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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

    \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

    */

/*!

    \internal

    \class QDeclarativeBind

    \brief The QDeclarativeBind class allows arbitrary property bindings to be created.

    Simple bindings are usually earier to do in-place rather than creating a

    QDeclarativeBind item. For that reason, QDeclarativeBind is usually used to transfer property information

    from Qml to C++.

    \sa cppqml

    */

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