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39 
40 #ifndef QGRAPHICSSCENEBSPTREE_P_H
41 #define QGRAPHICSSCENEBSPTREE_P_H
42 
43 //
44 //  W A R N I N G
45 //  -------------
46 //
47 // This file is not part of the Qt API.  It exists for the convenience
48 // of other Qt classes.  This header file may change from version to
49 // version without notice, or even be removed.
50 //
51 // We mean it.
52 //
53 
54 #include <QtWidgets/private/qtwidgetsglobal_p.h>
55 #include <QtCore/qlist.h>
56 
57 #include <QtCore/qrect.h>
58 #include <QtCore/qset.h>
59 #include <QtCore/qvector.h>
60 
61 QT_REQUIRE_CONFIG(graphicsview);
62 
63 QT_BEGIN_NAMESPACE
64 
65 class QGraphicsItem;
66 class QGraphicsSceneBspTreeVisitor;
67 class QGraphicsSceneInsertItemBspTreeVisitor;
68 class QGraphicsSceneRemoveItemBspTreeVisitor;
69 class QGraphicsSceneFindItemBspTreeVisitor;
70 
71 class QGraphicsSceneBspTree
72 {
73 public:
74     struct Node
75     {
76         enum Type { Horizontal, Vertical, Leaf };
77         union {
78             qreal offset;
79             int leafIndex;
80         };
81         Type type;
82     };
83 
84     QGraphicsSceneBspTree();
85     ~QGraphicsSceneBspTree();
86 
87     void initialize(const QRectF &rect, int depth);
88     void clear();
89 
90     void insertItem(QGraphicsItem *item, const QRectF &rect);
91     void removeItem(QGraphicsItem *item, const QRectF &rect);
92     void removeItems(const QSet<QGraphicsItem *> &items);
93 
94     QList<QGraphicsItem *> items(const QRectF &rect, bool onlyTopLevelItems = false) const;
95     int leafCount() const;
96 
firstChildIndex(int index)97     inline int firstChildIndex(int index) const
98     { return index * 2 + 1; }
99 
parentIndex(int index)100     inline int parentIndex(int index) const
101     { return index > 0 ? ((index & 1) ? ((index - 1) / 2) : ((index - 2) / 2)) : -1; }
102 
103     QString debug(int index) const;
104 
105 private:
106     void initialize(const QRectF &rect, int depth, int index);
107     void climbTree(QGraphicsSceneBspTreeVisitor *visitor, const QRectF &rect, int index = 0) const;
108     QRectF rectForIndex(int index) const;
109 
110     QVector<Node> nodes;
111     QVector<QList<QGraphicsItem *> > leaves;
112     int leafCnt;
113     QRectF rect;
114 
115     QGraphicsSceneInsertItemBspTreeVisitor *insertVisitor;
116     QGraphicsSceneRemoveItemBspTreeVisitor *removeVisitor;
117     QGraphicsSceneFindItemBspTreeVisitor *findVisitor;
118 };
119 
120 class QGraphicsSceneBspTreeVisitor
121 {
122 public:
~QGraphicsSceneBspTreeVisitor()123     virtual ~QGraphicsSceneBspTreeVisitor() { }
124     virtual void visit(QList<QGraphicsItem *> *items) = 0;
125 };
126 
127 QT_END_NAMESPACE
128 
129 #endif // QGRAPHICSSCENEBSPTREE_P_H
130