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Diffstat (limited to 'src/corelib/statemachine/qhistorystate.cpp')
-rw-r--r-- | src/corelib/statemachine/qhistorystate.cpp | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/src/corelib/statemachine/qhistorystate.cpp b/src/corelib/statemachine/qhistorystate.cpp new file mode 100644 index 0000000..517faa8 --- /dev/null +++ b/src/corelib/statemachine/qhistorystate.cpp @@ -0,0 +1,223 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (qt-info@nokia.com) +** +** This file is part of the QtCore module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain +** additional rights. These rights are described in the Nokia Qt LGPL +** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at qt-sales@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qhistorystate.h" +#include "qhistorystate_p.h" + +QT_BEGIN_NAMESPACE + +/*! + \class QHistoryState + + \brief The QHistoryState class provides a means of returning to a previously active substate. + + \since 4.6 + \ingroup statemachine + + A history state is a pseudo-state that represents the child state that the + parent state was in the last time the parent state was exited. A transition + with a history state as its target is in fact a transition to one of the + other child states of the parent state. QHistoryState is part of \l{The + State Machine Framework}. + + Use the setDefaultState() function to set the state that should be entered + if the parent state has never been entered. Example: + + \code + QStateMachine machine; + + QState *s1 = new QState(); + QState *s11 = new QState(s1); + QState *s12 = new QState(s1); + + QHistoryState *s1h = new QHistoryState(s1); + s1h->setDefaultState(s11); + + machine.addState(s1); + + QState *s2 = new QState(); + machine.addState(s2); + + QPushButton *button = new QPushButton(); + // Clicking the button will cause the state machine to enter the child state + // that s1 was in the last time s1 was exited, or the history state's default + // state if s1 has never been entered. + s1->addTransition(button, SIGNAL(clicked()), s1h); + \endcode + + By default a history state is shallow, meaning that it won't remember nested + states. This can be configured through the historyType property. +*/ + +/*! + \property QHistoryState::defaultState + + \brief the default state of this history state +*/ + +/*! + \property QHistoryState::historyType + + \brief the type of history that this history state records + + The default value of this property is QHistoryState::ShallowHistory. +*/ + +/*! + \enum QHistoryState::HistoryType + + This enum specifies the type of history that a QHistoryState records. + + \value ShallowHistory Only the immediate child states of the parent state + are recorded. In this case a transition with the history state as its + target will end up in the immediate child state that the parent was in the + last time it was exited. This is the default. + + \value DeepHistory Nested states are recorded. In this case a transition + with the history state as its target will end up in the most deeply nested + descendant state the parent was in the last time it was exited. +*/ + +QHistoryStatePrivate::QHistoryStatePrivate() + : defaultState(0) +{ +} + +QHistoryStatePrivate *QHistoryStatePrivate::get(QHistoryState *q) +{ + return q->d_func(); +} + +/*! + Constructs a new shallow history state with the given \a parent state. +*/ +QHistoryState::QHistoryState(QState *parent) + : QAbstractState(*new QHistoryStatePrivate, parent) +{ + Q_D(QHistoryState); + d->historyType = ShallowHistory; +} +/*! + Constructs a new history state of the given \a type, with the given \a + parent state. +*/ +QHistoryState::QHistoryState(HistoryType type, QState *parent) + : QAbstractState(*new QHistoryStatePrivate, parent) +{ + Q_D(QHistoryState); + d->historyType = type; +} + +/*! + Destroys this history state. +*/ +QHistoryState::~QHistoryState() +{ +} + +/*! + Returns this history state's default state. The default state indicates the + state to transition to if the parent state has never been entered before. +*/ +QAbstractState *QHistoryState::defaultState() const +{ + Q_D(const QHistoryState); + return d->defaultState; +} + +/*! + Sets this history state's default state to be the given \a state. + \a state must be a sibling of this history state. +*/ +void QHistoryState::setDefaultState(QAbstractState *state) +{ + Q_D(QHistoryState); + if (state && state->parentState() != parentState()) { + qWarning("QHistoryState::setDefaultState: state %p does not belong " + "to this history state's group (%p)", state, parentState()); + return; + } + d->defaultState = state; +} + +/*! + Returns the type of history that this history state records. +*/ +QHistoryState::HistoryType QHistoryState::historyType() const +{ + Q_D(const QHistoryState); + return d->historyType; +} + +/*! + Sets the \a type of history that this history state records. +*/ +void QHistoryState::setHistoryType(HistoryType type) +{ + Q_D(QHistoryState); + d->historyType = type; +} + +/*! + \reimp +*/ +void QHistoryState::onEntry(QEvent *event) +{ + Q_UNUSED(event); +} + +/*! + \reimp +*/ +void QHistoryState::onExit(QEvent *event) +{ + Q_UNUSED(event); +} + +/*! + \reimp +*/ +bool QHistoryState::event(QEvent *e) +{ + return QAbstractState::event(e); +} + +QT_END_NAMESPACE |