codelab/rssexample/MyRssReader3.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.codelab.rssexample;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.graphics.Typeface;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.List;

public class MyRssReader3 extends Activity{

    private ArrayList<RssItem> mFeeds;
    ListView mRssList;
    ArrayAdapter mAdap;
    private static final int ADD_ELEMENT_REQUEST = 1;

    @Override
    public void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);

        // Load screen layout.
        setContentView(R.layout.main_screen2);

       // Populate our list
        mFeeds = initializeList();

         // Populate ArrayAdapter and bind it to ListView
        mRssList = (ListView)findViewById(R.id.rssListView);
        mAdap = new RssDataAdapter<RssItem>(this, R.layout.list_element, mFeeds);
        mRssList.setAdapter(mAdap);

        // Set the last selected item.
        // (icicle is only set if this is being restarted).
        if(savedInstanceState != null && savedInstanceState.containsKey("lastIndexItem"))
            mRssList.setSelection(savedInstanceState.getInteger("lastIndexItem"));
    }

    // Store our state before we are potentially bumped from memory.
    // We'd like to store the current ListView selection.
    @Override
    protected void onSaveInstanceState(Bundle outState){
        int index = mRssList.getSelectedItemIndex();
        if(index > -1){
            outState.putInteger("lastIndexItem", index);
        }
    }


    // Add our initial menu options. We will tweak this menu when it's loaded swap out
    // "start service" or "stop service", depending on whether the service is currently running.
    @Override
    public boolean onCreateOptionsMenu(Menu menu)
    {
        // Always call the superclass implementation to
        // provide standard items.
        super.onCreateOptionsMenu(menu);

        menu.add(0, 0, R.string.menu_option_start, null);
        menu.add(0, 1, R.string.menu_option_stop, null);
        menu.add(0, 2, R.string.menu_option_add, null);
        menu.add(0, 3, R.string.menu_option_delete, null);
        menu.add(0, 4, R.string.menu_option_update, null);

        return true;
    }

    // Toggle out start service/stop service depending on whether the service is running.
    @Override
    public boolean onPrepareOptionsMenu(Menu menu){
        return true;
    }

    // Handle our menu clicks.
    @Override
    public boolean onOptionsItemSelected(Menu.Item item){
        super.onOptionsItemSelected(item);

        switch (item.getId()){
            case 0:     // Start service
                showAlert(null, "You clicked 'start'!", "ok", null, false, null);
                break;
            case 1:    // Stop service
                showAlert(null, "You clicked stop!", "ok", null, false, null);
                break;
            case 2:     // Add Item
                Intent addIntent = new Intent(AddRssItem.class);

                // Use an ID so that if we create a "remove item" form we
                // can tell which form is returning a value.
                startActivityForResult(addIntent, ADD_ELEMENT_REQUEST);
                break;
            case 3:     // Delete item.
                if(mRssList.hasFocus()){
                    Object selectedItem = mRssList.getSelectedItem();
                    mAdap.removeObject(mRssList.getSelectedItem());
                }
                break;
            case 4:    // Update all
                showAlert(null, "You clicked 'Update'!", "ok", null, false, null);
                break;
            default:
                showAlert(null, "I have no idea what you clicked!", "ok", null, false, null);
                break;
        }
        return true;
    }

    // Called by the "Add RSS Item" floating screen when it closes.
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data){
        if(resultCode == RESULT_OK){
            switch (requestCode){
                case ADD_ELEMENT_REQUEST:
                    RssItem newIt = new RssItem(
                            data.getStringExtra("url").toString(),
                            data.getStringExtra("title").toString());
                    mAdap.addObject(newIt);
                    mRssList.setSelection(mRssList.getCount() - 1);
                break;
                default:
                    break;
            }
        }
    }

    // Our private ArrayAdapter implementation that returns a bold TextView for
    // RSS items that are unread, or a normal TextView for items that have been read.
    private class RssDataAdapter<T> extends ArrayAdapter<T> {
        public RssDataAdapter(Context context, int resource, List objects) {
            super(context, resource, objects);
        }

        // Here's our only important override--returning the list item.
        @Override
        public View getView(int position, View convertView, ViewGroup parent){

            // Get the item from the underlying array,
            // Create a TextView wrapper, and change the typeface, if necessary.
            RssItem item = (RssItem)this.getItem(position);
            TextView view = new TextView(parent.getContext());
            view.setText(item.toString());

            if(! item.hasBeenRead){
                Typeface type = view.getTypeface();
                view.setTypeface(Typeface.create(type, Typeface.BOLD_ITALIC));
            }
            return view;
        }
    }

    // Method to initialize our list of RSS items.
    private ArrayList<RssItem> initializeList(){
      ArrayList<RssItem> list = new ArrayList<RssItem>();
      list.add(new RssItem("http://www.sciam.com/xml/sciam.xml", "Scientific American"));
      list.add(new RssItem("http://newsrss.bbc.co.uk/rss/newsonline_world_edition/front_page/rss.xml", "BBC"));
      list.add(new RssItem("http://feeds.theonion.com/theonion/daily", "The Onion"));
      list.add(new RssItem("http://feeds.engadget.com/weblogsinc/engadget", "Engadget"));
      return list;
    }
}