Add a guestinstance attribute to webviews reflecting their current guest

instance ID and allowing moving a guest instance to a new webview.

lib/renderer/web-view/guest-view-internal.js

@@ -7,6 +7,7 @@ var requestId = 0
 
 var WEB_VIEW_EVENTS = {
   'load-commit': ['url', 'isMainFrame'],
+  'did-attach': [],
   'did-finish-load': [],
   'did-fail-load': ['errorCode', 'errorDescription', 'validatedURL', 'isMainFrame'],
   'did-frame-finish-load': ['isMainFrame'],
@@ -62,6 +63,15 @@ var dispatchEvent = function (webView, eventName, eventKey, ...args) {
 
 module.exports = {
   registerEvents: function (webView, viewInstanceId) {
+    ipcRenderer.on('ELECTRON_GUEST_VIEW_INTERNAL_DESTROY_GUEST-' + viewInstanceId, function () {
+      var domEvent
+      webFrame.detachGuest(webView.internalInstanceId)
+      webView.guestInstanceId = undefined
+      webView.reset()
+      domEvent = new Event('destroyed')
+      webView.dispatchEvent(domEvent)
+    })
+
     ipcRenderer.on('ELECTRON_GUEST_VIEW_INTERNAL_DISPATCH_EVENT-' + viewInstanceId, function (event, eventName, ...args) {
       dispatchEvent.apply(null, [webView, eventName, eventName].concat(args))
     })
@@ -85,6 +95,7 @@ module.exports = {
     })
   },
   deregisterEvents: function (viewInstanceId) {
+    ipcRenderer.removeAllListeners('ELECTRON_GUEST_VIEW_INTERNAL_DESTROY_GUEST-' + viewInstanceId)
     ipcRenderer.removeAllListeners('ELECTRON_GUEST_VIEW_INTERNAL_DISPATCH_EVENT-' + viewInstanceId)
     ipcRenderer.removeAllListeners('ELECTRON_GUEST_VIEW_INTERNAL_IPC_MESSAGE-' + viewInstanceId)
     return ipcRenderer.removeAllListeners('ELECTRON_GUEST_VIEW_INTERNAL_SIZE_CHANGED-' + viewInstanceId)

lib/renderer/web-view/web-view-attributes.js

@@ -130,6 +130,46 @@ class PartitionAttribute extends WebViewAttribute {
   }
 }
 
+// An attribute that controls the guest instance this webview is connected to
+class GuestInstanceAttribute extends WebViewAttribute {
+  constructor (webViewImpl) {
+    super(webViewConstants.ATTRIBUTE_GUESTINSTANCE, webViewImpl)
+  }
+
+  // Retrieves and returns the attribute's value.
+  getValue () {
+    if (this.webViewImpl.webviewNode.hasAttribute(this.name)) {
+      return parseInt(this.webViewImpl.webviewNode.getAttribute(this.name))
+    }
+    return undefined
+  }
+
+  // Sets the attribute's value.
+  setValue (value) {
+    if (!value) {
+      return this.webViewImpl.webviewNode.removeAttribute(this.name)
+    }
+    if (isNaN(value)) {
+      return
+    }
+    return this.webViewImpl.webviewNode.setAttribute(this.name, value)
+  }
+
+  handleMutation (oldValue, newValue) {
+    if (!newValue) {
+      this.webViewImpl.reset()
+      return
+    }
+
+    const intVal = parseInt(newValue)
+    if (!isNaN(newValue) && remote.getGuestWebContents(intVal)) {
+      this.webViewImpl.attachGuestInstance(intVal)
+    } else {
+      this.setValueIgnoreMutation(oldValue)
+    }
+  }
+}
+
 // Attribute that handles the location and navigation of the webview.
 class SrcAttribute extends WebViewAttribute {
   constructor (webViewImpl) {
@@ -287,6 +327,7 @@ WebViewImpl.prototype.setupWebViewAttributes = function () {
   this.attributes[webViewConstants.ATTRIBUTE_PRELOAD] = new PreloadAttribute(this)
   this.attributes[webViewConstants.ATTRIBUTE_BLINKFEATURES] = new BlinkFeaturesAttribute(this)
   this.attributes[webViewConstants.ATTRIBUTE_DISABLEBLINKFEATURES] = new DisableBlinkFeaturesAttribute(this)
+  this.attributes[webViewConstants.ATTRIBUTE_GUESTINSTANCE] = new GuestInstanceAttribute(this)
 
