Update ILayoutEventListener.ts

Update notifyOnActiveDocumentChange return value to Promise<void>

Author: Steven-L-42

src/interfaces/ILayoutEventListener.ts

@@ -17,12 +17,12 @@ export interface ILayoutEventListener {
     onContainerResized?(dockManager: DockManager, dockContainer: IDockContainer): void;
     onTabChanged?(dockManager: DockManager, tabpage: TabPage): void;
     onActivePanelChange?(dockManager: DockManager, panel?: PanelContainer, previousPanel?: PanelContainer): void;
-    onActiveDocumentChange?(dockManager: DockManager, panel?: PanelContainer, previousPanel?: PanelContainer): void;
+    onActiveDocumentChange?(dockManager: DockManager, panel?: PanelContainer, previousPanel?: PanelContainer): Promise<void>;
 
     /**
     * The Dock Manager notifies the listeners of layout changes so client containers that have
     * costly layout structures can detach and reattach themself to avoid reflow
     */
     onSuspendLayout?(dockManager: DockManager, panel: IDockContainer): void;
     onResumeLayout?(dockManager: DockManager, panel: IDockContainer): void;
-}
+}