Java tutorial
/* * Copyright (C) 2007 The Android Open Source Project * * 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 net.dahanne.spring.android.ch3.restful.example.recipeapp; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import org.springframework.http.HttpEntity; import org.springframework.http.HttpHeaders; import org.springframework.http.HttpMethod; import org.springframework.http.ResponseEntity; import org.springframework.http.converter.json.MappingJacksonHttpMessageConverter; import org.springframework.web.client.RestClientException; import org.springframework.web.client.RestTemplate; import android.app.ListActivity; import android.app.ProgressDialog; import android.content.ComponentName; import android.content.ContentUris; import android.content.Context; import android.content.Intent; import android.net.Uri; import android.os.Bundle; import android.util.Log; import android.view.ContextMenu; import android.view.ContextMenu.ContextMenuInfo; import android.view.LayoutInflater; import android.view.Menu; import android.view.MenuInflater; import android.view.MenuItem; import android.view.View; import android.view.ViewGroup; import android.widget.AdapterView; import android.widget.ArrayAdapter; import android.widget.ListAdapter; import android.widget.ListView; import android.widget.TextView; import android.widget.Toast; public class RecipesList extends ListActivity { // For logging and debugging private static final String TAG = "RecipesList"; private static final int ACTION_EDIT = 10; private static final int ACTION_ADD = 20; private ProgressDialog progressDialog; private boolean destroyed = false; private List<Recipe> recipes; @Override protected void onDestroy() { super.onDestroy(); this.destroyed = true; } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); getListView().setOnCreateContextMenuListener(this); } @Override protected void onResume() { super.onResume(); // we go and get the recipes, that will get added to the ListAdapter new GetRecipesTask().execute(); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate menu from XML resource MenuInflater inflater = getMenuInflater(); inflater.inflate(R.menu.list_options_menu, menu); Intent intent = new Intent(null, getIntent().getData()); intent.addCategory(Intent.CATEGORY_ALTERNATIVE); menu.addIntentOptions(Menu.CATEGORY_ALTERNATIVE, 0, 0, new ComponentName(this, RecipesList.class), null, intent, 0, null); return super.onCreateOptionsMenu(menu); } @Override public boolean onPrepareOptionsMenu(Menu menu) { super.onPrepareOptionsMenu(menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case R.id.menu_add: startActivityForResult(new Intent(this, RecipeEditor.class).putExtra(RecipeEditor.NEW_RECIPE, true), ACTION_ADD); return true; default: return super.onOptionsItemSelected(item); } } @Override public void onCreateContextMenu(ContextMenu menu, View view, ContextMenuInfo menuInfo) { // The data from the menu item. AdapterView.AdapterContextMenuInfo info; // Tries to get the position of the item in the ListView that was long-pressed. try { // Casts the incoming data object into the type for AdapterView objects. info = (AdapterView.AdapterContextMenuInfo) menuInfo; } catch (ClassCastException e) { // If the menu object can't be cast, logs an error. Log.e(TAG, "bad menuInfo", e); return; } Intent intent = new Intent(null, Uri.withAppendedPath(getIntent().getData(), Integer.toString((int) info.id))); intent.addCategory(Intent.CATEGORY_ALTERNATIVE); menu.addIntentOptions(Menu.CATEGORY_ALTERNATIVE, 0, 0, new ComponentName(this, RecipesList.class), null, intent, 0, null); } @Override public boolean onContextItemSelected(MenuItem item) { // The data from the menu item. AdapterView.AdapterContextMenuInfo info; try { // Casts the data object in the item into the type for AdapterView objects. info = (AdapterView.AdapterContextMenuInfo) item.getMenuInfo(); } catch (ClassCastException e) { // If the object can't be cast, logs an error Log.e(TAG, "bad menuInfo", e); // Triggers default processing of the menu item. return false; } // Appends the selected recipe's ID to the URI sent