1 files changed, 318 insertions, 0 deletions
diff --git a/browser/actors/DOMFullscreenParent.sys.mjs b/browser/actors/DOMFullscreenParent.sys.mjs
new file mode 100644
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+++ b/browser/actors/DOMFullscreenParent.sys.mjs
@@ -0,0 +1,318 @@
+/* vim: set ts=2 sw=2 sts=2 et tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+export class DOMFullscreenParent extends JSWindowActorParent {
+  // These properties get set by browser-fullScreenAndPointerLock.js.
+  // TODO: Bug 1743703 - Consider moving the messaging component of
+  //       browser-fullScreenAndPointerLock.js into the actor
+  waitingForChildEnterFullscreen = false;
+  waitingForChildExitFullscreen = false;
+  // Cache the next message recipient actor and in-process browsing context that
+  // is computed by _getNextMsgRecipientActor() of
+  // browser-fullScreenAndPointerLock.js, this is used to ensure the fullscreen
+  // cleanup messages goes the same route as fullscreen request, especially for
+  // the cleanup that happens after actor is destroyed.
+  // TODO: Bug 1743703 - Consider moving the messaging component of
+  //       browser-fullScreenAndPointerLock.js into the actor
+  nextMsgRecipient = null;
+
+  updateFullscreenWindowReference(aWindow) {
+    if (aWindow.document.documentElement.hasAttribute("inDOMFullscreen")) {
+      this._fullscreenWindow = aWindow;
+    } else {
+      delete this._fullscreenWindow;
+    }
+  }
+
+  cleanupDomFullscreen(aWindow) {
+    if (!aWindow.FullScreen) {
+      return;
+    }
+
+    // If we don't need to wait for child reply, i.e. cleanupDomFullscreen
+    // doesn't message to child, and we've exit the fullscreen, there won't be
+    // DOMFullscreen:Painted message from child and it is possible that no more
+    // paint would be triggered, so just notify fullscreen-painted observer.
+    if (
+      !aWindow.FullScreen.cleanupDomFullscreen(this) &&
+      !aWindow.document.fullscreen
+    ) {
+      Services.obs.notifyObservers(aWindow, "fullscreen-painted");
+    }
+  }
+
+  /**
+   * Clean up fullscreen state and resume chrome UI if window is in fullscreen
+   * and this actor is the one where the original fullscreen enter or
+   * exit request comes.
+   */
+  _cleanupFullscreenStateAndResumeChromeUI(aWindow) {
+    this.cleanupDomFullscreen(aWindow);
+    if (this.requestOrigin == this && aWindow.document.fullscreen) {
+      aWindow.windowUtils.remoteFrameFullscreenReverted();
+    }
+  }
+
+  didDestroy() {
+    this._didDestroy = true;
+
+    let window = this._fullscreenWindow;
+    if (!window) {
+      let topBrowsingContext = this.browsingContext.top;
+      let browser = topBrowsingContext.embedderElement;
+      if (!browser) {
+        return;
+      }
+
+      if (
+        this.waitingForChildExitFullscreen ||
+        this.waitingForChildEnterFullscreen
+      ) {
+        this.waitingForChildExitFullscreen = false;
+        this.waitingForChildEnterFullscreen = false;
+        // We were destroyed while waiting for our DOMFullscreenChild to exit
+        // or enter fullscreen, run cleanup steps anyway.
+        this._cleanupFullscreenStateAndResumeChromeUI(browser.ownerGlobal);
+      }
+
+      if (this != this.requestOrigin) {
+        // The current fullscreen requester should handle the fullsceen event
+        // if any.
+        this.removeListeners(browser.ownerGlobal);
+      }
+      return;
+    }
+
+    if (this.waitingForChildEnterFullscreen) {
+      this.waitingForChildEnterFullscreen = false;
+      if (window.document.fullscreen) {
+        // We were destroyed while waiting for our DOMFullscreenChild
+        // to transition to fullscreen so we abort the entire
+        // fullscreen transition to prevent getting stuck in a
+        // partial fullscreen state. We need to go through the
+        // document since window.Fullscreen could be undefined
+        // at this point.
