From bffb642858c3caba3b61bd044b7f8dc63d3ab323 Mon Sep 17 00:00:00 2001
From: Carlos Garnacho <carlosg@gnome.org>
Date: Fri, 26 Sep 2025 04:38:56 +0200
Subject: [PATCH] slider: Port to using a pan gesture

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/3912>
---
 js/ui/slider.js | 96 ++++++++++++-------------------------------------
 1 file changed, 22 insertions(+), 74 deletions(-)

diff --git a/js/ui/slider.js b/js/ui/slider.js
index 013624f7c..ede76cca5 100644
--- a/js/ui/slider.js
+++ b/js/ui/slider.js
@@ -25,10 +25,15 @@ export const Slider = GObject.registerClass({
         });
 
         this._releaseId = 0;
-        this._dragging = false;
-
         this._handleRadius = 0;
 
+        this._panGesture = new Clutter.PanGesture();
+        this._panGesture.set_begin_threshold(0);
+        this._panGesture.connect('recognize', this._onPanBegin.bind(this));
+        this._panGesture.connect('pan-update', this._onPanUpdate.bind(this));
+        this._panGesture.connect('end', this._onPanEnd.bind(this));
+        this.add_action(this._panGesture);
+
         this._customAccessible.connect('get-minimum-increment', this._getMinimumIncrement.bind(this));
     }
 
@@ -75,76 +80,35 @@ export const Slider = GObject.registerClass({
         return Math.max(barWidth, handleWidth);
     }
 
-    vfunc_button_press_event(event) {
-        return this.startDragging(event);
-    }
-
-    startDragging(event) {
-        if (this._dragging)
-            return Clutter.EVENT_PROPAGATE;
-
-        this._dragging = true;
-
+    _onPanBegin() {
         this._grab = global.stage.grab(this);
 
-        const backend = global.stage.get_context().get_backend();
-        const sprite = backend.get_sprite(global.stage, event);
-        this._sprite = sprite;
-
         // We need to emit 'drag-begin' before moving the handle to make
         // sure that no 'notify::value' signal is emitted before this one.
         this.emit('drag-begin');
 
-        const [absX, absY] = event.get_coords();
-        this._moveHandle(absX, absY);
+        const coords = this._panGesture.get_centroid_abs();
+        this._moveHandle(coords.x, coords.y);
         return Clutter.EVENT_STOP;
     }
 
-    _endDragging() {
-        if (this._dragging) {
-            if (this._releaseId) {
-                this.disconnect(this._releaseId);
-                this._releaseId = 0;
-            }
-
-            if (this._grab) {
-                this._grab.dismiss();
-                this._grab = null;
-            }
-
-            this._dragging = false;
-
-            this.emit('drag-end');
+    _onPanEnd() {
+        if (this._releaseId) {
+            this.disconnect(this._releaseId);
+            this._releaseId = 0;
         }
-        return Clutter.EVENT_STOP;
-    }
 
-    vfunc_button_release_event(event) {
-        const backend = global.stage.get_context().get_backend();
-        const sprite = backend.get_sprite(global.stage, event);
-
-        if (this._dragging && this._sprite === sprite)
-            return this._endDragging();
+        if (this._grab) {
+            this._grab.dismiss();
+            this._grab = null;
+        }
 
-        return Clutter.EVENT_PROPAGATE;
+        this.emit('drag-end');
     }
 
-    vfunc_touch_event(event) {
-        const backend = global.stage.get_context().get_backend();
-        const sprite = backend.get_sprite(global.stage, event);
-
-        if (!this._dragging &&
-            event.type() === Clutter.EventType.TOUCH_BEGIN) {
-            this.startDragging(event);
-            return Clutter.EVENT_STOP;
-        } else if (this._sprite === sprite) {
-            if (event.type() === Clutter.EventType.TOUCH_UPDATE)
-                return this._motionEvent(this, event);
-            else if (event.type() === Clutter.EventType.TOUCH_END)
-                return this._endDragging();
-        }
-
-        return Clutter.EVENT_PROPAGATE;
+    _onPanUpdate() {
+        const coords = this._panGesture.get_centroid_abs();
+        this._moveHandle(coords.x, coords.y);
     }
 
     step(nSteps) {
@@ -185,22 +149,6 @@ export const Slider = GObject.registerClass({
         return Clutter.EVENT_STOP;
     }
 
-    vfunc_motion_event(event) {
-        const backend = global.stage.get_context().get_backend();
-        const sprite = backend.get_sprite(global.stage, event);
-
-        if (this._dragging && this._sprite === sprite)
-            return this._motionEvent(this, event);
-
-        return Clutter.EVENT_PROPAGATE;
-    }
-
-    _motionEvent(actor, event) {
-        const [absX, absY] = event.get_coords();
-        this._moveHandle(absX, absY);
-        return Clutter.EVENT_STOP;
-    }
-
     vfunc_key_press_event(event) {
         const key = event.get_key_symbol();
         if (key === Clutter.KEY_Right || key === Clutter.KEY_Left) {
-- 
2.39.5