From 2ea50c48871da00cb4715b53be628c2db24636f3 Mon Sep 17 00:00:00 2001
From: Andres <andres@integragroupe.com>
Date: Sat, 21 Feb 2026 03:19:13 -0400
Subject: [PATCH 01/16] feat(workspaces): add smooth horizontal wheel switching
 for spaces

---
 src/zen/workspaces/ZenWorkspaces.mjs | 182 ++++++++++++++++++++++++---
 1 file changed, 167 insertions(+), 15 deletions(-)

diff --git a/src/zen/workspaces/ZenWorkspaces.mjs b/src/zen/workspaces/ZenWorkspaces.mjs
index 135a2bd986..3a1aec4560 100644
--- a/src/zen/workspaces/ZenWorkspaces.mjs
+++ b/src/zen/workspaces/ZenWorkspaces.mjs
@@ -41,6 +41,10 @@ class nsZenWorkspaces {
   _workspaceCache = [];
 
   #lastScrollTime = 0;
+  #lastHorizontalWheelEventTime = 0;
+  #horizontalScrollAccumulator = 0;
+  #horizontalScrollFinalizeTimer = null;
+  #horizontalWheelGestureActive = false;
 
   bookmarkMenus = [
     "PlacesToolbar",
@@ -526,17 +530,25 @@ class nsZenWorkspaces {
     if (!this.workspaceEnabled || !gNavToolbox.matches(":hover")) {
       return;
     }
+    // Some devices emit AppCommand and wheel for the same horizontal wheel action.
+    // Ignore AppCommand if a horizontal wheel event just occurred.
+    if (Date.now() - this.#lastHorizontalWheelEventTime < 250) {
+      return;
+    }
+    if (this.#horizontalWheelGestureActive) {
+      this.#cancelHorizontalWheelGesture();
+    }
 
     const direction = this.naturalScroll ? -1 : 1;
     // event is forward or back
     switch (event.command) {
       case "Forward":
-        this.changeWorkspaceShortcut(1 * direction);
+        this.changeWorkspaceShortcut(1 * direction, true);
         event.stopImmediatePropagation();
         event.preventDefault();
         break;
       case "Back":
-        this.changeWorkspaceShortcut(-1 * direction);
+        this.changeWorkspaceShortcut(-1 * direction, true);
         event.stopImmediatePropagation();
         event.preventDefault();
         break;
@@ -551,8 +563,9 @@ class nsZenWorkspaces {
   #setupSidebarHandlers() {
     const toolbox = gNavToolbox;
 
-    const scrollCooldown = 200; // Milliseconds to wait before allowing another scroll
-    const scrollThreshold = 1; // Minimum scroll delta to trigger workspace change
+    const verticalScrollCooldown = 200; // Milliseconds to wait before allowing another scroll
+    const verticalScrollThreshold = 1;
+    const horizontalSnapPositionThreshold = 55;
 
     toolbox.addEventListener(
       "wheel",
@@ -561,12 +574,20 @@ class nsZenWorkspaces {
           return;
         }
 
-        // Only process non-gesture scrolls
-        if (event.deltaMode !== 1) {
+        const absDeltaX = Math.abs(event.deltaX);
+        const absDeltaY = Math.abs(event.deltaY);
+        const isHorizontalScroll = absDeltaX > 0 && absDeltaX >= absDeltaY;
+        const isVerticalScroll = absDeltaY > 0 && absDeltaY > absDeltaX;
+
+        if (!isHorizontalScroll && !isVerticalScroll) {
           return;
         }
 
-        const isVerticalScroll = event.deltaY && !event.deltaX;
+        // Horizontal mouse wheels can report pixel deltas, so only enforce
+        // line-based deltas for vertical scrolling.
+        if (!isHorizontalScroll && event.deltaMode !== 1) {
+          return;
+        }
 
         //if the scroll is vertical this checks that a modifier key is used before proceeding
         if (isVerticalScroll) {
@@ -585,20 +606,61 @@ class nsZenWorkspaces {
           }
         }
 
-        let currentTime = Date.now();
-        if (currentTime - this.#lastScrollTime < scrollCooldown) {
+        const currentTime = Date.now();
+
+        if (isHorizontalScroll) {
+          if (this.#inChangingWorkspace) {
+            return;
+          }
+          this.#startHorizontalWheelGesture();
+          const scrollDirection = this.naturalScroll ? -1 : 1;
+          const deltaPixels = this.#normalizeHorizontalWheelDelta(event) * scrollDirection;
+          if (!deltaPixels) {
+            return;
+          }
+          this.#lastHorizontalWheelEventTime = currentTime;
+          if (
+            this.#horizontalScrollAccumulator !== 0 &&
+            Math.sign(this.#horizontalScrollAccumulator) !== Math.sign(deltaPixels)
+          ) {
+            this.#horizontalScrollAccumulator = 0;
+          }
+          this.#horizontalScrollAccumulator += deltaPixels;
+          const stripWidth =
+            window.windowUtils.getBoundsWithoutFlushing(
+              document.getElementById("navigator-toolbox")
+            ).width +
+            window.windowUtils.getBoundsWithoutFlushing(
+              document.getElementById("zen-sidebar-splitter")
+            ).width *
+              2;
+          let translateX = this.#horizontalScrollAccumulator;
+          let forceMultiplier = Math.max(0.5, 1 - Math.abs(translateX) / (stripWidth * 4.5));
+          translateX *= forceMultiplier;
+          if (Math.abs(deltaPixels) > 0.8) {
+            this._swipeState.direction = deltaPixels > 0 ? "left" : "right";
+          }
+          const currentWorkspace = this.getActiveWorkspaceFromCache();
+          this._organizeWorkspaceStripLocations(currentWorkspace, true, translateX);
+          if (Math.abs(translateX) >= horizontalSnapPositionThreshold) {
+            void this.#finalizeHorizontalWheelGesture(true);
+            return;
+          }
+          this.#scheduleHorizontalWheelGestureFinalize();
           return;
         }
 
-        //this decides which delta to use
-        const delta = isVerticalScroll ? event.deltaY : event.deltaX;
-        if (Math.abs(delta) < scrollThreshold) {
+        if (this.#horizontalWheelGestureActive) {
+          this.#cancelHorizontalWheelGesture();
+        }
+        if (currentTime - this.#lastScrollTime < verticalScrollCooldown) {
+          return;
+        }
+        if (Math.abs(event.deltaY) < verticalScrollThreshold) {
           return;
         }
 
-        // Determine scroll direction
-        let rawDirection = delta > 0 ? 1 : -1;
-
+        const rawDirection = event.deltaY > 0 ? 1 : -1;
         let direction = this.naturalScroll ? -1 : 1;
         this.changeWorkspaceShortcut(rawDirection * direction);
 
