1 package com.android.launcher3.graphics;
2 
3 import static com.android.launcher3.util.Executors.UI_HELPER_EXECUTOR;
4 
5 import android.content.ContentProvider;
6 import android.content.ContentValues;
7 import android.content.res.XmlResourceParser;
8 import android.database.Cursor;
9 import android.database.MatrixCursor;
10 import android.graphics.Bitmap;
11 import android.net.Uri;
12 import android.os.Bundle;
13 import android.os.ParcelFileDescriptor;
14 import android.os.ParcelFileDescriptor.AutoCloseOutputStream;
15 import android.text.TextUtils;
16 import android.util.Log;
17 import android.util.Xml;
18 
19 import com.android.launcher3.InvariantDeviceProfile;
20 import com.android.launcher3.InvariantDeviceProfile.GridOption;
21 import com.android.launcher3.R;
22 
23 import org.xmlpull.v1.XmlPullParser;
24 import org.xmlpull.v1.XmlPullParserException;
25 
26 import java.io.FileNotFoundException;
27 import java.io.IOException;
28 import java.util.ArrayList;
29 import java.util.Collections;
30 import java.util.List;
31 import java.util.concurrent.Future;
32 
33 /**
34  * Exposes various launcher grid options and allows the caller to change them.
35  * APIs:
36  *      /list_options: List the various available grip options, has following columns
37  *          name: name of the grid
38  *          rows: number of rows in the grid
39  *          cols: number of columns in the grid
40  *          preview_count: number of previews available for this grid option. The preview uri
41  *                         looks like /preview/<grid-name>/<preview index starting with 0>
42  *          is_default: true if this grid is currently active
43  *
44  *     /preview: Opens a file stream for the grid preview
45  *
46  *     /default_grid: Call update to set the current grid, with values
47  *          name: name of the grid to apply
48  */
49 public class GridOptionsProvider extends ContentProvider {
50 
51     private static final String TAG = "GridOptionsProvider";
52 
53     private static final String KEY_NAME = "name";
54     private static final String KEY_ROWS = "rows";
55     private static final String KEY_COLS = "cols";
56     private static final String KEY_PREVIEW_COUNT = "preview_count";
57     private static final String KEY_IS_DEFAULT = "is_default";
58 
59     private static final String KEY_LIST_OPTIONS = "/list_options";
60     private static final String KEY_DEFAULT_GRID = "/default_grid";
61 
62     private static final String KEY_PREVIEW = "preview";
63     private static final String MIME_TYPE_PNG = "image/png";
64 
65     public static final PipeDataWriter<Future<Bitmap>> BITMAP_WRITER =
66             new PipeDataWriter<Future<Bitmap>>() {
67                 @Override
68                 public void writeDataToPipe(ParcelFileDescriptor output, Uri uri, String s,
69                         Bundle bundle, Future<Bitmap> bitmap) {
70                     try (AutoCloseOutputStream os = new AutoCloseOutputStream(output)) {
71                         bitmap.get().compress(Bitmap.CompressFormat.PNG, 100, os);
72                     } catch (Exception e) {
73                         Log.w(TAG, "fail to write to pipe", e);
74                     }
75                 }
76             };
77 
78     @Override
onCreate()79     public boolean onCreate() {
80         return true;
81     }
82 
83     @Override
query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder)84     public Cursor query(Uri uri, String[] projection, String selection,
85             String[] selectionArgs, String sortOrder) {
86         if (!KEY_LIST_OPTIONS.equals(uri.getPath())) {
87             return null;
88         }
89         MatrixCursor cursor = new MatrixCursor(new String[] {
90                 KEY_NAME, KEY_ROWS, KEY_COLS, KEY_PREVIEW_COUNT, KEY_IS_DEFAULT});
91         InvariantDeviceProfile idp = InvariantDeviceProfile.INSTANCE.get(getContext());
92         for (GridOption gridOption : parseAllGridOptions()) {
93             cursor.newRow()
94                     .add(KEY_NAME, gridOption.name)
