From 5b24e614a445d046cb0c107b6da469993959ed6e Mon Sep 17 00:00:00 2001 From: Lars Knoll Date: Thu, 16 Aug 2012 09:39:59 +0200 Subject: Move the statemachine documentation into qtcore Moved the documentation from qtdoc to here, so the statemachine class docs can link to it. Change-Id: I49a10cc7c418d415c64ea538376eb9bd7b031c27 Reviewed-by: Thiago Macieira Reviewed-by: Casper van Donderen --- .../doc/images/statemachine-button-history.png | Bin 0 -> 8493 bytes .../doc/images/statemachine-button-nested.png | Bin 0 -> 7051 bytes src/corelib/doc/images/statemachine-button.png | Bin 0 -> 4233 bytes .../doc/images/statemachine-customevents.png | Bin 0 -> 2544 bytes .../doc/images/statemachine-customevents2.png | Bin 0 -> 6713 bytes src/corelib/doc/images/statemachine-examples.png | Bin 0 -> 3326 bytes src/corelib/doc/images/statemachine-finished.png | Bin 0 -> 5518 bytes .../doc/images/statemachine-nonparallel.png | Bin 0 -> 5350 bytes src/corelib/doc/images/statemachine-parallel.png | Bin 0 -> 8631 bytes .../doc/snippets/statemachine/eventtest.cpp | 73 +++ src/corelib/doc/snippets/statemachine/main.cpp | 87 ++++ src/corelib/doc/snippets/statemachine/main2.cpp | 91 ++++ src/corelib/doc/snippets/statemachine/main3.cpp | 60 +++ src/corelib/doc/snippets/statemachine/main4.cpp | 110 ++++ src/corelib/doc/snippets/statemachine/main5.cpp | 172 +++++++ src/corelib/doc/src/statemachine.qdoc | 570 +++++++++++++++++++++ 16 files changed, 1163 insertions(+) create mode 100644 src/corelib/doc/images/statemachine-button-history.png create mode 100644 src/corelib/doc/images/statemachine-button-nested.png create mode 100644 src/corelib/doc/images/statemachine-button.png create mode 100644 src/corelib/doc/images/statemachine-customevents.png create mode 100644 src/corelib/doc/images/statemachine-customevents2.png create mode 100644 src/corelib/doc/images/statemachine-examples.png create mode 100644 src/corelib/doc/images/statemachine-finished.png create mode 100644 src/corelib/doc/images/statemachine-nonparallel.png create mode 100644 src/corelib/doc/images/statemachine-parallel.png create mode 100644 src/corelib/doc/snippets/statemachine/eventtest.cpp create mode 100644 src/corelib/doc/snippets/statemachine/main.cpp create mode 100644 src/corelib/doc/snippets/statemachine/main2.cpp create mode 100644 src/corelib/doc/snippets/statemachine/main3.cpp create mode 100644 src/corelib/doc/snippets/statemachine/main4.cpp create mode 100644 src/corelib/doc/snippets/statemachine/main5.cpp create mode 100644 src/corelib/doc/src/statemachine.qdoc (limited to 'src/corelib') diff --git a/src/corelib/doc/images/statemachine-button-history.png b/src/corelib/doc/images/statemachine-button-history.png new file mode 100644 index 0000000000..7f51cae3f2 Binary files /dev/null and b/src/corelib/doc/images/statemachine-button-history.png differ diff --git a/src/corelib/doc/images/statemachine-button-nested.png b/src/corelib/doc/images/statemachine-button-nested.png new file mode 100644 index 0000000000..762ac14df1 Binary files /dev/null and b/src/corelib/doc/images/statemachine-button-nested.png differ diff --git a/src/corelib/doc/images/statemachine-button.png b/src/corelib/doc/images/statemachine-button.png new file mode 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+/**************************************************************************** +** +** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/ +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:BSD$ +** You may use this file under the terms of the BSD license as follows: +** +** "Redistribution and use in source and binary forms, with or without +** modification, are permitted provided that the following conditions are +** met: +** * Redistributions of source code must retain the above copyright +** notice, this list of conditions and the following disclaimer. +** * Redistributions in binary form must reproduce the above copyright +** notice, this list of conditions and the following disclaimer in +** the documentation and/or other materials provided with the +** distribution. +** * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor +** the names of its contributors may be used to endorse or promote +** products derived from this software without specific prior written +** permission. +** +** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include + +class MyTransition : public QAbstractTransition +{ + Q_OBJECT +public: + MyTransition() {} + +protected: +//![0] + bool eventTest(QEvent *event) + { + if (event->type() == QEvent::Wrapped) { + QEvent *wrappedEvent = static_cast(event)->event(); + if (wrappedEvent->type() == QEvent::KeyPress) { + QKeyEvent *keyEvent = static_cast(wrappedEvent); + // Do your event test + } + } + return false; + } +//![0] + + void onTransition(QEvent *event) + { + + } +}; + +int main(int argv, char **args) +{ + return 0; +} diff --git a/src/corelib/doc/snippets/statemachine/main.cpp b/src/corelib/doc/snippets/statemachine/main.cpp new file mode 100644 index 0000000000..ee0cfd6700 --- /dev/null +++ b/src/corelib/doc/snippets/statemachine/main.cpp @@ -0,0 +1,87 @@ +/**************************************************************************** +** +** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/ +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:BSD$ +** You may use this file under the terms of the BSD license as follows: +** +** "Redistribution and use in source and binary forms, with or without +** modification, are permitted provided that the following conditions are +** met: +** * Redistributions of source code must retain the above copyright +** notice, this list of conditions and the following disclaimer. +** * Redistributions in binary form must reproduce the above copyright +** notice, this list of conditions and the following disclaimer in +** the documentation and/or other materials provided with the +** distribution. +** * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor +** the names of its contributors may be used to endorse or promote +** products derived from this software without specific prior written +** permission. +** +** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include + +int main(int argv, char **args) +{ + QApplication app(argv, args); + + QLabel *label = new QLabel; + +//![0] + QStateMachine machine; + QState *s1 = new QState(); + QState *s2 = new QState(); + QState *s3 = new QState(); +//![0] + +//![4] + s1->assignProperty(label, "text", "In state s1"); + s2->assignProperty(label, "text", "In state s2"); + s3->assignProperty(label, "text", "In state s3"); +//![4] + +//![5] + QObject::connect(s3, SIGNAL(entered()), button, SLOT(showMaximized())); + QObject::connect(s3, SIGNAL(exited()), button, SLOT(showMinimized())); +//![5] + +//![1] + s1->addTransition(button, SIGNAL(clicked()), s2); + s2->addTransition(button, SIGNAL(clicked()), s3); + s3->addTransition(button, SIGNAL(clicked()), s1); +//![1] + +//![2] + machine.addState(s1); + machine.addState(s2); + machine.addState(s3); + machine.setInitialState(s1); +//![2] + +//![3] + machine.start(); +//![3] + + label->show(); + + return app.exec(); +} diff --git a/src/corelib/doc/snippets/statemachine/main2.cpp b/src/corelib/doc/snippets/statemachine/main2.cpp new file mode 100644 index 0000000000..931a29676e --- /dev/null +++ b/src/corelib/doc/snippets/statemachine/main2.cpp @@ -0,0 +1,91 @@ +/**************************************************************************** +** +** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/ +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:BSD$ +** You may use this file under the terms of the BSD license as follows: +** +** "Redistribution and use in source and binary forms, with or without +** modification, are permitted provided that the following conditions are +** met: +** * Redistributions of source code must retain the above copyright +** notice, this list of conditions and the following disclaimer. +** * Redistributions in binary form must reproduce the above copyright +** notice, this list of conditions and the following disclaimer in +** the documentation and/or other materials provided with the +** distribution. +** * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor +** the names of its contributors may be used to endorse or promote +** products derived from this software without specific prior written +** permission. +** +** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include + +int main(int argv, char **args) +{ + QApplication app(argv, args); + + QStateMachine machine; + +//![0] + QState *s1 = new QState(); + QState *s11 = new QState(s1); + QState *s12 = new QState(s1); + QState *s13 = new QState(s1); + s1->setInitialState(s11); + machine.addState(s1); +//![0] + +//![2] + s12->addTransition(quitButton, SIGNAL(clicked()), s12); +//![2] + +//![1] + QFinalState *s2 = new QFinalState(); + s1->addTransition(quitButton, SIGNAL(clicked()), s2); + machine.addState(s2); + + QObject::connect(&machine, SIGNAL(finished()), QApplication::instance(), SLOT(quit())); +//![1] + + QButton *interruptButton = new QPushButton("Interrupt Button"); + QWidget *mainWindow = new QWidget(); + +//![3] + QHistoryState *s1h = new QHistoryState(s1); + + QState *s3 = new QState(); + s3->assignProperty(label, "text", "In s3"); + QMessageBox *mbox = new QMessageBox(mainWindow); + mbox->addButton(QMessageBox::Ok); + mbox->setText("Interrupted!"); + mbox->setIcon(QMessageBox::Information); + QObject::connect(s3, SIGNAL(entered()), mbox, SLOT(exec())); + s3->addTransition(s1h); + machine.addState(s3); + + s1->addTransition(interruptButton, SIGNAL(clicked()), s3); +//![3] + + return app.exec(); +} + diff --git a/src/corelib/doc/snippets/statemachine/main3.cpp