com.infine.android.devoxx.ui.TwitterFragment2.java Source code

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Here is the source code for com.infine.android.devoxx.ui.TwitterFragment2.java

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/*
 * 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.infine.android.devoxx.ui;

import android.database.ContentObserver;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.os.SystemClock;
import android.support.v4.app.ListFragment;
import android.util.Log;
import android.view.View;
import android.widget.ListView;

import com.infine.android.devoxx.R;
import com.infine.android.devoxx.provider.ScheduleContract;
import com.infine.android.devoxx.provider.query.TweetsQuery;
import com.infine.android.devoxx.ui.adapter.TwitterCursorAdapter;
import com.infine.android.devoxx.util.NotifyingAsyncQueryHandler;

/**
 * A {@link ListFragment} showing a list of sessions.
 */
public class TwitterFragment2 extends ListFragment implements NotifyingAsyncQueryHandler.AsyncQueryListener {

    public static final String EXTRA_SCHEDULE_TIME_STRING = "com.infine.android.devoxx.extra.SCHEDULE_TIME_STRING";

    private static final String STATE_CHECKED_POSITION = "checkedPosition";

    private static final int REFRESH_INTERVAL_MINUTES = 5;

    private static final String TAG = "TwitterFragment2";

    private Cursor mCursor;
    private TwitterCursorAdapter mAdapter;
    private int mCheckedPosition = -1;
    private boolean mHasSetEmptyText = false;

    private NotifyingAsyncQueryHandler mHandler;

    private Handler mMessageQueueHandler = new Handler();

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mHandler = new NotifyingAsyncQueryHandler(getActivity().getContentResolver(), this);
        reloadFromArguments(getArguments());

    }

    public void reloadFromArguments(Bundle arguments) {
        // Teardown from previous arguments
        if (mCursor != null) {
            getActivity().stopManagingCursor(mCursor);
            mCursor = null;
        }

        mCheckedPosition = -1;
        setListAdapter(null);

        mHandler.cancelOperation(TweetsQuery._TOKEN);

        // Load new arguments
        // final Intent intent =
        // BaseActivity.fragmentArgumentsToIntent(arguments);
        // final Uri tweetsUri = intent.getData();
        final Uri tweetsUri = ScheduleContract.Tweets.CONTENT_URI;
        final int tweetQueryToken = TweetsQuery._TOKEN;

        String[] projection = TweetsQuery.PROJECTION;
        mAdapter = new TwitterCursorAdapter(getActivity());

        setListAdapter(mAdapter);

        // Start background query to load sessions
        mHandler.startQuery(tweetQueryToken, null, tweetsUri, projection, null, null,
                ScheduleContract.Tweets.DEFAULT_SORT);

    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        // getListView().setChoiceMode(ListView.CHOICE_MODE_SINGLE);
        getListView().setClickable(false);
        getListView().setOnItemClickListener(null);

        if (savedInstanceState != null) {
            mCheckedPosition = savedInstanceState.getInt(STATE_CHECKED_POSITION, -1);
        }

        if (!mHasSetEmptyText) {
            // Could be a bug, but calling this twice makes it become visible
            // when it shouldn't
            // be visible.
            setEmptyText(getString(R.string.empty_tweets));
            mHasSetEmptyText = true;
        }
    }

    /** {@inheritDoc} */
    public void onQueryComplete(int token, Object cookie, Cursor cursor) {
        if (getActivity() == null) {
            return;
        }

        if (token == TweetsQuery._TOKEN) {
            onTweetsQueryComplete(cursor);
        } else {
            if (Log.isLoggable(TAG, Log.DEBUG)) {
                Log.d("SessionsFragment/onQueryComplete", "Query complete, Not Actionable: " + token);
            }
            cursor.close();
        }
    }

    /**
     * Handle {@link SessionsQuery} {@link Cursor}.
     */
    private void onTweetsQueryComplete(Cursor cursor) {
        if (mCursor != null) {
            // In case cancelOperation() doesn't work and we end up with
            // consecutive calls to this
            // callback.
            getActivity().stopManagingCursor(mCursor);
            mCursor = null;
        }

        mCursor = cursor;
        getActivity().startManagingCursor(mCursor);
        mAdapter.changeCursor(mCursor);
        // if (mCheckedPosition >= 0 && getView() != null) {
        // getListView().setItemChecked(mCheckedPosition, true);
        // }
    }

    @Override
    public void onListItemClick(ListView l, View v, int position, long id) {
        // nothing for now
        // super.onListItemClick(l, v, position, id);
    }

    @Override
    public void onResume() {
        super.onResume();
        mMessageQueueHandler.post(mRefreshTweetsRunnable);
        getActivity().getContentResolver().registerContentObserver(ScheduleContract.Tweets.CONTENT_URI, true,
                mTweetChangesObserver);
        if (mCursor != null) {
            mCursor.requery();
        }
    }

    @Override
    public void onPause() {
        super.onPause();
        mMessageQueueHandler.removeCallbacks(mRefreshTweetsRunnable);
        getActivity().getContentResolver().unregisterContentObserver(mTweetChangesObserver);
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putInt(STATE_CHECKED_POSITION, mCheckedPosition);
    }

    private ContentObserver mTweetChangesObserver = new ContentObserver(new Handler()) {
        @Override
        public void onChange(boolean selfChange) {
            if (mCursor != null) {
                mCursor.requery();
            }
        }
    };

    private Runnable mRefreshTweetsRunnable = new Runnable() {
        public void run() {
            if (mAdapter != null) {
                mAdapter.notifyDataSetChanged();
            }

            // Check again on the next quarter hour, with some padding to
            // account for network
            // time differences.
            long nextQuarterHour = (SystemClock.uptimeMillis() / 900000 + 1) * 900000 + 5000;
            mMessageQueueHandler.postAtTime(mRefreshTweetsRunnable, nextQuarterHour);
        }
    };

}