Revision control
++ // Copyright (C) 2016 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
++ // Qt-Security score:significant reason:default
++
++ #include "qquicktransitionmanager_p_p.h"
++
++ #include "qquicktransition_p.h"
++ #include "qquickstate_p_p.h"
++
++ #include <private/qqmlbinding_p.h>
++ #include <private/qqmlglobal_p.h>
++ #include <private/qqmlproperty_p.h>
++
++ #include <QtCore/qdebug.h>
++ #include <private/qanimationjobutil_p.h>
++
++ QT_BEGIN_NAMESPACE
++
++ class QQuickTransitionManagerPrivate
++ {
++ public:
++ QQuickTransitionManagerPrivate()
++ : state(nullptr), transitionInstance(nullptr) {}
++
++ void applyBindings();
++ typedef QList<QQuickSimpleAction> SimpleActionList;
++ QQuickState *state;
++ QQuickTransitionInstance *transitionInstance;
++ QQuickStateOperation::ActionList bindingsList;
++ SimpleActionList completeList;
++ };
++
++ QQuickTransitionManager::QQuickTransitionManager()
++ : d(new QQuickTransitionManagerPrivate)
++ {
++ }
++
++ void QQuickTransitionManager::setState(QQuickState *s)
++ {
++ d->state = s;
++ }
++
++ QQuickTransitionManager::~QQuickTransitionManager()
++ {
++ delete d->transitionInstance;
++ d->transitionInstance = nullptr;
++ delete d; d = nullptr;
++ }
++
++ bool QQuickTransitionManager::isRunning() const
++ {
++ return d->transitionInstance && d->transitionInstance->isRunning();
++ }
++
++ void QQuickTransitionManager::complete()
++ {
++ d->applyBindings();
++
++ // Explicitly take a copy in case the write action triggers a script that modifies the list.
++ QQuickTransitionManagerPrivate::SimpleActionList completeListCopy = d->completeList;
++ for (const QQuickSimpleAction &action : std::as_const(completeListCopy))
++ action.property().write(action.value());
++
++ d->completeList.clear();
++
++ if (d->state)
++ static_cast<QQuickStatePrivate*>(QObjectPrivate::get(d->state))->complete();
++
++ finished();
++ }
++
++ void QQuickTransitionManagerPrivate::applyBindings()
++ {
++ for (const QQuickStateAction &action : std::as_const(bindingsList)) {
++ if (auto binding = action.toBinding; binding) {
++ binding.installOn(action.property, QQmlAnyBinding::RespectInterceptors);
++ } else if (action.event) {
++ if (action.reverseEvent)
++ action.event->reverse();
++ else
++ action.event->execute();
++ }
++
++ }
++
++ bindingsList.clear();
++ }
++
++ void QQuickTransitionManager::finished()
++ {
++ }
++
++ void QQuickTransitionManager::transition(const QList<QQuickStateAction> &list,
++ QQuickTransition *transition,
++ QObject *defaultTarget)
++ {
++ RETURN_IF_DELETED(cancel());
++
++ // The copy below is ON PURPOSE, because firing actions might involve scripts that modify the list.
++ QQuickStateOperation::ActionList applyList = list;
++
++ // Determine which actions are binding changes and disable any current bindings
++ for (const QQuickStateAction &action : std::as_const(applyList)) {
++ if (action.toBinding)
++ d->bindingsList << action;
++ if (action.fromBinding) {
++ auto property = action.property;
++ QQmlAnyBinding::removeBindingFrom(property); // Disable current binding
++ }
++ if (action.event && action.event->changesBindings()) { //### assume isReversable()?
++ d->bindingsList << action;
++ action.event->clearBindings();
++ }
++ }
++
++ // Animated transitions need both the start and the end value for
++ // each property change. In the presence of bindings, the end values
++ // are non-trivial to calculate. As a "best effort" attempt, we first
++ // apply all the property and binding changes, then read all the actual
++ // final values, then roll back the changes and proceed as normal.
++ //
++ // This doesn't catch everything, and it might be a little fragile in
++ // some cases - but whatcha going to do?
