A LiveFolder is a special folder whose content is provided by a
{@link android.content.ContentProvider}. To create a live folder, two components
are required:
- An activity that can respond to the intent action {@link #ACTION_CREATE_LIVE_FOLDER}. The
activity is responsible for creating the live folder.
- A {@link android.content.ContentProvider} to provide the live folder items.
Lifecycle
When a user wants to create a live folder, the system looks for all activities with the
intent filter action {@link #ACTION_CREATE_LIVE_FOLDER} and presents the list to the user.
When the user chooses one of the activities, the activity is invoked with the
{@link #ACTION_CREATE_LIVE_FOLDER} action. The activity then creates the live folder and
passes it back to the system by setting it as an
{@link android.app.Activity#setResult(int, android.content.Intent) activity result}. The
live folder is described by a content provider URI, a name, an icon and a display mode.
Finally, when the user opens the live folder, the system queries the content provider
to retrieve the folder's content.
Setting up the live folder activity
The following code sample shows how to write an activity that creates a live folder:
public static class MyLiveFolder extends Activity {
public static final Uri CONTENT_URI = Uri.parse("content://my.app/live");
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
final Intent intent = getIntent();
final String action = intent.getAction();
if (LiveFolders.ACTION_CREATE_LIVE_FOLDER.equals(action)) {
setResult(RESULT_OK, createLiveFolder(this, CONTENT_URI, "My LiveFolder",
R.drawable.ic_launcher_contacts_phones));
} else {
setResult(RESULT_CANCELED);
}
finish();
}
private static Intent createLiveFolder(Context context, Uri uri, String name,
int icon) {
final Intent intent = new Intent();
intent.setData(uri);
intent.putExtra(LiveFolders.EXTRA_LIVE_FOLDER_NAME, name);
intent.putExtra(LiveFolders.EXTRA_LIVE_FOLDER_ICON,
Intent.ShortcutIconResource.fromContext(context, icon));
intent.putExtra(LiveFolders.EXTRA_LIVE_FOLDER_DISPLAY_MODE, LiveFolders.DISPLAY_MODE_LIST);
return intent;
}
}
The live folder is described by an {@link android.content.Intent} as follows:
| Component | Type | Description | Required |
|---|
| URI |
URI |
The ContentProvider URI |
Yes |
|---|
| {@link #EXTRA_LIVE_FOLDER_NAME} |
Extra String |
The name of the live folder |
Yes |
|---|
| {@link #EXTRA_LIVE_FOLDER_ICON} |
Extra {@link android.content.Intent.ShortcutIconResource} |
The icon of the live folder |
Yes |
|---|
| {@link #EXTRA_LIVE_FOLDER_DISPLAY_MODE} |
Extra int |
The display mode of the live folder. The value must be either
{@link #DISPLAY_MODE_GRID} or {@link #DISPLAY_MODE_LIST}. |
Yes |
|---|
| {@link #EXTRA_LIVE_FOLDER_BASE_INTENT} |
Extra Intent |
When the user clicks an item inside a live folder, the system will either fire
the intent associated with that item or, if present, the live folder's base intent
with the id of the item appended to the base intent's URI. |
No |
|---|
Setting up the content provider
The live folder's content provider must, upon query, return a {@link android.database.Cursor}
whose columns match the following names:
| Column | Type | Description | Required |
|---|
| {@link #NAME} |
String |
The name of the item |
Yes |
|---|
| {@link #DESCRIPTION} |
String |
The description of the item. The description is ignored when the live folder's
display mode is {@link #DISPLAY_MODE_GRID}. |
No |
|---|
| {@link #INTENT} |
{@link android.content.Intent} |
The intent to fire when the item is clicked. Ignored when the live folder defines
a base intent. |
No |
|---|
| {@link #ICON_BITMAP} |
Bitmap |
The icon for the item. When this column value is not null, the values for the
columns {@link #ICON_PACKAGE} and {@link #ICON_RESOURCE} must be null. |
No |
|---|
| {@link #ICON_PACKAGE} |
String |
The package of the item's icon. When this value is not null, the value for the
column {@link #ICON_RESOURCE} must be specified and the value for the column
{@link #ICON_BITMAP} must be null. |
No |
|---|
| {@link #ICON_RESOURCE} |
String |
The resource name of the item's icon. When this value is not null, the value for the
column {@link #ICON_PACKAGE} must be specified and the value for the column
{@link #ICON_BITMAP} must be null. |
No |
|---|
|