@@ -608,6 +670,90 @@ class nsZenWorkspaces {
     );
   }
 
+  #startHorizontalWheelGesture() {
+    if (this.#horizontalWheelGestureActive) {
+      return;
+    }
+    this.#horizontalWheelGestureActive = true;
+    gZenFolders.cancelPopupTimer();
+    document.documentElement.setAttribute("swipe-gesture", "true");
+    document.addEventListener("popupshown", this.popupOpenHandler, { once: true });
+    this._swipeState = {
+      isGestureActive: true,
+      lastDelta: 0,
+      direction: null,
+    };
+    Services.prefs.setBoolPref("zen.swipe.is-fast-swipe", true);
+  }
+
+  #normalizeHorizontalWheelDelta(event) {
+    switch (event.deltaMode) {
+      case event.DOM_DELTA_LINE:
+        return event.deltaX * 40;
+      case event.DOM_DELTA_PAGE:
+        return event.deltaX * 160;
+      case event.DOM_DELTA_PIXEL:
+      default:
+        return event.deltaX * 0.35;
+    }
+  }
+
+  #scheduleHorizontalWheelGestureFinalize() {
+    if (this.#horizontalScrollFinalizeTimer) {
+      clearTimeout(this.#horizontalScrollFinalizeTimer);
+    }
+    this.#horizontalScrollFinalizeTimer = setTimeout(() => {
+      this.#horizontalScrollFinalizeTimer = null;
+      void this.#finalizeHorizontalWheelGesture();
+    }, 180);
+  }
+
+  async #finalizeHorizontalWheelGesture(forceSwitch = false) {
+    if (!this.#horizontalWheelGestureActive) {
+      return;
+    }
+    const threshold = 55;
+    const shouldSwitch = forceSwitch || Math.abs(this.#horizontalScrollAccumulator) >= threshold;
+    const workspaceOffset = this.#horizontalScrollAccumulator > 0 ? -1 : 1;
+    this.#horizontalScrollAccumulator = 0;
+    if (shouldSwitch) {
+      await this.changeWorkspaceShortcut(workspaceOffset, true);
+      this.#lastScrollTime = Date.now();
+    } else {
+      this._cancelSwipeAnimation();
+    }
+    this.#cleanupHorizontalWheelGesture();
+  }
+
+  #cancelHorizontalWheelGesture() {
+    if (!this.#horizontalWheelGestureActive) {
+      return;
+    }
+    if (this.#horizontalScrollFinalizeTimer) {
+      clearTimeout(this.#horizontalScrollFinalizeTimer);
+      this.#horizontalScrollFinalizeTimer = null;
+    }
+    this.#horizontalScrollAccumulator = 0;
+    this._cancelSwipeAnimation();
+    this.#cleanupHorizontalWheelGesture();
+  }
+
+  #cleanupHorizontalWheelGesture() {
+    this.#horizontalWheelGestureActive = false;
+    this._swipeState = {
+      isGestureActive: false,
+      lastDelta: 0,
+      direction: null,
+    };
+    Services.prefs.setBoolPref("zen.swipe.is-fast-swipe", false);
+    document.documentElement.removeAttribute("swipe-gesture");
+    gZenUIManager.tabsWrapper.style.removeProperty("scrollbar-width");
+    document.documentElement.style.setProperty("--zen-background-opacity", "1");
+    delete this._hasAnimatedBackgrounds;
+    this.updateTabsContainers();
+    document.removeEventListener("popupshown", this.popupOpenHandler, { once: true });
+  }
+
   initializeGestureHandlers() {
     const elements = [
       gNavToolbox,
@@ -651,6 +797,12 @@ class nsZenWorkspaces {
   _popupOpenHandler() {
     // If a popup is opened, we should stop the swipe gesture
     if (this._swipeState?.isGestureActive) {
+      if (this.#horizontalScrollFinalizeTimer) {
+        clearTimeout(this.#horizontalScrollFinalizeTimer);
+        this.#horizontalScrollFinalizeTimer = null;
+      }
+      this.#horizontalWheelGestureActive = false;
+      this.#horizontalScrollAccumulator = 0;
       document.documentElement.removeAttribute("swipe-gesture");
       gZenUIManager.tabsWrapper.style.removeProperty("scrollbar-width");
       this.updateTabsContainers();

From 83cfd55116e1a6c4f81b0884a4efd28f50529280 Mon Sep 17 00:00:00 2001
From: Andres <andres@integragroupe.com>
Date: Sun, 22 Feb 2026 04:06:32 -0400
Subject: [PATCH 02/16] refactor(workspaces): replace horizontal finalize magic
 number

---
 src/zen/workspaces/ZenWorkspaces.mjs | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/zen/workspaces/ZenWorkspaces.mjs b/src/zen/workspaces/ZenWorkspaces.mjs
index 3a1aec4560..7afc3c08cb 100644
--- a/src/zen/workspaces/ZenWorkspaces.mjs
+++ b/src/zen/workspaces/ZenWorkspaces.mjs
@@ -566,6 +566,9 @@ class nsZenWorkspaces {
     const verticalScrollCooldown = 200; // Milliseconds to wait before allowing another scroll
     const verticalScrollThreshold = 1;
     const horizontalSnapPositionThreshold = 55;
+    // Keep this short so wheel gestures feel responsive, but long enough to
+    // wait for bursty horizontal wheel events before deciding where to snap.
+    const horizontalGestureFinalizeDelay = 180;
 
     toolbox.addEventListener(
       "wheel",
@@ -646,7 +649,7 @@ class nsZenWorkspaces {
             void this.#finalizeHorizontalWheelGesture(true);
             return;
           }
-          this.#scheduleHorizontalWheelGestureFinalize();
+          this.#scheduleHorizontalWheelGestureFinalize(horizontalGestureFinalizeDelay);
           return;
         }
 
@@ -698,14 +701,14 @@ class nsZenWorkspaces {
     }
   }
 
-  #scheduleHorizontalWheelGestureFinalize() {
+  #scheduleHorizontalWheelGestureFinalize(finalizeDelay) {
     if (this.#horizontalScrollFinalizeTimer) {
       clearTimeout(this.#horizontalScrollFinalizeTimer);
     }
     this.#horizontalScrollFinalizeTimer = setTimeout(() => {
       this.#horizontalScrollFinalizeTimer = null;
       void this.#finalizeHorizontalWheelGesture();
-    }, 180);
+    }, finalizeDelay);
   }
 
   async #finalizeHorizontalWheelGesture(forceSwitch = false) {

From 9484ccf942fb65fcdabe50cfa1d7dbc160e9add3 Mon Sep 17 00:00:00 2001
From: Andres <andres@integragroupe.com>
Date: Tue, 24 Feb 2026 19:03:56 -0400
Subject: [PATCH 03/16] refactor(workspaces): migrate sidebar swipe handling to
 wheel events

---
 src/zen/workspaces/ZenWorkspaces.mjs | 201 +++++----------------------
 1 file changed, 37 insertions(+), 164 deletions(-)

diff --git a/src/zen/workspaces/ZenWorkspaces.mjs b/src/zen/workspaces/ZenWorkspaces.mjs
index 7afc3c08cb..5ac88ba245 100644
--- a/src/zen/workspaces/ZenWorkspaces.mjs
+++ b/src/zen/workspaces/ZenWorkspaces.mjs
@@ -42,7 +42,6 @@ class nsZenWorkspaces {
 
   #lastScrollTime = 0;
   #lastHorizontalWheelEventTime = 0;
-  #horizontalScrollAccumulator = 0;
   #horizontalScrollFinalizeTimer = null;
   #horizontalWheelGestureActive = false;
 
@@ -179,7 +178,6 @@ class nsZenWorkspaces {
       this.workspaceEnabled &&
       !this.isPrivateWindow
     ) {
-      this.initializeGestureHandlers();
       this.initializeWorkspaceNavigation();
     }
   }
@@ -623,28 +621,12 @@ class nsZenWorkspaces {
           }
           this.#lastHorizontalWheelEventTime = currentTime;
           if (
-            this.#horizontalScrollAccumulator !== 0 &&
-            Math.sign(this.#horizontalScrollAccumulator) !== Math.sign(deltaPixels)
+            this._swipeState.lastDelta !== 0 &&
+            Math.sign(this._swipeState.lastDelta) !== Math.sign(deltaPixels)
           ) {
-            this.#horizontalScrollAccumulator = 0;
+            this._swipeState.lastDelta = 0;
           }
-          this.#horizontalScrollAccumulator += deltaPixels;
-          const stripWidth =
-            window.windowUtils.getBoundsWithoutFlushing(
-              document.getElementById("navigator-toolbox")
-            ).width +
-            window.windowUtils.getBoundsWithoutFlushing(
-              document.getElementById("zen-sidebar-splitter")
-            ).width *
-              2;
-          let translateX = this.#horizontalScrollAccumulator;
-          let forceMultiplier = Math.max(0.5, 1 - Math.abs(translateX) / (stripWidth * 4.5));
-          translateX *= forceMultiplier;
-          if (Math.abs(deltaPixels) > 0.8) {
-            this._swipeState.direction = deltaPixels > 0 ? "left" : "right";
-          }
-          const currentWorkspace = this.getActiveWorkspaceFromCache();
-          this._organizeWorkspaceStripLocations(currentWorkspace, true, translateX);
+          const translateX = this.#applyHorizontalSwipeDelta(deltaPixels);
           if (Math.abs(translateX) >= horizontalSnapPositionThreshold) {
             void this.#finalizeHorizontalWheelGesture(true);
             return;
@@ -701,6 +683,32 @@ class nsZenWorkspaces {
     }
   }
 
