Java tutorial
/** Copyright 2012 Fahad Al-Khameesi, Madeleine Appert, Niklas Logren, Arild Matsson and Jonathan Orr. This file is part of Bibbla. Bibbla is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. Bibbla is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with Bibbla. If not, see <http://www.gnu.org/licenses/>. **/ package dat255.grupp06.bibbla.fragments; import java.io.UnsupportedEncodingException; import java.net.URLEncoder; import java.util.ArrayList; import android.os.Bundle; import android.support.v4.app.FragmentManager; import android.support.v4.app.FragmentTransaction; import android.util.Log; import android.view.KeyEvent; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.view.inputmethod.EditorInfo; import android.widget.Button; import android.widget.EditText; import android.widget.ProgressBar; import android.widget.TextView; import android.widget.TextView.OnEditorActionListener; import android.widget.Toast; import com.actionbarsherlock.app.SherlockFragment; import dat255.grupp06.bibbla.R; import dat255.grupp06.bibbla.backend.Backend; import dat255.grupp06.bibbla.backend.BackendFactory; import dat255.grupp06.bibbla.model.Book; import dat255.grupp06.bibbla.utils.Callback; import dat255.grupp06.bibbla.utils.Message; /** * A fragment that holds the search bar, button * and a ListFragment that displays search results * * @author Jonathan Orr */ public class SearchFragment extends SherlockFragment { SearchListFragment listFragment; EditText searchEdit; Button searchButton; ProgressBar searchProgress; @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { FragmentManager fragmentManager = getFragmentManager(); FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction(); if(listFragment == null) { listFragment = new SearchListFragment(); fragmentTransaction.add(R.id.list_container, listFragment); } else { fragmentTransaction.attach(listFragment); } fragmentTransaction.commit(); return inflater.inflate(R.layout.fragment_search, container, false); } @Override public void onDestroyView() { FragmentManager fragmentManager = getFragmentManager(); FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction(); fragmentTransaction.detach(listFragment); fragmentTransaction.commit(); super.onDestroyView(); } @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); // Get our GUI elements. searchButton = (Button)getSherlockActivity().findViewById(R.id.button_search); searchEdit = (EditText)getSherlockActivity().findViewById(R.id.edit_search); searchEdit.setTextColor(0xfff0641e); searchProgress = (ProgressBar)getSherlockActivity().findViewById(R.id.progress_search); // Create a listener for keyboard "enter" button. OnEditorActionListener listener = new OnEditorActionListener() { public boolean onEditorAction(TextView v, int actionId, KeyEvent event) { if (actionId == EditorInfo.IME_ACTION_SEARCH) { // Simulate click on the search button. searchButton.performClick(); return true; } return false; } }; // Add our newly created listener to the text field. searchEdit.setOnEditorActionListener(listener); } /** * Starts searching procedure in backend. */ public void searchClicked() { // Convert search string to UTF-8. String searchString = searchEdit.getText().toString(); try { searchString = URLEncoder.encode(searchString, "UTF-8"); } catch (UnsupportedEncodingException e) {} // Display progress bar. setProgressBarVisibility(true); // No input? No need to search. if("".equals(searchString)) { listFragment.updateList(new ArrayList<Book>()); return; } // Create a new callback object, which refers to our searchDone(). Callback c = new Callback() { public void handleMessage(Message msg) { SearchFragment.this.searchDone(msg); } }; // Call backend search. BackendFactory.getBackend().search(searchString, 0, c); listFragment.setLastSearchString(searchString); } /** * Is used to get more search results after the first page has already been * fetched. * @param page - What page do you want? * @param searchString - What are you searching for? */ public void getMoreSearchResults(int page, String searchString) { setProgressBarVisibility(true); // Create a new callback object, which refers to our searchDone(). Callback c = new Callback() { public void handleMessage(Message msg) { SearchFragment.this.moreSearchDone(msg); } }; // Call backend search. Log.d("Jonis", "searching..... on page "+page); BackendFactory.getBackend().search(searchString, page, c); } /** * Is called from a callback object when backend searching is done. * @param msg - Message object that contains all the books that searchJob * finds. Also the occasional error message. */ public void searchDone(Message msg) { // Hide progress bar. setProgressBarVisibility(false); // Did the job fail? if (msg.error != null) { // Log, Log.e("searching", "Searching failed: "+msg.error); // And toast user. Toast.makeText(getSherlockActivity().getApplicationContext(), "Searching failed: "+msg.error, Toast.LENGTH_LONG).show(); return; } // Convert results to ArrayList<Book>. @SuppressWarnings("unchecked") ArrayList<Book> books = (ArrayList<Book>) msg.obj; // Did we get no results? if (books.size() == 0) { Toast.makeText(getSherlockActivity().getApplicationContext(), "No results found.", Toast.LENGTH_LONG).show(); } // Update list with titles (empty or not). listFragment.updateList(books); } /** * Is called from a callback object when backend searching is done. * It is different from searchDone since we want to append the search * results to the current list instead of replacing it. * @param msg - Contains the books found by the search job and also * an error message if there was an error. */ public void moreSearchDone(Message msg) { // Hide progress bar. setProgressBarVisibility(false); // Did the job fail? if (msg.error != null) { // Log, Log.e("searching", "Searching failed: "+msg.error); // And toast user. Toast.makeText(getSherlockActivity().getApplicationContext(), "Searching failed: "+msg.error, Toast.LENGTH_LONG).show(); return; } // Convert results to List<Book>. @SuppressWarnings("unchecked") ArrayList<Book> books = (ArrayList<Book>) msg.obj; // Did we get no results? if (books.size() == 0) { Toast.makeText(getSherlockActivity().getApplicationContext(), "No results found.", Toast.LENGTH_LONG).show(); } // Update list with titles (empty or not). listFragment.appendList(books); } /** * Changes the visibility of the progress bar. * @param visible - should we show or hide the progress bar? */ private void setProgressBarVisibility(boolean visible) { // Do only this if searchProgress exists. if (searchProgress != null) { // setVisibility takes an int. int visibilityCode = (visible) ? View.VISIBLE : View.GONE; searchProgress.setVisibility(visibilityCode); } } }