diff options
Diffstat (limited to 'src/qml/types/qqmlbind.cpp')
| -rw-r--r-- | src/qml/types/qqmlbind.cpp | 142 |
1 files changed, 137 insertions, 5 deletions
diff --git a/src/qml/types/qqmlbind.cpp b/src/qml/types/qqmlbind.cpp index 513f7f2997..1ba015f796 100644 --- a/src/qml/types/qqmlbind.cpp +++ b/src/qml/types/qqmlbind.cpp @@ -43,6 +43,8 @@ #include <private/qqmlproperty_p.h> #include <private/qqmlbinding_p.h> #include <private/qqmlmetatype_p.h> +#include <private/qqmlvmemetaobject_p.h> +#include <private/qv4persistent_p.h> #include <qqmlengine.h> #include <qqmlcontext.h> @@ -60,7 +62,21 @@ QT_BEGIN_NAMESPACE class QQmlBindPrivate : public QObjectPrivate { public: - QQmlBindPrivate() : obj(nullptr), componentComplete(true), delayed(false), pendingEval(false) {} + QQmlBindPrivate() + : obj(nullptr) + , prevBind(QQmlAbstractBinding::Ptr()) + , prevIsVariant(false) + , componentComplete(true) + , delayed(false) + , pendingEval(false) + , restoreBinding(true) +#if QT_VERSION < QT_VERSION_CHECK(5, 15, 0) + , restoreValue(false) + , restoreModeExplicit(false) +#else + , restoreValue(true) +#endif + {} ~QQmlBindPrivate() { } QQmlNullableValue<bool> when; @@ -69,11 +85,20 @@ public: QQmlNullableValue<QVariant> value; QQmlProperty prop; QQmlAbstractBinding::Ptr prevBind; + QV4::PersistentValue v4Value; + QVariant prevValue; + bool prevIsVariant:1; bool componentComplete:1; bool delayed:1; bool pendingEval:1; + bool restoreBinding:1; + bool restoreValue:1; +#if QT_VERSION < QT_VERSION_CHECK(5, 15, 0) + bool restoreModeExplicit:1; +#endif void validate(QObject *binding) const; + void clearPrev(); }; void QQmlBindPrivate::validate(QObject *binding) const @@ -323,6 +348,57 @@ void QQmlBind::setDelayed(bool delayed) eval(); } +/*! + \qmlproperty enumeration QtQml::Binding::restoreMode + \since 5.14 + + This property can be used to describe if and how the original value should + be restored when the binding is disabled. + + The possible values are: + \list + \li Binding.RestoreNone The original value is not restored at all + \li Binding.RestoreBinding The original value is restored if it was another + binding. In that case the old binding is in effect again. + \li Binding.RestoreValue The original value is restored if it was a plain + value rather than a binding. + \li Binding.RestoreBindingOrValue The original value is always restored. + \list + + \warning The default value is Binding.RestoreBinding. This will change in + Qt 5.15 to Binding.RestoreBindingOrValue. + + If you rely on any specific behavior regarding the restoration of plain + values when bindings get disabled you should migrate to explicitly set the + restoreMode. + + Reliance on a restoreMode that doesn't restore the previous binding or value + for a specific property results in a run-time warning. +*/ +QQmlBind::RestorationMode QQmlBind::restoreMode() const +{ + Q_D(const QQmlBind); + unsigned result = RestoreNone; + if (d->restoreValue) + result |= RestoreValue; + if (d->restoreBinding) + result |= RestoreBinding; + return RestorationMode(result); +} + +void QQmlBind::setRestoreMode(RestorationMode newMode) +{ + Q_D(QQmlBind); + if (newMode != restoreMode()) { + d->restoreValue = (newMode & RestoreValue); + d->restoreBinding = (newMode & RestoreBinding); +#if QT_VERSION < QT_VERSION_CHECK(5, 15, 0) + d->restoreModeExplicit = true; +#endif + emit restoreModeChanged(); + } +} + void QQmlBind::setTarget(const QQmlProperty &p) { Q_D(QQmlBind); @@ -358,6 +434,14 @@ void QQmlBind::prepareEval() } } +void QQmlBindPrivate::clearPrev() +{ + prevBind = nullptr; + v4Value.clear(); + prevValue.clear(); + prevIsVariant = false; +} + void QQmlBind::eval() { Q_D(QQmlBind); @@ -369,16 +453,64 @@ void QQmlBind::eval() if (!d->when) { //restore any previous binding if (d->prevBind) { - QQmlAbstractBinding::Ptr p = d->prevBind; - d->prevBind = nullptr; - QQmlPropertyPrivate::setBinding(p.data()); + if (d->restoreBinding) { + QQmlAbstractBinding::Ptr p = d->prevBind; + d->clearPrev(); // Do that before setBinding(), as setBinding() may recurse. + QQmlPropertyPrivate::setBinding(p.data()); + } + } else if (!d->v4Value.isEmpty()) { + if (d->restoreValue) { + auto propPriv = QQmlPropertyPrivate::get(d->prop); + QQmlVMEMetaObject *vmemo = QQmlVMEMetaObject::get(propPriv->object); + Q_ASSERT(vmemo); + vmemo->setVMEProperty(propPriv->core.coreIndex(), *d->v4Value.valueRef()); + d->clearPrev(); +#if QT_VERSION < QT_VERSION_CHECK(5, 15, 0) + } else if (!d->restoreModeExplicit) { + qmlWarning(this) + << "Not restoring previous value because restoreMode has not been set." + << "This behavior is deprecated." + << "In Qt < 5.15 the default is Binding.RestoreBinding." + << "In Qt >= 5.15 the default is Binding.RestoreBindingOrValue."; +#endif + } + } else if (d->prevIsVariant) { + if (d->restoreValue) { + d->prop.write(d->prevValue); + d->clearPrev(); +#if QT_VERSION < QT_VERSION_CHECK(5, 15, 0) + } else if (!d->restoreModeExplicit) { + qmlWarning(this) + << "Not restoring previous value because restoreMode has not been set." + << "This behavior is deprecated." + << "In Qt < 5.15 the default is Binding.RestoreBinding." + << "In Qt >= 5.15 the default is Binding.RestoreBindingOrValue."; +#endif + } } return; } //save any set binding for restoration - if (!d->prevBind) + if (!d->prevBind && d->v4Value.isEmpty() && !d->prevIsVariant) { + // try binding first d->prevBind = QQmlPropertyPrivate::binding(d->prop); + + if (!d->prevBind) { // nope, try a V4 value next + auto propPriv = QQmlPropertyPrivate::get(d->prop); + auto propData = propPriv->core; + if (!propPriv->valueTypeData.isValid() && propData.isVarProperty()) { + QQmlVMEMetaObject *vmemo = QQmlVMEMetaObject::get(propPriv->object); + Q_ASSERT(vmemo); + auto retVal = vmemo->vmeProperty(propData.coreIndex()); + d->v4Value = QV4::PersistentValue(vmemo->engine, retVal); + } else { // nope, use the meta object to get a QVariant + d->prevValue = d->prop.read(); + d->prevIsVariant = true; + } + } + } + QQmlPropertyPrivate::removeBinding(d->prop); } |