Add window helpers to TouchBar class

lib/browser/api/touch-bar.js

@@ -10,6 +10,7 @@ class TouchBar extends EventEmitter {
       throw new Error('The items object provided has to be an array')
     }
 
+    this.windowListeners = {}
     this.items = {}
     this.ordereredItems = []
     const registerItem = (item) => {
@@ -28,13 +29,45 @@ class TouchBar extends EventEmitter {
       }
       registerItem(item)
     })
+  }
 
-    this.on('interaction', (itemID, details) => {
+  // Called by BrowserWindow.setTouchBar
+  _addToWindow (window) {
+    const {id} = window
+
+    // Already added to window
+    if (this.windowListeners.hasOwnProperty(id)) return
+
+    const changeListener = (itemID) => {
+      window._refreshTouchBarItem(itemID)
+    }
+    this.on('change', changeListener)
+
+    const interactionListener = (event, itemID, details) => {
       const item = this.items[itemID]
       if (item != null && item.onInteraction != null) {
         item.onInteraction(details)
       }
-    })
+    }
+    window.on('-touch-bar-interaction', interactionListener)
+
+    const removeListeners = () => {
+      this.removeListener('change', changeListener)
+      window.removeListener('-touch-bar-interaction', interactionListener)
+      window.removeListener('closed', removeListeners)
+      window._touchBar = null
+      delete this.windowListeners[id]
+    }
+    window.once('closed', removeListeners)
+    this.windowListeners[id] = removeListeners
+
+    window._setTouchBar(this.ordereredItems)
+  }
+
+  // Called by BrowserWindow.setTouchBar
+  _removeFromWindow (window) {
+    const removeListeners = this.windowListeners[window.id]
+    if (removeListeners != null) removeListeners()
   }
 }