1 files changed, 101 insertions, 0 deletions
diff --git a/Source/WebCore/style/RenderTreePosition.h b/Source/WebCore/style/RenderTreePosition.h
new file mode 100644
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+++ b/Source/WebCore/style/RenderTreePosition.h
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+/*
+ * Copyright (C) 2015 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include "RenderElement.h"
+#include "RenderNamedFlowThread.h"
+#include "RenderText.h"
+#include "RenderView.h"
+
+namespace WebCore {
+
+class RenderTreePosition {
+public:
+    explicit RenderTreePosition(RenderView& root)
+        : m_parent(root)
+        , m_hasValidNextSibling(true)
+    {
+    }
+    
+    explicit RenderTreePosition(RenderElement& parent)
+        : m_parent(parent)
+    {
+    }
+    
+#if ENABLE(CSS_REGIONS)
+    static RenderTreePosition insertionPositionForFlowThread(Element* insertionParent, Element& child, const RenderStyle&);
+#endif
+
+    RenderElement& parent() const { return m_parent; }
+    void insert(RenderObject&);
+    bool canInsert(RenderElement&) const;
+    bool canInsert(RenderText&) const;
+
+    void computeNextSibling(const Node&);
+    void invalidateNextSibling() { m_hasValidNextSibling = false; }
+    void invalidateNextSibling(const RenderObject&);
+
+    RenderObject* previousSiblingRenderer(const Text&) const;
+    RenderObject* nextSiblingRenderer(const Node&) const;
+    static bool isRendererReparented(const RenderObject&);
+
+private:
+#if ENABLE(CSS_REGIONS)
+    RenderTreePosition(RenderFlowThread& parent, RenderObject* nextSibling)
+        : m_parent(parent)
+        , m_nextSibling(nextSibling)
+        , m_hasValidNextSibling(true)
+    {
+    }
+#endif
+
+    RenderElement& m_parent;
+    RenderObject* m_nextSibling { nullptr };
+    bool m_hasValidNextSibling { false };
+#if !ASSERT_DISABLED
+    unsigned m_assertionLimitCounter { 0 };
+#endif
+};
+
+inline bool RenderTreePosition::canInsert(RenderElement& renderer) const
+{
+    ASSERT(!renderer.parent());
+    return m_parent.isChildAllowed(renderer, renderer.style());
+}
+
+inline bool RenderTreePosition::canInsert(RenderText& renderer) const
+{
+    ASSERT(!renderer.parent());
+    return m_parent.isChildAllowed(renderer, m_parent.style());
+}
+
+inline void RenderTreePosition::insert(RenderObject& renderer)
+{
+    ASSERT(m_hasValidNextSibling);
+    m_parent.addChild(&renderer, m_nextSibling);
+}
+
+} // namespace WebCore