition, there is one more constraint
28 // ("fixed set constraint") described below.
29 //
30 // A clustered album (not including album set) and its base sets are fixed.
31 // For example,
32 //
33 // /cluster/{base_set}/time/7
34 //
35 // This set and all sets inside base_set (recursively) are fixed because
36 // 1. We can not change this set to use another clustering condition (like
37 //    changing "time" to "location").
38 // 2. Neither can we change any set in the base_set.
39 // The reason is in both cases the 7th set may not exist in the new clustering.
40 // ---------------------
41 // newPath operation: create a new path based on a source path and put an extra
42 // condition on top of it:
43 //
44 // T = newFilterPath(S, filterType);
45 // T = newClusterPath(S, clusterType);
46 //
47 // Similar functions can be used to replace the current condition (if there is one).
48 //
49 // T = switchFilterPath(S, filterType);
50 // T = switchClusterPath(S, clusterType);
51 //
52 // For all fixed set in the path defined above, if some clusterType and
53 // filterType are already used, they cannot not be used as parameter for these
54 // functions. setupMenuItems() makes sure those types cannot be selected.
55 //
56 public class FilterUtils {
57     @SuppressWarnings("unused")
58     private static final String TAG = "FilterUtils";
59 
60     public static final int CLUSTER_BY_ALBUM = 1;
61     public static final int CLUSTER_BY_TIME = 2;
62     public static final int CLUSTER_BY_LOCATION = 4;
63     public static final int CLUSTER_BY_TAG = 8;
64     public static final int CLUSTER_BY_SIZE = 16;
65     public static final int CLUSTER_BY_FACE = 32;
66 
67     public static final int FILTER_IMAGE_ONLY = 1;
68     public static final int FILTER_VIDEO_ONLY = 2;
69     public static final int FILTER_ALL = 4;
70 
71     // These are indices of the return values of getAppliedFilters().
72     // The _F suffix means "fixed".
73     private static final int CLUSTER_TYPE = 0;
74     private static final int FILTER_TYPE = 1;
75     private static final int CLUSTER_TYPE_F = 2;
76     private static final int FILTER_TYPE_F = 3;
77     private static final int CLUSTER_CURRENT_TYPE = 4;
78     private static final int FILTER_CURRENT_TYPE = 5;
79 
setupMenuItems(GalleryActionBar actionBar, Path path, boolean inAlbum)80     public static void setupMenuItems(GalleryActionBar actionBar, Path path, boolean inAlbum) {
81         int[] result = new int[6];
82         getAppliedFilters(path, result);
83         int ctype = result[CLUSTER_TYPE];
84         int ftype = result[FILTER_TYPE];
85         int ftypef = result[FILTER_TYPE_F];
86         int ccurrent = result[CLUSTER_CURRENT_TYPE];
87         int fcurrent = result[FILTER_CURRENT_TYPE];
88 
89         setMenuItemApplied(actionBar, CLUSTER_BY_TIME,
90                 (ctype & CLUSTER_BY_TIME) != 0, (ccurrent & CLUSTER_BY_TIME) != 0);
91         setMenuItemApplied(actionBar, CLUSTER_BY_LOCATION,
92                 (ctype & CLUSTER_BY_LOCATION) != 0, (ccurrent & CLUSTER_BY_LOCATION) != 0);
93         setMenuItemApplied(actionBar, CLUSTER_BY_TAG,
94                 (ctype & CLUSTER_BY_TAG) != 0, (ccurrent & CLUSTER_BY_TAG) != 0);
95         setMenuItemApplied(actionBar, CLUSTER_BY_FACE,
96                 (ctype & CLUSTER_BY_FACE) != 0, (ccurrent & CLUSTER_BY_FACE) != 0);
97 
98         actionBar.setClusterItemVisibility(CLUSTER_BY_ALBUM, !inAlbum || ctype == 0);
99 
100         setMenuItemApplied(actionBar, R.id.action_cluster_album, ctype == 0,
101                 ccurrent == 0);
102 
103         // A filtering is available if it's not applied, and the old filtering
104         // (if any) is not fixed.
105         setMenuItemAppliedEnabled(actionBar, R.string.show_images_only,
106                 (ftype & FILTER_IMAGE_ONLY) != 0,
107                 (ftype & FILTER_IMAGE_ONLY) == 0 && ftypef == 0,
108                 (fcurrent & FILTER_IMAGE_ONLY) != 0);
109         setMenuItemAppliedEnabled(actionBar, R.string.show_videos_only,
110                 (ftype & FILTER_VIDEO_ONLY) != 0,
111                 (ftype & FILTER_VIDEO_ONLY) == 0 && ftypef == 0,
112                 (fcurrent & FILTER_VIDEO_ONLY) != 0);
113         setMenuItemAppliedEnabled(actionBar, R.string.show_all,
114                 ftype == 0, ftype != 0 && ftypef == 0, fcurrent == 0);
115     }
116 
117     // Gets the filters applied in the path.
getAppliedFilters(Path path, int[] result)118     private static void getAppliedFilters(Path path, int[] result) {
119         getAppliedFilters(path, result, false);
120     }
121 
getAppliedFilters(Path path, int[] result, boolean underCluster)122     private static void getAppliedFilters(Path path, int[] result, boolean underCluster) {
123         String[] segments = path.split();
124         // Recurse into sub media sets.
