qdeclarativestate.cpp

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#include "private/qdeclarativestate_p_p.h"
#include "private/qdeclarativestate_p.h"

#include "private/qdeclarativetransition_p.h"
#include "private/qdeclarativestategroup_p.h"
#include "private/qdeclarativestateoperations_p.h"
#include "private/qdeclarativeanimation_p.h"
#include "private/qdeclarativeanimation_p_p.h"

#include <qdeclarativebinding_p.h>
#include <qdeclarativeglobal_p.h>

#include <QtCore/qdebug.h>

QT_BEGIN_NAMESPACE

DEFINE_BOOL_CONFIG_OPTION(stateChangeDebug, STATECHANGE_DEBUG);

QDeclarativeAction::QDeclarativeAction()
: restore(true), actionDone(false), reverseEvent(false), deletableToBinding(false), fromBinding(0), event(0),
  specifiedObject(0)
{
}

QDeclarativeAction::QDeclarativeAction(QObject *target, const QString &propertyName,
               const QVariant &value)
: restore(true), actionDone(false), reverseEvent(false), deletableToBinding(false), 
  property(target, propertyName, qmlEngine(target)), toValue(value),
  fromBinding(0), event(0),
  specifiedObject(target), specifiedProperty(propertyName)
{
    if (property.isValid())
        fromValue = property.read();
}

QDeclarativeAction::QDeclarativeAction(QObject *target, const QString &propertyName,
               QDeclarativeContext *context, const QVariant &value)
: restore(true), actionDone(false), reverseEvent(false), deletableToBinding(false),
  property(target, propertyName, context), toValue(value),
  fromBinding(0), event(0),
  specifiedObject(target), specifiedProperty(propertyName)
{
    if (property.isValid())
        fromValue = property.read();
}


QDeclarativeActionEvent::~QDeclarativeActionEvent()
{
}

QString QDeclarativeActionEvent::typeName() const
{
    return QString();
}

void QDeclarativeActionEvent::execute(Reason)
{
}

bool QDeclarativeActionEvent::isReversable()
{
    return false;
}

void QDeclarativeActionEvent::reverse(Reason)
{
}

bool QDeclarativeActionEvent::changesBindings()
{
    return false;
}

void QDeclarativeActionEvent::clearBindings()
{
}

bool QDeclarativeActionEvent::override(QDeclarativeActionEvent *other)
{
    Q_UNUSED(other);
    return false;
}

QDeclarativeStateOperation::QDeclarativeStateOperation(QObjectPrivate &dd, QObject *parent)
    : QObject(dd, parent)
{
}

QDeclarativeState::QDeclarativeState(QObject *parent)
: QObject(*(new QDeclarativeStatePrivate), parent)
{
    Q_D(QDeclarativeState);
    d->transitionManager.setState(this);
}

QDeclarativeState::~QDeclarativeState()
{
    Q_D(QDeclarativeState);
    if (d->group)
        d->group->removeState(this);

    /*
      destroying an active state does not return us to the
      base state, so we need to clean up our revert list to
      prevent leaks. In the future we may want to redconsider
      this overall architecture.
    */
    for (int i = 0; i < d->revertList.count(); ++i) {
        if (d->revertList.at(i).binding()) {
            d->revertList.at(i).binding()->destroy();
        }
    }
}

QString QDeclarativeState::name() const
{
    Q_D(const QDeclarativeState);
    return d->name;
}

void QDeclarativeState::setName(const QString &n)
{
    Q_D(QDeclarativeState);
    d->name = n;
    d->named = true;
}

bool QDeclarativeState::isNamed() const
{
    Q_D(const QDeclarativeState);
    return d->named;
}

bool QDeclarativeState::isWhenKnown() const
{
    Q_D(const QDeclarativeState);
    return d->when != 0;
}

QDeclarativeBinding *QDeclarativeState::when() const
{
    Q_D(const QDeclarativeState);
    return d->when;
}

void QDeclarativeState::setWhen(QDeclarativeBinding *when)
{
    Q_D(QDeclarativeState);
    d->when = when;
    if (d->group)
        d->group->updateAutoState();
}

QString QDeclarativeState::extends() const
{
    Q_D(const QDeclarativeState);
    return d->extends;
}

void QDeclarativeState::setExtends(const QString &extends)
{
    Q_D(QDeclarativeState);
    d->extends = extends;
}

QDeclarativeListProperty<QDeclarativeStateOperation> QDeclarativeState::changes()
{
    Q_D(QDeclarativeState);
    return QDeclarativeListProperty<QDeclarativeStateOperation>(this, &d->operations, QDeclarativeStatePrivate::operations_append,
                                              QDeclarativeStatePrivate::operations_count, QDeclarativeStatePrivate::operations_at,
                                              QDeclarativeStatePrivate::operations_clear);
}

int QDeclarativeState::operationCount() const
{
    Q_D(const QDeclarativeState);
    return d->operations.count();
}

