Java tutorial
/* * Copyright (c) 2015 Algolia * http://www.algolia.com/ * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ package algolia.com.demo.moviesearch.ui; import android.app.SearchManager; import android.content.Context; import android.os.Build; import android.os.Bundle; import android.support.v4.view.MenuItemCompat; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.SearchView; import android.view.Menu; import android.view.View; import android.view.ViewGroup; import android.widget.AbsListView; import android.widget.ArrayAdapter; import android.widget.ImageView; import android.widget.ListView; import android.widget.TextView; import com.algolia.search.saas.AlgoliaException; import com.algolia.search.saas.Client; import com.algolia.search.saas.CompletionHandler; import com.algolia.search.saas.Index; import com.algolia.search.saas.Query; import com.nostra13.universalimageloader.core.DisplayImageOptions; import com.nostra13.universalimageloader.core.ImageLoader; import com.nostra13.universalimageloader.core.ImageLoaderConfiguration; import com.nostra13.universalimageloader.core.display.FadeInBitmapDisplayer; import org.json.JSONObject; import java.util.Collection; import java.util.List; import algolia.com.demo.moviesearch.R; import algolia.com.demo.moviesearch.io.SearchResultsJsonParser; import algolia.com.demo.moviesearch.model.HighlightedResult; import algolia.com.demo.moviesearch.model.Movie; public class MovieSearchActivity extends AppCompatActivity implements SearchView.OnQueryTextListener, AbsListView.OnScrollListener { // BL: private Client client; private Index index; private Query query; private SearchResultsJsonParser resultsParser = new SearchResultsJsonParser(); private int lastSearchedSeqNo; private int lastDisplayedSeqNo; private int lastRequestedPage; private int lastDisplayedPage; private boolean endReached; // UI: private SearchView searchView; private ListView moviesListView; private MovieAdapter moviesListAdapter; private ImageLoader imageLoader; private DisplayImageOptions displayImageOptions; private HighlightRenderer highlightRenderer; // Constants private static final int HITS_PER_PAGE = 20; /** Number of items before the end of the list past which we start loading more content. */ private static final int LOAD_MORE_THRESHOLD = 5; // Lifecycle @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_movie_search); // Bind UI components. moviesListView = (ListView) findViewById(R.id.listview_movies); moviesListView.setAdapter(moviesListAdapter = new MovieAdapter(this, R.layout.cell_movie)); moviesListView.setOnScrollListener(this); // Init Algolia. client = new Client("latency", "dce4286c2833e8cf4b7b1f2d3fa1dbcb"); index = client.initIndex("movies"); // Pre-build query. query = new Query(); query.setAttributesToRetrieve("title", "image", "rating", "year"); query.setAttributesToHighlight("title"); query.setHitsPerPage(HITS_PER_PAGE); // Configure Universal Image Loader. displayImageOptions = new DisplayImageOptions.Builder().cacheOnDisk(true).resetViewBeforeLoading(true) .displayer(new FadeInBitmapDisplayer(300)).build(); new Thread(new Runnable() { @Override public void run() { imageLoader = ImageLoader.getInstance(); ImageLoaderConfiguration configuration = new ImageLoaderConfiguration.Builder( MovieSearchActivity.this).memoryCacheSize(2 * 1024 * 1024).memoryCacheSizePercentage(13) // default .build(); imageLoader.init(configuration); } }).start(); highlightRenderer = new HighlightRenderer(this); } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.menu_movie_search, menu); // Configure search view. SearchManager searchManager = (SearchManager) getSystemService(Context.SEARCH_SERVICE); searchView = (SearchView) MenuItemCompat.getActionView(menu.findItem(R.id.search)); searchView.setSearchableInfo(searchManager.getSearchableInfo(getComponentName())); searchView.setIconifiedByDefault(false); searchView.setOnQueryTextListener(this); return true; } // Actions private void search() { final int currentSearchSeqNo = ++lastSearchedSeqNo; query.setQuery(searchView.getQuery().toString()); lastRequestedPage = 0; lastDisplayedPage = -1; endReached = false; index.searchAsync(query, new CompletionHandler() { @Override public void requestCompleted(JSONObject content, AlgoliaException error) { if (content != null && error == null) { // NOTE: Check that the received results are newer that the last displayed results. // // Rationale: Although TCP imposes a server to send responses in the same order as // requests, nothing prevents the system from opening multiple connections to the // same server, nor the Algolia client to transparently switch to another server // between two requests. Therefore the order of responses is not guaranteed. if (currentSearchSeqNo <= lastDisplayedSeqNo) return; List<HighlightedResult<Movie>> results = resultsParser.parseResults(content); if (results.isEmpty()) { endReached = true; } else { moviesListAdapter.clear(); moviesListAdapter.addAll(results); moviesListAdapter.notifyDataSetChanged(); lastDisplayedSeqNo = currentSearchSeqNo; lastDisplayedPage = 0; } // Scroll the list back to the top. moviesListView.smoothScrollToPosition(0); } } }); } private void loadMore() { Query loadMoreQuery = new Query(query); loadMoreQuery.setPage(++lastRequestedPage); final int currentSearchSeqNo = lastSearchedSeqNo; index.searchAsync(loadMoreQuery, new CompletionHandler() { @Override public void requestCompleted(JSONObject content, AlgoliaException error) { if (content != null && error == null) { // Ignore results if they are for an older query. if (lastDisplayedSeqNo != currentSearchSeqNo) return; List<HighlightedResult<Movie>> results = resultsParser.parseResults(content); if (results.isEmpty()) { endReached = true; } else { moviesListAdapter.addAll(results); moviesListAdapter.notifyDataSetChanged(); lastDisplayedPage = lastRequestedPage; } } } }); } // Data sources private class MovieAdapter extends ArrayAdapter<HighlightedResult<Movie>> { public MovieAdapter(Context context, int resource) { super(context, resource); } @Override public View getView(int position, View convertView, ViewGroup parent) { ViewGroup cell = (ViewGroup) convertView; if (cell == null) { cell = (ViewGroup) getLayoutInflater().inflate(R.layout.cell_movie, null); } ImageView posterImageView = (ImageView) cell.findViewById(R.id.imageview_poster); TextView titleTextView = (TextView) cell.findViewById(R.id.textview_title); TextView yearTextView = (TextView) cell.findViewById(R.id.textview_year); HighlightedResult<Movie> result = moviesListAdapter.getItem(position); imageLoader.displayImage(result.getResult().getImage(), posterImageView, displayImageOptions); titleTextView.setText( highlightRenderer.renderHighlights(result.getHighlight("title").getHighlightedValue())); yearTextView.setText(String.format("%d", result.getResult().getYear())); return cell; } @Override public void addAll(Collection<? extends HighlightedResult<Movie>> items) { if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) { super.addAll(items); } else { for (HighlightedResult<Movie> item : items) { add(item); } } } } // SearchView.OnQueryTextListener @Override public boolean onQueryTextSubmit(String query) { // Nothing to do: the search has already been performed by `onQueryTextChange()`. // We do try to close the keyboard, though. searchView.clearFocus(); return true; } @Override public boolean onQueryTextChange(String newText) { search(); return true; } // AbsListView.OnScrollListener @Override public void onScrollStateChanged(AbsListView view, int scrollState) { // Nothing to do. } @Override public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { // Abort if list is empty or the end has already been reached. if (totalItemCount == 0 || endReached) return; // Ignore if a new page has already been requested. if (lastRequestedPage > lastDisplayedPage) return; // Load more if we are sufficiently close to the end of the list. int firstInvisibleItem = firstVisibleItem + visibleItemCount; if (firstInvisibleItem + LOAD_MORE_THRESHOLD >= totalItemCount) loadMore(); } }