125         for (int i = 0; i < segments.length; i++) {
126             if (segments[i].startsWith("{")) {
127                 String[] sets = Path.splitSequence(segments[i]);
128                 for (int j = 0; j < sets.length; j++) {
129                     Path sub = Path.fromString(sets[j]);
130                     getAppliedFilters(sub, result, underCluster);
131                 }
132             }
133         }
134 
135         // update current selection
136         if (segments[0].equals("cluster")) {
137             // if this is a clustered album, set underCluster to true.
138             if (segments.length == 4) {
139                 underCluster = true;
140             }
141 
142             int ctype = toClusterType(segments[2]);
143             result[CLUSTER_TYPE] |= ctype;
144             result[CLUSTER_CURRENT_TYPE] = ctype;
145             if (underCluster) {
146                 result[CLUSTER_TYPE_F] |= ctype;
147             }
148         }
149     }
150 
toClusterType(String s)151     private static int toClusterType(String s) {
152         if (s.equals("time")) {
153             return CLUSTER_BY_TIME;
154         } else if (s.equals("location")) {
155             return CLUSTER_BY_LOCATION;
156         } else if (s.equals("tag")) {
157             return CLUSTER_BY_TAG;
158         } else if (s.equals("size")) {
159             return CLUSTER_BY_SIZE;
160         } else if (s.equals("face")) {
161             return CLUSTER_BY_FACE;
162         }
163         return 0;
164     }
165 
setMenuItemApplied( GalleryActionBar model, int id, boolean applied, boolean updateTitle)166     private static void setMenuItemApplied(
167             GalleryActionBar model, int id, boolean applied, boolean updateTitle) {
168         model.setClusterItemEnabled(id, !applied);
169     }
170 
setMenuItemAppliedEnabled(GalleryActionBar model, int id, boolean applied, boolean enabled, boolean updateTitle)171     private static void setMenuItemAppliedEnabled(GalleryActionBar model, int id, boolean applied, boolean enabled, boolean updateTitle) {
172         model.setClusterItemEnabled(id, enabled);
173     }
174 
175     // Add a specified filter to the path.
newFilterPath(String base, int filterType)176     public static String newFilterPath(String base, int filterType) {
177         int mediaType;
178         switch (filterType) {
179             case FILTER_IMAGE_ONLY:
180                 mediaType = MediaObject.MEDIA_TYPE_IMAGE;
181                 break;
182             case FILTER_VIDEO_ONLY:
183                 mediaType = MediaObject.MEDIA_TYPE_VIDEO;
184                 break;
185             default:  /* FILTER_ALL */
186                 return base;
187         }
188 
189         return "/filter/mediatype/" + mediaType + "/{" + base + "}";
190     }
191 
192     // Add a specified clustering to the path.
newClusterPath(String base, int clusterType)193     public static String newClusterPath(String base, int clusterType) {
194         String kind;
195         switch (clusterType) {
196             case CLUSTER_BY_TIME:
197                 kind = "time";
198                 break;
199             case CLUSTER_BY_LOCATION:
200                 kind = "location";
201                 break;
202             case CLUSTER_BY_TAG:
203                 kind = "tag";
204                 break;
205             case CLUSTER_BY_SIZE:
206                 kind = "size";
207                 break;
208             case CLUSTER_BY_FACE:
209                 kind = "face";
210                 break;
211             default: /* CLUSTER_BY_ALBUM */
212                 return base;
213         }
214 
215         return "/cluster/{" + base + "}/" + kind;
216     }
217 
218     // Change the topmost clustering to the specified type.
switchClusterPath(String base, int clusterType)219     public static String switchClusterPath(String base, int clusterType) {
220         return newClusterPath(removeOneClusterFromPath(base), clusterType);
221     }
222 
223     // Remove the topmost clustering (if any) from the path.
removeOneClusterFromPath(String base)224     private static String removeOneClusterFromPath(String base) {
225         boolean[] done = new boolean[1];
226         return removeOneClusterFromPath(base, done);
227     }
228 
removeOneClusterFromPath(String base, boolean[] done)229     private static String removeOneClusterFromPath(String base, boolean[] done) {
230         if (done[0]) return base;
231 
232         String[] segments = Path.split(base);
233         if (segments[0].equals("cluster")) {
234             done[0] = true;
235             return Path.splitSequence(segments[1])[0];
236         }
237 
238         StringBuilder sb = new StringBuilder();
239         for (int i = 0; i < segments.length; i++) {
240             sb.append("/");
241             if (segments[i].startsWith("{")) {
242                 sb.append("{");
243                 String[] sets = Path.splitSequence(segments[i]);
244                 for (int j = 0; j < sets.length; j++) {
245                     if (j > 0) {
246                         sb.append(",");
247                     }
248                     sb.append(removeOneClusterFromPath(sets[j], done));
249                 }
250                 sb.append("}");
251             } else {
252                 sb.append(segments[i]);
253             }
254         }
255         return sb.toString();
256     }
257 }
258