QDeclarativeStateOperation *QDeclarativeState::operationAt(int index) const
{
    Q_D(const QDeclarativeState);
    return d->operations.at(index);
}

QDeclarativeState &QDeclarativeState::operator<<(QDeclarativeStateOperation *op)
{
    Q_D(QDeclarativeState);
    d->operations.append(QDeclarativeStatePrivate::OperationGuard(op, &d->operations));
    return *this;
}

void QDeclarativeStatePrivate::complete()
{
    Q_Q(QDeclarativeState);

    for (int ii = 0; ii < reverting.count(); ++ii) {
        for (int jj = 0; jj < revertList.count(); ++jj) {
            if (revertList.at(jj).property() == reverting.at(ii)) {
                revertList.removeAt(jj);
                break;
            }
        }
    }
    reverting.clear();

    emit q->completed();
}

// Generate a list of actions for this state.  This includes coelescing state
// actions that this state "extends"
QDeclarativeStateOperation::ActionList
QDeclarativeStatePrivate::generateActionList(QDeclarativeStateGroup *group) const
{
    QDeclarativeStateOperation::ActionList applyList;
    if (inState)
        return applyList;

    // Prevent "extends" recursion
    inState = true;

    if (!extends.isEmpty()) {
        QList<QDeclarativeState *> states = group->states();
        for (int ii = 0; ii < states.count(); ++ii)
            if (states.at(ii)->name() == extends) {
                qmlExecuteDeferred(states.at(ii));
                applyList = static_cast<QDeclarativeStatePrivate*>(states.at(ii)->d_func())->generateActionList(group);
            }
    }

    foreach(QDeclarativeStateOperation *op, operations)
        applyList << op->actions();

    inState = false;
    return applyList;
}

QDeclarativeStateGroup *QDeclarativeState::stateGroup() const
{
    Q_D(const QDeclarativeState);
    return d->group;
}

void QDeclarativeState::setStateGroup(QDeclarativeStateGroup *group)
{
    Q_D(QDeclarativeState);
    d->group = group;
}

void QDeclarativeState::cancel()
{
    Q_D(QDeclarativeState);
    d->transitionManager.cancel();
}

void QDeclarativeAction::deleteFromBinding()
{
    if (fromBinding) {
        QDeclarativePropertyPrivate::setBinding(property, 0);
        fromBinding->destroy();
        fromBinding = 0;
    }
}

bool QDeclarativeState::containsPropertyInRevertList(QObject *target, const QString &name) const
{
    Q_D(const QDeclarativeState);

    if (isStateActive()) {
        QListIterator<QDeclarativeSimpleAction> revertListIterator(d->revertList);

        while (revertListIterator.hasNext()) {
            const QDeclarativeSimpleAction &simpleAction = revertListIterator.next();
            if (simpleAction.specifiedObject() == target && simpleAction.specifiedProperty() == name)
                return true;
        }
    }

    return false;
}

bool QDeclarativeState::changeValueInRevertList(QObject *target, const QString &name, const QVariant &revertValue)
{
    Q_D(QDeclarativeState);

    if (isStateActive()) {
        QMutableListIterator<QDeclarativeSimpleAction> revertListIterator(d->revertList);

        while (revertListIterator.hasNext()) {
            QDeclarativeSimpleAction &simpleAction = revertListIterator.next();
            if (simpleAction.specifiedObject() == target && simpleAction.specifiedProperty() == name) {
                    simpleAction.setValue(revertValue);
                    return true;
            }
        }
    }

    return false;
}

bool QDeclarativeState::changeBindingInRevertList(QObject *target, const QString &name, QDeclarativeAbstractBinding *binding)
{
    Q_D(QDeclarativeState);

    if (isStateActive()) {
        QMutableListIterator<QDeclarativeSimpleAction> revertListIterator(d->revertList);

        while (revertListIterator.hasNext()) {
            QDeclarativeSimpleAction &simpleAction = revertListIterator.next();
            if (simpleAction.specifiedObject() == target && simpleAction.specifiedProperty() == name) {
                if (simpleAction.binding())
                    simpleAction.binding()->destroy();

                simpleAction.setBinding(binding);
                return true;
            }
        }
    }

    return false;
}

bool QDeclarativeState::removeEntryFromRevertList(QObject *target, const QString &name)
{
    Q_D(QDeclarativeState);

    if (isStateActive()) {
        QMutableListIterator<QDeclarativeSimpleAction> revertListIterator(d->revertList);

        while (revertListIterator.hasNext()) {
            QDeclarativeSimpleAction &simpleAction = revertListIterator.next();
            if (simpleAction.property().object() == target && simpleAction.property().name() == name) {
                QDeclarativeAbstractBinding *oldBinding = QDeclarativePropertyPrivate::binding(simpleAction.property());
                if (oldBinding) {
                    QDeclarativePropertyPrivate::setBinding(simpleAction.property(), 0);
                    oldBinding->destroy();
                }

                simpleAction.property().write(simpleAction.value());
                if (simpleAction.binding())
                    QDeclarativePropertyPrivate::setBinding(simpleAction.property(), simpleAction.binding());

                revertListIterator.remove();
                return true;
            }
        }
    }

    return false;
}

void QDeclarativeState::addEntryToRevertList(const QDeclarativeAction &action)
{
    Q_D(QDeclarativeState);

