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#include "private/qdeclarativebind_p.h" | |
#include "private/qdeclarativenullablevalue_p_p.h" | |
#include <qdeclarativeengine.h> | |
#include <qdeclarativecontext.h> | |
#include <qdeclarativeproperty.h> | |
#include <QtCore/qfile.h> | |
#include <QtCore/qdebug.h> | |
#include <QtScript/qscriptvalue.h> | |
#include <QtScript/qscriptcontext.h> | |
#include <QtScript/qscriptengine.h> | |
#include <private/qobject_p.h> | |
QT_BEGIN_NAMESPACE | |
class QDeclarativeBindPrivate : public QObjectPrivate | |
{ | |
public: | |
QDeclarativeBindPrivate() : when(true), componentComplete(true), obj(0) {} | |
bool when : 1; | |
bool componentComplete : 1; | |
QObject *obj; | |
QString prop; | |
QDeclarativeNullableValue<QVariant> value; | |
}; | |
/*! | |
\qmlclass Binding QDeclarativeBind | |
\ingroup qml-working-with-data | |
\since 4.7 | |
\brief The Binding element allows arbitrary property bindings to be created. | |
Sometimes it is necessary to bind to a property of an object that wasn't | |
directly instantiated by QML - generally a property of a class exported | |
to QML by C++. In these cases, regular property binding doesn't work. Binding | |
allows you to bind any value to any property. | |
For example, imagine a C++ application that maps an "app.enteredText" | |
property into QML. You could use Binding to update the enteredText property | |
like this. | |
\code | |
TextEdit { id: myTextField; text: "Please type here..." } | |
Binding { target: app; property: "enteredText"; value: myTextField.text } | |
\endcode | |
Whenever the text in the TextEdit is updated, the C++ property will be | |
updated also. | |
If the binding target or binding property is changed, the bound value is | |
immediately pushed onto the new target. | |
\sa QtDeclarative | |
*/ | |
QDeclarativeBind::QDeclarativeBind(QObject *parent) | |
: QObject(*(new QDeclarativeBindPrivate), parent) | |
{ | |
} | |
QDeclarativeBind::~QDeclarativeBind() | |
{ | |
} | |
/*! | |
\qmlproperty bool Binding::when | |
This property holds when the binding is active. | |
This should be set to an expression that evaluates to true when you want the binding to be active. | |
\code | |
Binding { | |
target: contactName; property: 'text' | |
value: name; when: list.ListView.isCurrentItem | |
} | |
\endcode | |
*/ | |
bool QDeclarativeBind::when() const | |
{ | |
Q_D(const QDeclarativeBind); | |
return d->when; | |
} | |
void QDeclarativeBind::setWhen(bool v) | |
{ | |
Q_D(QDeclarativeBind); | |
d->when = v; | |
eval(); | |
} | |
/*! | |
\qmlproperty Object Binding::target | |
The object to be updated. | |
*/ | |
QObject *QDeclarativeBind::object() | |
{ | |
Q_D(const QDeclarativeBind); | |
return d->obj; | |
} | |
void QDeclarativeBind::setObject(QObject *obj) | |
{ | |
Q_D(QDeclarativeBind); | |
d->obj = obj; | |
eval(); | |
} | |
/*! | |
\qmlproperty string Binding::property | |
The property to be updated. | |
*/ | |
QString QDeclarativeBind::property() const | |
{ | |
Q_D(const QDeclarativeBind); | |
return d->prop; | |
} | |
void QDeclarativeBind::setProperty(const QString &p) | |
{ | |
Q_D(QDeclarativeBind); | |
d->prop = p; | |
eval(); | |
} | |
/*! | |
\qmlproperty any Binding::value | |
The value to be set on the target object and property. This can be a | |
constant (which isn't very useful), or a bound expression. | |
*/ | |
QVariant QDeclarativeBind::value() const | |
{ | |
Q_D(const QDeclarativeBind); | |
return d->value.value; | |
} | |
void QDeclarativeBind::setValue(const QVariant &v) | |
{ | |
Q_D(QDeclarativeBind); | |
d->value.value = v; | |
d->value.isNull = false; | |
eval(); | |
} | |
void QDeclarativeBind::classBegin() | |
{ | |
Q_D(QDeclarativeBind); | |
d->componentComplete = false; | |
} | |
void QDeclarativeBind::componentComplete() | |
{ | |
Q_D(QDeclarativeBind); | |
d->componentComplete = true; | |
eval(); | |
} | |
void QDeclarativeBind::eval() | |
{ | |
Q_D(QDeclarativeBind); | |
if (!d->obj || d->value.isNull || !d->when || !d->componentComplete) | |
return; | |
QDeclarativeProperty prop(d->obj, d->prop); | |
prop.write(d->value.value); | |
} | |
QT_END_NAMESPACE |