++ if (transition && !d->bindingsList.isEmpty()) {
++
++ // Apply all the property and binding changes
++ for (const QQuickStateAction &action : std::as_const(applyList)) {
++ if (auto binding = action.toBinding; binding) {
++ binding.installOn(action.property);
++ } else if (!action.event) {
++ QQmlPropertyPrivate::write(action.property, action.toValue, QQmlPropertyData::BypassInterceptor | QQmlPropertyData::DontRemoveBinding);
++ } else if (action.event->isReversable()) {
++ if (action.reverseEvent)
++ action.event->reverse();
++ else
++ action.event->execute();
++ }
++ }
++
++ // Read all the end values for binding changes.
++ for (auto it = applyList.begin(), eit = applyList.end(); it != eit; ++it) {
++ if (it->event) {
++ it->event->saveTargetValues();
++ continue;
++ }
++ const QQmlProperty &prop = it->property;
++ if (it->toBinding || !it->toValue.isValid())
++ it->toValue = prop.read();
++ }
++
++ // Revert back to the original values
++ for (const QQuickStateAction &action : std::as_const(applyList)) {
++ if (action.event) {
++ if (action.event->isReversable()) {
++ action.event->clearBindings();
++ action.event->rewind();
++ action.event->clearBindings(); //### shouldn't be needed
++ }
++ continue;
++ }
++
++ if (action.toBinding) {
++ auto property = action.property;
++ QQmlAnyBinding::removeBindingFrom(property); // Make sure this is disabled during the transition
++ }
++
++ QQmlPropertyPrivate::write(action.property, action.fromValue, QQmlPropertyData::BypassInterceptor | QQmlPropertyData::DontRemoveBinding);
++ }
++ }
++
++ if (transition) {
++ QList<QQmlProperty> touched;
++ QQuickTransitionInstance *oldInstance = d->transitionInstance;
++ d->transitionInstance = transition->prepare(applyList, touched, this, defaultTarget);
++ d->transitionInstance->start();
++ if (oldInstance && oldInstance != d->transitionInstance)
++ delete oldInstance;
++
++ // Modify the action list to remove actions handled in the transition
++ auto isHandledInTransition = [this, touched](const QQuickStateAction &action) {
++ if (action.event) {
++ return action.actionDone;
++ } else {
++ if (touched.contains(action.property)) {
++ if (action.toValue != action.fromValue)
++ d->completeList << QQuickSimpleAction(action, QQuickSimpleAction::EndState);
++ return true;
++ }
++ }
++ return false;
++ };
++
++ applyList.removeIf(isHandledInTransition);
++ }
++
++ // Any actions remaining have not been handled by the transition and should
++ // be applied immediately. We skip applying bindings, as they are all
++ // applied at the end in applyBindings() to avoid any nastiness mid
++ // transition
++ for (const QQuickStateAction &action : std::as_const(applyList)) {
++ if (action.event && !action.event->changesBindings()) {
++ if (action.event->isReversable() && action.reverseEvent)
++ action.event->reverse();
++ else
++ action.event->execute();
++ } else if (!action.event && !action.toBinding) {
++ action.property.write(action.toValue);
++ }
++ }
++ if (lcStates().isDebugEnabled()) {
++ for (const QQuickStateAction &action : std::as_const(applyList)) {
++ if (action.event)
++ qCDebug(lcStates) << "no transition for event:" << action.event->type();
++ else
++ qCDebug(lcStates) << "no transition for:" << action.property.object()
++ << action.property.name() << "from:" << action.fromValue
++ << "to:" << action.toValue;
++ }
++ }
++
++ if (!transition)
++ complete();
++ }
++
++ void QQuickTransitionManager::cancel()
++ {
++ if (d->transitionInstance && d->transitionInstance->isRunning())
++ RETURN_IF_DELETED(d->transitionInstance->stop());
++
++ for (const QQuickStateAction &action : std::as_const(d->bindingsList)) {
++ if (action.toBinding && action.deletableToBinding) {
++ auto property = action.property;
++ QQmlAnyBinding::removeBindingFrom(property);
++ } else if (action.event) {
++ //### what do we do here?
++ }
++
++ }
++ d->bindingsList.clear();
++ d->completeList.clear();
++ }
++
++ QT_END_NAMESPACE