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// 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