1/*
2 * Copyright (C) 2012 Apple Inc.  All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26
27#ifndef RenderRegionSet_h
28#define RenderRegionSet_h
29
30#include "RenderRegion.h"
31#include "RenderBoxRegionInfo.h"
32
33namespace WebCore {
34
35class RenderFlowThread;
36
37// RenderRegionSet represents a set of regions that all have the same width and height. It is a "composite region box" that
38// can be used to represent a single run of contiguous regions.
39//
40// By combining runs of same-size columns or pages into a single object, we significantly reduce the number of unique RenderObjects
41// required to represent those objects.
42//
43// This class is abstract and is only intended for use by renderers that generate anonymous runs of identical regions, i.e.,
44// columns and printing. RenderMultiColumnSet and RenderPageSet represent runs of columns and pages respectively.
45//
46// FIXME: For now we derive from RenderRegion, but this may change at some point.
47
48class RenderRegionSet : public RenderRegion {
49public:
50    void expandToEncompassFlowThreadContentsIfNeeded();
51
52protected:
53    RenderRegionSet(Document&, PassRef<RenderStyle>, RenderFlowThread&);
54
55private:
56    virtual void installFlowThread() override final;
57
58    virtual const char* renderName() const = 0;
59
60    virtual bool isRenderRegionSet() const override final { return true; }
61};
62
63} // namespace WebCore
64
65#endif // RenderRegionSet_h
66
67