1 files changed, 28 insertions, 0 deletions
diff --git a/dom/base/nsViewportInfo.cpp b/dom/base/nsViewportInfo.cpp
new file mode 100644
index 0000000000..5a69faa92d
--- /dev/null
+++ b/dom/base/nsViewportInfo.cpp
@@ -0,0 +1,28 @@
+/* -*- 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 "nsViewportInfo.h"
+#include "mozilla/Assertions.h"
+#include <algorithm>
+
+using namespace mozilla;
+
+void
+nsViewportInfo::ConstrainViewportValues()
+{
+  // Constrain the min/max zoom as specified at:
+  // dev.w3.org/csswg/css-device-adapt section 6.2
+  mMaxZoom = std::max(mMinZoom, mMaxZoom);
+
+  if (mDefaultZoom > mMaxZoom) {
+    mDefaultZoomValid = false;
+    mDefaultZoom = mMaxZoom;
+  }
+  if (mDefaultZoom < mMinZoom) {
+    mDefaultZoomValid = false;
+    mDefaultZoom = mMinZoom;
+  }
+}