Added support for split views persisting between sessions

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

@@ -58,6 +58,11 @@ tab-group[split-view-group] {
       right: 50%;
       transform: translateX(50%);
     }
+
+    & .tab-content {
+      min-width: 0;
+      justify-content: unset !important;
+    }
   }
 
   &:has(> tab:is([visuallyselected], [multiselected])) {

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

@@ -365,7 +365,7 @@ menuitem {
   }
 
   & .zen-toast {
-    padding: 0.9rem 0.8rem;
+    padding: 0.5rem 0.6rem;
     border-radius: 12px;
     background: linear-gradient(
       170deg,

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

@@ -1722,6 +1722,33 @@ class ZenViewSplitter extends ZenDOMOperatedFeature {
 
     return null;
   }
+
+  storeDataForSessionStore() {
+    // We cant store any tab or browser elements in the session store
+    // so we need to store the tab indexes and group indexes
+    const data = this._data.map((group) => {
+      return {
+        groupId: group.tabs[0].group?.id,
+        gridType: group.gridType,
+      };
+    });
+    return data;
+  }
+
+  restoreDataFromSessionStore(data) {
+    if (!data) {
+      return;
+    }
+    // We can just get the tab group with document.getElementById(group.groupId)
+    // and add the tabs to it
+    for (const group of data) {
+      const groupElement = document.getElementById(group.groupId);
+      if (groupElement) {
+        const tabs = groupElement.querySelectorAll('tab');
+        this.splitTabs([...tabs], group.gridType);
+      }
+    }
+  }
 }
 
 window.gZenViewSplitter = new ZenViewSplitter();

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

@@ -263,12 +263,13 @@ var ZenWorkspaces = new (class extends ZenMultiWindowFeature {
   _organizeTabsToWorkspaceSections(workspace, section, pinnedSection, tabs) {
     const workspaceTabs = Array.from(tabs).filter((tab) => tab.getAttribute('zen-workspace-id') === workspace.uuid);
     let firstNormalTab = null;
-    for (const tab of workspaceTabs) {
+    for (let tab of workspaceTabs) {
       if (tab.hasAttribute('zen-essential')) {
         continue; // Ignore essentials as they need to be in their own section
       }
       // remove tab from list
       tabs.splice(tabs.indexOf(tab), 1);
+      tab = tab.group ?? tab;
       if (tab.pinned) {
         pinnedSection.insertBefore(tab, pinnedSection.nextSibling);
       } else {
@@ -2323,6 +2324,23 @@ var ZenWorkspaces = new (class extends ZenMultiWindowFeature {
     return this._allStoredTabs;
   }
 
+  get allTabGroups() {
+    if (!this._hasInitializedTabsStrip) {
+      let children = this.tabboxChildren;
+      return children.filter((node) => node.tagName == 'tab-group');
+    }
+    const pinnedContainers = document.querySelectorAll('#vertical-pinned-tabs-container .zen-workspace-tabs-section');
+    const normalContainers = document.querySelectorAll('#tabbrowser-arrowscrollbox .zen-workspace-tabs-section');
+    const containers = [...pinnedContainers, ...normalContainers];
+    const tabGroups = [];
+    for (const container of containers) {
+      for (const tabGroup of container.querySelectorAll('tab-group')) {
+        tabGroups.push(tabGroup);
+      }
+    }
+    return tabGroups;
+  }
+
   get allUsedBrowsers() {
     if (!this._hasInitializedTabsStrip) {
       return gBrowser.browsers;