PostListFragment.java

package se.alexanderblom.delicious.fragments;

import java.io.IOException;
import java.util.List;

import se.alexanderblom.delicious.DeliciousAccount;
import se.alexanderblom.delicious.R;
import se.alexanderblom.delicious.adapter.PostsAdapter;
import se.alexanderblom.delicious.http.Request;
import se.alexanderblom.delicious.http.Response;
import se.alexanderblom.delicious.model.Post;
import se.alexanderblom.delicious.model.PostsParser;
import se.alexanderblom.delicious.ui.BaseActivity;
import se.alexanderblom.delicious.ui.MainActivity;
import se.alexanderblom.delicious.util.AsyncLoader;
import android.app.Activity;
import android.app.LoaderManager.LoaderCallbacks;
import android.content.Context;
import android.content.Intent;
import android.content.Loader;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.util.SparseBooleanArray;
import android.view.ActionMode;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.ListView;
import android.widget.ShareActionProvider;

public class PostListFragment extends ErrorListFragment implements LoaderCallbacks<List<Post>> {
	private static final String TAG = "PostListFragment";
	
	private static final String RECENTS_URL = "https://api.del.icio.us/v1/json/posts/recent";

	private static final String ARG_TAG = "tag";
	private static final int POSTS_LOADER = 1;

	private PostsAdapter adapter;
	
	private String tag;
	
	public static PostListFragment newInstance(String tag) {
		PostListFragment f = new PostListFragment();
		f.setArguments(createArgs(tag));
		
		return f;
	}
	
	public static Bundle createArgs(String tag) {
		Bundle args = new Bundle();
		args.putString(ARG_TAG, tag);
		
		return args;
	}

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		
		Bundle args = getArguments() != null ? getArguments() : Bundle.EMPTY;
		tag = args.getString(ARG_TAG);
		
		adapter = new PostsAdapter(getActivity());
		
		setListAdapter(adapter);
		setHasOptionsMenu(true);
	}

	@Override
	public void onActivityCreated(Bundle savedInstanceState) {
		super.onActivityCreated(savedInstanceState);
		
		getListView().setChoiceMode(ListView.CHOICE_MODE_MULTIPLE_MODAL);
		getListView().setMultiChoiceModeListener(new PostActionMode());

		BaseActivity activity = (BaseActivity) getActivity();
		if (activity.hasAccount()) {
			setListShown(false);
			getLoaderManager().initLoader(POSTS_LOADER, null, this);
		}
	}
	
	@Override
	public void onStart() {
		super.onStart();
		
		Activity activity = getActivity();
		if (tag != null) {
			activity.setTitle(getString(R.string.page_tag, tag));
		} else {
			activity.setTitle(R.string.page_recent);
		}
		
		if (tag == null && activity instanceof MainActivity) {
			MainActivity main = (MainActivity) activity;
			main.setSelectedPage(R.id.page_recent);
		}
	}

	@Override
	public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
		super.onCreateOptionsMenu(menu, inflater);

		inflater.inflate(R.menu.menu_refresh, menu);
	}

	@Override
	public boolean onOptionsItemSelected(MenuItem item) {
		if (item.getItemId() == R.id.menu_refresh) {
			Log.d(TAG, "Refreshing posts");
			getLoaderManager().restartLoader(POSTS_LOADER, null, this);

			return true;
		} else {
			return super.onOptionsItemSelected(item);
		}
	}

	@Override
	public void onListItemClick(ListView l, View v, int position, long id) {
		Post post = adapter.getItem(position);

		Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(post.getLink()));
		startActivity(intent);
	}

	@Override
	public Loader<List<Post>> onCreateLoader(int id, Bundle args) {
		String url = RECENTS_URL;
		if (tag != null) {
			url = Uri.parse("https://api.del.icio.us/v1/json/posts/all").buildUpon()
					.appendQueryParameter("tag", tag)
					.build()
					.toString();
		} 
		
		setListShown(false);
		return new PostsLoader(getActivity(), DeliciousAccount.get(getActivity()), url);
	}

	@Override
	public void onLoadFinished(Loader<List<Post>> loader, List<Post> posts) {
		if (posts != null) {
			adapter.setList(posts);
			setListShown(true);
		} else {
			// There was an error
			showLoadingError();
		}
	}

	@Override
	public void onLoaderReset(Loader<List<Post>> loader) {
		adapter.clear();
	}
	
	@Override
	protected void onRetry() {
		getLoaderManager().initLoader(POSTS_LOADER, null, this);
	}

	private void showLoadingError() {
		getLoaderManager().destroyLoader(POSTS_LOADER);

		showError();
	}

	private static class PostsLoader extends AsyncLoader<List<Post>> {
		private static final String TAG = "PostsLoader";

		private DeliciousAccount account;
		private String url;

		public PostsLoader(Context context, DeliciousAccount account, String url) {
			super(context);

			this.account = account;
			this.url = url;
		}

		@Override
		public List<Post> loadInBackground() {
			try {
				Response response = Request.get(url)
						.addAuth(account)
						.execute();

				try {
					return new PostsParser(response.getReader()).getPosts();
				} finally {
					response.disconnect();
				}
			} catch (IOException e) {
				Log.e(TAG, "Failed to fetch posts", e);

				return null;
			}
		}
	}
	
	private class PostActionMode implements ListView.MultiChoiceModeListener, ShareActionProvider.OnShareTargetSelectedListener {
		private ActionMode actionMode;
		private ShareActionProvider provider;
		
		@Override
		public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
			return false;
		}

		@Override
		public boolean onCreateActionMode(ActionMode mode, Menu menu) {
			actionMode = mode;
			
			MenuInflater inflater = mode.getMenuInflater();
			inflater.inflate(R.menu.context_post, menu);
			
			return true;
		}

		@Override
		public void onDestroyActionMode(ActionMode mode) {
			actionMode = null;
			provider = null;
		}

		@Override
		public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
			provider = (ShareActionProvider) menu.findItem(R.id.menu_share).getActionProvider();
			provider.setOnShareTargetSelectedListener(this);
			
			return false;
		}

		@Override
		public void onItemCheckedStateChanged(ActionMode mode, int position, long id, boolean checked) {
			if (checked) {
				// Only allow the user to check one item
				SparseBooleanArray checkedArray = getListView().getCheckedItemPositions();
				checkedArray.clear();
				checkedArray.put(position, true);
				
				provider.setShareIntent(createShareIntent(adapter.getItem(position)));
			} else {
				mode.finish();
			}
		}
		
		@Override
		public boolean onShareTargetSelected(ShareActionProvider source, Intent intent) {
			// Close action mode after user has shared
			actionMode.finish();
			
			return false;
		}
		
		private Intent createShareIntent(Post post) {
			return new Intent(Intent.ACTION_SEND)
					.setType("text/plain")
					.addFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET)
					.putExtra(Intent.EXTRA_SUBJECT, post.getTitle())
					.putExtra(Intent.EXTRA_TEXT, post.getLink());
		}
	}
}