   const autosizeAttributes = [webViewConstants.ATTRIBUTE_MAXHEIGHT, webViewConstants.ATTRIBUTE_MAXWIDTH, webViewConstants.ATTRIBUTE_MINHEIGHT, webViewConstants.ATTRIBUTE_MINWIDTH]
   autosizeAttributes.forEach((attribute) => {

lib/renderer/web-view/web-view-constants.js

@@ -17,6 +17,7 @@ module.exports = {
   ATTRIBUTE_USERAGENT: 'useragent',
   ATTRIBUTE_BLINKFEATURES: 'blinkfeatures',
   ATTRIBUTE_DISABLEBLINKFEATURES: 'disableblinkfeatures',
+  ATTRIBUTE_GUESTINSTANCE: 'guestinstance',
 
   // Internal attribute.
   ATTRIBUTE_INTERNALINSTANCEID: 'internalinstanceid',

lib/renderer/web-view/web-view.js

@@ -71,12 +71,13 @@ var WebViewImpl = (function () {
     // that we don't end up allocating a second guest.
     if (this.guestInstanceId) {
       guestViewInternal.destroyGuest(this.guestInstanceId)
-      this.webContents = null
       this.guestInstanceId = void 0
-      this.beforeFirstNavigation = true
-      this.attributes[webViewConstants.ATTRIBUTE_PARTITION].validPartitionId = true
     }
-    this.internalInstanceId = 0
+
+    this.webContents = null
+    this.attributes[webViewConstants.ATTRIBUTE_GUESTINSTANCE].setValueIgnoreMutation(undefined)
+    this.beforeFirstNavigation = true
+    this.attributes[webViewConstants.ATTRIBUTE_PARTITION].validPartitionId = true
   }
 
   // Sets the <webview>.request property.
@@ -184,7 +185,7 @@ var WebViewImpl = (function () {
 
   WebViewImpl.prototype.createGuest = function () {
     return guestViewInternal.createGuest(this.buildParams(), (event, guestInstanceId) => {
-      this.attachWindow(guestInstanceId)
+      this.attachGuestInstance(guestInstanceId)
     })
   }
 
@@ -257,8 +258,9 @@ var WebViewImpl = (function () {
     return params
   }
 
-  WebViewImpl.prototype.attachWindow = function (guestInstanceId) {
+  WebViewImpl.prototype.attachGuestInstance = function (guestInstanceId) {
     this.guestInstanceId = guestInstanceId
+    this.attributes[webViewConstants.ATTRIBUTE_GUESTINSTANCE].setValueIgnoreMutation(guestInstanceId)
     this.webContents = remote.getGuestWebContents(this.guestInstanceId)
     if (!this.internalInstanceId) {
       return true
@@ -324,10 +326,11 @@ var registerWebViewElement = function () {
     }
     guestViewInternal.deregisterEvents(internal.viewInstanceId)
     internal.elementAttached = false
-    return internal.reset()
+    internal.reset()
+    this.internalInstanceId = 0
   }
   proto.attachedCallback = function () {
-    var internal
+    var internal, instance
     internal = v8Util.getHiddenValue(this, 'internal')
     if (!internal) {
       return
@@ -335,6 +338,10 @@ var registerWebViewElement = function () {
     if (!internal.elementAttached) {
       guestViewInternal.registerEvents(internal, internal.viewInstanceId)
       internal.elementAttached = true
+      instance = internal.attributes[webViewConstants.ATTRIBUTE_GUESTINSTANCE].getValue()
+      if (instance) {
+        return internal.attachGuestInstance(instance)
+      }
       return internal.attributes[webViewConstants.ATTRIBUTE_SRC].parse()
     }
   }