95                     .add(KEY_ROWS, gridOption.numRows)
96                     .add(KEY_COLS, gridOption.numColumns)
97                     .add(KEY_PREVIEW_COUNT, 1)
98                     .add(KEY_IS_DEFAULT, idp.numColumns == gridOption.numColumns
99                             && idp.numRows == gridOption.numRows);
100         }
101         return cursor;
102     }
103 
parseAllGridOptions()104     private List<GridOption> parseAllGridOptions() {
105         List<GridOption> result = new ArrayList<>();
106         try (XmlResourceParser parser = getContext().getResources().getXml(R.xml.device_profiles)) {
107             final int depth = parser.getDepth();
108             int type;
109             while (((type = parser.next()) != XmlPullParser.END_TAG ||
110                     parser.getDepth() > depth) && type != XmlPullParser.END_DOCUMENT) {
111                 if ((type == XmlPullParser.START_TAG)
112                         && GridOption.TAG_NAME.equals(parser.getName())) {
113                     result.add(new GridOption(getContext(), Xml.asAttributeSet(parser)));
114                 }
115             }
116         } catch (IOException | XmlPullParserException e) {
117             Log.e(TAG, "Error parsing device profile", e);
118             return Collections.emptyList();
119         }
120         return result;
121     }
122 
123     @Override
getType(Uri uri)124     public String getType(Uri uri) {
125         List<String> segments = uri.getPathSegments();
126         if (segments.size() > 0 && KEY_PREVIEW.equals(segments.get(0))) {
127             return MIME_TYPE_PNG;
128         }
129         return "vnd.android.cursor.dir/launcher_grid";
130     }
131 
132     @Override
insert(Uri uri, ContentValues initialValues)133     public Uri insert(Uri uri, ContentValues initialValues) {
134         return null;
135     }
136 
137     @Override
delete(Uri uri, String selection, String[] selectionArgs)138     public int delete(Uri uri, String selection, String[] selectionArgs) {
139         return 0;
140     }
141 
142     @Override
update(Uri uri, ContentValues values, String selection, String[] selectionArgs)143     public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
144         if (!KEY_DEFAULT_GRID.equals(uri.getPath())) {
145             return 0;
146         }
147 
148         String gridName = values.getAsString(KEY_NAME);
149         // Verify that this is a valid grid option
150         GridOption match = null;
151         for (GridOption option : parseAllGridOptions()) {
152             if (option.name.equals(gridName)) {
153                 match = option;
154                 break;
155             }
156         }
157         if (match == null) {
158             return 0;
159         }
160 
161         InvariantDeviceProfile.INSTANCE.get(getContext()).setCurrentGrid(getContext(), gridName);
162         return 1;
163     }
164 
165     @Override
openFile(Uri uri, String mode)166     public ParcelFileDescriptor openFile(Uri uri, String mode) throws FileNotFoundException {
167         List<String> segments = uri.getPathSegments();
168         if (segments.size() < 2 || !KEY_PREVIEW.equals(segments.get(0))) {
169             throw new FileNotFoundException("Invalid preview url");
170         }
171         String profileName = segments.get(1);
172         if (TextUtils.isEmpty(profileName)) {
173             throw new FileNotFoundException("Invalid preview url");
174         }
175 
176         InvariantDeviceProfile idp;
177         try {
178             idp = new InvariantDeviceProfile(getContext(), profileName);
179         } catch (Exception e) {
180             throw new FileNotFoundException(e.getMessage());
181         }
182 
183         try {
184             return openPipeHelper(uri, MIME_TYPE_PNG, null,
185                     UI_HELPER_EXECUTOR.submit(new LauncherPreviewRenderer(getContext(), idp)),
186                     BITMAP_WRITER);
187         } catch (Exception e) {
188             throw new FileNotFoundException(e.getMessage());
189         }
190     }
191 }
192