TimelineActivity.java

/*
 * Copyright (C) 2015 Twitter, Inc.
 *
 * 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.app.tweetui;

import android.app.Activity;
import android.os.Bundle;
import android.support.v4.widget.SwipeRefreshLayout;
import android.support.v7.app.ActionBar;
import android.view.View;
import android.widget.AbsListView;
import android.widget.ListView;
import android.widget.Toast;

import com.example.app.BaseActivity;
import com.example.app.R;
import com.example.app.twittercore.TwitterCoreMainActivity;
import com.twitter.sdk.android.core.Callback;
import com.twitter.sdk.android.core.Result;
import com.twitter.sdk.android.core.TwitterAuthException;
import com.twitter.sdk.android.core.TwitterException;
import com.twitter.sdk.android.core.models.Tweet;
import com.twitter.sdk.android.tweetui.SearchTimeline;
import com.twitter.sdk.android.tweetui.TimelineResult;
import com.twitter.sdk.android.tweetui.TweetTimelineListAdapter;

import java.lang.ref.WeakReference;

/**
 * TimelineActivity shows a full screen timeline which is useful for screenshots.
 */
public class TimelineActivity extends BaseActivity {

    final WeakReference<Activity> activityRef = new WeakReference<>(TimelineActivity.this);

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.tweetui_swipe_timeline);
        ActionBar actionBar = getSupportActionBar();
        if (actionBar != null) {
            actionBar.setTitle(R.string.refresh_timeline_title);
        }

        // launch the app login activity when a guest user tries to favorite a Tweet
        final Callback<Tweet> actionCallback = new Callback<Tweet>() {
            @Override
            public void success(Result<Tweet> result) {
                // Intentionally blank
            }
            @Override
            public void failure(TwitterException exception) {
                if (exception instanceof TwitterAuthException) {
                    startActivity(TwitterCoreMainActivity.newIntent(TimelineActivity.this));
                }
            }
        };

        final SwipeRefreshLayout swipeLayout = findViewById(R.id.swipe_layout);
        final View emptyView = findViewById(android.R.id.empty);
        final ListView listView = findViewById(android.R.id.list);
        listView.setEmptyView(emptyView);

        final SearchTimeline timeline = new SearchTimeline.Builder().query("#twitter").build();
        final TweetTimelineListAdapter adapter = new TweetTimelineListAdapter.Builder(this)
                .setTimeline(timeline)
                .setViewStyle(R.style.tw__TweetLightWithActionsStyle)
                .setOnActionCallback(actionCallback)
                .build();
        listView.setAdapter(adapter);

        swipeLayout.setColorSchemeResources(R.color.twitter_blue, R.color.twitter_dark);

        // set custom scroll listener to enable swipe refresh layout only when at list top
        listView.setOnScrollListener(new AbsListView.OnScrollListener() {
            boolean enableRefresh = false;
            @Override
            public void onScrollStateChanged(AbsListView view, int scrollState) {}
            @Override
            public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount,
                                 int totalItemCount) {
                if (listView != null && listView.getChildCount() > 0) {
                    // check that the first item is visible and that its top matches the parent
                    enableRefresh = listView.getFirstVisiblePosition() == 0 &&
                            listView.getChildAt(0).getTop() >= 0;
                } else {
                    enableRefresh = false;
                }
                swipeLayout.setEnabled(enableRefresh);
            }
        });

        // specify action to take on swipe refresh
        swipeLayout.setOnRefreshListener(() -> {
            swipeLayout.setRefreshing(true);
            adapter.refresh(new Callback<TimelineResult<Tweet>>() {
                @Override
                public void success(Result<TimelineResult<Tweet>> result) {
                    swipeLayout.setRefreshing(false);
                }

                @Override
                public void failure(TwitterException exception) {
                    swipeLayout.setRefreshing(false);
                    final Activity activity = activityRef.get();
                    if (activity != null && !activity.isFinishing()) {
                        Toast.makeText(activity, exception.getMessage(),
                                Toast.LENGTH_SHORT).show();
                    }
                }
            });
        });
    }
}