Refactor how workspaces are tracked upon workspace context change.

js/ui/workspacesView.js

@@ -444,9 +444,46 @@ class WorkspacesView extends WorkspacesViewBase {
         this.set_child_above_sibling(activeWorkspace, null);
     }
 
+    _refreshMetaWorkspace(metaWorkspace, idx) {
+
+        // If the current element at idx matches metaWorkspace don't do anything
+        if (idx < this._workspaces.length) {
+            if (this._workspaces[idx].metaWorkspace.get_id() === metaWorkspace.get_id()) {
+                return;
+            }
+        }
+
+        let workspace = new Workspace.Workspace(
+            metaWorkspace,
+            this._monitorIndex,
+            this._overviewAdjustment);
+
+
+        if (idx < this._workspaces.length) {
+            // Replace a current entry
+            let old = this._workspaces[idx];
+            this._workspaces[idx] = workspace;
+            this.add_actor(workspace);
+            this.set_child_at_index(workspace, idx);
+            old.destroy();
+        } else {
+            // Append a new entry
+            this.add_actor(workspace);
+            this._workspaces.push(workspace);
+        }
+    }
+
     _refreshWorkspaces() {
-        for (let ws = this._workspaces.pop(); ws; ws = this._workspaces.pop()) {
-            ws.destroy();
+        let workspaceManager = global.workspace_manager;
+        let nWorkspaces = workspaceManager.n_workspaces;
+
+        for (let i = 0; i < nWorkspaces; i++) {
+            let metaWorkspace = workspaceManager.get_workspace_by_index(i);
+            this._refreshMetaWorkspace(metaWorkspace, i);
+        }
+        for (let i = this._workspaces.length - 1; i >= nWorkspaces; i--) {
+            this._workspaces[i].destroy();
+            this._workspaces.splice(i, 1);
         }
         this._updateWorkspaces();
     }