1 files changed, 96 insertions, 0 deletions
diff --git a/layout/generic/nsBackdropFrame.cpp b/layout/generic/nsBackdropFrame.cpp
new file mode 100644
index 000000000..687c5b2e3
--- /dev/null
+++ b/layout/generic/nsBackdropFrame.cpp
@@ -0,0 +1,96 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+// vim:cindent:ts=2:et:sw=2:
+/* 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/. */
+
+/* rendering object for CSS "::backdrop" */
+
+#include "nsBackdropFrame.h"
+
+#include "nsDisplayList.h"
+
+using namespace mozilla;
+
+NS_IMPL_FRAMEARENA_HELPERS(nsBackdropFrame)
+
+/* virtual */ nsIAtom*
+nsBackdropFrame::GetType() const
+{
+  return nsGkAtoms::backdropFrame;
+}
+
+#ifdef DEBUG_FRAME_DUMP
+nsresult
+nsBackdropFrame::GetFrameName(nsAString& aResult) const
+{
+  return MakeFrameName(NS_LITERAL_STRING("Backdrop"), aResult);
+}
+#endif
+
+/* virtual */ nsStyleContext*
+nsBackdropFrame::GetParentStyleContext(nsIFrame** aProviderFrame) const
+{
+  // Style context of backdrop pseudo-element does not inherit from
+  // any element, per the Fullscreen API spec.
+  *aProviderFrame = nullptr;
+  return nullptr;
+}
+
+/* virtual */ void
+nsBackdropFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
+                                  const nsRect& aDirtyRect,
+                                  const nsDisplayListSet& aLists)
+{
+  DO_GLOBAL_REFLOW_COUNT_DSP("nsBackdropFrame");
+  // We want this frame to always be there even if its display value is
+  // none or contents so that we can respond to style change on it. To
+  // support those values, we skip painting ourselves in those cases.
+  auto display = StyleDisplay()->mDisplay;
+  if (display == mozilla::StyleDisplay::None ||
+      display == mozilla::StyleDisplay::Contents) {
+    return;
+  }
+
+  DisplayBorderBackgroundOutline(aBuilder, aLists);
+}
+
+/* virtual */ LogicalSize
+nsBackdropFrame::ComputeAutoSize(nsRenderingContext* aRenderingContext,
+                                 WritingMode         aWM,
+                                 const LogicalSize&  aCBSize,
+                                 nscoord             aAvailableISize,
+                                 const LogicalSize&  aMargin,
+                                 const LogicalSize&  aBorder,
+                                 const LogicalSize&  aPadding,
+                                 ComputeSizeFlags    aFlags)
+{
+  // Note that this frame is a child of the viewport frame.
+  LogicalSize result(aWM, 0xdeadbeef, NS_UNCONSTRAINEDSIZE);
+  if (aFlags & ComputeSizeFlags::eShrinkWrap) {
+    result.ISize(aWM) = 0;
+  } else {
+    result.ISize(aWM) = aAvailableISize - aMargin.ISize(aWM) -
+                        aBorder.ISize(aWM) - aPadding.ISize(aWM);
+  }
+  return result;
+}
+
+/* virtual */ void
+nsBackdropFrame::Reflow(nsPresContext* aPresContext,
+                        ReflowOutput& aDesiredSize,
+                        const ReflowInput& aReflowInput,
+                        nsReflowStatus& aStatus)
+{
+  MarkInReflow();
+  DO_GLOBAL_REFLOW_COUNT("nsBackdropFrame");
+  DISPLAY_REFLOW(aPresContext, this, aReflowInput, aDesiredSize, aStatus);
+
+  // Note that this frame is a child of the viewport frame.
+  WritingMode wm = aReflowInput.GetWritingMode();
+  LogicalMargin borderPadding = aReflowInput.ComputedLogicalBorderPadding();
+  nscoord isize = aReflowInput.ComputedISize() + borderPadding.IStartEnd(wm);
+  nscoord bsize = aReflowInput.ComputedBSize() + borderPadding.BStartEnd(wm);
+  aDesiredSize.SetSize(wm, LogicalSize(wm, isize, bsize));
+  aStatus = NS_FRAME_COMPLETE;
+}