implement the actual theme change

app/src/main/AndroidManifest.xml

@@ -47,7 +47,9 @@
 
         <activity
             android:name=".activities.SettingsActivity"
-            android:label="@string/settings"/>
+            android:allowTaskReparenting="true"
+            android:label="@string/settings"
+            android:parentActivityName=".activities.MainActivity"/>
 
         <receiver
             android:name=".MyWidgetProvider"

app/src/main/java/com/simplemobiletools/calendar/activities/AboutActivity.java

@@ -5,7 +5,6 @@ import android.content.Intent;
 import android.content.res.Resources;
 import android.net.Uri;
 import android.os.Bundle;
-import android.support.v7.app.AppCompatActivity;
 import android.text.Html;
 import android.text.method.LinkMovementMethod;
 import android.view.View;
@@ -21,7 +20,7 @@ import butterknife.BindView;
 import butterknife.ButterKnife;
 import butterknife.OnClick;
 
-public class AboutActivity extends AppCompatActivity {
+public class AboutActivity extends SimpleActivity {
     @BindView(R.id.about_copyright) TextView mCopyright;
     @BindView(R.id.about_email) TextView mEmailTV;
     @BindView(R.id.about_rate_us) View mRateUs;

app/src/main/java/com/simplemobiletools/calendar/activities/DayActivity.java

@@ -9,7 +9,6 @@ import android.os.Bundle;
 import android.support.design.widget.CoordinatorLayout;
 import android.support.design.widget.Snackbar;
 import android.support.v7.app.AlertDialog;
-import android.support.v7.app.AppCompatActivity;
 import android.util.SparseBooleanArray;
 import android.view.ActionMode;
 import android.view.Menu;
@@ -40,7 +39,7 @@ import butterknife.BindView;
 import butterknife.ButterKnife;
 import butterknife.OnClick;
 
-public class DayActivity extends AppCompatActivity
+public class DayActivity extends SimpleActivity
         implements DBHelper.DBOperationsListener, AdapterView.OnItemClickListener, AbsListView.MultiChoiceModeListener {
     @BindView(R.id.top_text) TextView mDateTV;
     @BindView(R.id.day_events) ListView mEventsList;

app/src/main/java/com/simplemobiletools/calendar/activities/EventActivity.java

@@ -5,7 +5,6 @@ import android.app.TimePickerDialog;
 import android.content.Context;
 import android.content.Intent;
 import android.os.Bundle;
-import android.support.v7.app.AppCompatActivity;
 import android.support.v7.widget.AppCompatSpinner;
 import android.view.Menu;
 import android.view.MenuItem;
@@ -34,7 +33,7 @@ import butterknife.ButterKnife;
 import butterknife.OnClick;
 import butterknife.OnItemSelected;
 
-public class EventActivity extends AppCompatActivity implements DBHelper.DBOperationsListener {
+public class EventActivity extends SimpleActivity implements DBHelper.DBOperationsListener {
     @BindView(R.id.event_start_date) TextView mStartDate;
     @BindView(R.id.event_start_time) TextView mStartTime;
     @BindView(R.id.event_end_date) TextView mEndDate;

app/src/main/java/com/simplemobiletools/calendar/activities/LicenseActivity.java

@@ -3,14 +3,13 @@ package com.simplemobiletools.calendar.activities;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
-import android.support.v7.app.AppCompatActivity;
 
 import com.simplemobiletools.calendar.R;
 
 import butterknife.ButterKnife;
 import butterknife.OnClick;
 
-public class LicenseActivity extends AppCompatActivity {
+public class LicenseActivity extends SimpleActivity {
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {

app/src/main/java/com/simplemobiletools/calendar/activities/MainActivity.java

@@ -8,7 +8,6 @@ import android.graphics.PorterDuff;
 import android.os.Bundle;
 import android.support.design.widget.CoordinatorLayout;
 import android.support.v7.app.AlertDialog;
-import android.support.v7.app.AppCompatActivity;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
@@ -37,7 +36,7 @@ import butterknife.BindView;
 import butterknife.ButterKnife;
 import butterknife.OnClick;
 
-public class MainActivity extends AppCompatActivity implements Calendar {
+public class MainActivity extends SimpleActivity implements Calendar {
     @BindView(R.id.top_left_arrow) ImageView mLeftArrow;
     @BindView(R.id.top_right_arrow) ImageView mRightArrow;
     @BindView(R.id.top_text) TextView mMonthTV;
@@ -62,11 +61,12 @@ public class MainActivity extends AppCompatActivity implements Calendar {
         setContentView(R.layout.activity_main);
         ButterKnife.bind(this);
 
