samples/NotePad/src/com/example/android/notepad/NotesList.java

/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.android.notepad;

import android.app.ListActivity;
import android.content.ComponentName;
import android.content.ContentUris;
import android.content.Intent;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.ContextMenu;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ContextMenu.ContextMenuInfo;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;

import com.example.android.notepad.NotePad.NoteColumns;

/**
 * Displays a list of notes. Will display notes from the {@link Uri}
 * provided in the intent if there is one, otherwise defaults to displaying the
 * contents of the {@link NoteProvider}
 */
public class NotesList extends ListActivity {
    private static final String TAG = "NotesList";

    /**
     * The columns we are interested in from the database
     */
    private static final String[] PROJECTION = new String[] {
        NoteColumns._ID, // 0
        NoteColumns.TITLE, // 1
    };

    /** The index of the title column */
    private static final int COLUMN_INDEX_TITLE = 1;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setDefaultKeyMode(DEFAULT_KEYS_SHORTCUT);

        // If no data was given in the intent (because we were started
        // as a MAIN activity), then use our default content provider.
        Intent intent = getIntent();
        if (intent.getData() == null) {
            intent.setData(NoteColumns.CONTENT_URI);
        }

        // Inform the list we provide context menus for items
        getListView().setOnCreateContextMenuListener(this);
        
        // Perform a managed query. The Activity will handle closing and requerying the cursor
        // when needed.
        Cursor cursor = managedQuery(getIntent().getData(), PROJECTION, null, null,
                                        NoteColumns.DEFAULT_SORT_ORDER);

        // Used to map notes entries from the database to views
        SimpleCursorAdapter adapter = new SimpleCursorAdapter(this, R.layout.noteslist_item, cursor,
                new String[] { NoteColumns.TITLE }, new int[] { android.R.id.text1 });
        setListAdapter(adapter);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate menu from XML resource
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.list_options_menu, menu);
        
        // Generate any additional actions that can be performed on the
        // overall list.  In a normal install, there are no additional
        // actions found here, but this allows other applications to extend
        // our menu with their own actions.
        Intent intent = new Intent(null, getIntent().getData());
        intent.addCategory(Intent.CATEGORY_ALTERNATIVE);
        menu.addIntentOptions(Menu.CATEGORY_ALTERNATIVE, 0, 0,
                new ComponentName(this, NotesList.class), null, intent, 0, null);

        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        case R.id.menu_add:
            // Launch activity to insert a new item
            startActivity(new Intent(Intent.ACTION_INSERT, getIntent().getData()));
            return true;
        default:
            return super.onOptionsItemSelected(item);
        }
    }

    @Override
    public void onCreateContextMenu(ContextMenu menu, View view, ContextMenuInfo menuInfo) {
        AdapterView.AdapterContextMenuInfo info;
        try {
             info = (AdapterView.AdapterContextMenuInfo) menuInfo;
        } catch (ClassCastException e) {
            Log.e(TAG, "bad menuInfo", e);
            return;
        }

        Cursor cursor = (Cursor) getListAdapter().getItem(info.position);
        if (cursor == null) {
            // For some reason the requested item isn't available, do nothing
            return;
        }

        // Inflate menu from XML resource
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.list_context_menu, menu);
        
        // Set the context menu header
        menu.setHeaderTitle(cursor.getString(COLUMN_INDEX_TITLE));
        
        // Append to the
        // menu items for any other activities that can do stuff with it
        // as well.  This does a query on the system for any activities that
        // implement the ALTERNATIVE_ACTION for our data, adding a menu item
        // for each one that is found.
        Intent intent = new Intent(null, Uri.withAppendedPath(getIntent().getData(), 
                                        Integer.toString((int) info.id) ));
        intent.addCategory(Intent.CATEGORY_ALTERNATIVE);
        menu.addIntentOptions(Menu.CATEGORY_ALTERNATIVE, 0, 0,
                new ComponentName(this, NotesList.class), null, intent, 0, null);
    }
        
    @Override
    public boolean onContextItemSelected(MenuItem item) {
        AdapterView.AdapterContextMenuInfo info;
        try {
             info = (AdapterView.AdapterContextMenuInfo) item.getMenuInfo();
        } catch (ClassCastException e) {
            Log.e(TAG, "bad menuInfo", e);
            return false;
        }
        
        Uri noteUri = ContentUris.withAppendedId(getIntent().getData(), info.id);

        switch (item.getItemId()) {
        case R.id.context_open:
            // Launch activity to view/edit the currently selected item
            startActivity(new Intent(Intent.ACTION_EDIT, noteUri));
            return true;
        case R.id.context_delete:
            // Delete the note that the context menu is for
            getContentResolver().delete(noteUri, null, null);
            return true;
        default:
            return super.onContextItemSelected(item);
        }
    }

    @Override
    protected void onListItemClick(ListView l, View v, int position, long id) {
        Uri noteUri = ContentUris.withAppendedId(getIntent().getData(), id);
        
        String action = getIntent().getAction();
        if (Intent.ACTION_PICK.equals(action) || Intent.ACTION_GET_CONTENT.equals(action)) {
            // The caller is waiting for us to return a note selected by
            // the user.  The have clicked on one, so return it now.
            setResult(RESULT_OK, new Intent().setData(noteUri));
        } else {
            // Launch activity to view/edit the currently selected item
            startActivity(new Intent(Intent.ACTION_EDIT, noteUri));
        }
    }
}