b/src/corelib/doc/snippets/statemachine/main3.cpp new file mode 100644 index 0000000000..446db541e8 --- /dev/null +++ b/src/corelib/doc/snippets/statemachine/main3.cpp @@ -0,0 +1,60 @@ +/**************************************************************************** +** +** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/ +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:BSD$ +** You may use this file under the terms of the BSD license as follows: +** +** "Redistribution and use in source and binary forms, with or without +** modification, are permitted provided that the following conditions are +** met: +** * Redistributions of source code must retain the above copyright +** notice, this list of conditions and the following disclaimer. +** * Redistributions in binary form must reproduce the above copyright +** notice, this list of conditions and the following disclaimer in +** the documentation and/or other materials provided with the +** distribution. +** * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor +** the names of its contributors may be used to endorse or promote +** products derived from this software without specific prior written +** permission. +** +** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include + +int main(int argv, char **args) +{ + QApplication app(argv, args); + +//![0] + QState *s1 = new QState(QState::ParallelStates); + // s11 and s12 will be entered in parallel + QState *s11 = new QState(s1); + QState *s12 = new QState(s1); +//![0] + +//![1] + s1->addTransition(s1, SIGNAL(finished()), s2); +//![1] + + return app.exec(); +} + diff --git a/src/corelib/doc/snippets/statemachine/main4.cpp b/src/corelib/doc/snippets/statemachine/main4.cpp new file mode 100644 index 0000000000..8c9a8aca0e --- /dev/null +++ b/src/corelib/doc/snippets/statemachine/main4.cpp @@ -0,0 +1,110 @@ +/**************************************************************************** +** +** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/ +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:BSD$ +** You may use this file under the terms of the BSD license as follows: +** +** "Redistribution and use in source and binary forms, with or without +** modification, are permitted provided that the following conditions are +** met: +** * Redistributions of source code must retain the above copyright +** notice, this list of conditions and the following disclaimer. +** * Redistributions in binary form must reproduce the above copyright +** notice, this list of conditions and the following disclaimer in +** the documentation and/or other materials provided with the +** distribution. +** * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor +** the names of its contributors may be used to endorse or promote +** products derived from this software without specific prior written +** permission. +** +** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include + + +//![0] +struct StringEvent : public QEvent +{ + StringEvent(const QString &val) + : QEvent(QEvent::Type(QEvent::User+1)), + value(val) {} + + QString value; +}; +//![0] + +//![1] +class StringTransition : public QAbstractTransition +{ +public: + StringTransition(const QString &value) + : m_value(value) {} + +protected: + virtual bool eventTest(QEvent *e) const + { + if (e->type() != QEvent::Type(QEvent::User+1)) // StringEvent + return false; + StringEvent *se = static_cast(e); + return (m_value == se->value); + } + + virtual void onTransition(QEvent *) {} + +private: + QString m_value; +}; +//![1] + +int main(int argv, char **args) +{ + QApplication app(argv, args); + +//![2] + QStateMachine machine; + QState *s1 = new QState(); + QState *s2 = new QState(); + QFinalState *done = new QFinalState(); + + StringTransition *t1 = new StringTransition("Hello"); + t1->setTargetState(s2); + s1->addTransition(t1); + StringTransition *t2 = new StringTransition("world"); + t2->setTargetState(done); + s2->addTransition(t2); + + machine.addState(s1); + machine.addState(s2); + machine.addState(done); + machine.setInitialState(s1); +//![2] + +//![3] + machine.postEvent(new StringEvent("Hello")); + machine.postEvent(new StringEvent("world")); +//![3] + + return app.exec(); +} + +#include "main4.moc" + diff --git a/src/corelib/doc/snippets/statemachine/main5.cpp b/src/corelib/doc/snippets/statemachine/main5.cpp new file mode 100644 index 0000000000..b801ad8982 --- /dev/null +++ b/src/corelib/doc/snippets/statemachine/main5.cpp @@ -0,0 +1,172 @@ +/**************************************************************************** +** +** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/ +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:BSD$ +** You may use this file under the terms of the BSD license as follows: +** +** "Redistribution and use in source and binary forms, with or without +** modification, are permitted provided that the following conditions are +** met: +** * Redistributions of source code must retain the above copyright +** notice, this list of conditions and the following disclaimer. +** * Redistributions in binary form must reproduce the above copyright +** notice, this list of conditions and the following disclaimer in +** the documentation and/or other materials provided with the +** distribution. +** * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor +** the names of its contributors may be used to endorse or promote +** products derived from this software without specific prior written +** permission. +** +** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include + +int main(int argv, char **args) +{ + QApplication app(argv, args); + QWidget *button; + + { +//![0] + QStateMachine machine; + machine.setGlobalRestorePolicy(QStateMachine::RestoreProperties); + + QState *s1 = new QState(); + s1->assignProperty(object, "fooBar", 1.0); + machine.addState(s1); + machine.setInitialState(s1); + + QState *s2 = new QState(); + machine.addState(s2); +//![0] + } + + { + +//![2] + QStateMachine machine; + machine.setGlobalRestorePolicy(QStateMachine::RestoreProperties); + + QState *s1 = new QState(); + s1->assignProperty(object, "fooBar", 1.0); + machine.addState(s1); + machine.setInitialState(s1); + + QState *s2 = new QState(s1); + s2->assignProperty(object, "fooBar", 2.0); + s1->setInitialState(s2); + + QState *s3 = new QState(s1); +//![2] + + } + + { +//![3] + QState *s1 = new QState(); + QState *s2 = new QState(); + + s1->assignProperty(button, "geometry", QRectF(0, 0, 50, 50)); + s2->assignProperty(button, "geometry", QRectF(0, 0, 100, 100)); + + s1->addTransition(button, SIGNAL(clicked()), s2); +//![3] + + } + + { +//![4] + QState *s1 = new QState(); + QState *s2 = new QState(); + + s1->assignProperty(button, "geometry", QRectF(0, 0, 50, 50)); + s2->assignProperty(button, "geometry", QRectF(0, 0, 100, 100)); + + QSignalTransition *transition = s1->addTransition(button, SIGNAL(clicked()), s2); + transition->addAnimation(new QPropertyAnimation(button, "geometry")); +//![4] + + } + + { + QMainWindow *mainWindow = 0; + +//![5] + QMessageBox *messageBox = new QMessageBox(mainWindow); + messageBox->addButton(QMessageBox::Ok); + messageBox->setText("Button geometry has been set!"); + messageBox->setIcon(QMessageBox::Information); + + QState *s1 = new QState(); + + QState *s2 = new QState(); + s2->assignProperty(button, "geometry", QRectF(0, 0, 50, 50)); + connect(s2, SIGNAL(entered()), messageBox, SLOT(exec())); + + s1->addTransition(button, SIGNAL(clicked()), s2); +//![5] + } + + { + QMainWindow *mainWindow = 0; + +//![6] + QMessageBox *messageBox = new QMessageBox(mainWindow); + messageBox->addButton(QMessageBox::Ok); + messageBox->setText("Button geometry has been set!"); + messageBox->setIcon(QMessageBox::Information); + + QState *s1 = new QState(); + + QState *s2 = new QState(); + s2->assignProperty(button, "geometry", QRectF(0, 0, 50, 50)); + + QState *s3 = new QState(); + connect(s3, SIGNAL(entered()), messageBox, SLOT(exec())); + + s1->addTransition(button, SIGNAL(clicked()), s2); + s2->addTransition(s2, SIGNAL(propertiesAssigned()), s3); +//![6] + + } + + { + +//![7] + QState *s1 = new QState(); + QState *s2 = new QState(); + + s2->assignProperty(object, "fooBar", 2.0); + s1->addTransition(s2); + + QStateMachine machine; + machine.setInitialState(s1); + machine.addDefaultAnimation(new QPropertyAnimation(object, "fooBar")); +//![7] + + } + + + + return app.exec(); +} + diff --git a/src/corelib/doc/src/statemachine.qdoc b/src/corelib/doc/src/statemachine.qdoc new file mode 100644 index 0000000000..12b37bbe2e --- /dev/null +++ b/src/corelib/doc/src/statemachine.qdoc @@ -0,0 +1,570 @@ +/**************************************************************************** +** +** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/ +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:FDL$ +** GNU Free Documentation License +** Alternatively, this file may be used under the terms of the GNU Free +** Documentation License version 1.3 as published by the Free Software +** Foundation and appearing in the file included in the packaging of +** this file. +** +** Other Usage +** Alternatively, this file may be used in accordance with the terms +** and conditions contained in a signed written agreement between you +** and Nokia. +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! + \group statemachine + \title State Machine Classes +*/ + +/*! + \page statemachine-api.html + \title The State Machine Framework + \brief An overview of the State Machine framework for constructing and executing state graphs. + + \ingroup frameworks-technologies + + \tableofcontents + + The State Machine framework provides classes for creating and executing + state