Implement menu item to switch between themes

app/src/main/java/org/isoron/uhabits/AboutActivity.java

@@ -29,6 +29,7 @@ import android.view.View;
 import android.widget.TextView;
 
 import org.isoron.uhabits.helpers.ColorHelper;
+import org.isoron.uhabits.helpers.UIHelper;
 
 public class AboutActivity extends Activity implements View.OnClickListener
 {
@@ -37,6 +38,8 @@ public class AboutActivity extends Activity implements View.OnClickListener
     protected void onCreate(Bundle savedInstanceState)
     {
         super.onCreate(savedInstanceState);
+        UIHelper.applyCurrentTheme(this);
+
         setContentView(R.layout.about);
 
         if (android.os.Build.VERSION.SDK_INT >= 21)

app/src/main/java/org/isoron/uhabits/BaseActivity.java

@@ -26,6 +26,7 @@ import android.os.Bundle;
 import android.widget.Toast;
 
 import org.isoron.uhabits.commands.Command;
+import org.isoron.uhabits.helpers.UIHelper;
 
 import java.util.LinkedList;
 
@@ -44,6 +45,8 @@ abstract public class BaseActivity extends Activity implements Thread.UncaughtEx
     {
         super.onCreate(savedInstanceState);
 
+        UIHelper.applyCurrentTheme(this);
+
         androidExceptionHandler = Thread.getDefaultUncaughtExceptionHandler();
         Thread.setDefaultUncaughtExceptionHandler(this);
 

app/src/main/java/org/isoron/uhabits/MainActivity.java

@@ -29,17 +29,19 @@ import android.content.SharedPreferences;
 import android.content.pm.PackageManager;
 import android.net.Uri;
 import android.os.AsyncTask;
+import android.os.Build;
 import android.os.Bundle;
 import android.preference.PreferenceManager;
 import android.support.annotation.NonNull;
 import android.support.v4.content.LocalBroadcastManager;
 import android.view.Menu;
 import android.view.MenuItem;
+import android.view.Window;
 
-import org.isoron.uhabits.helpers.DateHelper;
-import org.isoron.uhabits.helpers.UIHelper;
 import org.isoron.uhabits.fragments.ListHabitsFragment;
+import org.isoron.uhabits.helpers.DateHelper;
 import org.isoron.uhabits.helpers.ReminderHelper;
+import org.isoron.uhabits.helpers.UIHelper;
 import org.isoron.uhabits.models.Habit;
 import org.isoron.uhabits.tasks.BaseTask;
 import org.isoron.uhabits.widgets.CheckmarkWidgetProvider;
@@ -70,6 +72,10 @@ public class MainActivity extends BaseActivity
     protected void onCreate(Bundle savedInstanceState)
     {
         super.onCreate(savedInstanceState);
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP)
+            getWindow().requestFeature(Window.FEATURE_ACTIVITY_TRANSITIONS);
+
         setContentView(R.layout.list_habits_activity);
 
         prefs = PreferenceManager.getDefaultSharedPreferences(this);
@@ -122,6 +128,10 @@ public class MainActivity extends BaseActivity
     public boolean onCreateOptionsMenu(Menu menu)
     {
         getMenuInflater().inflate(R.menu.list_habits_menu, menu);
+
+        MenuItem nightModeItem = menu.findItem(R.id.action_night_mode);
+        nightModeItem.setChecked(UIHelper.isNightMode());
+
         return true;
     }
 
@@ -130,6 +140,17 @@ public class MainActivity extends BaseActivity
     {
         switch (item.getItemId())
         {
+            case R.id.action_night_mode:
+            {
+                if(UIHelper.isNightMode())
+                    UIHelper.setCurrentTheme(UIHelper.THEME_LIGHT);
+                else
+                    UIHelper.setCurrentTheme(UIHelper.THEME_DARK);
+
+                refreshTheme();
+                return true;
+            }
+
             case R.id.action_settings:
             {
                 Intent intent = new Intent(this, SettingsActivity.class);
@@ -158,6 +179,20 @@ public class MainActivity extends BaseActivity
         }
     }
 
