switch between dark and light theme in "File Selection" activity

term/src/main/java/com/termoneplus/shortcuts/FileSelection.java

@@ -17,6 +17,7 @@
 package com.termoneplus.shortcuts;
 
 import android.content.Intent;
+import android.content.SharedPreferences;
 import android.net.Uri;
 import android.os.Bundle;
 import android.os.Environment;
@@ -27,6 +28,7 @@
 import android.support.v7.widget.Toolbar;
 import android.view.KeyEvent;
 import android.view.LayoutInflater;
+import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
 import android.view.ViewGroup;
@@ -42,6 +44,9 @@
 import jackpal.androidterm.R;
 
 public class FileSelection extends AppCompatActivity {
+    private final String PREFERENCES_FILE = "file_selection";
+    private final String PREFERENCE_LIGHT_THEME = "light_theme";
+
     private final String STATE_CWD = "CWD";
 
     private String cwd; // current working directory
@@ -49,7 +54,16 @@ public class FileSelection extends AppCompatActivity {
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
+        {
+            SharedPreferences preferences = getSharedPreferences(PREFERENCES_FILE, MODE_PRIVATE);
+            boolean light = preferences.getBoolean(PREFERENCE_LIGHT_THEME, false);
+
+            // override activity theme defined in manifest file
+            if (light)
+                setTheme(R.style.AppTheme_Light_NoActionBar);
+        }
         super.onCreate(savedInstanceState);
+
         setContentView(R.layout.activity_file_selection);
 
         setResult(RESULT_CANCELED);
@@ -123,11 +137,20 @@ public boolean onKey(View v, int keyCode, KeyEvent event) {
         }
     }
 
+    @Override
+    public boolean onCreateOptionsMenu(Menu menu) {
+        getMenuInflater().inflate(R.menu.menu_file_selection, menu);
+        return true;
+    }
+
     public boolean onOptionsItemSelected(MenuItem item) {
         switch (item.getItemId()) {
             case android.R.id.home: // Action bar home/up button selected
                 finish();
                 return true;
+            case R.id.menu_switch_theme:
+                onSwitchTheme();
+                return true;
         }
         return super.onOptionsItemSelected(item);
     }
@@ -138,6 +161,23 @@ protected void onSaveInstanceState(Bundle outState) {
         outState.putString(STATE_CWD, cwd);
     }
 
+    private void onSwitchTheme() {
+        SharedPreferences preferences = getSharedPreferences(PREFERENCES_FILE, MODE_PRIVATE);
+        boolean light = preferences.getBoolean(PREFERENCE_LIGHT_THEME, false);
+
+        {
+            SharedPreferences.Editor editor = preferences.edit();
+            editor.putBoolean("light_theme", !light);
+            editor.apply();
+        }
+
+        Intent intent = getIntent();
+        intent.addFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT);
+        intent.putExtra("COMMAND_PATH", cwd);
+        startActivityForResult(intent, -1);
+        finish();
+    }
+
     @IntDef({
             ViewType.UP_ENTRY,
             ViewType.DIR_ENTRY,

term/src/main/res/menu/menu_file_selection.xml

+<?xml version="1.0" encoding="utf-8"?>
+<menu
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto">
+    <item
+        android:id="@+id/menu_switch_theme"
+        android:title="@string/fsnavigator_change_theme"/>
+</menu>

term/src/main/res/values/styles.xml

@@ -43,4 +43,17 @@
     </style>
     <style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar"/>
     <style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light"/>
+
+    <style name="AppTheme.Light" parent="Theme.AppCompat.Light">
+        <!-- Customize TermOnePlus theme here. -->
+        <item name="colorPrimary">@color/colorPrimary</item>
+        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
+        <item name="colorAccent">@color/colorAccent</item>
+    </style>
+    <style name="AppTheme.Light.NoActionBar">
+        <item name="windowActionBar">false</item>
+        <item name="windowNoTitle">true</item>
+    </style>
+    <style name="AppTheme.Light.AppBarOverlay" parent="ThemeOverlay.AppCompat.ActionBar"/>
+    <style name="AppTheme.Light.PopupOverlay" parent="ThemeOverlay.AppCompat"/>
 </resources>