Question

So i’m trying to understand all the code from the NotePad sample, but i’m having some difficulties :

first, how to tell that our project starts from the “X” file ? like an “index” file..?

(i guess it’s starting from the NoteList page) In this NoteList page, we get the current intent with getIntent(), then the data from it : but :

• which activity started the note list? (i think none, and all the activities in this project have this getIntent() method, so is there an intent “sent” automatically when a project is launched?)
• we set the data to the new intent variable, but we then pull the data in the cursor like this : getIntent().getData() : is it passed by “reference” or something like that? so that using the new intent variable or getIntent() is the same?

Thanks for your help 😉

>

// 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.
);

Answer 1

NoteList is the main entry point of the App. Refer to the AndroidManifest.xml to see the Launcher and Main intent filters

 <activity android:name="NotesList" android:label="@string/title_notes_list">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
        <intent-filter>
            <action android:name="android.intent.action.VIEW" />
            <action android:name="android.intent.action.EDIT" />
            <action android:name="android.intent.action.PICK" />
            <category android:name="android.intent.category.DEFAULT" />
            <data android:mimeType="vnd.android.cursor.dir/vnd.google.note" />
        </intent-filter>
        <intent-filter>
            <action android:name="android.intent.action.GET_CONTENT" />
            <category android:name="android.intent.category.DEFAULT" />
            <data android:mimeType="vnd.android.cursor.item/vnd.google.note" />
        </intent-filter>
    </activity>

Each Activity is started by an Intent. getIntent() call in a Activity. This call returns the Intent object which started it. In notepad NoteID -(which is a URI) is passed from one activity to as a parameter in the Intent object.