+        //
+        // This could reject if we're not currently in fullscreen
+        // so just ignore rejection.
+        window.document.exitFullscreen().catch(() => {});
+        return;
+      }
+      this.cleanupDomFullscreen(window);
+    }
+
+    // Need to resume Chrome UI if the window is still in fullscreen UI
+    // to avoid the window stays in fullscreen problem. (See Bug 1620341)
+    if (window.document.documentElement.hasAttribute("inDOMFullscreen")) {
+      this.cleanupDomFullscreen(window);
+      if (window.windowUtils) {
+        window.windowUtils.remoteFrameFullscreenReverted();
+      }
+    } else if (this.waitingForChildExitFullscreen) {
+      this.waitingForChildExitFullscreen = false;
+      // We were destroyed while waiting for our DOMFullscreenChild to exit
+      // run cleanup steps anyway.
+      this._cleanupFullscreenStateAndResumeChromeUI(window);
+    }
+    this.updateFullscreenWindowReference(window);
+  }
+
+  receiveMessage(aMessage) {
+    let topBrowsingContext = this.browsingContext.top;
+    let browser = topBrowsingContext.embedderElement;
+
+    if (!browser) {
+      // No need to go further when the browser is not accessible anymore
+      // (which can happen when the tab is closed for instance),
+      return;
+    }
+
+    let window = browser.ownerGlobal;
+    switch (aMessage.name) {
+      case "DOMFullscreen:Request": {
+        this.manager.fullscreen = true;
+        this.waitingForChildExitFullscreen = false;
+        this.requestOrigin = this;
+        this.addListeners(window);
+        window.windowUtils.remoteFrameFullscreenChanged(browser);
+        break;
+      }
+      case "DOMFullscreen:NewOrigin": {
+        // Don't show the warning if we've already exited fullscreen.
+        if (window.document.fullscreen) {
+          window.PointerlockFsWarning.showFullScreen(
+            aMessage.data.originNoSuffix
+          );
+        }
+        this.updateFullscreenWindowReference(window);
+        break;
+      }
+      case "DOMFullscreen:Entered": {
+        this.manager.fullscreen = true;
+        this.nextMsgRecipient = null;
+        this.waitingForChildEnterFullscreen = false;
+        window.FullScreen.enterDomFullscreen(browser, this);
+        this.updateFullscreenWindowReference(window);
+        break;
+      }
+      case "DOMFullscreen:Exit": {
+        this.manager.fullscreen = false;
+        this.waitingForChildEnterFullscreen = false;
+        window.windowUtils.remoteFrameFullscreenReverted();
+        break;
+      }
+      case "DOMFullscreen:Exited": {
+        this.manager.fullscreen = false;
+        this.waitingForChildExitFullscreen = false;
+        this.cleanupDomFullscreen(window);
+        this.updateFullscreenWindowReference(window);
+        break;
+      }
+      case "DOMFullscreen:Painted": {
+        this.waitingForChildExitFullscreen = false;
+        Services.obs.notifyObservers(window, "fullscreen-painted");
+        this.sendAsyncMessage("DOMFullscreen:Painted", {});
+        TelemetryStopwatch.finish("FULLSCREEN_CHANGE_MS");
+        break;
+      }
+    }
+  }
+
+  handleEvent(aEvent) {
+    let window = aEvent.currentTarget.ownerGlobal;
+    // We can not get the corresponding browsing context from actor if the actor
+    // has already destroyed, so use event target to get browsing context
+    // instead.
+    let requestOrigin = window.browsingContext.fullscreenRequestOrigin?.get();
+    if (this != requestOrigin) {
+      // The current fullscreen requester should handle the fullsceen event,
+      // ignore them if we are not the current requester.
+      this.removeListeners(window);
+      return;
+    }
+
+    switch (aEvent.type) {
+      case "MozDOMFullscreen:Entered": {
+        // The event target is the element which requested the DOM
+        // fullscreen. If we were entering DOM fullscreen for a remote
+        // browser, the target would be the browser which was the parameter of
+        // `remoteFrameFullscreenChanged` call. If the fullscreen
+        // request was initiated from an in-process browser, we need
+        // to get its corresponding browser here.
