fix: improve workspace session restoration and scrolling behavior

src/browser/base/content/zen-styles/zen-workspaces.css

@@ -130,6 +130,9 @@
     overflow: hidden;
     display: flex;
     gap: 0.5ch;
+    overflow-x: auto;
+    scrollbar-width: none;
+    scroll-behavior: smooth;
   }
 }
 

src/browser/base/zen-components/ZenViewSplitter.mjs

@@ -981,7 +981,9 @@ class ZenViewSplitter extends ZenDOMOperatedFeature {
       layoutTree: this.calculateLayoutTree(tabs, gridType),
     };
     this._data.push(splitData);
-    window.gBrowser.selectedTab = tabs[0];
+    if (!this._sessionRestoring) {
+      window.gBrowser.selectedTab = tabs[0];
+    }
 
     // Add tabs to the split view group
     let splitGroup = this._getSplitViewGroup(tabs);
@@ -1739,6 +1741,7 @@ class ZenViewSplitter extends ZenDOMOperatedFeature {
     if (!data) {
       return;
     }
+    this._sessionRestoring = true;
     // We can just get the tab group with document.getElementById(group.groupId)
     // and add the tabs to it
     for (const group of data) {
@@ -1748,6 +1751,15 @@ class ZenViewSplitter extends ZenDOMOperatedFeature {
         this.splitTabs([...tabs], group.gridType);
       }
     }
+    delete this._sessionRestoring;
+  }
+
+  onAfterWorkspaceSessionRestore() {
+    if (this.currentView >= 0) {
+      // Activate all browsers in the split view
+      this.currentView = -1;
+      this.onLocationChange(gBrowser.selectedTab.linkedBrowser);
+    }
   }
 }
 

src/browser/base/zen-components/ZenWorkspaces.mjs

@@ -405,6 +405,7 @@ var ZenWorkspaces = new (class extends ZenMultiWindowFeature {
 
   _handleSwipeMayStart(event) {
     if (!this.workspaceEnabled) return;
+    if (event.target.closest('#zen-sidebar-bottom-buttons')) return;
 
     // Only handle horizontal swipes
     if (event.direction === event.DIRECTION_LEFT || event.direction === event.DIRECTION_RIGHT) {
@@ -648,6 +649,7 @@ var ZenWorkspaces = new (class extends ZenMultiWindowFeature {
     if (gZenVerticalTabsManager._canReplaceNewTab && showed) {
       BrowserCommands.openTab();
     }
+    gZenViewSplitter.onAfterWorkspaceSessionRestore();
   }
 
   handleInitialTab(tab, isEmpty) {
@@ -2415,6 +2417,17 @@ var ZenWorkspaces = new (class extends ZenMultiWindowFeature {
       const maxWidth = 100 / numButtons;
       parent.style.setProperty('--zen-overflowed-workspace-button-width', `${maxWidth}%`);
       this._processingResize = false;
+
+      // Scroll to the active workspace button if it's not visible
+      const activeButton = parent.querySelector('.zen-workspace-button.active');
+      if (!activeButton) {
+        return;
+      }
+      const parentRect = parent.getBoundingClientRect();
+      const activeRect = activeButton.getBoundingClientRect();
+      if (activeRect.left < parentRect.left || activeRect.right > parentRect.right) {
+        parent.scrollLeft = activeButton.offsetLeft;
+      }
     });
   }
 })();