with the incoming Intent. Uri recipeUri = ContentUris.withAppendedId(getIntent().getData(), info.id); /* * Gets the menu item's ID and compares it to known actions. */ switch (item.getItemId()) { case R.id.context_open: // Launch activity to view/edit the currently selected item startActivity(new Intent(Intent.ACTION_EDIT, recipeUri)); return true; case R.id.context_delete: getContentResolver().delete(recipeUri, // The URI of the provider null, // No where clause is needed, since only a single recipe ID is being // passed in. null // No where clause is used, so no where arguments are needed. ); // Returns to the caller and skips further processing. return true; default: return super.onContextItemSelected(item); } } @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { //we are back in the list activity, and we know the user has successfully updated the list, let's get it back from the server if (resultCode == RESULT_OK || requestCode == ACTION_ADD) { new GetRecipesTask().execute(); } } @Override protected void onListItemClick(ListView l, View v, int position, long id) { // Sends out an Intent to start an Activity that can handle ACTION_EDIT. The // Intent's data is the recipe ID URI. The effect is to call RecipeEdit. startActivityForResult(new Intent(this, RecipeEditor.class) .putExtra(RecipeEditor.RECIPE_ID, getListAdapter().getItemId(position)) .putExtra(RecipeEditor.NEW_RECIPE, false), ACTION_EDIT); } /** * AsyncTask to fetch all recipes from the recipe web service */ private class GetRecipesTask extends RecipeAbstractAsyncTask<Void, Void, List<Recipe>> { @Override protected void onPreExecute() { showProgressDialog("Loading recipes. Please wait..."); } @Override protected List<Recipe> doInBackground(Void... params) { HttpHeaders requestHeaders = prepareHeadersWithMediaTypeAndBasicAuthentication(); // Populate the headers in an HttpEntity object to use for the request HttpEntity<?> requestEntity = new HttpEntity<Object>(requestHeaders); // Create a new RestTemplate instance RestTemplate restTemplate = new RestTemplate(); restTemplate.getMessageConverters().add(new MappingJacksonHttpMessageConverter()); try { // Perform the HTTP GET request ResponseEntity<Recipe[]> responseEntity = restTemplate.exchange( getString(R.string.recipe_resource_url), HttpMethod.GET, requestEntity, Recipe[].class); return Arrays.asList(responseEntity.getBody()); } catch (RestClientException e) { Log.e(TAG, e.getMessage(), e); exception = e; return null; } } @Override protected void onPostExecute(List<Recipe> result) { dismissProgressDialog(); if (result != null) { recipes = result; } else { String message = exception != null ? exception.getMessage() : "unknown reason"; Toast.makeText(RecipesList.this, "A problem occurred during the reception of all recipes : " + message, Toast.LENGTH_LONG) .show(); recipes = new ArrayList<Recipe>(); } ListAdapter adapter = new RecipeAdapter(RecipesList.this, R.layout.recipeslist_item, recipes); setListAdapter(adapter); } } private class RecipeAdapter extends ArrayAdapter<Recipe> { public RecipeAdapter(RecipesList recipesList, int recipeslistItem, List<Recipe> recipes) { super(recipesList, recipeslistItem, recipes); } @Override public long getItemId(int position) { return getItem(position).getId(); } @Override public View getView(int position, View convertView, ViewGroup parent) { View rowView; LayoutInflater mInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE); if (null == convertView) { rowView = mInflater.inflate(R.layout.recipeslist_item, null); } else { rowView = convertView; } Recipe item = getItem(position); TextView titleView = (TextView) rowView.findViewById(android.R.id.text1); titleView.setText(item.getTitle()); return titleView; } } private void showProgressDialog(CharSequence message) { if (this.progressDialog == null) { this.progressDialog = new ProgressDialog(this); this.progressDialog.setIndeterminate(true); } this.progressDialog.setMessage(message); this.progressDialog.show(); } private void dismissProgressDialog() { if (this.progressDialog != null && !this.destroyed) { this.progressDialog.dismiss(); } } }