refactor: drop unecessary binding on focusKeydown

Author: keithamus

index.js

@@ -225,9 +225,7 @@ class MarkdownToolbarElement extends HTMLElement {
     if (!this.hasAttribute('role')) {
       this.setAttribute('role', 'toolbar')
     }
-    const focusKeydownfn = focusKeydown.bind(null, this)
-    this.addEventListener('keydown', focusKeydownfn)
-    focusListeners.set(this, focusKeydownfn)
+    this.addEventListener('keydown', focusKeydown)
     const fn = shortcut.bind(null, this)
     if (this.field) {
       this.field.addEventListener('keydown', fn)
@@ -243,10 +241,7 @@ class MarkdownToolbarElement extends HTMLElement {
       this.field.removeEventListener('keydown', fn)
       shortcutListeners.delete(this)
     }
-    const focusKeydownfn = focusListeners.get(this)
-    if (focusKeydownfn) {
-      this.removeEventListener('keydown', focusKeydownfn)
-    }
+    this.removeEventListener('keydown', focusKeydown)
   }
 
   get field(): ?HTMLTextAreaElement {
@@ -257,15 +252,15 @@ class MarkdownToolbarElement extends HTMLElement {
   }
 }
 
-const focusListeners = new WeakMap()
-
-function focusKeydown(toolbar: MarkdownToolbarElement, event: KeyboardEvent) {
+function focusKeydown(event: KeyboardEvent) {
   const key = event.key
   if (key !== 'ArrowRight' && key !== 'ArrowLeft' && key !== 'Home' && key !== 'End') return
   const target = event.target
+  const toolbar = event.currentTarget
   if (!(target instanceof HTMLElement)) return
+  if (!(toolbar instanceof HTMLElement)) return
   if (!target.hasAttribute('data-md-button')) return
-  if (target.closest('markdown-toolbar') !== event.currentTarget) return
+  if (target.closest('markdown-toolbar') !== toolbar) return
 
   const buttons = []
   for (const button of toolbar.querySelectorAll('[data-md-button]')) {