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3 | ** Copyright (C) 2016 The Qt Company Ltd. |
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6 | ** This file is part of the Qt Designer of the Qt Toolkit. |
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28 | |
29 | // |
30 | // W A R N I N G |
31 | // ------------- |
32 | // |
33 | // This file is not part of the Qt API. It exists for the convenience |
34 | // of Qt Designer. This header |
35 | // file may change from version to version without notice, or even be removed. |
36 | // |
37 | // We mean it. |
38 | // |
39 | |
40 | #ifndef DESIGNERWIDGETITEM_H |
41 | #define DESIGNERWIDGETITEM_H |
42 | |
43 | #include "shared_global_p.h" |
44 | |
45 | #include <QtWidgets/qlayoutitem.h> |
46 | #include <QtCore/qobject.h> |
47 | |
48 | QT_BEGIN_NAMESPACE |
49 | |
50 | class QDesignerFormEditorInterface; |
51 | |
52 | namespace qdesigner_internal { |
53 | |
54 | // QDesignerWidgetItem: A Layout Item that is used for non-containerextension- |
55 | // containers (QFrame, etc) on Designer forms. It prevents its widget |
56 | // from being slammed to size 0 if the widget has no layout: |
57 | // Pre 4.5, this item ensured only that QWidgets and QFrames were not squeezed |
58 | // to size 0 since they have an invalid size hint when non-laid out. |
59 | // Since 4.5, the item is used for every non-containerextension-container. |
60 | // In case the container has itself a layout, it merely tracks the minimum |
61 | // size. If the container has no layout and is not subject to some stretch |
62 | // factor, it will return the last valid size. The effect is that after |
63 | // breaking a layout on a container within a layout, it just maintains its |
64 | // last size and is not slammed to 0,0. In addition, it can be resized. |
65 | // The class keeps track of the containing layout by tracking widget reparent |
66 | // and destroyed slots as Designer will for example re-create grid layouts to |
67 | // shrink them. |
68 | |
69 | class QDESIGNER_SHARED_EXPORT QDesignerWidgetItem : public QObject, public QWidgetItemV2 { |
70 | Q_DISABLE_COPY_MOVE(QDesignerWidgetItem) |
71 | Q_OBJECT |
72 | public: |
73 | explicit QDesignerWidgetItem(const QLayout *containingLayout, QWidget *w, Qt::Orientations o = Qt::Horizontal|Qt::Vertical); |
74 | |
75 | const QLayout *containingLayout() const; |
76 | |
77 | inline QWidget *constWidget() const { return const_cast<QDesignerWidgetItem*>(this)->widget(); } |
78 | |
79 | QSize minimumSize() const override; |
80 | QSize sizeHint() const override; |
81 | |
82 | // Resize: Takes effect if the contained widget does not have a layout |
83 | QSize nonLaidOutMinSize() const; |
84 | void setNonLaidOutMinSize(const QSize &s); |
85 | |
86 | QSize nonLaidOutSizeHint() const; |
87 | void setNonLaidOutSizeHint(const QSize &s); |
88 | |
89 | // Check whether a QDesignerWidgetItem should be installed |
90 | static bool check(const QLayout *layout, QWidget *w, Qt::Orientations *ptrToOrientations = nullptr); |
91 | |
92 | // Register itself using QLayoutPrivate's widget item factory method hook |
93 | static void install(); |
94 | static void deinstall(); |
95 | |
96 | // Check for a non-container extension container |
97 | static bool isContainer(const QDesignerFormEditorInterface *core, QWidget *w); |
98 | |
99 | static bool subjectToStretch(const QLayout *layout, QWidget *w); |
100 | |
101 | bool eventFilter(QObject * watched, QEvent * event) override; |
102 | |
103 | private slots: |
104 | void layoutChanged(); |
105 | |
106 | private: |
107 | void expand(QSize *s) const; |
108 | bool subjectToStretch() const; |
109 | |
110 | const Qt::Orientations m_orientations; |
111 | mutable QSize m_nonLaidOutMinSize; |
112 | mutable QSize m_nonLaidOutSizeHint; |
113 | mutable const QLayout *m_cachedContainingLayout; |
114 | }; |
115 | |
116 | // Helper class that ensures QDesignerWidgetItem is installed while an |
117 | // instance is in scope. |
118 | |
119 | class QDESIGNER_SHARED_EXPORT QDesignerWidgetItemInstaller { |
120 | Q_DISABLE_COPY_MOVE(QDesignerWidgetItemInstaller) |
121 | |
122 | public: |
123 | QDesignerWidgetItemInstaller(); |
124 | ~QDesignerWidgetItemInstaller(); |
125 | |
126 | private: |
127 | static int m_instanceCount; |
128 | }; |
129 | |
130 | } // namespace qdesigner_internal |
131 | |
132 | QT_END_NAMESPACE |
133 | |
134 | #endif |
135 | |