FileBrowserHelper.java

/*
 * Copyright (c) 2015, Nils Braden
 *
 * This file is part of ttrss-reader-fork. 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.ttrssreader.preferences;

import org.ttrssreader.BuildConfig;
import org.ttrssreader.R;
import org.ttrssreader.controllers.Controller;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.Fragment;
import android.content.ActivityNotFoundException;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.Uri;
import android.os.Build;
import android.support.v4.content.FileProvider;
import android.text.InputType;
import android.util.Log;
import android.widget.EditText;

import java.io.File;

/**
 * Copied from https://code.google.com/p/k9mail/
 */
public class FileBrowserHelper {
	/**
	 * A string array that specifies the name of the intent to use, and the scheme to use with it
	 * when setting the data for the intent.
	 */
	private static final String[][] PICK_DIRECTORY_INTENTS = {
			{"org.openintents.action.PICK_DIRECTORY", "file://"}, // OI File Manager
			{"com.estrongs.action.PICK_DIRECTORY", "file://"}, // ES File Explorer
			{Intent.ACTION_PICK, "folder://"}, // Blackmoon File Browser (maybe others)
			{"com.androidworkz.action.PICK_DIRECTORY", "file://"} // SystemExplorer
	};

	private static FileBrowserHelper instance;

	/**
	 * callbackDownloadPath class to provide the result of the fallback textedit path dialog
	 */
	public interface FileBrowserFailOverCallback {
		/**
		 * the user has entered a path
		 *
		 * @param path the path as String
		 */
		void onPathEntered(String path);

		/**
		 * the user has cancel the inputtext dialog
		 */
		void onCancel();
	}

	// Singleton
	private FileBrowserHelper() {
	}

	public synchronized static FileBrowserHelper getInstance() {
		if (instance == null) {
			instance = new FileBrowserHelper();
		}
		return instance;
	}

	/**
	 * tries to open known filebrowsers.
	 * If no filebrowser is found and fallback textdialog is shown
	 *
	 * @param c           the context as activity
	 * @param startPath   : the default value, where the filebrowser will start.
	 *                    if startPath = null => the default path is used
	 * @param requestcode : the int you will get as requestcode in onActivityResult
	 *                    (only used if there is a filebrowser installed)
	 * @param callback    : the callbackDownloadPath (only used when no filebrowser is installed.
	 *                    if a filebrowser is installed => override the onActivtyResult Method
	 * @return true: if a filebrowser has been found (the result will be in the onActivityResult
	 * false: a fallback textinput has been shown. The Result will be sent with the callbackDownloadPath method
	 */
	public boolean showFileBrowserActivity(Fragment c, File startPath, int requestcode,
	                                       FileBrowserFailOverCallback callback) {
		boolean success = false;

		if (startPath == null) {
			startPath = new File(Controller.getInstance().saveAttachmentPath());
		}

		int listIndex = 0;
		do {
			String intentAction = PICK_DIRECTORY_INTENTS[listIndex][0];
			String uriPrefix = PICK_DIRECTORY_INTENTS[listIndex][1];
			Intent intent = new Intent(intentAction);
			if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
				String authority = BuildConfig.APPLICATION_ID + ".provider";
				Uri uri = FileProvider.getUriForFile(c.getContext(), authority, startPath);
				intent.setData(uri);
			} else {
				intent.setData(Uri.parse(uriPrefix + startPath.getPath()));
			}
			try {
				c.startActivityForResult(intent, requestcode);
				success = true;
			} catch (ActivityNotFoundException e) {
				// Try the next intent in the list
				listIndex++;
			}
		} while (!success && (listIndex < PICK_DIRECTORY_INTENTS.length));

		if (listIndex == PICK_DIRECTORY_INTENTS.length) {
			// No Filebrowser is installed => show a fallback textdialog
			showPathTextInput(c.getActivity(), startPath, callback);
			success = false;
		}

		return success;
	}

	private void showPathTextInput(final Activity c, final File startPath, final FileBrowserFailOverCallback
			callback) {
		AlertDialog.Builder alert = new AlertDialog.Builder(c);

		alert.setTitle(c.getString(R.string.Utils_FileSaveTitle));
		alert.setMessage(c.getString(R.string.Utils_FileSaveMessage));
		final EditText input = new EditText(c);
		input.setInputType(InputType.TYPE_CLASS_TEXT);
		if (startPath != null) input.setText(startPath.toString());
		alert.setView(input);

		alert.setPositiveButton(c.getString(R.string.Utils_OkayAction), new DialogInterface.OnClickListener() {
			public void onClick(DialogInterface dialog, int whichButton) {
				String path = input.getText().toString();
				callback.onPathEntered(path);
			}
		});

		alert.setNegativeButton(c.getString(R.string.Utils_CancelAction), new DialogInterface.OnClickListener() {
			public void onClick(DialogInterface dialog, int whichButton) {
				callback.onCancel();
			}
		});

		alert.show();
	}
}