+        let browser;
+        if (aEvent.target.ownerGlobal == window) {
+          browser = aEvent.target;
+        } else {
+          browser = aEvent.target.ownerGlobal.docShell.chromeEventHandler;
+        }
+
+        // Addon installation should be cancelled when entering fullscreen for security and usability reasons.
+        // Installation prompts in fullscreen can trick the user into installing unwanted addons.
+        // In fullscreen the notification box does not have a clear visual association with its parent anymore.
+        if (window.gXPInstallObserver) {
+          window.gXPInstallObserver.removeAllNotifications(browser);
+        }
+
+        TelemetryStopwatch.start("FULLSCREEN_CHANGE_MS");
+        window.FullScreen.enterDomFullscreen(browser, this);
+        this.updateFullscreenWindowReference(window);
+
+        if (!this.hasBeenDestroyed() && this.requestOrigin) {
+          window.PointerlockFsWarning.showFullScreen(
+            this.requestOrigin.manager.documentPrincipal.originNoSuffix
+          );
+        }
+        break;
+      }
+      case "MozDOMFullscreen:Exited": {
+        TelemetryStopwatch.start("FULLSCREEN_CHANGE_MS");
+
+        // Make sure that the actor has not been destroyed before
+        // accessing its browsing context. Otherwise, a error may
+        // occur and hence cleanupDomFullscreen not executed, resulting
+        // in the browser window being in an unstable state.
+        // (Bug 1590138).
+        if (!this.hasBeenDestroyed() && !this.requestOrigin) {
+          this.requestOrigin = this;
+        }
+        this.cleanupDomFullscreen(window);
+        this.updateFullscreenWindowReference(window);
+
+        // If the document is supposed to be in fullscreen, keep the listener to wait for
+        // further events.
+        if (!this.manager.fullscreen) {
+          this.removeListeners(window);
+        }
+        break;
+      }
+    }
+  }
+
+  addListeners(aWindow) {
+    aWindow.addEventListener(
+      "MozDOMFullscreen:Entered",
+      this,
+      /* useCapture */ true,
+      /* wantsUntrusted */
+      false
+    );
+    aWindow.addEventListener(
+      "MozDOMFullscreen:Exited",
+      this,
+      /* useCapture */ true,
+      /* wantsUntrusted */ false
+    );
+  }
+
+  removeListeners(aWindow) {
+    aWindow.removeEventListener("MozDOMFullscreen:Entered", this, true);
+    aWindow.removeEventListener("MozDOMFullscreen:Exited", this, true);
+  }
+
+  /**
+   * Get the actor where the original fullscreen
+   * enter or exit request comes from.
+   */
+  get requestOrigin() {
+    let chromeBC = this.browsingContext.topChromeWindow?.browsingContext;
+    let requestOrigin = chromeBC?.fullscreenRequestOrigin;
+    return requestOrigin && requestOrigin.get();
+  }
+
+  /**
+   * Store the actor where the original fullscreen
+   * enter or exit request comes from in the top level
+   * browsing context.
+   */
+  set requestOrigin(aActor) {
+    let chromeBC = this.browsingContext.topChromeWindow?.browsingContext;
+    if (!chromeBC) {
+      console.error("not able to get browsingContext for chrome window.");
+      return;
+    }
+
+    if (aActor) {
+      chromeBC.fullscreenRequestOrigin = Cu.getWeakReference(aActor);
+    } else {
+      delete chromeBC.fullscreenRequestOrigin;
+    }
+  }
+
+  hasBeenDestroyed() {
+    if (this._didDestroy) {
+      return true;
+    }
+
+    // The 'didDestroy' callback is not always getting called.
+    // So we can't rely on it here. Instead, we will try to access
+    // the browsing context to judge wether the actor has
+    // been destroyed or not.
+    try {
+      return !this.browsingContext;
+    } catch {
+      return true;
+    }
+  }
+}