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42 #ifndef QQMLACCESSORS_P_H
43 #define QQMLACCESSORS_P_H
45 #include <QtQml/qtqmlglobal.h>
46 #include <QtCore/qvector.h>
47 #include <QtCore/qhash.h>
48 #include <QtCore/QReadWriteLock>
57 // QML "accessor properties" allow V4 and V8 to bypass Qt's meta system to read and, more
58 // importantly, subscribe to properties directly. Any property that is primarily read
59 // from bindings is a candidate for inclusion as an accessor property.
61 // To define accessor properties, use the QML_DECLARE_PROPERTIES() and QML_DEFINE_PROPERTIES()
62 // macros. The QML_DECLARE_PROPERTIES() macro is used to specify the properties, and the
63 // QML_DEFINE_PROPERTIES() macro to register the properties with the
64 // QQmlAccessorProperties singleton.
66 // A class with accessor properties must also add the Q_CLASSINFO("qt_HasQmlAccessors", "true")
67 // tag to its declaration. This is essential for QML to maintain internal consistency,
68 // and forgetting to do so will probably cause your application to qFatal() with a
69 // helpful reminder of this requirement.
71 // It is important that QML_DEFINE_PROPERTIES() has been called before QML ever sees
72 // the type with the accessor properties. As QML_DEFINE_PROPERTIES() is idempotent, it is
73 // recommended to call it in the type's constructor as well as when the type is registered
74 // as a QML element (if it ever is). QML_DEFINE_PROPERTIES() is a very cheap operation
75 // if registration has already occurred.
77 #define QML_DECLARE_PROPERTIES(type) \
78 static volatile bool qqml_accessor_properties_isregistered_ ## type = false; \
79 static QQmlAccessorProperties::Property qqml_accessor_properties_ ## type[] =
81 #define QML_DEFINE_PROPERTIES(type) \
83 if (!qqml_accessor_properties_isregistered_ ## type) { \
84 int count = sizeof(qqml_accessor_properties_ ## type) / \
85 sizeof(QQmlAccessorProperties::Property); \
86 QQmlAccessorProperties::registerProperties(&type::staticMetaObject, count, \
87 qqml_accessor_properties_ ## type);\
88 qqml_accessor_properties_isregistered_ ## type = true; \
92 #define QML_PRIVATE_ACCESSOR(clazz, cpptype, name, variable) \
93 static void clazz ## _ ## name ## Read(QObject *o, intptr_t, void *rv) \
95 clazz ## Private *d = clazz ## Private::get(static_cast<clazz *>(o)); \
96 *static_cast<cpptype *>(rv) = d->variable; \
99 #define QML_PROPERTY_NAME(name) #name, sizeof #name - 1
104 void (*read)(QObject *object, intptr_t property, void *output);
105 void (*notifier)(QObject *object, intptr_t property, QQmlNotifier **notifier);
108 namespace QQmlAccessorProperties {
111 unsigned int nameLength;
113 QQmlAccessors *accessors;
118 Properties(Property *, int);
120 bool operator==(const Properties &o) const {
121 return count == o.count && properties == o.properties;
124 inline Property *property(const char *name);
127 Property *properties;
131 Properties properties(const QMetaObject *);
132 void Q_QML_EXPORT registerProperties(const QMetaObject *, int, Property *);
135 QQmlAccessorProperties::Property *
136 QQmlAccessorProperties::Properties::property(const char *name)
141 unsigned int length = strlen(name);
145 if (nameMask & (1 << qMin(31U, length - 1))) {
147 for (int ii = 0; ii < count; ++ii) {
148 if (properties[ii].nameLength == length && 0 == qstrcmp(name, properties[ii].name))
149 return &properties[ii];
157 QQmlAccessorProperties::Properties::Properties()
158 : count(0), properties(0), nameMask(0)
166 #endif // QQMLACCESSORS_P_H