+    private void refreshTheme()
+    {
+        runOnUiThread(new Runnable()
+        {
+            @Override
+            public void run()
+            {
+                Intent intent = new Intent(MainActivity.this, MainActivity.class);
+                MainActivity.this.finish();
+                startActivity(intent);
+            }
+        });
+    }
+
     @Override
     protected void onActivityResult(int requestCode, int resultCode, Intent data)
     {

app/src/main/java/org/isoron/uhabits/SettingsActivity.java

@@ -23,6 +23,7 @@ import android.app.Activity;
 import android.os.Bundle;
 
 import org.isoron.uhabits.fragments.SettingsFragment;
+import org.isoron.uhabits.helpers.UIHelper;
 
 public class SettingsActivity extends Activity
 {
@@ -30,6 +31,9 @@ public class SettingsActivity extends Activity
     protected void onCreate(Bundle savedInstanceState)
     {
         super.onCreate(savedInstanceState);
+
+        UIHelper.applyCurrentTheme(this);
+
         getFragmentManager().beginTransaction()
                 .replace(android.R.id.content, new SettingsFragment())
                 .commit();

app/src/main/java/org/isoron/uhabits/helpers/UIHelper.java

@@ -19,6 +19,7 @@
 
 package org.isoron.uhabits.helpers;
 
+import android.app.Activity;
 import android.content.Context;
 import android.content.SharedPreferences;
 import android.content.res.Resources;
@@ -36,14 +37,19 @@ import android.view.View;
 import android.view.inputmethod.InputMethodManager;
 
 import org.isoron.uhabits.BuildConfig;
+import org.isoron.uhabits.HabitsApplication;
+import org.isoron.uhabits.R;
 import org.isoron.uhabits.commands.Command;
 
 import java.util.Locale;
 
 public abstract class UIHelper
 {
-
     public static final String ISORON_NAMESPACE = "http://isoron.org/android";
+
+    public static final int THEME_LIGHT = 0;
+    public static final int THEME_DARK = 1;
+
     private static Typeface fontawesome;
 
     public interface OnSavedListener
@@ -190,4 +196,38 @@ public abstract class UIHelper
 
         return bool;
     }
+
+    public static void applyCurrentTheme(Activity activity)
+    {
+        switch(getCurrentTheme())
+        {
+            case THEME_DARK:
+                activity.setTheme(R.style.AppBaseThemeDark);
+                break;
+
+            case THEME_LIGHT:
+            default:
+                activity.setTheme(R.style.AppBaseTheme);
+                break;
+        }
+    }
+
+    private static int getCurrentTheme()
+    {
+        Context appContext = HabitsApplication.getContext();
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(appContext);
+        return prefs.getInt("pref_theme", THEME_LIGHT);
+    }
+
+    public static void setCurrentTheme(int theme)
+    {
+        Context appContext = HabitsApplication.getContext();
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(appContext);
+        prefs.edit().putInt("pref_theme", theme).apply();
+    }
+
+    public static boolean isNightMode()
+    {
+        return getCurrentTheme() == THEME_DARK;
+    }
 }

app/src/main/res/menu/list_habits_menu.xml

@@ -28,6 +28,12 @@
         android:enabled="true"
         android:title="@string/show_archived"/>
 
+    <item
+        android:id="@+id/action_night_mode"
+        android:checkable="true"
+        android:enabled="true"
+        android:title="@string/night_mode"/>
+
     <item
         android:id="@+id/action_settings"
         android:orderInCategory="100"

app/src/main/res/values/strings.xml

@@ -156,4 +156,5 @@
     <string name="generate_bug_report">Generate bug report</string>
     <string name="troubleshooting">Troubleshooting</string>
     <string name="help_translate">Help translate this app</string>
+    <string name="night_mode">Night mode</string>
 </resources>