1 files changed, 442 insertions, 0 deletions
diff --git a/dom/base/PointerLockManager.cpp b/dom/base/PointerLockManager.cpp
new file mode 100644
index 0000000000..78f1d600af
--- /dev/null
+++ b/dom/base/PointerLockManager.cpp
@@ -0,0 +1,442 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 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/. */
+
+#include "PointerLockManager.h"
+
+#include "mozilla/AsyncEventDispatcher.h"
+#include "mozilla/EventStateManager.h"
+#include "mozilla/PresShell.h"
+#include "mozilla/ScopeExit.h"
+#include "mozilla/StaticPrefs_full_screen_api.h"
+#include "mozilla/dom/BindingDeclarations.h"
+#include "mozilla/dom/BrowserChild.h"
+#include "mozilla/dom/BrowserParent.h"
+#include "mozilla/dom/BrowsingContext.h"
+#include "mozilla/dom/Document.h"
+#include "mozilla/dom/Element.h"
+#include "mozilla/dom/WindowContext.h"
+#include "nsCOMPtr.h"
+#include "nsSandboxFlags.h"
+
+namespace mozilla {
+
+using mozilla::dom::BrowserChild;
+using mozilla::dom::BrowserParent;
+using mozilla::dom::BrowsingContext;
+using mozilla::dom::CallerType;
+using mozilla::dom::Document;
+using mozilla::dom::Element;
+using mozilla::dom::WindowContext;
+
+// Reference to the pointer locked element.
+static nsWeakPtr sLockedElement;
+
+// Reference to the document which requested pointer lock.
+static nsWeakPtr sLockedDoc;
+
+// Reference to the BrowserParent requested pointer lock.
+static BrowserParent* sLockedRemoteTarget = nullptr;
+
+/* static */
+bool PointerLockManager::sIsLocked = false;
+
+/* static */
+already_AddRefed<dom::Element> PointerLockManager::GetLockedElement() {
+  nsCOMPtr<Element> element = do_QueryReferent(sLockedElement);
+  return element.forget();
+}
+
+/* static */
+already_AddRefed<dom::Document> PointerLockManager::GetLockedDocument() {
+  nsCOMPtr<Document> document = do_QueryReferent(sLockedDoc);
+  return document.forget();
+}
+
+/* static */
+BrowserParent* PointerLockManager::GetLockedRemoteTarget() {
+  MOZ_ASSERT(XRE_IsParentProcess());
+  return sLockedRemoteTarget;
+}
+
+static void DispatchPointerLockChange(Document* aTarget) {
+  if (!aTarget) {
+    return;
+  }
+
+  RefPtr<AsyncEventDispatcher> asyncDispatcher =
+      new AsyncEventDispatcher(aTarget, u"pointerlockchange"_ns,
+                               CanBubble::eYes, ChromeOnlyDispatch::eNo);
+  asyncDispatcher->PostDOMEvent();
+}
+
+static void DispatchPointerLockError(Document* aTarget, const char* aMessage) {
+  if (!aTarget) {
+    return;
+  }
+
+  RefPtr<AsyncEventDispatcher> asyncDispatcher =
+      new AsyncEventDispatcher(aTarget, u"pointerlockerror"_ns, CanBubble::eYes,
+                               ChromeOnlyDispatch::eNo);
+  asyncDispatcher->PostDOMEvent();
+  nsContentUtils::ReportToConsole(nsIScriptError::warningFlag, "DOM"_ns,
+                                  aTarget, nsContentUtils::eDOM_PROPERTIES,
+                                  aMessage);
+}
+
+static const char* GetPointerLockError(Element* aElement, Element* aCurrentLock,
+                                       bool aNoFocusCheck = false) {
+  // Check if pointer lock pref is enabled
+  if (!StaticPrefs::full_screen_api_pointer_lock_enabled()) {
+    return "PointerLockDeniedDisabled";
+  }
+
+  nsCOMPtr<Document> ownerDoc = aElement->OwnerDoc();
+  if (aCurrentLock && aCurrentLock->OwnerDoc() != ownerDoc) {
+    return "PointerLockDeniedInUse";
+  }
+
+  if (!aElement->IsInComposedDoc()) {
+    return "PointerLockDeniedNotInDocument";
+  }
+
+  if (ownerDoc->GetSandboxFlags() & SANDBOXED_POINTER_LOCK) {
+    return "PointerLockDeniedSandboxed";
+  }
+
+  // Check if the element is in a document with a docshell.
