Dynamically update Top App Bar in Settings

lawnchair/res/drawable/ic_back.xml

@@ -0,0 +1,14 @@
+<vector
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:name="vector"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24"
+    android:tint="?android:attr/textColorPrimary">
+    <path
+        android:name="path"
+        android:pathData="M 20 11 L 7.83 11 L 13.42 5.41 L 12 4 L 4 12 L 12 20 L 13.41 18.59 L 7.83 13 L 20 13 L 20 11 Z"
+        android:fillColor="#000"
+        android:strokeWidth="1"/>
+</vector>

lawnchair/res/drawable/ic_general.xml

@@ -0,0 +1,14 @@
+<vector
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:name="vector"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24"
+    android:tint="?android:attr/textColorPrimary">
+    <path
+        android:name="path_2"
+        android:pathData="M 3 17 L 3 19 L 9 19 L 9 17 L 3 17 Z M 3 5 L 3 7 L 13 7 L 13 5 L 3 5 Z M 13 21 L 13 19 L 21 19 L 21 17 L 13 17 L 13 15 L 11 15 L 11 21 L 13 21 Z M 7 9 L 7 11 L 3 11 L 3 13 L 7 13 L 7 15 L 9 15 L 9 9 L 7 9 Z M 21 13 L 21 11 L 11 11 L 11 13 L 21 13 Z M 15 9 L 17 9 L 17 7 L 21 7 L 21 5 L 17 5 L 17 3 L 15 3 L 15 9 Z"
+        android:fillColor="#000"
+        android:strokeWidth="1"/>
+</vector>

lawnchair/res/drawable/ic_home_screen.xml

@@ -0,0 +1,19 @@
+<vector
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:name="vector"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24"
+    android:tint="?android:attr/textColorPrimary">
+    <path
+        android:name="path"
+        android:pathData="M 12 5.5 L 18 10 L 18 19 L 6 19 L 6 10 L 12 5.5 Z M 12 3 L 4 9 L 4 21 L 20 21 L 20 9 L 12 3 Z"
+        android:fillColor="#000000"
+        android:strokeWidth="1"/>
+    <path
+        android:name="path_1"
+        android:pathData="M 10 13 L 10 19 L 14 19 L 14 13 L 10 13 Z"
+        android:fillColor="#000000"
+        android:strokeWidth="1"/>
+</vector>

lawnchair/res/xml/general_settings.xml

@@ -7,7 +7,6 @@
         android:key="pref_icon_badging"
         android:title="@string/notification_dots_title"
         android:persistent="false"
-        app:iconSpaceReserved="false"
         android:widgetLayout="@layout/notification_pref_warning" >
         <intent android:action="android.settings.NOTIFICATION_SETTINGS">
             <extra

lawnchair/res/xml/home_screen_settings.xml

@@ -8,22 +8,19 @@
         android:title="@string/auto_add_shortcuts_label"
         android:summary="@string/auto_add_shortcuts_description"
         android:defaultValue="true"
-        android:persistent="true"
-        app:iconSpaceReserved="false"/>
+        android:persistent="true" />
 
     <SwitchPreference
         android:key="pref_allowRotation"
         android:title="@string/allow_rotation_title"
         android:summary="@string/allow_rotation_desc"
         android:defaultValue="@bool/allow_rotation"
-        android:persistent="true"
-        app:iconSpaceReserved="false"/>
+        android:persistent="true" />
 
     <SwitchPreference
         android:key="pref_grid_options"
         android:title="Enable grid options"
         android:defaultValue="false"
-        android:persistent="true"
-        app:iconSpaceReserved="false"/>
+        android:persistent="true" />
 
 </androidx.preference.PreferenceScreen>

lawnchair/res/xml/settings.xml

@@ -5,11 +5,13 @@
     <Preference
         android:title="General"
         android:summary="Notification Dots"
+        android:icon="@drawable/ic_general"
         android:fragment="ch.deletescape.lawnchair.settings.GeneralSettingsFragment" />
 
     <Preference
         android:title="Home Screen"
-        android:summary="Icon Pack, Grid Options"
+        android:summary="Rotation, Grid Options"
+        android:icon="@drawable/ic_home_screen"
         android:fragment="ch.deletescape.lawnchair.settings.HomeScreenSettingsFragment" />
 
 </androidx.preference.PreferenceScreen>

lawnchair/src/ch/deletescape/lawnchair/settings/SettingsActivity.kt

@@ -3,6 +3,7 @@ package ch.deletescape.lawnchair.settings
 import android.os.Bundle
 import android.view.View
 import androidx.appcompat.app.AppCompatActivity
+import androidx.core.content.ContextCompat
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.FragmentManager
 import androidx.preference.Preference
@@ -12,9 +13,15 @@ import com.google.android.material.appbar.MaterialToolbar
 
 class SettingsActivity : AppCompatActivity(), PreferenceFragmentCompat.OnPreferenceStartFragmentCallback {
     private lateinit var topAppBar: MaterialToolbar
+    private val context = this
 
     private val fragmentListener = object: FragmentManager.FragmentLifecycleCallbacks() {
         override fun onFragmentViewCreated(fm: FragmentManager, fragment: Fragment, v: View, savedInstanceState: Bundle?) {
+            if (fragment !is SettingsFragment && topAppBar.navigationIcon == null) {
+                topAppBar.navigationIcon = ContextCompat.getDrawable(context, R.drawable.ic_back)
+            } else {
+                topAppBar.navigationIcon = null
+            }
             topAppBar.title = (fragment as? TitledFragment)?.title
         }
     }
@@ -23,6 +30,9 @@ class SettingsActivity : AppCompatActivity(), PreferenceFragmentCompat.OnPrefere
         super.onCreate(savedInstanceState)
         setContentView(R.layout.settings_activity)
         topAppBar = findViewById(R.id.top_app_bar)
+        topAppBar.setNavigationOnClickListener {
+            supportFragmentManager.popBackStack()
+        }
         supportFragmentManager.registerFragmentLifecycleCallbacks(fragmentListener, false)
         supportFragmentManager
             .beginTransaction()