    QDeclarativeSimpleAction simpleAction(action);

    d->revertList.append(simpleAction);
}

void QDeclarativeState::removeAllEntriesFromRevertList(QObject *target)
{
     Q_D(QDeclarativeState);

     if (isStateActive()) {
         QMutableListIterator<QDeclarativeSimpleAction> revertListIterator(d->revertList);

         while (revertListIterator.hasNext()) {
             QDeclarativeSimpleAction &simpleAction = revertListIterator.next();
             if (simpleAction.property().object() == target) {
                 QDeclarativeAbstractBinding *oldBinding = QDeclarativePropertyPrivate::binding(simpleAction.property());
                 if (oldBinding) {
                     QDeclarativePropertyPrivate::setBinding(simpleAction.property(), 0);
                     oldBinding->destroy();
                 }

                 simpleAction.property().write(simpleAction.value());
                 if (simpleAction.binding())
                     QDeclarativePropertyPrivate::setBinding(simpleAction.property(), simpleAction.binding());

                 revertListIterator.remove();
             }
         }
     }
}

void QDeclarativeState::addEntriesToRevertList(const QList<QDeclarativeAction> &actionList)
{
    Q_D(QDeclarativeState);
    if (isStateActive()) {
        QList<QDeclarativeSimpleAction> simpleActionList;

        QListIterator<QDeclarativeAction> actionListIterator(actionList);
        while(actionListIterator.hasNext()) {
            const QDeclarativeAction &action = actionListIterator.next();
            QDeclarativeSimpleAction simpleAction(action);
            action.property.write(action.toValue);
            if (!action.toBinding.isNull()) {
                QDeclarativeAbstractBinding *oldBinding = QDeclarativePropertyPrivate::binding(simpleAction.property());
                if (oldBinding)
                    QDeclarativePropertyPrivate::setBinding(simpleAction.property(), 0);
                QDeclarativePropertyPrivate::setBinding(simpleAction.property(), action.toBinding.data(), QDeclarativePropertyPrivate::DontRemoveBinding);
            }

            simpleActionList.append(simpleAction);
        }

        d->revertList.append(simpleActionList);
    }
}

QVariant QDeclarativeState::valueInRevertList(QObject *target, const QString &name) const
{
    Q_D(const QDeclarativeState);

    if (isStateActive()) {
        QListIterator<QDeclarativeSimpleAction> revertListIterator(d->revertList);

        while (revertListIterator.hasNext()) {
            const QDeclarativeSimpleAction &simpleAction = revertListIterator.next();
            if (simpleAction.specifiedObject() == target && simpleAction.specifiedProperty() == name)
                return simpleAction.value();
        }
    }

    return QVariant();
}

QDeclarativeAbstractBinding *QDeclarativeState::bindingInRevertList(QObject *target, const QString &name) const
{
    Q_D(const QDeclarativeState);

    if (isStateActive()) {
        QListIterator<QDeclarativeSimpleAction> revertListIterator(d->revertList);

        while (revertListIterator.hasNext()) {
            const QDeclarativeSimpleAction &simpleAction = revertListIterator.next();
            if (simpleAction.specifiedObject() == target && simpleAction.specifiedProperty() == name)
                return simpleAction.binding();
        }
    }

    return 0;
}

bool QDeclarativeState::isStateActive() const
{
    return stateGroup() && stateGroup()->state() == name();
}

void QDeclarativeState::apply(QDeclarativeStateGroup *group, QDeclarativeTransition *trans, QDeclarativeState *revert)
{
    Q_D(QDeclarativeState);

    qmlExecuteDeferred(this);

    cancel();
    if (revert)
        revert->cancel();
    d->revertList.clear();
    d->reverting.clear();

    if (revert) {
        QDeclarativeStatePrivate *revertPrivate =
            static_cast<QDeclarativeStatePrivate*>(revert->d_func());
        d->revertList = revertPrivate->revertList;
        revertPrivate->revertList.clear();
    }

    // List of actions caused by this state
    QDeclarativeStateOperation::ActionList applyList = d->generateActionList(group);

