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39 
40 #ifndef QLAYOUTITEM_H
41 #define QLAYOUTITEM_H
42 
43 #include <QtWidgets/qtwidgetsglobal.h>
44 #include <QtWidgets/qsizepolicy.h>
45 #include <QtCore/qrect.h>
46 
47 #include <limits.h>
48 
49 QT_BEGIN_NAMESPACE
50 
51 
52 static const Q_DECL_UNUSED int QLAYOUTSIZE_MAX = INT_MAX/256/16;
53 
54 class QLayout;
55 class QLayoutItem;
56 class QSpacerItem;
57 class QWidget;
58 class QSize;
59 
60 class Q_WIDGETS_EXPORT QLayoutItem
61 {
62 public:
63     inline explicit QLayoutItem(Qt::Alignment alignment = Qt::Alignment());
64     virtual ~QLayoutItem();
65     virtual QSize sizeHint() const = 0;
66     virtual QSize minimumSize() const = 0;
67     virtual QSize maximumSize() const = 0;
68     virtual Qt::Orientations expandingDirections() const = 0;
69     virtual void setGeometry(const QRect&) = 0;
70     virtual QRect geometry() const = 0;
71     virtual bool isEmpty() const = 0;
72     virtual bool hasHeightForWidth() const;
73     virtual int heightForWidth(int) const;
74     virtual int minimumHeightForWidth(int) const;
75     virtual void invalidate();
76 
77 #if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
78     virtual QWidget *widget();
79 #else
80     virtual QWidget *widget() const;
81 #endif
82     virtual QLayout *layout();
83     virtual QSpacerItem *spacerItem();
84 
alignment()85     Qt::Alignment alignment() const { return align; }
86     void setAlignment(Qt::Alignment a);
87     virtual QSizePolicy::ControlTypes controlTypes() const;
88 
89 protected:
90     Qt::Alignment align;
91 };
92 
QLayoutItem(Qt::Alignment aalignment)93 inline QLayoutItem::QLayoutItem(Qt::Alignment aalignment)
94     : align(aalignment) { }
95 
96 class Q_WIDGETS_EXPORT QSpacerItem : public QLayoutItem
97 {
98 public:
99     QSpacerItem(int w, int h,
100                  QSizePolicy::Policy hData = QSizePolicy::Minimum,
101                  QSizePolicy::Policy vData = QSizePolicy::Minimum)
width(w)102         : width(w), height(h), sizeP(hData, vData) { }
103     ~QSpacerItem();
104 
105     void changeSize(int w, int h,
106                      QSizePolicy::Policy hData = QSizePolicy::Minimum,
107                      QSizePolicy::Policy vData = QSizePolicy::Minimum);
108     QSize sizeHint() const override;
109     QSize minimumSize() const override;
110     QSize maximumSize() const override;
111     Qt::Orientations expandingDirections() const override;
112     bool isEmpty() const override;
113     void setGeometry(const QRect&) override;
114     QRect geometry() const override;
115     QSpacerItem *spacerItem() override;
sizePolicy()116     QSizePolicy sizePolicy() const { return sizeP; }
117 
118 private:
119     int width;
120     int height;
121     QSizePolicy sizeP;
122     QRect rect;
123 };
124 
125 class Q_WIDGETS_EXPORT QWidgetItem : public QLayoutItem
126 {
Q_DISABLE_COPY(QWidgetItem)127     Q_DISABLE_COPY(QWidgetItem)
128 
129 public:
130     explicit QWidgetItem(QWidget *w) : wid(w) { }
131     ~QWidgetItem();
132 
133     QSize sizeHint() const override;
134     QSize minimumSize() const override;
135     QSize maximumSize() const override;
136     Qt::Orientations expandingDirections() const override;
137     bool isEmpty() const override;
138     void setGeometry(const QRect&) override;
139     QRect geometry() const override;
140 #if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
141     QWidget *widget() override;
142 #else
143     QWidget *widget() const override;
144 #endif
145 
146     bool hasHeightForWidth() const override;
147     int heightForWidth(int) const override;
148     QSizePolicy::ControlTypes controlTypes() const override;
149 protected:
150     QWidget *wid;
151 };
152 
153 class Q_WIDGETS_EXPORT QWidgetItemV2 : public QWidgetItem
154 {
155 public:
156     explicit QWidgetItemV2(QWidget *widget);
157     ~QWidgetItemV2();
158 
159     QSize sizeHint() const override;
160     QSize minimumSize() const override;
161     QSize maximumSize() const override;
162     int heightForWidth(int width) const override;
163 
164 private:
165     enum { Dirty = -123, HfwCacheMaxSize = 3 };
166 
167     inline bool useSizeCache() const;
168     void updateCacheIfNecessary() const;
invalidateSizeCache()169     inline void invalidateSizeCache() {
170         q_cachedMinimumSize.setWidth(Dirty);
171         q_hfwCacheSize = 0;
172     }
173 
174     mutable QSize q_cachedMinimumSize;
175     mutable QSize q_cachedSizeHint;
176     mutable QSize q_cachedMaximumSize;
177     mutable QSize q_cachedHfws[HfwCacheMaxSize];
178     mutable short q_firstCachedHfw;
179     mutable short q_hfwCacheSize;
180     void *d;
181 
182     friend class QWidgetPrivate;
183 
184     Q_DISABLE_COPY(QWidgetItemV2)
185 };
186 
187 QT_END_NAMESPACE
188 
189 #endif // QLAYOUTITEM_H
190