FilePickerDialog.java

/*
 * Copyright (C) 2016 Álinson Santos Xavier <isoron@gmail.com>
 *
 * This file is part of Loop Habit Tracker.
 *
 * Loop Habit Tracker 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.
 *
 * Loop Habit Tracker 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.isoron.uhabits.activities.common.dialogs;

import android.content.*;
import android.support.annotation.*;
import android.support.v7.app.*;
import android.view.*;
import android.view.WindowManager.*;
import android.widget.*;

import com.google.auto.factory.*;

import org.isoron.uhabits.activities.*;

import java.io.*;
import java.util.*;

/**
 * Dialog that allows the user to pick a file.
 */
@AutoFactory(allowSubclasses = true)
public class FilePickerDialog implements AdapterView.OnItemClickListener
{
    private static final String PARENT_DIR = "..";

    private final Context context;

    private ListView list;

    private AppCompatDialog dialog;

    private File currentPath;

    private OnFileSelectedListener listener;

    public FilePickerDialog(@Provided @ActivityContext Context context,
                            File initialDirectory)
    {
        this.context = context;

        list = new ListView(context);
        list.setOnItemClickListener(this);

        dialog = new AppCompatDialog(context);
        dialog.setContentView(list);
        dialog
            .getWindow()
            .setLayout(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);

        navigateTo(initialDirectory);
    }

    public AppCompatDialog getDialog()
    {
        return dialog;
    }

    @Override
    public void onItemClick(AdapterView<?> parent,
                            View view,
                            int which,
                            long id)
    {
        String filename = (String) list.getItemAtPosition(which);
        File file;

        if (filename.equals(PARENT_DIR)) file = currentPath.getParentFile();
        else file = new File(currentPath, filename);

        if (file.isDirectory())
        {
            navigateTo(file);
        }
        else
        {
            if (listener != null) listener.onFileSelected(file);
            dialog.dismiss();
        }
    }

    public void setListener(OnFileSelectedListener listener)
    {
        this.listener = listener;
    }

    public void show()
    {
        dialog.show();
    }

    @NonNull
    private String[] getFileList(File path, File[] dirs, File[] files)
    {
        int count = 0;
        int length = dirs.length + files.length;
        String[] fileList;

        if (path.getParentFile() == null || !path.getParentFile().canRead())
        {
            fileList = new String[length];
        }
        else
        {
            fileList = new String[length + 1];
            fileList[count++] = PARENT_DIR;
        }

        Arrays.sort(dirs);
        Arrays.sort(files);

        for (File dir : dirs)
            fileList[count++] = dir.getName();

        for (File file : files)
            fileList[count++] = file.getName();

        return fileList;
    }

    private void navigateTo(File path)
    {
        if (!path.exists()) return;

        File[] dirs = path.listFiles(new ReadableDirFilter());
        File[] files = path.listFiles(new RegularReadableFileFilter());
        if (dirs == null || files == null) return;

        this.currentPath = path;
        dialog.setTitle(currentPath.getPath());
        list.setAdapter(new FilePickerAdapter(getFileList(path, dirs, files)));
    }

    public interface OnFileSelectedListener
    {
        void onFileSelected(File file);
    }

    private static class ReadableDirFilter implements FileFilter
    {
        @Override
        public boolean accept(File file)
        {
            return (file.isDirectory() && file.canRead());
        }
    }

    private class FilePickerAdapter extends ArrayAdapter<String>
    {
        public FilePickerAdapter(@NonNull String[] fileList)
        {
            super(FilePickerDialog.this.context,
                android.R.layout.simple_list_item_1, fileList);
        }

        @Override
        public View getView(int pos, View view, ViewGroup parent)
        {
            view = super.getView(pos, view, parent);
            TextView tv = (TextView) view;
            tv.setSingleLine(true);
            return view;
        }
    }

    private class RegularReadableFileFilter implements FileFilter
    {
        @Override
        public boolean accept(File file)
        {
            return !file.isDirectory() && file.canRead();
        }
    }
}