Unify GeometryPropertyTreeState and PropertyTreeState

third_party/WebKit/Source/platform/graphics/paint/PropertyTreeState.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef PropertyTreeState_h
+#define PropertyTreeState_h
+
+#include "platform/graphics/paint/ClipPaintPropertyNode.h"
+#include "platform/graphics/paint/EffectPaintPropertyNode.h"
+#include "platform/graphics/paint/ScrollPaintPropertyNode.h"
+#include "platform/graphics/paint/TransformPaintPropertyNode.h"
+#include "wtf/HashFunctions.h"
+#include "wtf/HashTraits.h"
+
+namespace blink {
+
+// A complete set of paint properties including those that are inherited from other objects.
+// RefPtrs are used to guard against use-after-free bugs and DCHECKs ensure PropertyTreeState
+// never retains the last reference to a property tree node.
+class PropertyTreeState {
+ public:
+  PropertyTreeState(const TransformPaintPropertyNode* transform,
+                    const ClipPaintPropertyNode* clip,
+                    const EffectPaintPropertyNode* effect,
+                    const ScrollPaintPropertyNode* scroll)
+      : m_transform(transform),
+        m_clip(clip),
+        m_effect(effect),
+        m_scroll(scroll) {
+    DCHECK(!m_transform->hasOneRef() && !m_clip->hasOneRef() &&
+           !m_effect->hasOneRef() && !m_scroll->hasOneRef());
+  }
+
+  const TransformPaintPropertyNode* transform() const {
+    DCHECK(!m_transform->hasOneRef());
+    return m_transform.get();
+  }
+  void setTransform(const TransformPaintPropertyNode* node) {
+    m_transform = node;
+    DCHECK(!node->hasOneRef());
+  }
+
+  const ClipPaintPropertyNode* clip() const {
+    DCHECK(!m_clip->hasOneRef());
+    return m_clip.get();
+  }
+  void setClip(const ClipPaintPropertyNode* node) {
+    m_clip = node;
+    DCHECK(!node->hasOneRef());
+  }
+
+  const EffectPaintPropertyNode* effect() const {
+    DCHECK(!m_effect->hasOneRef());
+    return m_effect.get();
+  }
+  void setEffect(const EffectPaintPropertyNode* node) {
+    m_effect = node;
+    DCHECK(!node->hasOneRef());
+  }
+
+  const ScrollPaintPropertyNode* scroll() const {
+    DCHECK(!m_scroll->hasOneRef());
+    return m_scroll.get();
+  }
+  void setScroll(const ScrollPaintPropertyNode* node) {
+    m_scroll = node;
+    DCHECK(!node->hasOneRef());
+  }
+
+ private:
+  RefPtr<const TransformPaintPropertyNode> m_transform;
+  RefPtr<const ClipPaintPropertyNode> m_clip;
+  RefPtr<const EffectPaintPropertyNode> m_effect;
+  RefPtr<const ScrollPaintPropertyNode> m_scroll;
+};
+}  // namespace blink
+
+#endif  // PropertyTreeState_h