+  #applyHorizontalSwipeDelta(deltaPixels) {
+    const stripWidth =
+      window.windowUtils.getBoundsWithoutFlushing(document.getElementById("navigator-toolbox"))
+        .width +
+      window.windowUtils.getBoundsWithoutFlushing(document.getElementById("zen-sidebar-splitter"))
+        .width *
+        2;
+    let translateX = this._swipeState.lastDelta + deltaPixels;
+    // Match workspace swipe resistance so wheel and gesture interactions feel consistent.
+    const forceMultiplier = Math.min(1, 1 - Math.abs(translateX) / (stripWidth * 4.5));
+    if (forceMultiplier > 0.5) {
+      translateX *= forceMultiplier;
+      this._swipeState.lastDelta = deltaPixels + (translateX - deltaPixels) * 0.5;
+    } else {
+      translateX = this._swipeState.lastDelta;
+    }
+
+    if (Math.abs(deltaPixels) > 0.8) {
+      this._swipeState.direction = deltaPixels > 0 ? "left" : "right";
+    }
+
+    const currentWorkspace = this.getActiveWorkspaceFromCache();
+    this._organizeWorkspaceStripLocations(currentWorkspace, true, translateX);
+    return translateX;
+  }
+
   #scheduleHorizontalWheelGestureFinalize(finalizeDelay) {
     if (this.#horizontalScrollFinalizeTimer) {
       clearTimeout(this.#horizontalScrollFinalizeTimer);
@@ -716,10 +724,11 @@ class nsZenWorkspaces {
       return;
     }
     const threshold = 55;
-    const shouldSwitch = forceSwitch || Math.abs(this.#horizontalScrollAccumulator) >= threshold;
-    const workspaceOffset = this.#horizontalScrollAccumulator > 0 ? -1 : 1;
-    this.#horizontalScrollAccumulator = 0;
-    if (shouldSwitch) {
+    const swipeDelta = this._swipeState.lastDelta;
+    const shouldSwitch = forceSwitch || Math.abs(swipeDelta) >= threshold;
+    const workspaceOffset = swipeDelta > 0 ? -1 : 1;
+    this._swipeState.lastDelta = 0;
+    if (shouldSwitch && swipeDelta !== 0) {
       await this.changeWorkspaceShortcut(workspaceOffset, true);
       this.#lastScrollTime = Date.now();
     } else {
@@ -736,7 +745,7 @@ class nsZenWorkspaces {
       clearTimeout(this.#horizontalScrollFinalizeTimer);
       this.#horizontalScrollFinalizeTimer = null;
     }
-    this.#horizontalScrollAccumulator = 0;
+    this._swipeState.lastDelta = 0;
     this._cancelSwipeAnimation();
     this.#cleanupHorizontalWheelGesture();
   }
@@ -757,46 +766,6 @@ class nsZenWorkspaces {
     document.removeEventListener("popupshown", this.popupOpenHandler, { once: true });
   }
 
-  initializeGestureHandlers() {
-    const elements = [
-      gNavToolbox,
-      // event handlers do not work on elements inside shadow DOM so we need to attach them directly
-      document.getElementById("tabbrowser-arrowscrollbox").shadowRoot.querySelector("scrollbox"),
-    ];
-
-    // Attach gesture handlers to each element
-    for (const element of elements) {
-      if (!element) {
-        continue;
-      }
-      this.attachGestureHandlers(element);
-    }
-  }
-
-  attachGestureHandlers(element) {
-    element.addEventListener("MozSwipeGestureMayStart", this._handleSwipeMayStart.bind(this), true);
-    element.addEventListener("MozSwipeGestureStart", this._handleSwipeStart.bind(this), true);
-    element.addEventListener("MozSwipeGestureUpdate", this._handleSwipeUpdate.bind(this), true);
-
-    // Use MozSwipeGesture instead of MozSwipeGestureEnd because MozSwipeGestureEnd is fired after animation ends,
-    // while MozSwipeGesture is fired immediately after swipe ends.
-    element.addEventListener("MozSwipeGesture", this._handleSwipeEnd.bind(this), true);
-
-    element.addEventListener(
-      "MozSwipeGestureEnd",
-      () => {
-        Services.prefs.setBoolPref("zen.swipe.is-fast-swipe", false);
-        document.documentElement.removeAttribute("swipe-gesture");
-        gZenUIManager.tabsWrapper.style.removeProperty("scrollbar-width");
-        document.documentElement.style.setProperty("--zen-background-opacity", "1");
-        delete this._hasAnimatedBackgrounds;
-        this.updateTabsContainers();
-        document.removeEventListener("popupshown", this.popupOpenHandler, { once: true });
-      },
-      true
-    );
-  }
-
   _popupOpenHandler() {
     // If a popup is opened, we should stop the swipe gesture
     if (this._swipeState?.isGestureActive) {
@@ -805,7 +774,7 @@ class nsZenWorkspaces {
         this.#horizontalScrollFinalizeTimer = null;
       }
       this.#horizontalWheelGestureActive = false;
-      this.#horizontalScrollAccumulator = 0;
+      this._swipeState.lastDelta = 0;
       document.documentElement.removeAttribute("swipe-gesture");
       gZenUIManager.tabsWrapper.style.removeProperty("scrollbar-width");
       this.updateTabsContainers();
@@ -813,102 +782,6 @@ class nsZenWorkspaces {
     }
   }
 
-  _handleSwipeMayStart(event) {
-    if (this.privateWindowOrDisabled || this.#inChangingWorkspace) {
-      return;
-    }
-    if (
-      event.target.closest("#zen-sidebar-foot-buttons") ||
-      event.target.closest('#urlbar[zen-floating-urlbar="true"]')
-    ) {
-      return;
-    }
-
-    // Only handle horizontal swipes
-    if (event.direction === event.DIRECTION_LEFT || event.direction === event.DIRECTION_RIGHT) {
-      event.preventDefault();
-      event.stopPropagation();
-
-      // Set allowed directions based on available workspaces
-      event.allowedDirections |= event.DIRECTION_LEFT | event.DIRECTION_RIGHT;
-    }
-  }
-
-  _handleSwipeStart(event) {
-    if (!this.workspaceEnabled) {
-      return;
-    }
-
-    gZenFolders.cancelPopupTimer();
-
-    document.documentElement.setAttribute("swipe-gesture", "true");
-    document.addEventListener("popupshown", this.popupOpenHandler, { once: true });
-
-    event.preventDefault();
-    event.stopPropagation();
-    this._swipeState = {
-      isGestureActive: true,
-      lastDelta: 0,
-      direction: null,
-    };
-    Services.prefs.setBoolPref("zen.swipe.is-fast-swipe", true);
-  }
-
-  _handleSwipeUpdate(event) {
-    if (!this.workspaceEnabled || !this._swipeState?.isGestureActive) {
-      return;
-    }
-
-    event.preventDefault();
-    event.stopPropagation();
-
-    const delta = event.delta * 300;
-    const stripWidth =
-      window.windowUtils.getBoundsWithoutFlushing(document.getElementById("navigator-toolbox"))
-        .width +
-      window.windowUtils.getBoundsWithoutFlushing(document.getElementById("zen-sidebar-splitter"))
-        .width *
-        2;
-    let translateX = this._swipeState.lastDelta + delta;
-    // Add a force multiplier as we are translating the strip depending on how close to the edge we are
-    let forceMultiplier = Math.min(1, 1 - Math.abs(translateX) / (stripWidth * 4.5)); // 4.5 instead of 4 to add a bit of a buffer
-    if (forceMultiplier > 0.5) {
-      translateX *= forceMultiplier;
-      this._swipeState.lastDelta = delta + (translateX - delta) * 0.5;
-    } else {
-      translateX = this._swipeState.lastDelta;
-    }
-
-    if (Math.abs(delta) > 0.8) {
-      this._swipeState.direction = delta > 0 ? "left" : "right";
-    }
-
-    // Apply a translateX to the tab strip to give the user feedback on the swipe
-    const currentWorkspace = this.getActiveWorkspaceFromCache();
-    this._organizeWorkspaceStripLocations(currentWorkspace, true, translateX);
-  }
-
-  async _handleSwipeEnd(event) {
-    if (!this.workspaceEnabled) {
-      return;
-    }
-    event.preventDefault();
-    event.stopPropagation();
-    const isRTL = document.documentElement.matches(":-moz-locale-dir(rtl)");
-    const moveForward = (event.direction === SimpleGestureEvent.DIRECTION_RIGHT) !== isRTL;
-
-    const rawDirection = moveForward ? 1 : -1;
-    const direction = this.naturalScroll ? -1 : 1;
-    await this.changeWorkspaceShortcut(rawDirection * direction, true);
-
-    // Reset swipe state
-    this._swipeState = {
-      isGestureActive: false,
-      lastDelta: 0,
-      direction: null,
-    };
-  }
-
   get activeWorkspace() {
     return this.#activeWorkspace;
   }