+  if (!ownerDoc->GetContainer()) {
+    return "PointerLockDeniedHidden";
+  }
+  nsCOMPtr<nsPIDOMWindowOuter> ownerWindow = ownerDoc->GetWindow();
+  if (!ownerWindow) {
+    return "PointerLockDeniedHidden";
+  }
+  nsCOMPtr<nsPIDOMWindowInner> ownerInnerWindow = ownerDoc->GetInnerWindow();
+  if (!ownerInnerWindow) {
+    return "PointerLockDeniedHidden";
+  }
+  if (ownerWindow->GetCurrentInnerWindow() != ownerInnerWindow) {
+    return "PointerLockDeniedHidden";
+  }
+
+  BrowsingContext* bc = ownerDoc->GetBrowsingContext();
+  BrowsingContext* topBC = bc ? bc->Top() : nullptr;
+  WindowContext* topWC = ownerDoc->GetTopLevelWindowContext();
+  if (!topBC || !topBC->IsActive() || !topWC ||
+      topWC != topBC->GetCurrentWindowContext()) {
+    return "PointerLockDeniedHidden";
+  }
+
+  if (!aNoFocusCheck) {
+    if (!IsInActiveTab(ownerDoc)) {
+      return "PointerLockDeniedNotFocused";
+    }
+  }
+
+  return nullptr;
+}
+
+/* static */
+void PointerLockManager::RequestLock(Element* aElement,
+                                     CallerType aCallerType) {
+  NS_ASSERTION(aElement,
+               "Must pass non-null element to PointerLockManager::RequestLock");
+
+  RefPtr<Document> doc = aElement->OwnerDoc();
+  nsCOMPtr<Element> pointerLockedElement = GetLockedElement();
+  if (aElement == pointerLockedElement) {
+    DispatchPointerLockChange(doc);
+    return;
+  }
+
+  if (const char* msg = GetPointerLockError(aElement, pointerLockedElement)) {
+    DispatchPointerLockError(doc, msg);
+    return;
+  }
+
+  bool userInputOrSystemCaller =
+      doc->HasValidTransientUserGestureActivation() ||
+      aCallerType == CallerType::System;
+  nsCOMPtr<nsIRunnable> request =
+      new PointerLockRequest(aElement, userInputOrSystemCaller);
+  doc->Dispatch(TaskCategory::Other, request.forget());
+}
+
+/* static */
+void PointerLockManager::Unlock(Document* aDoc) {
+  if (!sIsLocked) {
+    return;
+  }
+
+  nsCOMPtr<Document> pointerLockedDoc = GetLockedDocument();
+  if (!pointerLockedDoc || (aDoc && aDoc != pointerLockedDoc)) {
+    return;
+  }
+  if (!SetPointerLock(nullptr, pointerLockedDoc, StyleCursorKind::Auto)) {
+    return;
+  }
+
+  nsCOMPtr<Element> pointerLockedElement = GetLockedElement();
+  ChangePointerLockedElement(nullptr, pointerLockedDoc, pointerLockedElement);
+
+  if (BrowserChild* browserChild =
+          BrowserChild::GetFrom(pointerLockedDoc->GetDocShell())) {
+    browserChild->SendReleasePointerLock();
+  }
+
+  AsyncEventDispatcher::RunDOMEventWhenSafe(
+      *pointerLockedElement, u"MozDOMPointerLock:Exited"_ns, CanBubble::eYes,
+      ChromeOnlyDispatch::eYes);
+}
+
+/* static */
+void PointerLockManager::ChangePointerLockedElement(
+    Element* aElement, Document* aDocument, Element* aPointerLockedElement) {
+  // aDocument here is not really necessary, as it is the uncomposed
+  // document of both aElement and aPointerLockedElement as far as one
+  // is not nullptr, and they wouldn't both be nullptr in any case.
+  // But since the caller of this function should have known what the
+  // document is, we just don't try to figure out what it should be.
+  MOZ_ASSERT(aDocument);
+  MOZ_ASSERT(aElement != aPointerLockedElement);
+  if (aPointerLockedElement) {
+    MOZ_ASSERT(aPointerLockedElement->GetComposedDoc() == aDocument);
+    aPointerLockedElement->ClearPointerLock();
+  }
+  if (aElement) {
+    MOZ_ASSERT(aElement->GetComposedDoc() == aDocument);
+    aElement->SetPointerLock();
+    sLockedElement = do_GetWeakReference(aElement);
+    sLockedDoc = do_GetWeakReference(aDocument);
+    NS_ASSERTION(sLockedElement && sLockedDoc,
+                 "aElement and this should support weak references!");
+  } else {
+    sLockedElement = nullptr;
+    sLockedDoc = nullptr;
+  }
+  // Retarget all events to aElement via capture or
+  // stop retargeting if aElement is nullptr.
