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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), toBinding(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), toValue(value), 

  fromBinding(0), toBinding(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), toBinding(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)

{

}

/*!

    \qmlclass State QDeclarativeState

    \since 4.7

    \brief The State element defines configurations of objects and properties.

    A \e state is a set of batched changes from the default configuration.

    All items have a default state that defines the default configuration of objects

    and property values. New states can be defined by adding State items to the \l {Item::states}{states} property to

    allow items to switch between different configurations. These configurations

    can, for example, be used to apply different sets of property values or execute

    different scripts.

    The following example displays a single \l Rectangle. In the default state, the rectangle

    is colored black. In the "clicked" state, a PropertyChanges element changes the

    rectangle's color to red. Clicking within the MouseArea toggles the rectangle's state

    between the default state and the "clicked" state, thus toggling the color of the

    rectangle between black and red.

    \snippet doc/src/snippets/declarative/state.qml 0

    Notice the default state is referred to using an empty string ("").

    animations when state changes occur.

    \note Setting the state of an object from within another state of the same object is

    not allowed.

*/

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);

}

/*!

    \qmlproperty string State::name

    This property holds the name of the state.

    Each state should have a unique name within its item.

*/

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;

}

/*!

    \qmlproperty bool State::when

    This property holds when the state should be applied.

    This should be set to an expression that evaluates to \c true when you want the state to

    be applied. For example, the following \l Rectangle changes in and out of the "hidden"

    state when the \l MouseArea is pressed:

    If multiple states in a group have \c when clauses that evaluate to \c true at the same time,

    the first matching state will be applied. For example, in the following snippet

    \c state1 will always be selected rather than \c state2 when sharedCondition becomes

    \c true.

    \qml

    states: [

        State { name: "state1"; when: sharedCondition },

        State { name: "state2"; when: sharedCondition }

    ]

    \endqml

*/

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();

}

/*!

    \qmlproperty string State::extend

    This property holds the state that this state extends.

    When a state extends another state, it inherits all the changes of that state.

    The state being extended is treated as the base state in regards to

    the changes specified by the extending state.

*/

QString QDeclarativeState::extends() const

{

    Q_D(const QDeclarativeState);

    return d->extends;

}

void QDeclarativeState::setExtends(const QString &extends)

{

    Q_D(QDeclarativeState);

    d->extends = extends;

}

/*!

    \qmlproperty list<Change> State::changes

    This property holds the changes to apply for this state

    \default

    By default these changes are applied against the default state. If the state

    extends another state, then the changes are applied against the state being

    extended.

*/

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)

                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;

    }

}

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 = 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);

}