Java tutorial
/* * Firetweet - Twitter client for Android * * Copyright (C) 2012-2014 Mariotaku Lee <mariotaku.lee@gmail.com> * * This program 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. * * This program 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 this program. If not, see <http://www.gnu.org/licenses/>. */ package org.getlantern.firetweet.fragment.support; import android.app.AlertDialog; import android.app.Dialog; import android.content.Context; import android.content.DialogInterface; import android.content.DialogInterface.OnClickListener; import android.content.res.Resources; import android.graphics.PorterDuff; import android.graphics.drawable.Drawable; import android.os.Bundle; import android.support.annotation.NonNull; import android.support.v4.app.FragmentActivity; import android.support.v4.app.LoaderManager.LoaderCallbacks; import android.support.v4.content.AsyncTaskLoader; import android.support.v4.content.Loader; import android.support.v4.content.res.ResourcesCompat; import android.text.TextUtils.TruncateAt; import android.view.View; import android.view.ViewGroup; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.ListView; import android.widget.TextView; import org.getlantern.firetweet.R; import org.getlantern.firetweet.adapter.ArrayAdapter; import org.getlantern.firetweet.fragment.iface.ISupportDialogFragmentCallback; import org.getlantern.firetweet.util.ThemeUtils; import org.getlantern.firetweet.util.FiretweetArrayUtils; import java.io.File; import java.util.ArrayList; import java.util.Collections; import java.util.Comparator; import java.util.List; import java.util.Locale; import java.util.regex.Pattern; import static android.os.Environment.getExternalStorageDirectory; public class FileSelectorDialogFragment extends BaseSupportDialogFragment implements LoaderCallbacks<List<File>>, OnClickListener, OnItemClickListener { private FilesAdapter mAdapter; @Override public void onActivityCreated(final Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); final Bundle args = getArguments(); getLoaderManager().initLoader(0, args, this); } @Override public void onCancel(final DialogInterface dialog) { super.onCancel(dialog); final FragmentActivity a = getActivity(); if (a instanceof Callback) { ((Callback) a).onCancelled(this); } } @Override public void onClick(final DialogInterface dialog, final int which) { switch (which) { case DialogInterface.BUTTON_POSITIVE: { final FragmentActivity a = getActivity(); if (isPickDirectory() && a instanceof Callback) { ((Callback) a).onFilePicked(getCurrentDirectory()); } dismiss(); break; } } } @NonNull @Override public Dialog onCreateDialog(final Bundle savedInstanceState) { mAdapter = new FilesAdapter(getActivity()); final AlertDialog.Builder builder = new AlertDialog.Builder(getActivity()); builder.setAdapter(mAdapter, this); builder.setTitle(R.string.pick_file); builder.setNegativeButton(android.R.string.cancel, null); if (isPickDirectory()) { builder.setPositiveButton(android.R.string.ok, this); } final AlertDialog dialog = builder.create(); final ListView listView = dialog.getListView(); listView.setOnItemClickListener(this); return dialog; } @Override public Loader<List<File>> onCreateLoader(final int id, final Bundle args) { final String[] extensions = args.getStringArray(EXTRA_FILE_EXTENSIONS); final String path = args.getString(EXTRA_PATH); File currentDir = path != null ? new File(path) : getExternalStorageDirectory(); if (currentDir == null) { currentDir = new File("/"); } getArguments().putString(EXTRA_PATH, currentDir.getAbsolutePath()); return new FilesLoader(getActivity(), currentDir, extensions); } @Override public void onDismiss(final DialogInterface dialog) { super.onDismiss(dialog); final FragmentActivity a = getActivity(); if (a instanceof Callback) { ((Callback) a).onDismissed(this); } } @Override public void onItemClick(final AdapterView<?