From f6d72f9c3ff141389f5116a95e6393e410644978 Mon Sep 17 00:00:00 2001
From: Elliott Marquez <emarquez@google.com>
Date: Thu, 27 Apr 2023 10:09:29 -0700
Subject: [PATCH] fix(menu): fix submenu closing when already opened and all
 menus closing when hovering over menuitem

PiperOrigin-RevId: 527611715
---
 menu/lib/menu.ts                      | 14 +++++++++++++-
 menu/lib/shared.ts                    | 20 ++++++++++++++++++++
 menu/lib/submenuitem/sub-menu-item.ts | 19 ++++++++++++++++++-
 3 files changed, 51 insertions(+), 2 deletions(-)

diff --git a/menu/lib/menu.ts b/menu/lib/menu.ts
index e2764bcf1d..0041b27dda 100644
--- a/menu/lib/menu.ts
+++ b/menu/lib/menu.ts
@@ -287,7 +287,9 @@ export abstract class Menu extends LitElement {
         @close-menu=${this.onCloseMenu}
         @deactivate-items=${this.onDeactivateItems}
         @deactivate-typeahead=${this.handleDeactivateTypeahead}
-        @activate-typeahead=${this.handleActivateTypeahead}></slot>`;
+        @activate-typeahead=${this.handleActivateTypeahead}
+        @stay-open-on-focusout=${this.handleStayOpenOnFocusout}
+        @close-on-focusout=${this.handleCloseOnFocusout}></slot>`;
   }
 
   /**
@@ -681,6 +683,16 @@ export abstract class Menu extends LitElement {
     this.typeaheadActive = true;
   }
 
+  private handleStayOpenOnFocusout(e:Event) {
+    e.stopPropagation();
+    this.stayOpenOnFocusout = true;
+  }
+
+  private handleCloseOnFocusout(e:Event) {
+    e.stopPropagation();
+    this.stayOpenOnFocusout = false;
+  }
+
   override focus() {
     this.listElement?.focus();
   }
diff --git a/menu/lib/shared.ts b/menu/lib/shared.ts
index 11fb36eb74..ead7fb1b4e 100644
--- a/menu/lib/shared.ts
+++ b/menu/lib/shared.ts
@@ -82,6 +82,26 @@ export class CloseMenuEvent<T extends Reason = DefaultReasons> extends Event {
   }
 }
 
+/**
+ * The event that signals to the menu that it should stay open on the focusout
+ * event.
+ */
+export class StayOpenOnFocusoutEvent extends Event {
+  constructor() {
+    super('stay-open-on-focusout', {bubbles: true, composed: true});
+  }
+}
+
+/**
+ * The event that signals to the menu that it should close open on the focusout
+ * event.
+ */
+export class CloseOnFocusoutEvent extends Event {
+  constructor() {
+    super('close-on-focusout', {bubbles: true, composed: true});
+  }
+}
+
 /**
  * The default close menu event used by md-menu. To create your own `close-menu`
  * event, you should subclass the `CloseMenuEvent` instead.
diff --git a/menu/lib/submenuitem/sub-menu-item.ts b/menu/lib/submenuitem/sub-menu-item.ts
index 8bb197212b..f01d8b09a2 100644
--- a/menu/lib/submenuitem/sub-menu-item.ts
+++ b/menu/lib/submenuitem/sub-menu-item.ts
@@ -10,7 +10,7 @@ import {property, queryAssignedElements} from 'lit/decorators.js';
 import {List} from '../../../list/lib/list.js';
 import {Corner, Menu} from '../menu.js';
 import {MenuItemEl} from '../menuitem/menu-item.js';
-import {ActivateTypeaheadEvent, CLOSE_REASON, CloseMenuEvent, DeactivateItemsEvent, DeactivateTypeaheadEvent, KEYDOWN_CLOSE_KEYS, NAVIGABLE_KEY, SELECTION_KEY} from '../shared.js';
+import {ActivateTypeaheadEvent, CLOSE_REASON, CloseMenuEvent, CloseOnFocusoutEvent, DeactivateItemsEvent, DeactivateTypeaheadEvent, KEYDOWN_CLOSE_KEYS, NAVIGABLE_KEY, SELECTION_KEY, StayOpenOnFocusoutEvent} from '../shared.js';
 
 function stopPropagation(e: Event) {
   e.stopPropagation();
@@ -23,6 +23,12 @@ function stopPropagation(e: Event) {
  *     to deactivate the typeahead functionality when a submenu opens
  * @fires activate-typeahead {DeactivateItemsEvent} Requests the parent menu to
  *     activate the typeahead functionality when a submenu closes
+ * @fires stay-open-on-focusout {StayOpenOnFocusoutEvent} Requests the parent
+ *     menu to stay open when focusout event is fired or has a `null`
+ *     `relatedTarget` when submenu is opened.
+ * @fires close-on-focusout {CloseOnFocusoutEvent} Requests the parent
+ *     menu to close when focusout event is fired or has a `null`
+ *     `relatedTarget` When submenu is closed.
  */
 export class SubMenuItem extends MenuItemEl {
   /**
@@ -152,6 +158,8 @@ export class SubMenuItem extends MenuItemEl {
 
   private onCloseSubmenu(e: CloseMenuEvent) {
     e.itemPath.push(this);
+    // Restore focusout behavior
+    this.dispatchEvent(new CloseOnFocusoutEvent());
     this.dispatchEvent(new ActivateTypeaheadEvent());
     // Escape should only close one menu not all of the menus unlike space or
     // click selection which should close all menus.
@@ -206,9 +214,16 @@ export class SubMenuItem extends MenuItemEl {
     // keyboard after hover.
     menu.defaultFocus = 'LIST_ROOT';
     menu.skipRestoreFocus = true;
+    menu.stayOpenOnOutsideClick = true;
+    menu.stayOpenOnFocusout = true;
 
     // Menu could already be opened because of mouse interaction
     const menuAlreadyOpen = menu.open;
+    // We want the parent to stay open in the case such that a middle submenu
+    // has a submenuitem hovered which opens a third submenut. Then if you hover
+    // on yet another middle menu-item (not submenuitem) then focusout Event's
+    // relatedTarget will be `null` thus, causing all the menus to close
+    this.dispatchEvent(new StayOpenOnFocusoutEvent());
     menu.show();
 
     // Deactivate other items. This can be the case if the user has tabbed
@@ -238,6 +253,8 @@ export class SubMenuItem extends MenuItemEl {
     this.dispatchEvent(new ActivateTypeaheadEvent());
     menu.quick = true;
     menu.close();
+    // Restore focusout behavior.
+    this.dispatchEvent(new CloseOnFocusoutEvent());
     this.active = false;
     this.selected = false;
     menu.addEventListener('closed', onClosed, {once: true});