+        final int baseColor = mConfig.getIsDarkTheme() ? Color.WHITE : Color.BLACK;
         mRes = getResources();
         Locale.setDefault(Locale.ENGLISH);
-        mTextColor = Utils.adjustAlpha(Color.BLACK, Constants.HIGH_ALPHA);
+        mTextColor = Utils.adjustAlpha(baseColor, Constants.HIGH_ALPHA);
         mTextColorWithEvent = Utils.adjustAlpha(mRes.getColor(R.color.colorPrimary), Constants.HIGH_ALPHA);
-        mWeakTextColor = Utils.adjustAlpha(Color.BLACK, Constants.LOW_ALPHA);
+        mWeakTextColor = Utils.adjustAlpha(baseColor, Constants.LOW_ALPHA);
         mWeakTextColorWithEvent = Utils.adjustAlpha(mRes.getColor(R.color.colorPrimary), Constants.LOW_ALPHA);
         mLeftArrow.getDrawable().mutate().setColorFilter(mTextColor, PorterDuff.Mode.SRC_ATOP);
         mRightArrow.getDrawable().mutate().setColorFilter(mTextColor, PorterDuff.Mode.SRC_ATOP);

app/src/main/java/com/simplemobiletools/calendar/activities/SettingsActivity.java

@@ -1,7 +1,7 @@
 package com.simplemobiletools.calendar.activities;
 
 import android.os.Bundle;
-import android.support.v7.app.AppCompatActivity;
+import android.support.v4.app.TaskStackBuilder;
 import android.support.v7.widget.SwitchCompat;
 
 import com.simplemobiletools.calendar.Config;
@@ -11,7 +11,7 @@ import butterknife.BindView;
 import butterknife.ButterKnife;
 import butterknife.OnClick;
 
-public class SettingsActivity extends AppCompatActivity {
+public class SettingsActivity extends SimpleActivity {
     @BindView(R.id.settings_dark_theme) SwitchCompat mDarkThemeSwitch;
 
     private static Config mConfig;
@@ -34,5 +34,10 @@ public class SettingsActivity extends AppCompatActivity {
     public void handleDarkTheme() {
         mDarkThemeSwitch.setChecked(!mDarkThemeSwitch.isChecked());
         mConfig.setIsDarkTheme(mDarkThemeSwitch.isChecked());
+        restartActivity();
+    }
+
+    private void restartActivity() {
+        TaskStackBuilder.create(getApplicationContext()).addNextIntentWithParentStack(getIntent()).startActivities();
     }
 }

app/src/main/java/com/simplemobiletools/calendar/activities/SimpleActivity.java

@@ -0,0 +1,19 @@
+package com.simplemobiletools.calendar.activities;
+
+import android.os.Bundle;
+import android.support.annotation.Nullable;
+import android.support.v7.app.AppCompatActivity;
+
+import com.simplemobiletools.calendar.Config;
+import com.simplemobiletools.calendar.R;
+
+public class SimpleActivity extends AppCompatActivity {
+    protected Config mConfig;
+
+    @Override
+    protected void onCreate(@Nullable Bundle savedInstanceState) {
+        mConfig = Config.newInstance(getApplicationContext());
+        setTheme(mConfig.getIsDarkTheme() ? R.style.AppTheme_Dark : R.style.AppTheme);
+        super.onCreate(savedInstanceState);
+    }
+}

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

@@ -13,6 +13,19 @@
         <item name="android:spinnerDropDownItemStyle">@style/SpinnerItem.DropDownItem</item>
     </style>
 
+    <style name="AppTheme.Dark" parent="Theme.AppCompat">
+        <item name="colorPrimary">@color/colorPrimary</item>
+        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
+        <item name="colorAccent">@color/colorAccent</item>
+        <item name="buttonStyle">@style/MyButton</item>
+        <item name="android:buttonStyle">@style/MyButton</item>
+        <item name="actionBarStyle">@style/AppTheme.ActionBarStyle</item>
+        <item name="android:textSize">@dimen/normal_text_size</item>
+        <item name="android:spinnerItemStyle">@style/SpinnerItem</item>
+        <item name="spinnerDropDownItemStyle">@style/SpinnerItem.DropDownItem</item>
+        <item name="android:spinnerDropDownItemStyle">@style/SpinnerItem.DropDownItem</item>
+    </style>
+
     <style name="DayView">
         <item name="android:gravity">center</item>
         <item name="android:textSize">@dimen/day_text_size</item>