+  PresShell::SetCapturingContent(aElement, CaptureFlags::PointerLock);
+  DispatchPointerLockChange(aDocument);
+}
+
+/* static */
+bool PointerLockManager::StartSetPointerLock(Element* aElement,
+                                             Document* aDocument) {
+  if (!SetPointerLock(aElement, aDocument, StyleCursorKind::None)) {
+    DispatchPointerLockError(aDocument, "PointerLockDeniedFailedToLock");
+    return false;
+  }
+
+  ChangePointerLockedElement(aElement, aDocument, nullptr);
+  nsContentUtils::DispatchEventOnlyToChrome(
+      aDocument, ToSupports(aElement), u"MozDOMPointerLock:Entered"_ns,
+      CanBubble::eYes, Cancelable::eNo, /* DefaultAction */ nullptr);
+
+  return true;
+}
+
+/* static */
+bool PointerLockManager::SetPointerLock(Element* aElement, Document* aDocument,
+                                        StyleCursorKind aCursorStyle) {
+  MOZ_ASSERT(!aElement || aElement->OwnerDoc() == aDocument,
+             "We should be either unlocking pointer (aElement is nullptr), "
+             "or locking pointer to an element in this document");
+#ifdef DEBUG
+  if (!aElement) {
+    nsCOMPtr<Document> pointerLockedDoc = GetLockedDocument();
+    MOZ_ASSERT(pointerLockedDoc == aDocument);
+  }
+#endif
+
+  PresShell* presShell = aDocument->GetPresShell();
+  if (!presShell) {
+    NS_WARNING("SetPointerLock(): No PresShell");
+    if (!aElement) {
+      sIsLocked = false;
+      // If we are unlocking pointer lock, but for some reason the doc
+      // has already detached from the presshell, just ask the event
+      // state manager to release the pointer.
+      EventStateManager::SetPointerLock(nullptr, nullptr);
+      return true;
+    }
+    return false;
+  }
+  nsPresContext* presContext = presShell->GetPresContext();
+  if (!presContext) {
+    NS_WARNING("SetPointerLock(): Unable to get PresContext");
+    return false;
+  }
+
+  nsCOMPtr<nsIWidget> widget;
+  nsIFrame* rootFrame = presShell->GetRootFrame();
+  if (!NS_WARN_IF(!rootFrame)) {
+    widget = rootFrame->GetNearestWidget();
+    NS_WARNING_ASSERTION(widget,
+                         "SetPointerLock(): Unable to find widget in "
+                         "presShell->GetRootFrame()->GetNearestWidget();");
+    if (aElement && !widget) {
+      return false;
+    }
+  }
+
+  sIsLocked = !!aElement;
+
+  // Hide the cursor and set pointer lock for future mouse events
+  RefPtr<EventStateManager> esm = presContext->EventStateManager();
+  esm->SetCursor(aCursorStyle, nullptr, {}, Nothing(), widget, true);
+  EventStateManager::SetPointerLock(widget, aElement);
+
+  return true;
+}
+
+/* static */
+bool PointerLockManager::IsInLockContext(BrowsingContext* aContext) {
+  if (!aContext) {
+    return false;
+  }
+
+  nsCOMPtr<Document> pointerLockedDoc = GetLockedDocument();
+  if (!pointerLockedDoc || !pointerLockedDoc->GetBrowsingContext()) {
+    return false;
+  }
+
+  BrowsingContext* lockTop = pointerLockedDoc->GetBrowsingContext()->Top();
+  BrowsingContext* top = aContext->Top();
+
+  return top == lockTop;
+}
+
+/* static */
+bool PointerLockManager::SetLockedRemoteTarget(BrowserParent* aBrowserParent) {
+  MOZ_ASSERT(XRE_IsParentProcess());
+  if (sLockedRemoteTarget) {
+    return sLockedRemoteTarget == aBrowserParent;
+  }
+
+  sLockedRemoteTarget = aBrowserParent;
+  return true;
+}
+
+/* static */
+void PointerLockManager::ReleaseLockedRemoteTarget(
+    BrowserParent* aBrowserParent) {
+  MOZ_ASSERT(XRE_IsParentProcess());
+  if (sLockedRemoteTarget == aBrowserParent) {
+    sLockedRemoteTarget = nullptr;
+  }
+}
+
+PointerLockManager::PointerLockRequest::PointerLockRequest(
+    Element* aElement, bool aUserInputOrChromeCaller)
+    : mozilla::Runnable("PointerLockRequest"),
+      mElement(do_GetWeakReference(aElement)),
