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#include "HTMLNames.h"
30#include "core/platform/text/WritingMode.h"
31#include "wtf/Noncopyable.h"
32#include "wtf/PassOwnPtr.h"
33
34namespace WebCore {
35
36class Document;
37class RenderBlock;
38class RenderObject;
39class RenderText;
40struct TextAutosizingWindowInfo;
41struct TextAutosizingClusterInfo;
42
43class TextAutosizer {
44    WTF_MAKE_NONCOPYABLE(TextAutosizer);
45
46public:
47    static PassOwnPtr<TextAutosizer> create(Document* document) { return adoptPtr(new TextAutosizer(document)); }
48
49    virtual ~TextAutosizer();
50
51    bool processSubtree(RenderObject* layoutRoot);
52    void recalculateMultipliers();
53
54    static float computeAutosizedFontSize(float specifiedSize, float multiplier);
55
56private:
57    enum TraversalDirection {
58        FirstToLast,
59        LastToFirst
60    };
61
62    explicit TextAutosizer(Document*);
63
64    float clusterMultiplier(WritingMode, const TextAutosizingWindowInfo&, float textWidth) const;
65
66    void processClusterInternal(TextAutosizingClusterInfo&, RenderBlock* container, RenderObject* subtreeRoot, const TextAutosizingWindowInfo&, float multiplier);
67    void processCluster(TextAutosizingClusterInfo&, RenderBlock* container, RenderObject* subtreeRoot, const TextAutosizingWindowInfo&);
68    void processCompositeCluster(Vector<TextAutosizingClusterInfo>&, const TextAutosizingWindowInfo&);
69    void processContainer(float multiplier, RenderBlock* container, TextAutosizingClusterInfo&, RenderObject* subtreeRoot, const TextAutosizingWindowInfo&);
70
71    void setMultiplier(RenderObject*, float);
72    void setMultiplierForList(RenderObject* renderer, float multiplier);
73
74    static bool isAutosizingContainer(const RenderObject*);
75    static bool isNarrowDescendant(const RenderBlock*, TextAutosizingClusterInfo& parentClusterInfo);
76    static bool isWiderDescendant(const RenderBlock*, const TextAutosizingClusterInfo& parentClusterInfo);
77    static bool isIndependentDescendant(const RenderBlock*);
78    static bool isAutosizingCluster(const RenderBlock*, TextAutosizingClusterInfo& parentClusterInfo);
79
80    static bool containerShouldBeAutosized(const RenderBlock* container);
81    static bool containerContainsOneOfTags(const RenderBlock* cluster, const Vector<QualifiedName>& tags);
82    static bool containerIsRowOfLinks(const RenderObject* container);
83    static bool contentHeightIsConstrained(const RenderBlock* container);
84    static bool clusterShouldBeAutosized(TextAutosizingClusterInfo&, float blockWidth);
85    static bool compositeClusterShouldBeAutosized(Vector<TextAutosizingClusterInfo>&, float blockWidth);
86    static void measureDescendantTextWidth(const RenderBlock* container, TextAutosizingClusterInfo&, float minTextWidth, float& textWidth);
87
88    // Use to traverse the tree of descendants, excluding descendants of containers (but returning the containers themselves).
89    static RenderObject* nextInPreOrderSkippingDescendantsOfContainers(const RenderObject*, const RenderObject* stayWithin);
90
91    static const RenderBlock* findDeepestBlockContainingAllText(const RenderBlock* cluster);
92
93    // Depending on the traversal direction specified, finds the first or the last leaf text node child that doesn't
94    // belong to any cluster.
95    static const RenderObject* findFirstTextLeafNotInCluster(const RenderObject*, size_t& depth, TraversalDirection);
96
97    // Returns groups of narrow descendants of a given autosizing cluster. The groups are combined
98    // by the difference between the width of the descendant and the width of the parent cluster's
99    // |blockContainingAllText|.
100    static void getNarrowDescendantsGroupedByWidth(const TextAutosizingClusterInfo& parentClusterInfo, Vector<Vector<TextAutosizingClusterInfo> >&);
101
102    Document* m_document;
103};
104
105} // namespace WebCore
106
107#endif // TextAutosizer_h
108