implement #93 - treat back button as a gesture

app/src/main/res/layout/home.xml

@@ -34,4 +34,18 @@
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent" />
 
+    <!-- only shown when µLauncher settings can't be reached by a gesture -->
+    <ImageView
+        android:id="@+id/button_fallback_settings"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:contentDescription="@string/settings"
+        android:visibility="gone"
+        tools:visibility="visible"
+        android:padding="20dp"
+        android:alpha="0.4"
+        app:layout_constraintTop_toTopOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:srcCompat="@drawable/baseline_settings_24"/>
+
 </androidx.constraintlayout.widget.ConstraintLayout>

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

@@ -3,6 +3,12 @@
 <resources>
     <!-- Default Apps for different actions (button-press, swipes ...) -->
 
+    <!-- Back - Apps list -->
+    <string-array name="default_back">
+        <item>{\"type\": \"action:launcher\", \"value\": \"choose\"}</item> <!-- All Apps -->
+    </string-array>
+
+
     <!-- Swipe up - Apps list -->
     <string-array name="default_up">
         <item>{\"type\": \"action:launcher\", \"value\": \"choose\"}</item> <!-- All Apps -->

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

@@ -25,6 +25,8 @@
       - Settings : Apps
       -
       -->
+    <string name="settings_gesture_back">Back</string>
+    <string name="settings_gesture_description_back">Back button / back gesture</string>
     <string name="settings_gesture_up">Up</string>
     <string name="settings_gesture_description_up">Swipe up</string>
     <string name="settings_gesture_double_up">Double Up</string>