Make workspace switch gesture follow natural scrolling setting

Author: lenemter

lib/Gestures/GestureBackend.vala

@@ -6,11 +6,18 @@
  */
 
 private interface Gala.GestureBackend : Object {
+    public enum DeviceType {
+        TOUCHPAD,
+        TOUCHSCREEN
+    }
+
     public signal bool on_gesture_detected (Gesture gesture, uint32 timestamp);
     public signal void on_begin (double percentage, uint64 time);
     public signal void on_update (double percentage, uint64 time);
     public signal void on_end (double percentage, uint64 time);
 
+    public abstract DeviceType device_type { get; }
+
     public virtual void prepare_gesture_handling () { }
 
     /**

lib/Gestures/GestureController.vala

@@ -44,6 +44,7 @@ public class Gala.GestureController : Object {
     public GestureAction action { get; construct; }
     public WindowManager wm { get; construct; }
     public Group group { get; construct; }
+    public bool follow_natural_scroll_settings { get; construct; }
 
     private unowned RootTarget? _target;
     public RootTarget target {
@@ -87,6 +88,8 @@ public class Gala.GestureController : Object {
 
     public bool recognizing { get; private set; }
 
+    private static GLib.Settings touchpad_settings = new GLib.Settings ("org.gnome.desktop.peripherals.touchpad");
+
     private ToucheggBackend? touchegg_backend;
     private TouchpadBackend? touchpad_backend;
     private ScrollBackend? scroll_backend;
@@ -101,8 +104,8 @@ public class Gala.GestureController : Object {
 
     private SpringTimeline? timeline;
 
-    public GestureController (GestureAction action, WindowManager wm, Group group = NONE) {
-        Object (action: action, wm: wm, group: group);
+    public GestureController (GestureAction action, WindowManager wm, Group group = NONE, bool follow_natural_scroll_settings = false) {
+        Object (action: action, wm: wm, group: group, follow_natural_scroll_settings: follow_natural_scroll_settings);
     }
 
     /**
@@ -185,6 +188,8 @@ public class Gala.GestureController : Object {
 
         prepare ();
 
+        handle_natural_scroll_settings (ref percentage);
+
         gesture_progress = progress;
         previous_percentage = percentage;
         previous_time = elapsed_time;
@@ -195,6 +200,8 @@ public class Gala.GestureController : Object {
             return;
         }
 
+        handle_natural_scroll_settings (ref percentage);
+
         var updated_delta = previous_delta;
         if (elapsed_time != previous_time) {
             double distance = percentage - previous_percentage;
@@ -222,6 +229,7 @@ public class Gala.GestureController : Object {
 
         recognizing = false;
 
+        handle_natural_scroll_settings (ref percentage);
         update_gesture_progress (percentage, previous_delta);
 
         var to = progress;
@@ -291,6 +299,25 @@ public class Gala.GestureController : Object {
         _action_info = null;
     }
 
+    private void handle_natural_scroll_settings (ref double percentage) requires (recognizing_backend != null) {
+        if (!follow_natural_scroll_settings) {
+            return;
+        }
+
+        var multiplier = 1.0;
+
+        switch (recognizing_backend.device_type) {
+            case TOUCHPAD:
+                multiplier = touchpad_settings.get_boolean ("natural-scroll") ? 1.0 : -1.0;
+                break;
+            case TOUCHSCREEN:
+                multiplier = 1.0;
+                break;
+        }
+
+        percentage *= multiplier;
+    }
+
     /**
      * Animates to the given progress value.
      * If the gesture is currently recognizing, it will do nothing.

lib/Gestures/ScrollBackend.vala

@@ -26,6 +26,8 @@ private class Gala.ScrollBackend : Object, GestureBackend {
     private const double FINISH_DELTA_HORIZONTAL = 40;
     private const double FINISH_DELTA_VERTICAL = 30;
 
+    public GestureBackend.DeviceType device_type { get { return TOUCHPAD; }}
+
     public Clutter.Orientation orientation { get; construct; }
     public GestureSettings settings { get; construct; }
 

lib/Gestures/ToucheggBackend.vala

@@ -76,6 +76,8 @@ private class Gala.ToucheggBackend : Object, GestureBackend {
      */
     private const double DELTA_MULTIPLIER = 0.01;
 
+    public GestureBackend.DeviceType device_type { get { return TOUCHPAD; }}
+
     /**
      * Single instance of the class.
      */

lib/Gestures/TouchpadBackend.vala

@@ -18,6 +18,8 @@ private class Gala.TouchpadBackend : Object, GestureBackend {
         ONGOING
     }
 
+    public GestureBackend.DeviceType device_type { get { return TOUCHPAD; }}
+
     public Clutter.Actor actor { get; construct; }
     public GestureController.Group group { get; construct; }
 

src/Widgets/MultitaskingView/MultitaskingView.vala

@@ -65,7 +65,7 @@ public class Gala.MultitaskingView : ActorTarget, RootTarget, ActivatableCompone
 
         workspaces = new WorkspaceRow (display);
 
-        workspaces_gesture_controller = new GestureController (SWITCH_WORKSPACE, wm, MULTITASKING_VIEW) {
+        workspaces_gesture_controller = new GestureController (SWITCH_WORKSPACE, wm, MULTITASKING_VIEW, true) {
             overshoot_upper_clamp = 0.1
         };
         workspaces_gesture_controller.enable_touchpad (wm.stage);