Lexical: Updated dropdown handling to match tinymce behaviour

Now toolbars stay open on mouse-out, and close on other toolbar open,
outside click or an accepted action.
To support:
- Added new system to track and manage open dropdowns.
- Added way for buttons to optionally emit events upon actions.
- Added way to listen for events.
- Used the above to control when dropdowns should hide on action, since
  some dont (like overflow containers and split dropdown buttons).

resources/js/wysiwyg/ui/framework/helpers/dropdowns.ts

@@ -34,57 +34,97 @@ function positionMenu(menu: HTMLElement, toggle: HTMLElement, showAside: boolean
     }
 }
 
-export function handleDropdown(options: HandleDropdownParams) {
-    const {menu, toggle, onClose, onOpen, showOnHover, showAside} = options;
-    let clickListener: Function|null = null;
+export class DropDownManager {
 
-    const hide = () => {
+    protected dropdownOptions: WeakMap<HTMLElement, HandleDropdownParams> = new WeakMap();
+    protected openDropdowns: Set<HTMLElement> = new Set();
+
+    constructor() {
+        this.onMenuMouseOver = this.onMenuMouseOver.bind(this);
+
+        window.addEventListener('click', (event: MouseEvent) => {
+            const target = event.target as HTMLElement;
+            this.closeAllNotContainingElement(target);
+        });
+    }
+
+    protected closeAllNotContainingElement(element: HTMLElement): void {
+        for (const menu of this.openDropdowns) {
+            if (!menu.parentElement?.contains(element)) {
+                this.closeDropdown(menu);
+            }
+        }
+    }
+
+    protected onMenuMouseOver(event: MouseEvent): void {
+        const target = event.target as HTMLElement;
+        this.closeAllNotContainingElement(target);
+    }
+
+    /**
+     * Close all open dropdowns.
+     */
+    public closeAll(): void {
+        for (const menu of this.openDropdowns) {
+            this.closeDropdown(menu);
+        }
+    }
+
+    protected closeDropdown(menu: HTMLElement): void {
         menu.hidden = true;
         menu.style.removeProperty('position');
         menu.style.removeProperty('left');
         menu.style.removeProperty('top');
-        if (clickListener) {
-            window.removeEventListener('click', clickListener as EventListener);
-        }
+
+        this.openDropdowns.delete(menu);
+        menu.removeEventListener('mouseover', this.onMenuMouseOver);
+
+        const onClose = this.getOptions(menu).onClose;
         if (onClose) {
             onClose();
         }
-    };
+    }
 
-    const show = () => {
+    protected openDropdown(menu: HTMLElement): void {
+        const {toggle, showAside, onOpen} = this.getOptions(menu);
         menu.hidden = false
         positionMenu(menu, toggle, Boolean(showAside));
-        clickListener = (event: MouseEvent) => {
-            if (!toggle.contains(event.target as HTMLElement) && !menu.contains(event.target as HTMLElement)) {
-                hide();
-            }
-        }
-        window.addEventListener('click', clickListener as EventListener);
+
+        this.openDropdowns.add(menu);
+        menu.addEventListener('mouseover', this.onMenuMouseOver);
+
         if (onOpen) {
             onOpen();
         }
-    };
-
-    const toggleShowing = (event: MouseEvent) => {
-        menu.hasAttribute('hidden') ? show() : hide();
-    };
-    toggle.addEventListener('click', toggleShowing);
-    if (showOnHover) {
-        toggle.addEventListener('mouseenter', toggleShowing);
     }
 
-    menu.parentElement?.addEventListener('mouseleave', (event: MouseEvent) => {
-
-        // Prevent mouseleave hiding if withing the same bounds of the toggle.
-        // Avoids hiding in the event the mouse is interrupted by a high z-index
-        // item like a browser scrollbar.
-        const toggleBounds = toggle.getBoundingClientRect();
-        const withinX = event.clientX <= toggleBounds.right && event.clientX >= toggleBounds.left;
-        const withinY = event.clientY <= toggleBounds.bottom && event.clientY >= toggleBounds.top;
-        const withinToggle = withinX && withinY;
-
-        if (!withinToggle) {
-            hide();
+    protected getOptions(menu: HTMLElement): HandleDropdownParams {
+        const options = this.dropdownOptions.get(menu);
+        if (!options) {
+            throw new Error(`Can't find options for dropdown menu`);
         }
-    });
+
+        return options;
+    }
+
+    /**
+     * Add handling for a new dropdown.
+     */
+     public handle(options: HandleDropdownParams) {
+        const {menu, toggle, showOnHover} = options;
+
+        // Register dropdown
+        this.dropdownOptions.set(menu, options);
+
+        // Configure default events
+        const toggleShowing = (event: MouseEvent) => {
+            menu.hasAttribute('hidden') ? this.openDropdown(menu) : this.closeDropdown(menu);
+        };
+        toggle.addEventListener('click', toggleShowing);
+        if (showOnHover) {
+            toggle.addEventListener('mouseenter', () => {
+                this.openDropdown(menu);
+            });
+        }
+    }
 }