From 5f957f33a90030f18844e4e5c1aa0f798ba26ffb Mon Sep 17 00:00:00 2001
From: Andres <andres@integragroupe.com>
Date: Tue, 24 Feb 2026 19:10:46 -0400
Subject: [PATCH 04/16] fix(workspaces): restore smoother wheel accumulator
 behavior

---
 src/zen/workspaces/ZenWorkspaces.mjs | 29 +++++++++++++---------------
 1 file changed, 13 insertions(+), 16 deletions(-)

diff --git a/src/zen/workspaces/ZenWorkspaces.mjs b/src/zen/workspaces/ZenWorkspaces.mjs
index 5ac88ba245..83bec1d748 100644
--- a/src/zen/workspaces/ZenWorkspaces.mjs
+++ b/src/zen/workspaces/ZenWorkspaces.mjs
@@ -42,6 +42,7 @@ class nsZenWorkspaces {
 
   #lastScrollTime = 0;
   #lastHorizontalWheelEventTime = 0;
+  #horizontalScrollAccumulator = 0;
   #horizontalScrollFinalizeTimer = null;
   #horizontalWheelGestureActive = false;
 
@@ -621,11 +622,12 @@ class nsZenWorkspaces {
           }
           this.#lastHorizontalWheelEventTime = currentTime;
           if (
-            this._swipeState.lastDelta !== 0 &&
-            Math.sign(this._swipeState.lastDelta) !== Math.sign(deltaPixels)
+            this.#horizontalScrollAccumulator !== 0 &&
+            Math.sign(this.#horizontalScrollAccumulator) !== Math.sign(deltaPixels)
           ) {
-            this._swipeState.lastDelta = 0;
+            this.#horizontalScrollAccumulator = 0;
           }
+          this.#horizontalScrollAccumulator += deltaPixels;
           const translateX = this.#applyHorizontalSwipeDelta(deltaPixels);
           if (Math.abs(translateX) >= horizontalSnapPositionThreshold) {
             void this.#finalizeHorizontalWheelGesture(true);
@@ -690,15 +692,10 @@ class nsZenWorkspaces {
       window.windowUtils.getBoundsWithoutFlushing(document.getElementById("zen-sidebar-splitter"))
         .width *
         2;
-    let translateX = this._swipeState.lastDelta + deltaPixels;
+    let translateX = this.#horizontalScrollAccumulator;
     // Match workspace swipe resistance so wheel and gesture interactions feel consistent.
-    const forceMultiplier = Math.min(1, 1 - Math.abs(translateX) / (stripWidth * 4.5));
-    if (forceMultiplier > 0.5) {
-      translateX *= forceMultiplier;
-      this._swipeState.lastDelta = deltaPixels + (translateX - deltaPixels) * 0.5;
-    } else {
-      translateX = this._swipeState.lastDelta;
-    }
+    const forceMultiplier = Math.max(0.5, 1 - Math.abs(translateX) / (stripWidth * 4.5));
+    translateX *= forceMultiplier;
 
     if (Math.abs(deltaPixels) > 0.8) {
       this._swipeState.direction = deltaPixels > 0 ? "left" : "right";
@@ -724,11 +721,11 @@ class nsZenWorkspaces {
       return;
     }
     const threshold = 55;
-    const swipeDelta = this._swipeState.lastDelta;
+    const swipeDelta = this.#horizontalScrollAccumulator;
     const shouldSwitch = forceSwitch || Math.abs(swipeDelta) >= threshold;
     const workspaceOffset = swipeDelta > 0 ? -1 : 1;
-    this._swipeState.lastDelta = 0;
-    if (shouldSwitch && swipeDelta !== 0) {
+    this.#horizontalScrollAccumulator = 0;
+    if (shouldSwitch) {
       await this.changeWorkspaceShortcut(workspaceOffset, true);
       this.#lastScrollTime = Date.now();
     } else {
@@ -745,7 +742,7 @@ class nsZenWorkspaces {
       clearTimeout(this.#horizontalScrollFinalizeTimer);
       this.#horizontalScrollFinalizeTimer = null;
     }
-    this._swipeState.lastDelta = 0;
+    this.#horizontalScrollAccumulator = 0;
     this._cancelSwipeAnimation();
     this.#cleanupHorizontalWheelGesture();
   }
@@ -774,7 +771,7 @@ class nsZenWorkspaces {
         this.#horizontalScrollFinalizeTimer = null;
       }
       this.#horizontalWheelGestureActive = false;
-      this._swipeState.lastDelta = 0;
+      this.#horizontalScrollAccumulator = 0;
       document.documentElement.removeAttribute("swipe-gesture");
       gZenUIManager.tabsWrapper.style.removeProperty("scrollbar-width");
       this.updateTabsContainers();

From db53d36626298a6f58cfbf0d98586f976487776f Mon Sep 17 00:00:00 2001
From: Andres <andres@integragroupe.com>
Date: Tue, 24 Feb 2026 19:12:36 -0400
Subject: [PATCH 05/16] docs(workspaces): explain wheel swipe smoothing
 decisions

---
 src/zen/workspaces/ZenWorkspaces.mjs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/zen/workspaces/ZenWorkspaces.mjs b/src/zen/workspaces/ZenWorkspaces.mjs
index 83bec1d748..913a8956ce 100644
--- a/src/zen/workspaces/ZenWorkspaces.mjs
+++ b/src/zen/workspaces/ZenWorkspaces.mjs
@@ -625,6 +625,8 @@ class nsZenWorkspaces {
             this.#horizontalScrollAccumulator !== 0 &&
             Math.sign(this.#horizontalScrollAccumulator) !== Math.sign(deltaPixels)
           ) {
+            // Reset on direction flips so small wheel nudges do not fight against
+            // stale momentum from the opposite side.
             this.#horizontalScrollAccumulator = 0;
           }
           this.#horizontalScrollAccumulator += deltaPixels;
@@ -692,6 +694,8 @@ class nsZenWorkspaces {
       window.windowUtils.getBoundsWithoutFlushing(document.getElementById("zen-sidebar-splitter"))
         .width *
         2;
+    // Keep an explicit wheel accumulator so low-amplitude wheel input still
+    // feels continuous instead of stepping between discrete event deltas.
     let translateX = this.#horizontalScrollAccumulator;
     // Match workspace swipe resistance so wheel and gesture interactions feel consistent.
     const forceMultiplier = Math.max(0.5, 1 - Math.abs(translateX) / (stripWidth * 4.5));
@@ -722,6 +726,8 @@ class nsZenWorkspaces {
     }
     const threshold = 55;
     const swipeDelta = this.#horizontalScrollAccumulator;
+    // forceSwitch is used when the visual strip translation already crossed
+    // the snap position threshold and should commit immediately.
     const shouldSwitch = forceSwitch || Math.abs(swipeDelta) >= threshold;
     const workspaceOffset = swipeDelta > 0 ? -1 : 1;
     this.#horizontalScrollAccumulator = 0;

From 9c7aae44fa1b171bcbbc09515a4def7bc42c9be9 Mon Sep 17 00:00:00 2001
From: Andres <andres@integragroupe.com>
Date: Tue, 24 Feb 2026 19:13:53 -0400
Subject: [PATCH 06/16] tune(workspaces): slightly lower horizontal wheel snap
 distance

