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diff --git a/core/SkBBoxHierarchy.h b/core/SkBBoxHierarchy.h
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+
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkBBoxHierarchy_DEFINED
+#define SkBBoxHierarchy_DEFINED
+
+#include "SkRect.h"
+#include "SkTDArray.h"
+#include "SkRefCnt.h"
+
+/**
+ * Interface for a client class that implements utility methods needed
+ * by SkBBoxHierarchy that require intrinsic knowledge of the data
+ * object type that is stored in the bounding box hierarchy.
+ */
+class SkBBoxHierarchyClient {
+public:
+    virtual ~SkBBoxHierarchyClient() {}
+
+    /**
+     * Implements a rewind stop condition used by rewindInserts
+     * Must returns true if 'data' points to an object that should be re-wound
+     * by rewinfInserts.
+     */
+    virtual bool shouldRewind(void* data) = 0;
+};
+
+/**
+ * Interface for a spatial data structure that associates user data pointers with axis-aligned
+ * bounding boxes, and allows efficient retrieval of intersections with query rectangles.
+ */
+class SkBBoxHierarchy : public SkRefCnt {
+public:
+    SK_DECLARE_INST_COUNT(SkBBoxHierarchy)
+
+    SkBBoxHierarchy() : fClient(NULL) {}
+
+    /**
+     * Insert a data pointer and corresponding bounding box
+     * @param data The data pointer, may be NULL
+     * @param bounds The bounding box, should not be empty
+     * @param defer Whether or not it is acceptable to delay insertion of this element (building up
+     *        an entire spatial data structure at once is often faster and produces better
+     *        structures than repeated inserts) until flushDeferredInserts is called or the first
+     *        search.
+     */
+    virtual void insert(void* data, const SkIRect& bounds, bool defer = false) = 0;
+
+    /**
+     * If any insertions have been deferred, this forces them to be inserted
+     */
+    virtual void flushDeferredInserts() = 0;
+
+    /**
+     * Populate 'results' with data pointers corresponding to bounding boxes that intersect 'query'
+     */
+    virtual void search(const SkIRect& query, SkTDArray<void*>* results) = 0;
+
+    virtual void clear() = 0;
+
+    /**
+     * Gets the number of insertions
+     */
+    virtual int getCount() const = 0;
+
+    /**
+     * Rewinds all the most recently inserted data elements until an element
+     * is encountered for which client->shouldRewind(data) returns false. May
+     * not rewind elements that were inserted prior to the last call to
+     * flushDeferredInserts.
+     */
+    virtual void rewindInserts() = 0;
+
+    void setClient(SkBBoxHierarchyClient* client) { fClient = client; }
+
+protected:
+    SkBBoxHierarchyClient* fClient;
+
+private:
+    typedef SkRefCnt INHERITED;
+};
+
+#endif