Java tutorial
/* * Copyright (C) 2012 Paul Burke * * 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 fr.umlv.lastproject.smart.browser; import java.io.File; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.content.IntentFilter; import android.net.Uri; import android.os.Bundle; import android.os.Environment; import android.support.v4.app.FragmentActivity; import android.support.v4.app.FragmentManager; import android.support.v4.app.FragmentManager.BackStackEntry; import android.support.v4.app.FragmentManager.OnBackStackChangedListener; import android.support.v4.app.FragmentTransaction; import android.view.Menu; import android.view.MenuItem; import android.widget.Toast; import fr.umlv.lastproject.smart.Preferences; import fr.umlv.lastproject.smart.PreferencesException; import fr.umlv.lastproject.smart.R; /** * Main Activity that handles the FileListFragments * * @version 2012-10-28 * * @author paulburke (ipaulpro), marc barat * */ public class FileChooserActivity extends FragmentActivity implements OnBackStackChangedListener { private FragmentManager mFragmentManager; private String mPath; private Preferences pref; private BroadcastReceiver mStorageListener = new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { Toast.makeText(context, R.string.storage_removed, Toast.LENGTH_LONG).show(); finishWithResult(null); } }; public static final String PATH = "path"; public static final String EXTERNAL_BASE_PATH = Environment.getExternalStorageDirectory().getAbsolutePath(); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); try { pref = Preferences.create(this); } catch (PreferencesException e) { Toast.makeText(this, getString(R.string.unableLoadPref), Toast.LENGTH_LONG).show(); } setTheme(pref.getTheme()); setContentView(R.layout.chooser); mFragmentManager = getSupportFragmentManager(); mFragmentManager.addOnBackStackChangedListener(this); if (savedInstanceState == null) { Bundle bundle = getIntent().getExtras(); mPath = (String) bundle.get(PATH); addFragment(); } else { mPath = savedInstanceState.getString(PATH); } setTitle(mPath); } @Override protected void onPause() { super.onPause(); unregisterStorageListener(); try { pref.save(); } catch (PreferencesException e) { Toast.makeText(this, getString(R.string.unableLoadPref), Toast.LENGTH_LONG).show(); } } @Override protected void onResume() { super.onResume(); registerStorageListener(); } @Override protected void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); outState.putString(PATH, mPath); } @Override public void onBackStackChanged() { mPath = EXTERNAL_BASE_PATH; int count = mFragmentManager.getBackStackEntryCount(); if (count > 0) { BackStackEntry fragment = mFragmentManager.getBackStackEntryAt(count - 1); mPath = fragment.getName(); } setTitle(mPath); } /** * Add the initial Fragment with given path. * * @param path * The absolute path of the file (directory) to display. */ private void addFragment() { FileListFragment explorerFragment = FileListFragment.newInstance(mPath); mFragmentManager.beginTransaction().add(R.id.explorer_fragment, explorerFragment).commit(); } /** * "Replace" the existing Fragment with a new one using given path. We're * really adding a Fragment to the back stack. * * @param path * The absolute path of the file (directory) to display. */ private void replaceFragment(String path) { FileListFragment explorerFragment = FileListFragment.newInstance(path); mFragmentManager.beginTransaction().replace(R.id.explorer_fragment, explorerFragment) .setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN).addToBackStack(path).commit(); } /** * Finish this Activity with a result code and URI of the selected file. * * @param file * The file selected. */ private void finishWithResult(File file) { if (file != null) { Uri uri = Uri.fromFile(file); setResult(RESULT_OK, new Intent().setData(uri)); finish(); } else { setResult(RESULT_CANCELED); finish(); } } /** * Called when the user selects a File * * @param file * The file that was selected */ protected void onFileSelected(File file) { if (file != null) { mPath = file.getAbsolutePath(); if (file.isDirectory()) { replaceFragment(mPath); } else { finishWithResult(file); } } else { Toast.makeText(FileChooserActivity.this, R.string.error_selecting_file, Toast.LENGTH_SHORT).show(); } } /** * Register the external storage BroadcastReceiver. */ private void registerStorageListener() { IntentFilter filter = new IntentFilter(); filter.addAction(Intent.ACTION_MEDIA_REMOVED); registerReceiver(mStorageListener, filter); } /** * Unregister the external storage BroadcastReceiver. */ private void unregisterStorageListener() { unregisterReceiver(mStorageListener); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.activity_smart, menu); menu.add(0, 1, 0, R.string.directory); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { finishWithResult(new File(mPath)); return true; } }