---
 src/zen/workspaces/ZenWorkspaces.mjs | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/zen/workspaces/ZenWorkspaces.mjs b/src/zen/workspaces/ZenWorkspaces.mjs
index 913a8956ce..e8c078a25d 100644
--- a/src/zen/workspaces/ZenWorkspaces.mjs
+++ b/src/zen/workspaces/ZenWorkspaces.mjs
@@ -45,6 +45,9 @@ class nsZenWorkspaces {
   #horizontalScrollAccumulator = 0;
   #horizontalScrollFinalizeTimer = null;
   #horizontalWheelGestureActive = false;
+  // Slightly lower than the previous 55 to reduce required wheel travel
+  // while keeping accidental switches uncommon.
+  #horizontalWheelSnapThreshold = 50;
 
   bookmarkMenus = [
     "PlacesToolbar",
@@ -564,7 +567,6 @@ class nsZenWorkspaces {
 
     const verticalScrollCooldown = 200; // Milliseconds to wait before allowing another scroll
     const verticalScrollThreshold = 1;
-    const horizontalSnapPositionThreshold = 55;
     // Keep this short so wheel gestures feel responsive, but long enough to
     // wait for bursty horizontal wheel events before deciding where to snap.
     const horizontalGestureFinalizeDelay = 180;
@@ -631,7 +633,7 @@ class nsZenWorkspaces {
           }
           this.#horizontalScrollAccumulator += deltaPixels;
           const translateX = this.#applyHorizontalSwipeDelta(deltaPixels);
-          if (Math.abs(translateX) >= horizontalSnapPositionThreshold) {
+          if (Math.abs(translateX) >= this.#horizontalWheelSnapThreshold) {
             void this.#finalizeHorizontalWheelGesture(true);
             return;
           }
@@ -724,11 +726,10 @@ class nsZenWorkspaces {
     if (!this.#horizontalWheelGestureActive) {
       return;
     }
-    const threshold = 55;
     const swipeDelta = this.#horizontalScrollAccumulator;
     // forceSwitch is used when the visual strip translation already crossed
     // the snap position threshold and should commit immediately.
-    const shouldSwitch = forceSwitch || Math.abs(swipeDelta) >= threshold;
+    const shouldSwitch = forceSwitch || Math.abs(swipeDelta) >= this.#horizontalWheelSnapThreshold;
     const workspaceOffset = swipeDelta > 0 ? -1 : 1;
     this.#horizontalScrollAccumulator = 0;
     if (shouldSwitch) {

From dca77471c4f8748ddca3b9283c41b4891ceebfd2 Mon Sep 17 00:00:00 2001
From: Andres <andres@integragroupe.com>
Date: Tue, 24 Feb 2026 19:19:22 -0400
Subject: [PATCH 07/16] tune(workspaces): increase wheel sensitivity without
 lowering snap threshold

---
 src/zen/workspaces/ZenWorkspaces.mjs | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/zen/workspaces/ZenWorkspaces.mjs b/src/zen/workspaces/ZenWorkspaces.mjs
index e8c078a25d..dacf8909bf 100644
--- a/src/zen/workspaces/ZenWorkspaces.mjs
+++ b/src/zen/workspaces/ZenWorkspaces.mjs
@@ -45,9 +45,10 @@ class nsZenWorkspaces {
   #horizontalScrollAccumulator = 0;
   #horizontalScrollFinalizeTimer = null;
   #horizontalWheelGestureActive = false;
-  // Slightly lower than the previous 55 to reduce required wheel travel
-  // while keeping accidental switches uncommon.
-  #horizontalWheelSnapThreshold = 50;
+  #horizontalWheelSnapThreshold = 55;
+  // Multiplier for wheel-derived deltas. Slightly >1 keeps behavior familiar
+  // while requiring a bit less physical wheel travel.
+  #horizontalWheelSensitivity = 1.12;
 
   bookmarkMenus = [
     "PlacesToolbar",
@@ -618,7 +619,10 @@ class nsZenWorkspaces {
           }
           this.#startHorizontalWheelGesture();
           const scrollDirection = this.naturalScroll ? -1 : 1;
-          const deltaPixels = this.#normalizeHorizontalWheelDelta(event) * scrollDirection;
+          const deltaPixels =
+            this.#normalizeHorizontalWheelDelta(event) *
+            scrollDirection *
+            this.#horizontalWheelSensitivity;
           if (!deltaPixels) {
             return;
           }

From ba9f00b22148ec870be8b3fdf3017c49a8218244 Mon Sep 17 00:00:00 2001
From: Andres <andres@integragroupe.com>
Date: Tue, 24 Feb 2026 19:23:31 -0400
Subject: [PATCH 08/16] tune(workspaces): finalize horizontal wheel swipe on
 idle

---
 src/zen/workspaces/ZenWorkspaces.mjs | 20 ++++----------------
 1 file changed, 4 insertions(+), 16 deletions(-)

diff --git a/src/zen/workspaces/ZenWorkspaces.mjs b/src/zen/workspaces/ZenWorkspaces.mjs
index dacf8909bf..63c94b110c 100644
--- a/src/zen/workspaces/ZenWorkspaces.mjs
+++ b/src/zen/workspaces/ZenWorkspaces.mjs
@@ -46,9 +46,6 @@ class nsZenWorkspaces {
   #horizontalScrollFinalizeTimer = null;
   #horizontalWheelGestureActive = false;
   #horizontalWheelSnapThreshold = 55;
-  // Multiplier for wheel-derived deltas. Slightly >1 keeps behavior familiar
-  // while requiring a bit less physical wheel travel.
-  #horizontalWheelSensitivity = 1.12;
 
   bookmarkMenus = [
     "PlacesToolbar",
@@ -619,10 +616,7 @@ class nsZenWorkspaces {
           }
           this.#startHorizontalWheelGesture();
           const scrollDirection = this.naturalScroll ? -1 : 1;
-          const deltaPixels =
-            this.#normalizeHorizontalWheelDelta(event) *
-            scrollDirection *
-            this.#horizontalWheelSensitivity;
+          const deltaPixels = this.#normalizeHorizontalWheelDelta(event) * scrollDirection;
           if (!deltaPixels) {
             return;
           }
@@ -636,11 +630,7 @@ class nsZenWorkspaces {
             this.#horizontalScrollAccumulator = 0;
           }
           this.#horizontalScrollAccumulator += deltaPixels;
-          const translateX = this.#applyHorizontalSwipeDelta(deltaPixels);
-          if (Math.abs(translateX) >= this.#horizontalWheelSnapThreshold) {
-            void this.#finalizeHorizontalWheelGesture(true);
-            return;
-          }
+          this.#applyHorizontalSwipeDelta(deltaPixels);
           this.#scheduleHorizontalWheelGestureFinalize(horizontalGestureFinalizeDelay);
           return;
         }
@@ -726,14 +716,12 @@ class nsZenWorkspaces {
     }, finalizeDelay);
   }
 
-  async #finalizeHorizontalWheelGesture(forceSwitch = false) {
+  async #finalizeHorizontalWheelGesture() {
     if (!this.#horizontalWheelGestureActive) {
       return;
     }
     const swipeDelta = this.#horizontalScrollAccumulator;
-    // forceSwitch is used when the visual strip translation already crossed
-    // the snap position threshold and should commit immediately.
-    const shouldSwitch = forceSwitch || Math.abs(swipeDelta) >= this.#horizontalWheelSnapThreshold;
+    const shouldSwitch = Math.abs(swipeDelta) >= this.#horizontalWheelSnapThreshold;
     const workspaceOffset = swipeDelta > 0 ? -1 : 1;
     this.#horizontalScrollAccumulator = 0;
     if (shouldSwitch) {

From a84a1e0e4df3bf3a069a91ad7a0b0305d1361a3f Mon Sep 17 00:00:00 2001
From: Andres <andres@integragroupe.com>
Date: Tue, 24 Feb 2026 19:28:41 -0400
Subject: [PATCH 09/16] tune(workspaces): snap horizontal wheel gesture only
 after idle

---
 src/zen/workspaces/ZenWorkspaces.mjs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/zen/workspaces/ZenWorkspaces.mjs b/src/zen/workspaces/ZenWorkspaces.mjs
index 63c94b110c..52c7ca3d66 100644
--- a/src/zen/workspaces/ZenWorkspaces.mjs
+++ b/src/zen/workspaces/ZenWorkspaces.mjs
@@ -567,7 +567,7 @@ class nsZenWorkspaces {
     const verticalScrollThreshold = 1;
     // Keep this short so wheel gestures feel responsive, but long enough to
     // wait for bursty horizontal wheel events before deciding where to snap.
-    const horizontalGestureFinalizeDelay = 180;
+    const horizontalGestureFinalizeDelay = 120;
 
     toolbox.addEventListener(
       "wheel",

From adbcab8d5e65afbcbaf7794a087b9f87bea615b9 Mon Sep 17 00:00:00 2001
From: Andres <andres@integragroupe.com>
Date: Tue, 24 Feb 2026 19:31:59 -0400
Subject: [PATCH 10/16] tune(workspaces): reduce horizontal wheel finalize
 delay

