1/*
2 * Copyright (C) 2012 Google 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 *
8 * 1.  Redistributions of source code must retain the above copyright
9 *     notice, this list of conditions and the following disclaimer.
10 * 2.  Redistributions in binary form must reproduce the above copyright
11 *     notice, this list of conditions and the following disclaimer in the
12 *     documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
15 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
16 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
17 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
18 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
19 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
20 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
21 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#ifndef TextAutosizer_h
27#define TextAutosizer_h
28
29#if ENABLE(TEXT_AUTOSIZING)
30
31#include "HTMLNames.h"
32#include "WritingMode.h"
33#include <wtf/Noncopyable.h>
34#include <wtf/PassOwnPtr.h>
35
36namespace WebCore {
37
38class Document;
39class RenderBlock;
40class RenderObject;
41class RenderText;
42struct TextAutosizingWindowInfo;
43struct TextAutosizingClusterInfo;
44
45class TextAutosizer {
46    WTF_MAKE_NONCOPYABLE(TextAutosizer);
47
48public:
49    static PassOwnPtr<TextAutosizer> create(Document* document) { return adoptPtr(new TextAutosizer(document)); }
50
51    virtual ~TextAutosizer();
52
53    bool processSubtree(RenderObject* layoutRoot);
54    void recalculateMultipliers();
55
56    static float computeAutosizedFontSize(float specifiedSize, float multiplier);
57
58private:
59    enum TraversalDirection {
60        FirstToLast,
61        LastToFirst
62    };
63
64    explicit TextAutosizer(Document*);
65
66    float clusterMultiplier(WritingMode, const TextAutosizingWindowInfo&, float textWidth) const;
67
68    void processClusterInternal(TextAutosizingClusterInfo&, RenderBlock* container, RenderObject* subtreeRoot, const TextAutosizingWindowInfo&, float multiplier);
69    void processCluster(TextAutosizingClusterInfo&, RenderBlock* container, RenderObject* subtreeRoot, const TextAutosizingWindowInfo&);
70    void processCompositeCluster(Vector<TextAutosizingClusterInfo>&, const TextAutosizingWindowInfo&);
71    void processContainer(float multiplier, RenderBlock* container, TextAutosizingClusterInfo&, RenderObject* subtreeRoot, const TextAutosizingWindowInfo&);
72
73    void setMultiplier(RenderObject*, float);
74
75    static bool isAutosizingContainer(const RenderObject*);
76    static bool isNarrowDescendant(const RenderBlock*, TextAutosizingClusterInfo& parentClusterInfo);
77    static bool isWiderDescendant(const RenderBlock*, const TextAutosizingClusterInfo& parentClusterInfo);
78    static bool isIndependentDescendant(const RenderBlock*);
79    static bool isAutosizingCluster(const RenderBlock*, TextAutosizingClusterInfo& parentClusterInfo);
80
81    static bool containerShouldBeAutosized(const RenderBlock* container);
82    static bool containerContainsOneOfTags(const RenderBlock* cluster, const Vector<QualifiedName>& tags);
83    static bool containerIsRowOfLinks(const RenderObject* container);
84    static bool contentHeightIsConstrained(const RenderBlock* container);
85    static bool clusterShouldBeAutosized(TextAutosizingClusterInfo&, float blockWidth);
86    static bool compositeClusterShouldBeAutosized(Vector<TextAutosizingClusterInfo>&, float blockWidth);
87    static void measureDescendantTextWidth(const RenderBlock* container, TextAutosizingClusterInfo&, float minTextWidth, float& textWidth);
88
89    // Use to traverse the tree of descendants, excluding descendants of containers (but returning the containers themselves).
90    static RenderObject* nextInPreOrderSkippingDescendantsOfContainers(const RenderObject*, const RenderObject* stayWithin);
91
92    static const RenderBlock* findDeepestBlockContainingAllText(const RenderBlock* cluster);
93
94    // Depending on the traversal direction specified, finds the first or the last leaf text node child that doesn't
95    // belong to any cluster.
96    static const RenderObject* findFirstTextLeafNotInCluster(const RenderObject*, size_t& depth, TraversalDirection);
97
98    // Returns groups of narrow descendants of a given autosizing cluster. The groups are combined
99    // by the difference between the width of the descendant and the width of the parent cluster's
100    // |blockContainingAllText|.
101    static void getNarrowDescendantsGroupedByWidth(const TextAutosizingClusterInfo& parentClusterInfo, Vector<Vector<TextAutosizingClusterInfo> >&);
102
103    Document* m_document;
104};
105
106} // namespace WebCore
107
108#endif // ENABLE(TEXT_AUTOSIZING)
109
110#endif // TextAutosizer_h
111