1// Copyright (C) 2023 The Qt Company Ltd.
2// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
3
4#ifndef QQUICKLAYOUTITEMPROXY_P_H
5#define QQUICKLAYOUTITEMPROXY_P_H
6
7//
8// W A R N I N G
9// -------------
10//
11// This file is not part of the Qt API. It exists purely as an
12// implementation detail. This header file may change from version to
13// version without notice, or even be removed.
14//
15// We mean it.
16//
17
18#include <private/qquickitem_p.h>
19#include <private/qquickrectangle_p.h>
20
21class QQuickLayoutItemProxyAttachedData;
22class QQuickLayoutItemProxyPrivate;
23class QQuickLayoutItemProxy : public QQuickItem
24{
25 Q_OBJECT
26
27 Q_PROPERTY(QQuickItem *target READ target WRITE setTarget NOTIFY targetChanged)
28 QML_NAMED_ELEMENT(LayoutItemProxy)
29 QML_ADDED_IN_VERSION(6, 6)
30
31public:
32 QQuickLayoutItemProxy(QQuickItem *parent = nullptr);
33 ~QQuickLayoutItemProxy() override;
34
35 void geometryChange(const QRectF &newGeom, const QRectF &oldGeom) override;
36 void itemChange(ItemChange c, const ItemChangeData &d) override;
37
38 QQuickItem *target() const;
39 void setTarget(QQuickItem *newTarget);
40 Q_INVOKABLE QQuickItem *effectiveTarget() const;
41 void clearTarget();
42
43 void maybeTakeControl();
44public slots:
45 void updatePos();
46
47private slots:
48 // We define some slots to react to changes to the Layout attached properties.
49 // They are all named following the same scheme, which allows us to use a macro.
50#define propertyForwarding(Property) \
51 void target##Property##Changed(); \
52 void proxy##Property##Changed();
53
54 propertyForwarding(MinimumWidth)
55 propertyForwarding(MinimumHeight)
56 propertyForwarding(PreferredWidth)
57 propertyForwarding(PreferredHeight)
58 propertyForwarding(MaximumWidth)
59 propertyForwarding(MaximumHeight)
60 propertyForwarding(FillWidth)
61 propertyForwarding(FillHeight)
62 propertyForwarding(Alignment)
63 propertyForwarding(HorizontalStretchFactor)
64 propertyForwarding(VerticalStretchFactor)
65 propertyForwarding(Margins)
66 propertyForwarding(LeftMargin)
67 propertyForwarding(TopMargin)
68 propertyForwarding(RightMargin)
69 propertyForwarding(BottomMargin)
70#undef propertyForwarding
71
72signals:
73 void targetChanged();
74
75private:
76 Q_DECLARE_PRIVATE(QQuickLayoutItemProxy)
77};
78
79class QQuickLayoutItemProxyPrivate : public QQuickItemPrivate
80{
81 Q_DECLARE_PUBLIC(QQuickLayoutItemProxy)
82
83public:
84 QQuickLayoutItemProxyPrivate();
85
86 // the target of the LayoutItem
87 QQuickItem *target = nullptr;
88
89 // These values are required to know why the Layout property of the proxy changed
90 // If it changed because the target changed we should keep the connection valid
91 // If a Layout property change is not invoked by the target, it was set
92 // explicitly by the application developer and we should disconnect the connection
93 // between target and proxy for this property.
94 unsigned m_expectProxyMinimumWidthChange : 1;
95 unsigned m_expectProxyMinimumHeightChange : 1;
96 unsigned m_expectProxyPreferredWidthChange : 1;
97 unsigned m_expectProxyPreferredHeightChange : 1;
98 unsigned m_expectProxyMaximumWidthChange : 1;
99 unsigned m_expectProxyMaximumHeightChange : 1;
100 unsigned m_expectProxyFillWidthChange : 1;
101 unsigned m_expectProxyFillHeightChange : 1;
102 unsigned m_expectProxyAlignmentChange : 1;
103 unsigned m_expectProxyHorizontalStretchFactorChange : 1;
104 unsigned m_expectProxyVerticalStretchFactorChange : 1;
105 unsigned m_expectProxyMarginsChange : 1;
106 unsigned m_expectProxyLeftMarginChange : 1;
107 unsigned m_expectProxyTopMarginChange : 1;
108 unsigned m_expectProxyRightMarginChange : 1;
109 unsigned m_expectProxyBottomMarginChange : 1;
110
111 friend class QQuickLayoutItemProxy;
112};
113
114class QQuickLayoutItemProxyAttachedData : public QObject
115{
116 Q_OBJECT
117
118 QML_ANONYMOUS
119 Q_PROPERTY(bool proxyHasControl READ proxyHasControl NOTIFY controllingProxyChanged)
120 Q_PROPERTY(QQuickLayoutItemProxy* controllingProxy READ getControllingProxy NOTIFY controllingProxyChanged)
121 Q_PROPERTY(QList<QQuickLayoutItemProxy*> proxies READ getProxies NOTIFY proxiesChanged)
122
123public:
124 QQuickLayoutItemProxyAttachedData(QObject *parent);
125 ~QQuickLayoutItemProxyAttachedData() override;
126 void registerProxy(QQuickLayoutItemProxy *proxy);
127 void releaseProxy(QQuickLayoutItemProxy *proxy);
128 bool takeControl(QQuickLayoutItemProxy *proxy);
129 void releaseControl(QQuickLayoutItemProxy *proxy);
130 QQuickLayoutItemProxy *getControllingProxy() const;
131 const QList<QQuickLayoutItemProxy*> &getProxies() const;
132 bool proxyHasControl() const;
133
134signals:
135 void controlTaken();
136 void controlReleased();
137 void controllingProxyChanged();
138 void proxiesChanged();
139
140private:
141 QList<QQuickLayoutItemProxy*> proxies;
142 QQuickLayoutItemProxy* controllingProxy;
143};
144
145Q_DECLARE_METATYPE(QQuickLayoutItemProxyAttachedData*);
146
147#endif // QQUICKLAYOUTITEMPROXY_P_H
148

source code of qtdeclarative/src/quicklayouts/qquicklayoutitemproxy_p.h