Use pan backend for dock reveal

src/ShellClients/HideTracker.vala

@@ -9,12 +9,14 @@ public class Gala.HideTracker : Object {
     private const uint UPDATE_TIMEOUT = 200;
 
     public signal void hide ();
-    public signal void show ();
+    public signal void show (GestureTracker? with_gesture_tracker);
 
     public Meta.Display display { get; construct; }
     public unowned PanelWindow panel { get; construct; }
     public Pantheon.Desktop.HideMode hide_mode { get; set; default = NEVER; }
 
+    private GestureTracker gesture_tracker;
+
     private bool hovered = false;
 
     private bool overlap = false;
@@ -60,6 +62,12 @@ public class Gala.HideTracker : Object {
         });
 
         display.get_workspace_manager ().active_workspace_changed.connect (schedule_update);
+
+        var size = new Utils.Size.actor_tracking ((Clutter.Actor) panel.window.get_compositor_private ());
+
+        gesture_tracker = new GestureTracker (PanelClone.ANIMATION_DURATION, PanelClone.ANIMATION_DURATION);
+        gesture_tracker.enable_pan (display.get_stage (), size);
+        gesture_tracker.on_gesture_detected.connect (check_valid_gesture);
     }
 
     //Can be removed with mutter > 45
@@ -181,7 +189,7 @@ public class Gala.HideTracker : Object {
         hovered = window_has_pointer ();
 #endif
 
-        if (should_hide && !hovered) {
+        if (should_hide && !hovered && !panel.window.has_focus ()) {
             // Don't hide if we have transients, e.g. an open popover, dialog, etc.
             var has_transients = false;
             panel.window.foreach_transient (() => {
@@ -195,7 +203,24 @@ public class Gala.HideTracker : Object {
 
             hide ();
         } else {
-            show ();
+            show (null);
         }
     }
+
+    private bool check_valid_gesture (Gesture gesture) {
+        warning ("DETECTED");
+        if (panel.anchor != BOTTOM) {
+            debug ("Swipe to reveal is currently only supported for bottom anchors");
+            return false;
+        }
+
+        var monitor_geom = display.get_monitor_geometry (panel.window.get_monitor ());
+        if ((gesture.origin_y - monitor_geom.y - monitor_geom.height).abs () < 50) { // Only start if the gesture starts near the bottom of the monitor
+            show (gesture_tracker);
+            panel.window.focus (Gdk.CURRENT_TIME);
+            return true;
+        }
+
+        return false;
+    }
 }

src/ShellClients/PanelClone.vala

@@ -6,7 +6,7 @@
  */
 
 public class Gala.PanelClone : Object {
-    private const int ANIMATION_DURATION = 250;
+    public const int ANIMATION_DURATION = 250;
 
     public WindowManager wm { get; construct; }
     public unowned PanelWindow panel { get; construct; }
@@ -32,7 +32,7 @@ public class Gala.PanelClone : Object {
 
     public bool panel_hidden { get; private set; default = true; }
 
-    private SafeWindowClone clone;
+    public SafeWindowClone clone;
     private Meta.WindowActor actor;
 
     private HideTracker? hide_tracker;
@@ -111,10 +111,12 @@ public class Gala.PanelClone : Object {
     }
 
     private void hide () {
-        if (panel_hidden) {
+        if (panel_hidden || animating) {
             return;
         }
 
+        animating = true;
+
         panel_hidden = true;
 
         if (panel.anchor != TOP && panel.anchor != BOTTOM) {
@@ -129,25 +131,51 @@ public class Gala.PanelClone : Object {
         clone.set_easing_duration (get_animation_duration ());
         clone.y = calculate_clone_y (true);
         clone.restore_easing_state ();
+
+        animating = false;
     }
 
-    public void show () {
-        if (!panel_hidden) {
+    private bool animating = false;
+    public void show (GestureTracker? with_gesture_tracker = null) {
+        if (!panel_hidden || animating) {
             return;
         }
 
-        var animation_duration = get_animation_duration ();
+        animating = true;
 
-        clone.save_easing_state ();
-        clone.set_easing_mode (Clutter.AnimationMode.EASE_OUT_QUAD);
-        clone.set_easing_duration (animation_duration);
-        clone.y = calculate_clone_y (false);
-        clone.restore_easing_state ();
+        var initial_y = clone.y;
+        var target_y = calculate_clone_y (false);
 
-        Timeout.add (animation_duration, () => {
-            clone.visible = false;
-            panel_hidden = false;
-            return Source.REMOVE;
-        });
+        GestureTracker.OnUpdate on_update = (percentage) => {
+            var value = GestureTracker.animation_value (initial_y, target_y, percentage, true);
+            clone.y = value;
+        };
+
+        GestureTracker.OnEnd on_end = (percentage, cancel_action, calculated_duration) => {
+            if (cancel_action) {
+                animating = false;
+                hide ();
+                return;
+            }
+
+            clone.save_easing_state ();
+            clone.set_easing_mode (Clutter.AnimationMode.EASE_OUT_QUAD);
+            clone.set_easing_duration (calculated_duration);
+            clone.y = calculate_clone_y (false);
+            clone.restore_easing_state ();
+
+            Timeout.add (calculated_duration, () => {
+                clone.visible = false;
+                panel_hidden = false;
+                animating = false;
+                return Source.REMOVE;
+            });
+        };
+
+        if (with_gesture_tracker != null) {
+            with_gesture_tracker.connect_handlers (null, (owned) on_update, (owned) on_end);
+        } else {
+            on_end (1, false, get_animation_duration ());
+        }
     }
 }

src/ShellClients/PanelWindow.vala

@@ -19,7 +19,7 @@ public class Gala.PanelWindow : Object {
 
     private Barrier? barrier;
 
-    private PanelClone clone;
+    public PanelClone clone;
 
     private uint idle_move_id = 0;
 
@@ -247,7 +247,7 @@ public class Gala.PanelWindow : Object {
             int.MAX
         );
 
-        barrier.trigger.connect (clone.show);
+        barrier.trigger.connect (() => clone.show ());
     }
 
 #if HAS_MUTTER45
@@ -268,6 +268,6 @@ public class Gala.PanelWindow : Object {
             int.MAX
         );
 
-        barrier.trigger.connect (clone.show);
+        barrier.trigger.connect (() => clone.show ());
     }
 }