1 files changed, 127 insertions, 0 deletions
diff --git a/dom/base/UserActivation.cpp b/dom/base/UserActivation.cpp
new file mode 100644
index 0000000000..95dc5fc7d0
--- /dev/null
+++ b/dom/base/UserActivation.cpp
@@ -0,0 +1,127 @@
+/* -*- 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 "mozilla/dom/UserActivation.h"
+
+#include "mozilla/TextEvents.h"
+
+namespace mozilla::dom {
+
+namespace {
+
+// The current depth of user and keyboard inputs. sUserInputEventDepth
+// is the number of any user input events, page load events and mouse over
+// events.  sUserKeyboardEventDepth is the number of keyboard input events.
+// Incremented whenever we start handling a user input, decremented when we
+// have finished handling a user input. This depth is *not* reset in case
+// of nested event loops.
+static int32_t sUserInputEventDepth = 0;
+static int32_t sUserKeyboardEventDepth = 0;
+
+// Time at which we began handling user input. Reset to the epoch
+// once we have finished handling user input.
+static TimeStamp sHandlingInputStart;
+
+// Time at which we began handling the latest user input. Not reset
+// at the end of the input.
+static TimeStamp sLatestUserInputStart;
+
+}  // namespace
+
+/* static */
+bool UserActivation::IsHandlingUserInput() { return sUserInputEventDepth > 0; }
+
+/* static */
+bool UserActivation::IsHandlingKeyboardInput() {
+  return sUserKeyboardEventDepth > 0;
+}
+
+/* static */
+bool UserActivation::IsUserInteractionEvent(const WidgetEvent* aEvent) {
+  if (!aEvent->IsTrusted()) {
+    return false;
+  }
+
+  switch (aEvent->mMessage) {
+    // eKeyboardEventClass
+    case eKeyPress:
+    case eKeyDown:
+    case eKeyUp:
+      // Not all keyboard events are treated as user input, so that popups
+      // can't be opened, fullscreen mode can't be started, etc at
+      // unexpected time.
+      return aEvent->AsKeyboardEvent()->CanTreatAsUserInput();
+    // eBasicEventClass
+    // eMouseEventClass
+    case eMouseClick:
+    case eMouseDown:
+    case eMouseUp:
+    // ePointerEventClass
+    case ePointerDown:
+    case ePointerUp:
+    // eTouchEventClass
+    case eTouchStart:
+    case eTouchEnd:
+      return true;
+    default:
+      return false;
+  }
+}
+
+/* static */
+void UserActivation::StartHandlingUserInput(EventMessage aMessage) {
+  ++sUserInputEventDepth;
+  if (sUserInputEventDepth == 1) {
+    sLatestUserInputStart = sHandlingInputStart = TimeStamp::Now();
+  }
+  if (WidgetEvent::IsKeyEventMessage(aMessage)) {
+    ++sUserKeyboardEventDepth;
+  }
+}
+
+/* static */
+void UserActivation::StopHandlingUserInput(EventMessage aMessage) {
+  --sUserInputEventDepth;
+  if (sUserInputEventDepth == 0) {
+    sHandlingInputStart = TimeStamp();
+  }
+  if (WidgetEvent::IsKeyEventMessage(aMessage)) {
+    --sUserKeyboardEventDepth;
+  }
+}
+
+/* static */
+TimeStamp UserActivation::GetHandlingInputStart() {
+  return sHandlingInputStart;
+}
+
+/* static */
+TimeStamp UserActivation::LatestUserInputStart() {
+  return sLatestUserInputStart;
+}
+
+//-----------------------------------------------------------------------------
+// mozilla::dom::AutoHandlingUserInputStatePusher
+//-----------------------------------------------------------------------------
+
+AutoHandlingUserInputStatePusher::AutoHandlingUserInputStatePusher(
+    bool aIsHandlingUserInput, WidgetEvent* aEvent)
+    : mMessage(aEvent ? aEvent->mMessage : eVoidEvent),
+      mIsHandlingUserInput(aIsHandlingUserInput) {
+  if (!aIsHandlingUserInput) {
+    return;
+  }
+  UserActivation::StartHandlingUserInput(mMessage);
+}
+
+AutoHandlingUserInputStatePusher::~AutoHandlingUserInputStatePusher() {
+  if (!mIsHandlingUserInput) {
+    return;
+  }
+  UserActivation::StopHandlingUserInput(mMessage);
+}
+
+}  // namespace mozilla::dom