---
 src/zen/workspaces/ZenWorkspaces.mjs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/zen/workspaces/ZenWorkspaces.mjs b/src/zen/workspaces/ZenWorkspaces.mjs
index 52c7ca3d66..c17cfd198a 100644
--- a/src/zen/workspaces/ZenWorkspaces.mjs
+++ b/src/zen/workspaces/ZenWorkspaces.mjs
@@ -567,7 +567,7 @@ class nsZenWorkspaces {
     const verticalScrollThreshold = 1;
     // Keep this short so wheel gestures feel responsive, but long enough to
     // wait for bursty horizontal wheel events before deciding where to snap.
-    const horizontalGestureFinalizeDelay = 120;
+    const horizontalGestureFinalizeDelay = 70;
 
     toolbox.addEventListener(
       "wheel",

From 5b31d0b1ba7d40ee4ba04b1f91ecbecdfd64340f Mon Sep 17 00:00:00 2001
From: Andres <andres@integragroupe.com>
Date: Tue, 24 Feb 2026 20:00:55 -0400
Subject: [PATCH 11/16] tune(workspaces): polish wheel scrub and settle timing

---
 src/zen/workspaces/ZenWorkspaces.mjs | 45 ++++++++++++++++------------
 1 file changed, 26 insertions(+), 19 deletions(-)

diff --git a/src/zen/workspaces/ZenWorkspaces.mjs b/src/zen/workspaces/ZenWorkspaces.mjs
index c17cfd198a..89aca606f9 100644
--- a/src/zen/workspaces/ZenWorkspaces.mjs
+++ b/src/zen/workspaces/ZenWorkspaces.mjs
@@ -565,9 +565,13 @@ class nsZenWorkspaces {
 
     const verticalScrollCooldown = 200; // Milliseconds to wait before allowing another scroll
     const verticalScrollThreshold = 1;
-    // Keep this short so wheel gestures feel responsive, but long enough to
-    // wait for bursty horizontal wheel events before deciding where to snap.
-    const horizontalGestureFinalizeDelay = 70;
+    const horizontalWheelSensitivity = 1.1;
+    // Keep settle timing fast for wheel UX, while still respecting platform
+    // transaction timing as an upper bound.
+    const horizontalGestureFinalizeDelay = Math.min(
+      Services.prefs.getIntPref("mousewheel.transaction.timeout", 150),
+      95
+    );
 
     toolbox.addEventListener(
       "wheel",
@@ -611,27 +615,30 @@ class nsZenWorkspaces {
         const currentTime = Date.now();
 
         if (isHorizontalScroll) {
-          if (this.#inChangingWorkspace) {
-            return;
-          }
-          this.#startHorizontalWheelGesture();
           const scrollDirection = this.naturalScroll ? -1 : 1;
-          const deltaPixels = this.#normalizeHorizontalWheelDelta(event) * scrollDirection;
+          const deltaPixels =
+            this.#normalizeHorizontalWheelDelta(event) *
+            scrollDirection *
+            horizontalWheelSensitivity;
           if (!deltaPixels) {
             return;
           }
           this.#lastHorizontalWheelEventTime = currentTime;
-          if (
-            this.#horizontalScrollAccumulator !== 0 &&
-            Math.sign(this.#horizontalScrollAccumulator) !== Math.sign(deltaPixels)
-          ) {
-            // Reset on direction flips so small wheel nudges do not fight against
-            // stale momentum from the opposite side.
-            this.#horizontalScrollAccumulator = 0;
+          if (this.#inChangingWorkspace) {
+            return;
           }
+          this.#startHorizontalWheelGesture();
           this.#horizontalScrollAccumulator += deltaPixels;
-          this.#applyHorizontalSwipeDelta(deltaPixels);
-          this.#scheduleHorizontalWheelGestureFinalize(horizontalGestureFinalizeDelay);
+          const translateX = this.#applyHorizontalSwipeDelta(deltaPixels);
+          if (Math.abs(translateX) >= this.#horizontalWheelSnapThreshold) {
+            if (this.#horizontalScrollFinalizeTimer) {
+              clearTimeout(this.#horizontalScrollFinalizeTimer);
+              this.#horizontalScrollFinalizeTimer = null;
+            }
+            void this.#finalizeHorizontalWheelGesture(true);
+          } else {
+            this.#scheduleHorizontalWheelGestureFinalize(horizontalGestureFinalizeDelay);
+          }
           return;
         }
 
@@ -716,12 +723,12 @@ class nsZenWorkspaces {
     }, finalizeDelay);
   }
 
-  async #finalizeHorizontalWheelGesture() {
+  async #finalizeHorizontalWheelGesture(forceSwitch = false) {
     if (!this.#horizontalWheelGestureActive) {
       return;
     }
     const swipeDelta = this.#horizontalScrollAccumulator;
-    const shouldSwitch = Math.abs(swipeDelta) >= this.#horizontalWheelSnapThreshold;
+    const shouldSwitch = forceSwitch || Math.abs(swipeDelta) >= this.#horizontalWheelSnapThreshold;
     const workspaceOffset = swipeDelta > 0 ? -1 : 1;
     this.#horizontalScrollAccumulator = 0;
     if (shouldSwitch) {

From 4d41a54fe0890f298cae9f274b5d9819fbcb66d1 Mon Sep 17 00:00:00 2001
From: Andres <andres@integragroupe.com>
Date: Tue, 24 Feb 2026 20:06:15 -0400
Subject: [PATCH 12/16] fix(workspaces): restore native trackpad swipe handlers

---
 src/zen/workspaces/ZenWorkspaces.mjs | 137 +++++++++++++++++++++++++++
 1 file changed, 137 insertions(+)

diff --git a/src/zen/workspaces/ZenWorkspaces.mjs b/src/zen/workspaces/ZenWorkspaces.mjs
index 89aca606f9..eb34cfdb10 100644
--- a/src/zen/workspaces/ZenWorkspaces.mjs
+++ b/src/zen/workspaces/ZenWorkspaces.mjs
@@ -180,6 +180,7 @@ class nsZenWorkspaces {
       this.workspaceEnabled &&
       !this.isPrivateWindow
     ) {
+      this.initializeGestureHandlers();
       this.initializeWorkspaceNavigation();
     }
   }
@@ -769,6 +770,46 @@ class nsZenWorkspaces {
     document.removeEventListener("popupshown", this.popupOpenHandler, { once: true });
   }
 
+  initializeGestureHandlers() {
+    const elements = [
+      gNavToolbox,
+      // event handlers do not work on elements inside shadow DOM so we need to attach them directly
+      document.getElementById("tabbrowser-arrowscrollbox").shadowRoot.querySelector("scrollbox"),
+    ];
+
+    // Attach gesture handlers to each element
+    for (const element of elements) {
+      if (!element) {
+        continue;
+      }
+      this.attachGestureHandlers(element);
+    }
+  }
+
+  attachGestureHandlers(element) {
+    element.addEventListener("MozSwipeGestureMayStart", this._handleSwipeMayStart.bind(this), true);
+    element.addEventListener("MozSwipeGestureStart", this._handleSwipeStart.bind(this), true);
+    element.addEventListener("MozSwipeGestureUpdate", this._handleSwipeUpdate.bind(this), true);
+
+    // Use MozSwipeGesture instead of MozSwipeGestureEnd because MozSwipeGestureEnd is fired after animation ends,
+    // while MozSwipeGesture is fired immediately after swipe ends.
+    element.addEventListener("MozSwipeGesture", this._handleSwipeEnd.bind(this), true);
+
+    element.addEventListener(
+      "MozSwipeGestureEnd",
+      () => {
+        Services.prefs.setBoolPref("zen.swipe.is-fast-swipe", false);
+        document.documentElement.removeAttribute("swipe-gesture");
+        gZenUIManager.tabsWrapper.style.removeProperty("scrollbar-width");
+        document.documentElement.style.setProperty("--zen-background-opacity", "1");
+        delete this._hasAnimatedBackgrounds;
+        this.updateTabsContainers();
+        document.removeEventListener("popupshown", this.popupOpenHandler, { once: true });
+      },
+      true
+    );
+  }
+
   _popupOpenHandler() {
     // If a popup is opened, we should stop the swipe gesture
     if (this._swipeState?.isGestureActive) {
@@ -785,6 +826,102 @@ class nsZenWorkspaces {
     }
   }
 
