I have a former exercise of "File Explorer", with Sorting in alphabetical order ignore case, and Sorting in lastModified time. Here, I will group them together to make buttons for user to select Sorting method.
Modify layout file to add buttons for sorting method.
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<Button
android:id="@+id/button_alphabetically"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="alphabetically"/>
<Button
android:id="@+id/button_lastDateModified"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="lastDateModified"/>
</LinearLayout>
<TextView
android:id="@+id/path"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
<ListView
android:id="@android:id/list"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
<TextView
android:id="@android:id/empty"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="No Data"
/>
</LinearLayout>
Main code:
package com.example.androidexplorer;
import java.io.File;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.List;
import android.os.Bundle;
import android.os.Environment;
import android.app.AlertDialog;
import android.app.ListActivity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
public class MainActivity extends ListActivity {
private List<String> item = null;
private List<String> path = null;
private String root;
private TextView myPath;
private String currentPath;
Comparator<? super File> comparator;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myPath = (TextView)findViewById(R.id.path);
comparator = filecomparatorByAlphabetically;
root = Environment.getExternalStorageDirectory().getPath();
getDir(root);
Button btnAlphabetically = (Button)findViewById(R.id.button_alphabetically);
btnAlphabetically.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View arg0) {
comparator = filecomparatorByAlphabetically;
getDir(currentPath);
}});
Button btnLastDateModified = (Button)findViewById(R.id.button_lastDateModified);
btnLastDateModified.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View arg0) {
comparator = filecomparatorByLastModified;
getDir(currentPath);
}});
}
private void getDir(String dirPath)
{
currentPath = dirPath;
myPath.setText("Location: " + dirPath);
item = new ArrayList<String>();
path = new ArrayList<String>();
File f = new File(dirPath);
File[] files = f.listFiles();
if(!dirPath.equals(root))
{
item.add(root);
path.add(root);
item.add("../");
path.add(f.getParent());
}
Arrays.sort(files, comparator);
for(int i=0; i < files.length; i++)
{
File file = files[i];
if(!file.isHidden() && file.canRead()){
path.add(file.getPath());
if(file.isDirectory()){
item.add(file.getName() + "/");
}else{
item.add(file.getName());
}
}
}
ArrayAdapter<String> fileList =
new ArrayAdapter<String>(this, R.layout.row, item);
setListAdapter(fileList);
}
Comparator<? super File> filecomparatorByLastModified = new Comparator<File>(){
public int compare(File file1, File file2) {
if(file1.isDirectory()){
if (file2.isDirectory()){
return Long.valueOf(file1.lastModified()).compareTo(file2.lastModified());
}else{
return -1;
}
}else {
if (file2.isDirectory()){
return 1;
}else{
return Long.valueOf(file1.lastModified()).compareTo(file2.lastModified());
}
}
}
};
Comparator<? super File> filecomparatorByAlphabetically = new Comparator<File>(){
public int compare(File file1, File file2) {
if(file1.isDirectory()){
if (file2.isDirectory()){
return String.valueOf(file1.getName().toLowerCase()).compareTo(file2.getName().toLowerCase());
}else{
return -1;
}
}else {
if (file2.isDirectory()){
return 1;
}else{
return String.valueOf(file1.getName().toLowerCase()).compareTo(file2.getName().toLowerCase());
}
}
}
};
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
// TODO Auto-generated method stub
File file = new File(path.get(position));
if (file.isDirectory())
{
if(file.canRead()){
getDir(path.get(position));
}else{
new AlertDialog.Builder(this)
.setIcon(R.drawable.ic_launcher)
.setTitle("[" + file.getName() + "] folder can't be read!")
.setPositiveButton("OK", null).show();
}
}else {
new AlertDialog.Builder(this)
.setIcon(R.drawable.ic_launcher)
.setTitle("[" + file.getName() + "]")
.setPositiveButton("OK", null).show();
}
}
}
/res/layout/row.xml, the layout of the rows in the list.
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/rowtext"
android:layout_width="fill_parent"
android:layout_height="30sp"
android:textSize="25sp" />
Please notice that if you target for minimum SDK of level 16, Android 4.1, you have to add permission of READ_EXTERNAL_STORAGE in AndroidManifest.xml.
Download the files.