+      mDocument(do_GetWeakReference(aElement->OwnerDoc())),
+      mUserInputOrChromeCaller(aUserInputOrChromeCaller) {}
+
+NS_IMETHODIMP
+PointerLockManager::PointerLockRequest::Run() {
+  nsCOMPtr<Element> element = do_QueryReferent(mElement);
+  nsCOMPtr<Document> document = do_QueryReferent(mDocument);
+
+  const char* error = nullptr;
+  if (!element || !document || !element->GetComposedDoc()) {
+    error = "PointerLockDeniedNotInDocument";
+  } else if (element->GetComposedDoc() != document) {
+    error = "PointerLockDeniedMovedDocument";
+  }
+  if (!error) {
+    nsCOMPtr<Element> pointerLockedElement = do_QueryReferent(sLockedElement);
+    if (element == pointerLockedElement) {
+      DispatchPointerLockChange(document);
+      return NS_OK;
+    }
+    // Note, we must bypass focus change, so pass true as the last parameter!
+    error = GetPointerLockError(element, pointerLockedElement, true);
+    // Another element in the same document is requesting pointer lock,
+    // just grant it without user input check.
+    if (!error && pointerLockedElement) {
+      ChangePointerLockedElement(element, document, pointerLockedElement);
+      return NS_OK;
+    }
+  }
+  // If it is neither user input initiated, nor requested in fullscreen,
+  // it should be rejected.
+  if (!error && !mUserInputOrChromeCaller && !document->Fullscreen()) {
+    error = "PointerLockDeniedNotInputDriven";
+  }
+
+  if (error) {
+    DispatchPointerLockError(document, error);
+    return NS_OK;
+  }
+
+  if (BrowserChild* browserChild =
+          BrowserChild::GetFrom(document->GetDocShell())) {
+    nsWeakPtr e = do_GetWeakReference(element);
+    nsWeakPtr doc = do_GetWeakReference(element->OwnerDoc());
+    nsWeakPtr bc = do_GetWeakReference(browserChild);
+    browserChild->SendRequestPointerLock(
+        [e, doc, bc](const nsCString& aError) {
+          nsCOMPtr<Document> document = do_QueryReferent(doc);
+          if (!aError.IsEmpty()) {
+            DispatchPointerLockError(document, aError.get());
+            return;
+          }
+
+          const char* error = nullptr;
+          auto autoCleanup = MakeScopeExit([&] {
+            if (error) {
+              DispatchPointerLockError(document, error);
+              // If we are failed to set pointer lock, notify parent to stop
+              // redirect mouse event to this process.
+              if (nsCOMPtr<nsIBrowserChild> browserChild =
+                      do_QueryReferent(bc)) {
+                static_cast<BrowserChild*>(browserChild.get())
+                    ->SendReleasePointerLock();
+              }
+            }
+          });
+
+          nsCOMPtr<Element> element = do_QueryReferent(e);
+          if (!element || !document || !element->GetComposedDoc()) {
+            error = "PointerLockDeniedNotInDocument";
+            return;
+          }
+
+          if (element->GetComposedDoc() != document) {
+            error = "PointerLockDeniedMovedDocument";
+            return;
+          }
+
+          nsCOMPtr<Element> pointerLockedElement = GetLockedElement();
+          error = GetPointerLockError(element, pointerLockedElement, true);
+          if (error) {
+            return;
+          }
+
+          if (!StartSetPointerLock(element, document)) {
+            error = "PointerLockDeniedFailedToLock";
+            return;
+          }
+        },
+        [doc](mozilla::ipc::ResponseRejectReason) {
+          // IPC layer error
+          nsCOMPtr<Document> document = do_QueryReferent(doc);
+          if (!document) {
+            return;
+          }
+
+          DispatchPointerLockError(document, "PointerLockDeniedFailedToLock");
+        });
+  } else {
+    StartSetPointerLock(element, document);
+  }
+
+  return NS_OK;
+}
+
+}  // namespace mozilla