+  _handleSwipeMayStart(event) {
+    if (this.privateWindowOrDisabled || this.#inChangingWorkspace) {
+      return;
+    }
+    if (
+      event.target.closest("#zen-sidebar-foot-buttons") ||
+      event.target.closest('#urlbar[zen-floating-urlbar="true"]')
+    ) {
+      return;
+    }
+
+    // Only handle horizontal swipes
+    if (event.direction === event.DIRECTION_LEFT || event.direction === event.DIRECTION_RIGHT) {
+      event.preventDefault();
+      event.stopPropagation();
+
+      // Set allowed directions based on available workspaces
+      event.allowedDirections |= event.DIRECTION_LEFT | event.DIRECTION_RIGHT;
+    }
+  }
+
+  _handleSwipeStart(event) {
+    if (!this.workspaceEnabled) {
+      return;
+    }
+
+    gZenFolders.cancelPopupTimer();
+
+    document.documentElement.setAttribute("swipe-gesture", "true");
+    document.addEventListener("popupshown", this.popupOpenHandler, { once: true });
+
+    event.preventDefault();
+    event.stopPropagation();
+    this._swipeState = {
+      isGestureActive: true,
+      lastDelta: 0,
+      direction: null,
+    };
+    Services.prefs.setBoolPref("zen.swipe.is-fast-swipe", true);
+  }
+
+  _handleSwipeUpdate(event) {
+    if (!this.workspaceEnabled || !this._swipeState?.isGestureActive) {
+      return;
+    }
+
+    event.preventDefault();
+    event.stopPropagation();
+
+    const delta = event.delta * 300;
+    const stripWidth =
+      window.windowUtils.getBoundsWithoutFlushing(document.getElementById("navigator-toolbox"))
+        .width +
+      window.windowUtils.getBoundsWithoutFlushing(document.getElementById("zen-sidebar-splitter"))
+        .width *
+        2;
+    let translateX = this._swipeState.lastDelta + delta;
+    // Add a force multiplier as we are translating the strip depending on how close to the edge we are
+    let forceMultiplier = Math.min(1, 1 - Math.abs(translateX) / (stripWidth * 4.5)); // 4.5 instead of 4 to add a bit of a buffer
+    if (forceMultiplier > 0.5) {
+      translateX *= forceMultiplier;
+      this._swipeState.lastDelta = delta + (translateX - delta) * 0.5;
+    } else {
+      translateX = this._swipeState.lastDelta;
+    }
+
+    if (Math.abs(delta) > 0.8) {
+      this._swipeState.direction = delta > 0 ? "left" : "right";
+    }
+
+    // Apply a translateX to the tab strip to give the user feedback on the swipe
+    const currentWorkspace = this.getActiveWorkspaceFromCache();
+    this._organizeWorkspaceStripLocations(currentWorkspace, true, translateX);
+  }
+
+  async _handleSwipeEnd(event) {
+    if (!this.workspaceEnabled) {
+      return;
+    }
+    event.preventDefault();
+    event.stopPropagation();
+    const isRTL = document.documentElement.matches(":-moz-locale-dir(rtl)");
+    const moveForward = (event.direction === SimpleGestureEvent.DIRECTION_RIGHT) !== isRTL;
+
+    const rawDirection = moveForward ? 1 : -1;
+    const direction = this.naturalScroll ? -1 : 1;
+    await this.changeWorkspaceShortcut(rawDirection * direction, true);
+
+    // Reset swipe state
+    this._swipeState = {
+      isGestureActive: false,
+      lastDelta: 0,
+      direction: null,
+    };
+  }
+
   get activeWorkspace() {
     return this.#activeWorkspace;
   }

From 212fbfeacf03d93b12170636257653e3c115d289 Mon Sep 17 00:00:00 2001
From: Andres <andres@integragroupe.com>
Date: Tue, 24 Feb 2026 20:34:02 -0400
Subject: [PATCH 13/16] fix(workspaces): isolate trackpad swipe from wheel
 workspace handling

---
 src/zen/workspaces/ZenWorkspaces.mjs | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/src/zen/workspaces/ZenWorkspaces.mjs b/src/zen/workspaces/ZenWorkspaces.mjs
index eb34cfdb10..a7ee7e4fed 100644
--- a/src/zen/workspaces/ZenWorkspaces.mjs
+++ b/src/zen/workspaces/ZenWorkspaces.mjs
@@ -42,6 +42,8 @@ class nsZenWorkspaces {
 
   #lastScrollTime = 0;
   #lastHorizontalWheelEventTime = 0;
+  #lastTrackpadSwipeEventTime = 0;
+  #trackpadPostSwipeSuppressionMs = 2000;
   #horizontalScrollAccumulator = 0;
   #horizontalScrollFinalizeTimer = null;
   #horizontalWheelGestureActive = false;
@@ -531,6 +533,9 @@ class nsZenWorkspaces {
     if (!this.workspaceEnabled || !gNavToolbox.matches(":hover")) {
       return;
     }
+    if (Date.now() - this.#lastTrackpadSwipeEventTime < this.#trackpadPostSwipeSuppressionMs) {
+      return;
+    }
     // Some devices emit AppCommand and wheel for the same horizontal wheel action.
     // Ignore AppCommand if a horizontal wheel event just occurred.
     if (Date.now() - this.#lastHorizontalWheelEventTime < 250) {
@@ -616,6 +621,12 @@ class nsZenWorkspaces {
         const currentTime = Date.now();
 
         if (isHorizontalScroll) {
+          if (
+            event.deltaMode === event.DOM_DELTA_PIXEL &&
+            currentTime - this.#lastTrackpadSwipeEventTime < this.#trackpadPostSwipeSuppressionMs
+          ) {
+            return;
+          }
           const scrollDirection = this.naturalScroll ? -1 : 1;
           const deltaPixels =
             this.#normalizeHorizontalWheelDelta(event) *
@@ -798,6 +809,7 @@ class nsZenWorkspaces {
     element.addEventListener(
       "MozSwipeGestureEnd",
       () => {
+        this.#lastTrackpadSwipeEventTime = Date.now();
         Services.prefs.setBoolPref("zen.swipe.is-fast-swipe", false);
         document.documentElement.removeAttribute("swipe-gesture");
         gZenUIManager.tabsWrapper.style.removeProperty("scrollbar-width");
@@ -827,6 +839,7 @@ class nsZenWorkspaces {
   }
 
   _handleSwipeMayStart(event) {
+    this.#lastTrackpadSwipeEventTime = Date.now();
     if (this.privateWindowOrDisabled || this.#inChangingWorkspace) {
       return;
     }
@@ -848,6 +861,7 @@ class nsZenWorkspaces {
   }
 
   _handleSwipeStart(event) {
+    this.#lastTrackpadSwipeEventTime = Date.now();
     if (!this.workspaceEnabled) {
       return;
     }
@@ -868,6 +882,7 @@ class nsZenWorkspaces {
   }
 
   _handleSwipeUpdate(event) {
+    this.#lastTrackpadSwipeEventTime = Date.now();
     if (!this.workspaceEnabled || !this._swipeState?.isGestureActive) {
       return;
     }
@@ -902,6 +917,7 @@ class nsZenWorkspaces {
   }
 
   async _handleSwipeEnd(event) {
+    this.#lastTrackpadSwipeEventTime = Date.now();
     if (!this.workspaceEnabled) {
       return;
     }

From 7140fe0f9562d3d6bcac8c13adb3294cc4bd7e0e Mon Sep 17 00:00:00 2001
From: Andres <andres@integragroupe.com>
Date: Tue, 24 Feb 2026 20:41:13 -0400
Subject: [PATCH 14/16] fix(workspaces): match mouse horizontal wheel to
 natural scroll direction

---
 src/zen/workspaces/ZenWorkspaces.mjs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/zen/workspaces/ZenWorkspaces.mjs b/src/zen/workspaces/ZenWorkspaces.mjs
index a7ee7e4fed..cedc84227d 100644
--- a/src/zen/workspaces/ZenWorkspaces.mjs
+++ b/src/zen/workspaces/ZenWorkspaces.mjs
@@ -545,7 +545,7 @@ class nsZenWorkspaces {
       this.#cancelHorizontalWheelGesture();
     }
 
-    const direction = this.naturalScroll ? -1 : 1;
+    const direction = this.naturalScroll ? 1 : -1;
     // event is forward or back
     switch (event.command) {
       case "Forward":
@@ -627,7 +627,7 @@ class nsZenWorkspaces {
           ) {
             return;
           }
-          const scrollDirection = this.naturalScroll ? -1 : 1;
+          const scrollDirection = this.naturalScroll ? 1 : -1;
           const deltaPixels =
             this.#normalizeHorizontalWheelDelta(event) *
             scrollDirection *

