Java tutorial
/* * Copyright (C) 2013 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 com.remote.client.filechooser; import android.app.Activity; import android.os.Bundle; import android.os.Environment; import android.support.v4.app.ListFragment; import android.support.v4.app.LoaderManager; import android.support.v4.content.Loader; import android.view.View; import android.widget.ListView; import com.remote.client.R; import java.io.File; import java.util.List; /** * Fragment that displays a list of Files in a given path. */ public class FileListFragment extends ListFragment implements LoaderManager.LoaderCallbacks<List<File>> { /** * Interface to listen for events. */ public interface Callbacks { /** * Called when a file is selected from the list. * * @param file The file selected */ public void onFileSelected(File file); } private static final int LOADER_ID = 0; private FileListAdapter mAdapter; private String mPath; private Callbacks mListener; /** * Create a new instance with the given file path. * * @param path The absolute path of the file (directory) to display. * @return A new Fragment with the given file path. */ public static FileListFragment newInstance(String path) { FileListFragment fragment = new FileListFragment(); Bundle args = new Bundle(); args.putString(FileChooserActivity.PATH, path); fragment.setArguments(args); return fragment; } @Override public void onAttach(Activity activity) { super.onAttach(activity); try { mListener = (Callbacks) activity; } catch (ClassCastException e) { throw new ClassCastException(activity.toString() + " must implement FileListFragment.Callbacks"); } } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mAdapter = new FileListAdapter(getActivity()); mPath = getArguments() != null ? getArguments().getString(FileChooserActivity.PATH) : Environment.getExternalStorageDirectory().getAbsolutePath(); } @Override public void onActivityCreated(Bundle savedInstanceState) { setEmptyText(getString(R.string.empty_directory)); setListAdapter(mAdapter); setListShown(false); getLoaderManager().initLoader(LOADER_ID, null, this); super.onActivityCreated(savedInstanceState); } @Override public void onListItemClick(ListView l, View v, int position, long id) { FileListAdapter adapter = (FileListAdapter) l.getAdapter(); if (adapter != null) { File file = (File) adapter.getItem(position); mPath = file.getAbsolutePath(); mListener.onFileSelected(file); } } @Override public Loader<List<File>> onCreateLoader(int id, Bundle args) { return new FileLoader(getActivity(), mPath); } @Override public void onLoadFinished(Loader<List<File>> loader, List<File> data) { mAdapter.setListItems(data); if (isResumed()) setListShown(true); else setListShownNoAnimation(true); } @Override public void onLoaderReset(Loader<List<File>> loader) { mAdapter.clear(); } }