From 78cd9ae4a90bc29132ceeeb792a14a5fc0162813 Mon Sep 17 00:00:00 2001
From: Elliott Marquez <emarquez@google.com>
Date: Thu, 5 Oct 2023 22:17:29 -0700
Subject: [PATCH] fix(menu): fix menu tapping behaviors on iOS and do not close
 on anchor click

fixes #5036
fixes #5015

iOS has some really bad behaviors when it comes to clicking and focus. clicking on the body on a non-clickable item (like anything outside a menu) does not tirgger a click event that bubbles to menu. Also, clicking on a button does not cause it to be focused, thus depriving us of information on focusout's related target. Therefore we have to assume the anchor is the trigger.

PiperOrigin-RevId: 571227552
---
 menu/internal/menu.ts | 75 ++++++++++++++++++++++---------------------
 1 file changed, 39 insertions(+), 36 deletions(-)

diff --git a/menu/internal/menu.ts b/menu/internal/menu.ts
index 2390fba22a9..c9617938286 100644
--- a/menu/internal/menu.ts
+++ b/menu/internal/menu.ts
@@ -209,7 +209,6 @@ export abstract class Menu extends LitElement {
    * The event path of the last window pointerdown event.
    */
   private pointerPath: EventTarget[] = [];
-  private isPointerDown = false;
   private readonly openCloseAnimationSignal = createAnimationSignal();
 
   private readonly listController = new ListController<MenuItem>({
@@ -303,7 +302,7 @@ export abstract class Menu extends LitElement {
     super();
     if (!isServer) {
       this.internals.role = 'menu';
-      this.addEventListener('keydown', this.listController.handleKeydown);
+      this.addEventListener('keydown', this.handleKeydown);
       // Capture so that we can grab the event before it reaches the menu item
       // istelf. Specifically useful for the case where typeahead encounters a
       // space and we don't want the menu item to close the menu.
@@ -358,6 +357,22 @@ export abstract class Menu extends LitElement {
     this.setAttribute('aria-hidden', 'true');
   }
 
+  override update(changed: PropertyValues<Menu>) {
+    if (changed.has('open')) {
+      if (this.open) {
+        window.addEventListener(
+            'pointerup', this.onWindowPointerup, {capture: true});
+        window.addEventListener('pointerdown', this.onWindowPointerdown);
+      } else {
+        window.removeEventListener(
+            'pointerup', this.onWindowPointerup, {capture: true});
+        window.removeEventListener('pointerdown', this.onWindowPointerdown);
+      }
+    }
+
+    super.update(changed);
+  }
+
   protected override render() {
     return this.renderSurface();
   }
@@ -411,25 +426,23 @@ export abstract class Menu extends LitElement {
   }
 
   private readonly handleFocusout = async (event: FocusEvent) => {
-    if (this.stayOpenOnFocusout || !this.open) {
+    const anchorEl = this.anchorElement!;
+    // Do not close if we focused out by clicking on the anchor element. We
+    // can't assume anchor buttons can be the related target because of iOS does
+    // not focus buttons.
+    if (this.stayOpenOnFocusout || !this.open ||
+        this.pointerPath.includes(anchorEl)) {
       return;
     }
 
     if (event.relatedTarget) {
       // Don't close the menu if we are switching focus between menu,
-      // md-menu-item, and md-list
-      if (isElementInSubtree(event.relatedTarget, this)) {
+      // md-menu-item, and md-list or if the anchor was click focused.
+      if (isElementInSubtree(event.relatedTarget, this) ||
+          isElementInSubtree(event.relatedTarget, anchorEl)) {
         return;
       }
-
-      const anchorEl = this.anchorElement!;
-      const wasAnchorClickFocused =
-          isElementInSubtree(event.relatedTarget, anchorEl) &&
-          this.isPointerDown;
-      if (wasAnchorClickFocused) {
-        return;
-      }
-    } else if (this.isPointerDown && this.pointerPath.includes(this)) {
+    } else if (this.pointerPath.includes(this)) {
       // If menu tabindex == -1 and the user clicks on the menu or a divider, we
       // want to keep the menu open.
       return;
@@ -752,34 +765,24 @@ export abstract class Menu extends LitElement {
     return animationEnded;
   }
 
-  override connectedCallback() {
-    super.connectedCallback();
-    if (!isServer) {
-      window.addEventListener('click', this.onWindowClick, {capture: true});
-      window.addEventListener('pointerdown', this.onWindowPointerdown);
-      window.addEventListener('pointerup', this.onWindowPointerup);
-    }
-  }
-
-  override disconnectedCallback() {
-    super.disconnectedCallback();
-    if (!isServer) {
-      window.removeEventListener('click', this.onWindowClick, {capture: true});
-      window.removeEventListener('pointerdown', this.onWindowPointerdown);
-      window.removeEventListener('pointerup', this.onWindowPointerup);
-    }
+  private handleKeydown(event: KeyboardEvent) {
+    // At any key event, the pointer interaction is done so we need to clear our
+    // cached pointerpath. This handles the case where the user clicks on the
+    // anchor, and then hits shift+tab
+    this.pointerPath = [];
+    this.listController.handleKeydown(event);
   }
 
   private readonly onWindowPointerdown = (event: PointerEvent) => {
-    this.isPointerDown = true;
     this.pointerPath = event.composedPath();
   };
 
-  private readonly onWindowPointerup = () => {
-    this.isPointerDown = false;
-  };
-
-  private readonly onWindowClick = (event: MouseEvent) => {
+  /**
+   * We cannot listen to window click because Safari on iOS will not fire a
+   * click event on window if the item clicked is not a "clickable" item such as
+   * <body>
+   */
+  private readonly onWindowPointerup = (event: Event) => {
     if (!this.open) {
       return;
     }