From 2e462805e0505af303a144199e986c9a66fbe825 Mon Sep 17 00:00:00 2001
From: Andres <andres@integragroupe.com>
Date: Wed, 25 Feb 2026 00:47:29 -0400
Subject: [PATCH 15/16] fix(workspaces): stabilize trackpad direction reversals
 in sidebar swipes

---
 src/zen/workspaces/ZenWorkspaces.mjs | 59 +++++++++++++++++++++++-----
 1 file changed, 50 insertions(+), 9 deletions(-)

diff --git a/src/zen/workspaces/ZenWorkspaces.mjs b/src/zen/workspaces/ZenWorkspaces.mjs
index cedc84227d..b4d4e88eef 100644
--- a/src/zen/workspaces/ZenWorkspaces.mjs
+++ b/src/zen/workspaces/ZenWorkspaces.mjs
@@ -48,6 +48,11 @@ class nsZenWorkspaces {
   #horizontalScrollFinalizeTimer = null;
   #horizontalWheelGestureActive = false;
   #horizontalWheelSnapThreshold = 55;
+  // Trackpad swipe deltas are cumulative; keep explicit state so slow gestures
+  // and mid-gesture reversals stay stable and deterministic.
+  #trackpadLastEventDelta = null;
+  #trackpadLastMotionDirection = 0;
+  #trackpadMotionBaseline = null;
 
   bookmarkMenus = [
     "PlacesToolbar",
@@ -840,7 +845,9 @@ class nsZenWorkspaces {
 
   _handleSwipeMayStart(event) {
     this.#lastTrackpadSwipeEventTime = Date.now();
-    if (this.privateWindowOrDisabled || this.#inChangingWorkspace) {
+    // Allow new swipe intent even while a previous workspace transition settles,
+    // otherwise reversing direction feels blocked until finger lift.
+    if (this.privateWindowOrDisabled) {
       return;
     }
     if (
@@ -878,6 +885,9 @@ class nsZenWorkspaces {
       lastDelta: 0,
       direction: null,
     };
+    this.#trackpadLastEventDelta = null;
+    this.#trackpadLastMotionDirection = 0;
+    this.#trackpadMotionBaseline = null;
     Services.prefs.setBoolPref("zen.swipe.is-fast-swipe", true);
   }
 
@@ -890,27 +900,49 @@ class nsZenWorkspaces {
     event.preventDefault();
     event.stopPropagation();
 
-    const delta = event.delta * 300;
+    const rawDelta = event.delta * 300;
+    if (this.#trackpadMotionBaseline === null) {
+      this.#trackpadMotionBaseline = rawDelta;
+    }
+    let delta = rawDelta - this.#trackpadMotionBaseline;
+    let stepDelta = 0;
+    if (typeof this.#trackpadLastEventDelta === "number") {
+      stepDelta = rawDelta - this.#trackpadLastEventDelta;
+    }
+    this.#trackpadLastEventDelta = rawDelta;
+
+    const motionStepThreshold = 0.8;
+    if (Math.abs(stepDelta) >= motionStepThreshold) {
+      const stepDirection = stepDelta > 0 ? 1 : -1;
+      if (
+        this.#trackpadLastMotionDirection &&
+        stepDirection !== this.#trackpadLastMotionDirection
+      ) {
+        // Rebase when reversing so the swipe starts immediately in the new direction
+        // instead of fighting the previous accumulated displacement.
+        this.#trackpadMotionBaseline = rawDelta;
+        delta = 0;
+        this._swipeState.lastDelta = 0;
+      }
+      this.#trackpadLastMotionDirection = stepDirection;
+      this._swipeState.direction = stepDirection > 0 ? "left" : "right";
+    }
     const stripWidth =
       window.windowUtils.getBoundsWithoutFlushing(document.getElementById("navigator-toolbox"))
         .width +
       window.windowUtils.getBoundsWithoutFlushing(document.getElementById("zen-sidebar-splitter"))
         .width *
         2;
-    let translateX = this._swipeState.lastDelta + delta;
+    let translateX = delta;
     // Add a force multiplier as we are translating the strip depending on how close to the edge we are
     let forceMultiplier = Math.min(1, 1 - Math.abs(translateX) / (stripWidth * 4.5)); // 4.5 instead of 4 to add a bit of a buffer
     if (forceMultiplier > 0.5) {
       translateX *= forceMultiplier;
-      this._swipeState.lastDelta = delta + (translateX - delta) * 0.5;
+      this._swipeState.lastDelta = translateX;
     } else {
       translateX = this._swipeState.lastDelta;
     }
 
-    if (Math.abs(delta) > 0.8) {
-      this._swipeState.direction = delta > 0 ? "left" : "right";
-    }
-
     // Apply a translateX to the tab strip to give the user feedback on the swipe
     const currentWorkspace = this.getActiveWorkspaceFromCache();
     this._organizeWorkspaceStripLocations(currentWorkspace, true, translateX);
@@ -924,7 +956,13 @@ class nsZenWorkspaces {
     event.preventDefault();
     event.stopPropagation();
     const isRTL = document.documentElement.matches(":-moz-locale-dir(rtl)");
-    const moveForward = (event.direction === SimpleGestureEvent.DIRECTION_RIGHT) !== isRTL;
+    let swipeDirection = event.direction;
+    if (this.#trackpadLastMotionDirection < 0) {
+      swipeDirection = SimpleGestureEvent.DIRECTION_RIGHT;
+    } else if (this.#trackpadLastMotionDirection > 0) {
+      swipeDirection = SimpleGestureEvent.DIRECTION_LEFT;
+    }
+    const moveForward = (swipeDirection === SimpleGestureEvent.DIRECTION_RIGHT) !== isRTL;
 
     const rawDirection = moveForward ? 1 : -1;
     const direction = this.naturalScroll ? -1 : 1;
@@ -936,6 +974,9 @@ class nsZenWorkspaces {
       lastDelta: 0,
       direction: null,
     };
+    this.#trackpadLastEventDelta = null;
+    this.#trackpadLastMotionDirection = 0;
+    this.#trackpadMotionBaseline = null;
   }
 
   get activeWorkspace() {

From 7fdf26e56ea0a2d5f59cc0ad3f8bef55ac86d6cb Mon Sep 17 00:00:00 2001
From: Andres <andres@integragroupe.com>
Date: Wed, 25 Feb 2026 01:06:02 -0400
Subject: [PATCH 16/16] fix(workspaces): smooth slow trackpad direction
 reversals

---
 src/zen/workspaces/ZenWorkspaces.mjs | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/src/zen/workspaces/ZenWorkspaces.mjs b/src/zen/workspaces/ZenWorkspaces.mjs
index b4d4e88eef..9e82c8bd50 100644
--- a/src/zen/workspaces/ZenWorkspaces.mjs
+++ b/src/zen/workspaces/ZenWorkspaces.mjs
@@ -911,19 +911,11 @@ class nsZenWorkspaces {
     }
     this.#trackpadLastEventDelta = rawDelta;
 
-    const motionStepThreshold = 0.8;
+    // Keep direction detection responsive at low swipe velocities so reversing
+    // mid-gesture does not stall around the strip center.
+    const motionStepThreshold = 0.35;
     if (Math.abs(stepDelta) >= motionStepThreshold) {
       const stepDirection = stepDelta > 0 ? 1 : -1;
-      if (
-        this.#trackpadLastMotionDirection &&
-        stepDirection !== this.#trackpadLastMotionDirection
-      ) {
-        // Rebase when reversing so the swipe starts immediately in the new direction
-        // instead of fighting the previous accumulated displacement.
-        this.#trackpadMotionBaseline = rawDelta;
-        delta = 0;
-        this._swipeState.lastDelta = 0;
-      }
       this.#trackpadLastMotionDirection = stepDirection;
       this._swipeState.direction = stepDirection > 0 ? "left" : "right";
     }
@@ -966,7 +958,13 @@ class nsZenWorkspaces {
 
     const rawDirection = moveForward ? 1 : -1;
     const direction = this.naturalScroll ? -1 : 1;
+    const previousWorkspaceId = this.activeWorkspace;
     await this.changeWorkspaceShortcut(rawDirection * direction, true);
+    if (this.activeWorkspace === previousWorkspaceId) {
+      // Ensure the strip recenters when a swipe gesture resolves without a committed
+      // workspace change (for example while another transition is still settling).
+      this._cancelSwipeAnimation();
+    }
 
     // Reset swipe state
     this._swipeState = {