1 files changed, 43 insertions, 0 deletions
diff --git a/widget/headless/HeadlessScreenHelper.cpp b/widget/headless/HeadlessScreenHelper.cpp
new file mode 100644
index 0000000000..4d8dbfa0d1
--- /dev/null
+++ b/widget/headless/HeadlessScreenHelper.cpp
@@ -0,0 +1,43 @@
+/* -*- 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 "HeadlessScreenHelper.h"
+
+#include "prenv.h"
+#include "mozilla/dom/DOMTypes.h"
+#include "mozilla/RefPtr.h"
+#include "nsTArray.h"
+
+namespace mozilla {
+namespace widget {
+
+/* static */
+LayoutDeviceIntRect HeadlessScreenHelper::GetScreenRect() {
+  char* ev = PR_GetEnv("MOZ_HEADLESS_WIDTH");
+  int width = 1366;
+  if (ev) {
+    width = atoi(ev);
+  }
+  ev = PR_GetEnv("MOZ_HEADLESS_HEIGHT");
+  int height = 768;
+  if (ev) {
+    height = atoi(ev);
+  }
+  return LayoutDeviceIntRect(0, 0, width, height);
+}
+
+HeadlessScreenHelper::HeadlessScreenHelper() {
+  AutoTArray<RefPtr<Screen>, 1> screenList;
+  LayoutDeviceIntRect rect = GetScreenRect();
+  auto ret = MakeRefPtr<Screen>(
+      rect, rect, 24, 24, 0, DesktopToLayoutDeviceScale(),
+      CSSToLayoutDeviceScale(), 96.0f, Screen::IsPseudoDisplay::No);
+  screenList.AppendElement(ret.forget());
+  ScreenManager::Refresh(std::move(screenList));
+}
+
+}  // namespace widget
+}  // namespace mozilla