1 | /**************************************************************************** |
2 | ** |
3 | ** Copyright (C) 2014 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Milian Wolff <milian.wolff@kdab.com> |
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39 | |
40 | #ifndef SIGNALHANDLER_H |
41 | #define SIGNALHANDLER_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 <Qt3DCore/qt3dcore_global.h> |
55 | #include <QtCore/QDebug> |
56 | #include <QtCore/QHash> |
57 | #include <QtCore/QMetaMethod> |
58 | #include <QtCore/QObject> |
59 | #include <QtCore/QVector> |
60 | |
61 | QT_BEGIN_NAMESPACE |
62 | |
63 | namespace Qt3DCore { |
64 | |
65 | class Q_3DCORESHARED_EXPORT PropertyChangeHandlerBase : public QObject |
66 | { |
67 | Q_OBJECT |
68 | public: |
69 | PropertyChangeHandlerBase(QObject *parent = nullptr); |
70 | |
71 | /** |
72 | * Connect to the change signal of @p property in @p object. |
73 | */ |
74 | void connectToPropertyChange(const QObject *object, int propertyIndex); |
75 | |
76 | /** |
77 | * Disconnect from the change signal of @p property in @p object. |
78 | */ |
79 | void disconnectFromPropertyChange(const QObject *object, int propertyIndex); |
80 | }; |
81 | |
82 | /** |
83 | * The property change handler is similar to QSignalSpy, but geared towards the usecase of Qt3D. |
84 | * |
85 | * It allows connecting to any number of property change signals of the receiver object and forwards |
86 | * the signal invocations to the Receiver by calling its propertyChanged function. |
87 | */ |
88 | template<class Receiver> |
89 | class PropertyChangeHandler : public PropertyChangeHandlerBase |
90 | { |
91 | public: |
92 | PropertyChangeHandler(Receiver *receiver, QObject *parent = nullptr); |
93 | |
94 | /** |
95 | * @internal |
96 | * |
97 | * Custom implementation of qt_metacall which calls propertyChanged() on the receiver for |
98 | * connected signals. |
99 | */ |
100 | int qt_metacall(QMetaObject::Call call, int methodId, void **args) override; |
101 | |
102 | private: |
103 | Receiver *m_receiver; |
104 | }; |
105 | |
106 | template<class Receiver> |
107 | PropertyChangeHandler<Receiver>::PropertyChangeHandler(Receiver *receiver, QObject *parent) |
108 | : PropertyChangeHandlerBase(parent) |
109 | , m_receiver(receiver) |
110 | { |
111 | } |
112 | |
113 | template<class Receiver> |
114 | int PropertyChangeHandler<Receiver>::qt_metacall(QMetaObject::Call call, int methodId, void **args) |
115 | { |
116 | methodId = QObject::qt_metacall(call, methodId, args); |
117 | if (methodId < 0) |
118 | return methodId; |
119 | |
120 | if (call == QMetaObject::InvokeMetaMethod) { |
121 | m_receiver->propertyChanged(methodId); |
122 | return -1; |
123 | } |
124 | return methodId; |
125 | } |
126 | |
127 | } |
128 | |
129 | QT_END_NAMESPACE |
130 | |
131 | #endif // SIGNALHANDLER_H |
132 | |