> view, final View child, final int position, final long id) { final File file = mAdapter.getItem(position); if (file == null) return; if (file.isDirectory()) { final Bundle args = getArguments(); args.putString(EXTRA_PATH, file.getAbsolutePath()); getLoaderManager().restartLoader(0, args, this); } else if (file.isFile() && !isPickDirectory()) { final FragmentActivity a = getActivity(); if (a instanceof Callback) { ((Callback) a).onFilePicked(file); } dismiss(); } } @Override public void onLoaderReset(final Loader<List<File>> loader) { mAdapter.setData(null, null); } @Override public void onLoadFinished(final Loader<List<File>> loader, final List<File> data) { final File currentDir = getCurrentDirectory(); if (currentDir != null) { mAdapter.setData(currentDir, data); if (currentDir.getParent() == null) { setTitle("/"); } else { setTitle(currentDir.getName()); } } } private File getCurrentDirectory() { final Bundle args = getArguments(); final String path = args.getString(EXTRA_PATH); return path != null ? new File(path) : null; } private boolean isPickDirectory() { final Bundle args = getArguments(); final String action = args != null ? args.getString(EXTRA_ACTION) : null; return INTENT_ACTION_PICK_DIRECTORY.equals(action); } private void setTitle(final CharSequence title) { final Dialog dialog = getDialog(); if (dialog == null) return; dialog.setTitle(title); } public static interface Callback extends ISupportDialogFragmentCallback { void onFilePicked(File file); } private static class FilesAdapter extends ArrayAdapter<File> { private final int mPadding; private final int mActionIconColor; private final Resources mResources; private File mCurrentPath; public FilesAdapter(final Context context) { super(context, android.R.layout.simple_list_item_1); mResources = context.getResources(); mActionIconColor = ThemeUtils.isDarkTheme(context) ? 0xffffffff : 0xc0333333; mPadding = (int) (4 * mResources.getDisplayMetrics().density); } @Override public long getItemId(final int position) { return getItem(position).hashCode(); } @Override public View getView(final int position, final View convertView, final ViewGroup parent) { final View view = super.getView(position, convertView, parent); final TextView text = (TextView) (view instanceof TextView ? view : view.findViewById(android.R.id.text1)); final File file = getItem(position); if (file == null || text == null) return view; if (mCurrentPath != null && file.equals(mCurrentPath.getParentFile())) { text.setText(".."); } else { text.setText(file.getName()); } text.setSingleLine(true); text.setEllipsize(TruncateAt.MARQUEE); text.setPadding(mPadding, mPadding, position, mPadding); final Drawable icon = ResourcesCompat.getDrawable(mResources, file.isDirectory() ? R.drawable.ic_folder : R.drawable.ic_file, null); icon.mutate(); icon.setColorFilter(mActionIconColor, PorterDuff.Mode.SRC_ATOP); text.setCompoundDrawablesWithIntrinsicBounds(icon, null, null, null); return view; } public void setData(final File current, final List<File> data) { mCurrentPath = current; clear(); if (data != null) { addAll(data); } } } private static class FilesLoader extends AsyncTaskLoader<List<File>> { private final File path; private final String[] extensions; private final Pattern extensions_regex; private static final Comparator<File> NAME_COMPARATOR = new Comparator<File>() { @Override public int compare(final File file1, final File file2) { final Locale loc = Locale.getDefault(); return file1.getName().toLowerCase(loc).compareTo(file2.getName().toLowerCase(loc)); } }; public FilesLoader(final Context context, final File path, final String[] extensions) { super(context); this.path = path; this.extensions = extensions; extensions_regex = extensions != null ? Pattern.compile(FiretweetArrayUtils.toString(extensions, '|', false), Pattern.CASE_INSENSITIVE) : null; } @Override public List<File> loadInBackground() { if (path == null || !path.isDirectory()) return Collections.emptyList(); final File[] listed_files = path.listFiles(); if (listed_files == null) return Collections.emptyList(); final List<File> dirs = new ArrayList<>(); final List<File> files = new ArrayList<>(); for (final File file : listed_files) { if (!file.canRead() || file.isHidden()) { continue; } if (file.isDirectory()) { dirs.add(file); } else if (file.isFile()) { final String name = file.getName(); final int idx = name.lastIndexOf("."); if (extensions == null || extensions.length == 0 || idx == -1 || idx > -1 && extensions_regex.matcher(name.substring(idx + 1)).matches()) { files.add(file); } } } Collections.sort(dirs, NAME_COMPARATOR); Collections.sort(files, NAME_COMPARATOR); final List<File> list = new ArrayList<>(); final File parent = path.getParentFile(); if (path.getParentFile() != null) { list.add(parent); } list.addAll(dirs); list.addAll(files); return list; } @Override protected void onStartLoading() { forceLoad(); } @Override protected void onStopLoading() { cancelLoad(); } } }