/** onCreate is called when Android starts this Activity from scratch. */
@Override
protected void OnCreate(Bundle savedInstanceState) throws Throwable {
super.OnCreate(savedInstanceState);
// The user does not need to hold down the key to use menu shortcuts.
setDefaultKeyMode(DEFAULT_KEYS_SHORTCUT);
/* If no data is given in the Intent that started this Activity, then this Activity
* was started when the intent filter matched a MAIN action. We should use the default
* provider URI.
*/
// Gets the intent that started this Activity.
Intent intent = getIntent();
// If there is no data associated with the Intent, sets the data to the default URI, which
// accesses a list of notes.
if (intent.getData() == null) {
intent.setData(NotePad.Notes.CONTENT_URI);
}
/*
* Sets the callback for context menu activation for the ListView. The listener is set
* to be this Activity. The effect is that context menus are enabled for items in the
* ListView, and the context menu is handled by a method in NotesList.
*/
getListView().setOnCreateContextMenuListener(this);
/* Performs a managed query. The Activity handles closing and requerying the cursor
* when needed.
*
* Please see the introductory note about performing provider operations on the UI thread.
*/
Cursor cursor =
managedQuery(
getIntent().getData(), // Use the default content URI for the provider.
PROJECTION, // Return the note ID and title for each note.
null, // No where clause, return all records.
null, // No where clause, therefore no where column values.
NotePad.Notes.DEFAULT_SORT_ORDER // Use the default sort order.
);
/*
* The following two arrays create a "map" between columns in the cursor and view IDs
* for items in the ListView. Each element in the dataColumns array represents
* a column name; each element in the viewID array represents the ID of a View.
* The SimpleCursorAdapter maps them in ascending order to determine where each column
* value will appear in the ListView.
*/
// The names of the cursor columns to display in the view, initialized to the title column
String[] dataColumns = {NotePad.Notes.COLUMN_NAME_TITLE};
// The view IDs that will display the cursor columns, initialized to the TextView in
// noteslist_item.xml
int[] viewIDs = {android.R.id.text1};
// Creates the backing adapter for the ListView.
SimpleCursorAdapter adapter =
new SimpleCursorAdapter(
this, // The Context for the ListView
R.layout.noteslist_item, // Points to the XML for a list item
cursor, // The cursor to get items from
dataColumns,
viewIDs);
// Sets the ListView's adapter to be the cursor adapter that was just created.
setListAdapter(adapter);
}
@Override
public boolean OnPrepareOptionsMenu(Menu menu) throws Throwable {
super.OnPrepareOptionsMenu(menu);
// The paste menu item is enabled if there is data on the clipboard.
ClipboardManager clipboard = (ClipboardManager) getSystemService(Context.CLIPBOARD_SERVICE);
MenuItem mPasteItem = menu.findItem(R.id.menu_paste);
// If the clipboard contains an item, enables the Paste option on the menu.
if (clipboard.hasPrimaryClip()) {
mPasteItem.setEnabled(true);
} else {
// If the clipboard is empty, disables the menu's Paste option.
mPasteItem.setEnabled(false);
}
// Gets the number of notes currently being displayed.
final boolean haveItems = getListAdapter().getCount() > 0;
// If there are any notes in the list (which implies that one of
// them is selected), then we need to generate the actions that
// can be performed on the current selection. This will be a combination
// of our own specific actions along with any extensions that can be
// found.
if (haveItems) {
// This is the selected item.
Uri uri = ContentUris.withAppendedId(getIntent().getData(), getSelectedItemId());
// Creates an array of Intents with one element. This will be used to send an Intent
// based on the selected menu item.
Intent[] specifics = new Intent[1];
// Sets the Intent in the array to be an EDIT action on the URI of the selected note.
specifics[0] = new Intent(Intent.ACTION_EDIT, uri);
// Creates an array of menu items with one element. This will contain the EDIT option.
MenuItem[] items = new MenuItem[1];
// Creates an Intent with no specific action, using the URI of the selected note.
Intent intent = new Intent(null, uri);
/* Adds the category ALTERNATIVE to the Intent, with the note ID URI as its
* data. This prepares the Intent as a place to group alternative options in the
* menu.
*/
intent.addCategory(Intent.CATEGORY_ALTERNATIVE);
/*
* Add alternatives to the menu
*/
menu.addIntentOptions(
Menu.CATEGORY_ALTERNATIVE, // Add the Intents as options in the alternatives group.
Menu.NONE, // A unique item ID is not required.
Menu.NONE, // The alternatives don't need to be in order.
null, // The caller's name is not excluded from the group.
specifics, // These specific options must appear first.
intent, // These Intent objects map to the options in specifics.
Menu.NONE, // No flags are required.
items // The menu items generated from the specifics-to-
// Intents mapping
);
// If the Edit menu item exists, adds shortcuts for it.
if (items[0] != null) {
// Sets the Edit menu item shortcut to numeric "1", letter "e"
items[0].setShortcut('1', 'e');
}
} else {
// If the list is empty, removes any existing alternative actions from the menu
menu.removeGroup(Menu.CATEGORY_ALTERNATIVE);
}
// Displays the menu
return true;
}