    // List of actions that need to be reverted to roll back (just) this state
    QDeclarativeStatePrivate::SimpleActionList additionalReverts;
    // First add the reverse of all the applyList actions
    for (int ii = 0; ii < applyList.count(); ++ii) {
        QDeclarativeAction &action = applyList[ii];

        if (action.event) {
            if (!action.event->isReversable())
                continue;
            bool found = false;
            for (int jj = 0; jj < d->revertList.count(); ++jj) {
                QDeclarativeActionEvent *event = d->revertList.at(jj).event();
                if (event && event->typeName() == action.event->typeName()) {
                    if (action.event->override(event)) {
                        found = true;

                        if (action.event != d->revertList.at(jj).event() && action.event->needsCopy()) {
                            action.event->copyOriginals(d->revertList.at(jj).event());

                            QDeclarativeSimpleAction r(action);
                            additionalReverts << r;
                            d->revertList.removeAt(jj);
                            --jj;
                        } else if (action.event->isRewindable())    //###why needed?
                            action.event->saveCurrentValues();

                        break;
                    }
                }
            }
            if (!found) {
                action.event->saveOriginals();
                // Only need to revert the applyList action if the previous
                // state doesn't have a higher priority revert already
                QDeclarativeSimpleAction r(action);
                additionalReverts << r;
            }
        } else {
            bool found = false;
            action.fromBinding = QDeclarativePropertyPrivate::binding(action.property);

            for (int jj = 0; jj < d->revertList.count(); ++jj) {
                if (d->revertList.at(jj).property() == action.property) {
                    found = true;
                    if (d->revertList.at(jj).binding() != action.fromBinding) {
                        action.deleteFromBinding();
                    }
                    break;
                }
            }

            if (!found) {
                if (!action.restore) {
                    action.deleteFromBinding();;
                } else {
                    // Only need to revert the applyList action if the previous
                    // state doesn't have a higher priority revert already
                    QDeclarativeSimpleAction r(action);
                    additionalReverts << r;
                }
            }
        }
    }

    // Any reverts from a previous state that aren't carried forth
    // into this state need to be translated into apply actions
    for (int ii = 0; ii < d->revertList.count(); ++ii) {
        bool found = false;
        if (d->revertList.at(ii).event()) {
            QDeclarativeActionEvent *event = d->revertList.at(ii).event();
            if (!event->isReversable())
                continue;
            for (int jj = 0; !found && jj < applyList.count(); ++jj) {
                const QDeclarativeAction &action = applyList.at(jj);
                if (action.event && action.event->typeName() == event->typeName()) {
                    if (action.event->override(event))
                        found = true;
                }
            }
        } else {
            for (int jj = 0; !found && jj < applyList.count(); ++jj) {
                const QDeclarativeAction &action = applyList.at(jj);
                if (action.property == d->revertList.at(ii).property())
                    found = true;
            }
        }
        if (!found) {
            QVariant cur = d->revertList.at(ii).property().read();
            QDeclarativeAbstractBinding *delBinding = 
                QDeclarativePropertyPrivate::setBinding(d->revertList.at(ii).property(), 0);
            if (delBinding)
                delBinding->destroy();

            QDeclarativeAction a;
            a.property = d->revertList.at(ii).property();
            a.fromValue = cur;
            a.toValue = d->revertList.at(ii).value();
            a.toBinding = QDeclarativeAbstractBinding::getPointer(d->revertList.at(ii).binding());
            a.specifiedObject = d->revertList.at(ii).specifiedObject();
            a.specifiedProperty = d->revertList.at(ii).specifiedProperty();
            a.event = d->revertList.at(ii).event();
            a.reverseEvent = d->revertList.at(ii).reverseEvent();
            if (a.event && a.event->isRewindable())
                a.event->saveCurrentValues();
            applyList << a;
            // Store these special reverts in the reverting list
            d->reverting << d->revertList.at(ii).property();
        }
    }
    // All the local reverts now become part of the ongoing revertList
    d->revertList << additionalReverts;

#ifndef QT_NO_DEBUG_STREAM
    // Output for debugging
    if (stateChangeDebug()) {
        foreach(const QDeclarativeAction &action, applyList) {
            if (action.event)
                qWarning() << "    QDeclarativeAction event:" << action.event->typeName();
            else
                qWarning() << "    QDeclarativeAction:" << action.property.object()
                           << action.property.name() << "From:" << action.fromValue 
                           << "To:" << action.toValue;
        }
    }
#endif

    d->transitionManager.transition(applyList, trans);
}

QDeclarativeStateOperation::ActionList QDeclarativeStateOperation::actions()
{
    return ActionList();
}

QDeclarativeState *QDeclarativeStateOperation::state() const
{
    Q_D(const QDeclarativeStateOperation);
    return d->m_state;
}

void QDeclarativeStateOperation::setState(QDeclarativeState *state)
{
    Q_D(QDeclarativeStateOperation);
    d->m_state = state;
}

QT_END_NAMESPACE