fix: focus event not emitted when <webview> is sandboxed

filenames.gni

@@ -74,6 +74,7 @@ filenames = {
     "lib/renderer/web-view/web-view-constants.js",
     "lib/renderer/web-view/web-view-element.js",
     "lib/renderer/web-view/web-view-impl.js",
+    "lib/renderer/web-view/web-view-init.js",
     "lib/renderer/api/exports/electron.js",
     "lib/renderer/api/crash-reporter.js",
     "lib/renderer/api/ipc-renderer.js",

lib/renderer/init.js

@@ -164,14 +164,8 @@ for (const preloadScript of preloadScripts) {
 // Warn about security issues
 require('@electron/internal/renderer/security-warnings')(nodeIntegration)
 
-// Report focus/blur events of webview to browser.
-// Note that while Chromium content APIs have observer for focus/blur, they
-// unfortunately do not work for webview.
 if (guestInstanceId) {
-  window.addEventListener('focus', () => {
-    ipcRenderer.send('ELECTRON_GUEST_VIEW_MANAGER_FOCUS_CHANGE', true, guestInstanceId)
-  })
-  window.addEventListener('blur', () => {
-    ipcRenderer.send('ELECTRON_GUEST_VIEW_MANAGER_FOCUS_CHANGE', false, guestInstanceId)
-  })
+  // Report focus/blur events of webview to browser.
+  const { handleFocusBlur } = require('@electron/internal/renderer/web-view/web-view-init')
+  handleFocusBlur(guestInstanceId)
 }

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

@@ -0,0 +1,16 @@
+'use strict'
+
+exports.handleFocusBlur = function (guestInstanceId) {
+  const ipcRenderer = require('@electron/internal/renderer/ipc-renderer-internal')
+
+  // Note that while Chromium content APIs have observer for focus/blur, they
+  // unfortunately do not work for webview.
+
+  window.addEventListener('focus', () => {
+    ipcRenderer.send('ELECTRON_GUEST_VIEW_MANAGER_FOCUS_CHANGE', true, guestInstanceId)
+  })
+
+  window.addEventListener('blur', () => {
+    ipcRenderer.send('ELECTRON_GUEST_VIEW_MANAGER_FOCUS_CHANGE', false, guestInstanceId)
+  })
+}

lib/sandboxed_renderer/init.js

@@ -121,12 +121,10 @@ switch (window.location.protocol) {
   }
 }
 
-if (binding.guestInstanceId) {
-  process.guestInstanceId = parseInt(binding.guestInstanceId)
-}
+const guestInstanceId = binding.guestInstanceId && parseInt(binding.guestInstanceId)
 
 // Don't allow recursive `<webview>`.
-if (!process.guestInstanceId && isWebViewTagEnabled) {
+if (!guestInstanceId && isWebViewTagEnabled) {
   const webViewImpl = require('@electron/internal/renderer/web-view/web-view-impl')
   const { setupWebView } = require('@electron/internal/renderer/web-view/web-view-element')
   setupWebView(v8Util, webViewImpl)
@@ -180,3 +178,9 @@ try {
 
 // Warn about security issues
 require('@electron/internal/renderer/security-warnings')()
+
+if (guestInstanceId) {
+  // Report focus/blur events of webview to browser.
+  const { handleFocusBlur } = require('@electron/internal/renderer/web-view/web-view-init')
+  handleFocusBlur(guestInstanceId)
+}

spec/webview-spec.js

@@ -1349,47 +1349,56 @@ describe('<webview> tag', function () {
       if (div != null) div.remove()
     })
 
-    it('emits resize events', async () => {
-      const firstResizeSignal = waitForEvent(webview, 'resize')
-      const domReadySignal = waitForEvent(webview, 'dom-ready')
+    const generateSpecs = (description, sandbox) => {
+      describe(description, () => {
+        it('emits resize events', async () => {
+          const firstResizeSignal = waitForEvent(webview, 'resize')
+          const domReadySignal = waitForEvent(webview, 'dom-ready')
 
-      webview.src = `file://${fixtures}/pages/a.html`
-      div.appendChild(webview)
-      document.body.appendChild(div)
+          webview.src = `file://${fixtures}/pages/a.html`
+          webview.webpreferences = `sandbox=${sandbox ? 'yes' : 'no'}`
+          div.appendChild(webview)
+          document.body.appendChild(div)
 
-      const firstResizeEvent = await firstResizeSignal
-      expect(firstResizeEvent.target).to.equal(webview)
-      expect(firstResizeEvent.newWidth).to.equal(100)
-      expect(firstResizeEvent.newHeight).to.equal(10)
+          const firstResizeEvent = await firstResizeSignal
+          expect(firstResizeEvent.target).to.equal(webview)
+          expect(firstResizeEvent.newWidth).to.equal(100)
+          expect(firstResizeEvent.newHeight).to.equal(10)
 
-      await domReadySignal
+          await domReadySignal
 
-      const secondResizeSignal = waitForEvent(webview, 'resize')
+          const secondResizeSignal = waitForEvent(webview, 'resize')
 
-      const newWidth = 1234
-      const newHeight = 789
-      div.style.width = `${newWidth}px`
-      div.style.height = `${newHeight}px`
+          const newWidth = 1234
+          const newHeight = 789
+          div.style.width = `${newWidth}px`
+          div.style.height = `${newHeight}px`
 
-      const secondResizeEvent = await secondResizeSignal
-      expect(secondResizeEvent.target).to.equal(webview)
-      expect(secondResizeEvent.newWidth).to.equal(newWidth)
-      expect(secondResizeEvent.newHeight).to.equal(newHeight)
-    })
+          const secondResizeEvent = await secondResizeSignal
+          expect(secondResizeEvent.target).to.equal(webview)
+          expect(secondResizeEvent.newWidth).to.equal(newWidth)
+          expect(secondResizeEvent.newHeight).to.equal(newHeight)
+        })
 
-    it('emits focus event', async () => {
-      const domReadySignal = waitForEvent(webview, 'dom-ready')
-      webview.src = `file://${fixtures}/pages/a.html`
-      document.body.appendChild(webview)
+        it('emits focus event', async () => {
+          const domReadySignal = waitForEvent(webview, 'dom-ready')
+          webview.src = `file://${fixtures}/pages/a.html`
+          webview.webpreferences = `sandbox=${sandbox ? 'yes' : 'no'}`
+          document.body.appendChild(webview)
 
-      await domReadySignal
+          await domReadySignal
 
-      // If this test fails, check if webview.focus() still works.
-      const focusSignal = waitForEvent(webview, 'focus')
-      webview.focus()
+          // If this test fails, check if webview.focus() still works.
+          const focusSignal = waitForEvent(webview, 'focus')
+          webview.focus()
 
-      await focusSignal
-    })
+          await focusSignal
+        })
+      })
+    }
+
+    generateSpecs('without sandbox', false)
+    generateSpecs('with sandbox', true)
   })
 
   describe('zoom behavior', () => {