1 files changed, 52 insertions, 0 deletions
diff --git a/layout/base/nsStyleChangeList.cpp b/layout/base/nsStyleChangeList.cpp
new file mode 100644
index 000000000..d47ee8d63
--- /dev/null
+++ b/layout/base/nsStyleChangeList.cpp
@@ -0,0 +1,52 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 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/. */
+
+/*
+ * a list of the recomputation that needs to be done in response to a
+ * style change
+ */
+
+#include "nsStyleChangeList.h"
+#include "nsIContent.h"
+#include "nsIFrame.h"
+#include "nsFrameManager.h"
+
+void
+nsStyleChangeList::AppendChange(nsIFrame* aFrame, nsIContent* aContent, nsChangeHint aHint)
+{
+  MOZ_ASSERT(aFrame || (aHint & nsChangeHint_ReconstructFrame),
+             "must have frame");
+  MOZ_ASSERT(aContent || !(aHint & nsChangeHint_ReconstructFrame),
+             "must have content");
+  // XXXbz we should make this take Element instead of nsIContent
+  MOZ_ASSERT(!aContent || aContent->IsElement() ||
+             // display:contents elements posts the changes for their children:
+             (aFrame && aContent->GetParent() &&
+             aFrame->PresContext()->FrameManager()->
+               GetDisplayContentsStyleFor(aContent->GetParent())),
+             "Shouldn't be trying to restyle non-elements directly, "
+             "except if it's a display:contents child");
+  MOZ_ASSERT(!(aHint & nsChangeHint_AllReflowHints) ||
+             (aHint & nsChangeHint_NeedReflow),
+             "Reflow hint bits set without actually asking for a reflow");
+
+  // Filter out all other changes for same content
+  if (!IsEmpty() && (aHint & nsChangeHint_ReconstructFrame)) {
+    if (aContent) {
+      // NOTE: This is captured by reference to please static analysis.
+      // Capturing it by value as a pointer should be fine in this case.
+      RemoveElementsBy([&](const nsStyleChangeData& aData) {
+        return aData.mContent == aContent;
+      });
+    }
+  }
+
+  if (!IsEmpty() && aFrame && aFrame == LastElement().mFrame) {
+    LastElement().mHint |= aHint;
+    return;
+  }
+
+  AppendElement(nsStyleChangeData { aFrame, aContent, aHint });
+}