graphs. The concepts and notation are based on those from Harel's + \l{Statecharts: A visual formalism for complex systems}{Statecharts}, which + is also the basis of UML state diagrams. The semantics of state machine + execution are based on \l{State Chart XML: State Machine Notation for + Control Abstraction}{State Chart XML (SCXML)}. + + Statecharts provide a graphical way of modeling how a system reacts to + stimuli. This is done by defining the possible \e states that the system can + be in, and how the system can move from one state to another (\e transitions + between states). A key characteristic of event-driven systems (such as Qt + applications) is that behavior often depends not only on the last or current + event, but also the events that preceded it. With statecharts, this + information is easy to express. + + The State Machine framework provides an API and execution model that can be + used to effectively embed the elements and semantics of statecharts in Qt + applications. The framework integrates tightly with Qt's meta-object system; + for example, transitions between states can be triggered by signals, and + states can be configured to set properties and invoke methods on QObjects. + Qt's event system is used to drive the state machines. + + The state graph in the State Machine framework is hierarchical. States can be nested inside of + other states, and the current configuration of the state machine consists of the set of states + which are currently active. All the states in a valid configuration of the state machine will + have a common ancestor. + + \section1 Classes in the State Machine Framework + + These classes are provided by qt for creating event-driven state machines. + + \annotatedlist statemachine + + \section1 A Simple State Machine + + To demonstrate the core functionality of the State Machine API, let's look + at a small example: A state machine with three states, \c s1, \c s2 and \c + s3. The state machine is controlled by a single QPushButton; when the button + is clicked, the machine transitions to another state. Initially, the state + machine is in state \c s1. The statechart for this machine is as follows: + + \image statemachine-button.png + \omit + \caption This is a caption + \endomit + + The following snippet shows the code needed to create such a state machine. + First, we create the state machine and states: + + \snippet statemachine/main.cpp 0 + + Then, we create the transitions by using the QState::addTransition() + function: + + \snippet statemachine/main.cpp 1 + + Next, we add the states to the machine and set the machine's initial state: + + \snippet statemachine/main.cpp 2 + + Finally, we start the state machine: + + \snippet statemachine/main.cpp 3 + + The state machine executes asynchronously, i.e. it becomes part of your + application's event loop. + + \section1 Doing Useful Work on State Entry and Exit + + The above state machine merely transitions from one state to another, it + doesn't perform any operations. The QState::assignProperty() function can be + used to have a state set a property of a QObject when the state is + entered. In the following snippet, the value that should be assigned to a + QLabel's text property is specified for each state: + + \snippet statemachine/main.cpp 4 + + When any of the states is entered, the label's text will be changed + accordingly. + + The QState::entered() signal is emitted when the state is entered, and the + QState::exited() signal is emitted when the state is exited. In the + following snippet, the button's showMaximized() slot will be called when + state \c s3 is entered, and the button's showMinimized() slot will be called + when \c s3 is exited: + + \snippet statemachine/main.cpp 5 + + Custom states can reimplement QAbstractState::onEntry() and + QAbstractState::onExit(). + + \section1 State Machines That Finish + + The state machine defined in the previous section never finishes. In order + for a state machine to be able to finish, it needs to have a top-level \e + final state (QFinalState object). When the state machine enters a top-level + final state, the machine will emit the QStateMachine::finished() signal and + halt. + + All you need to do to introduce a final state in the graph is create a + QFinalState object and use it as the target of one or more transitions. + + \section1 Sharing Transitions By Grouping States + + Assume we wanted the user to be able to quit the application at any time by + clicking a Quit button. In order to achieve this, we need to create a final + state and make it the target of a transition associated with the Quit + button's clicked() signal. We could add a transition from each of \c s1, \c + s2 and \c s3; however, this seems redundant, and one would also have to + remember to add such a transition from every new state that is added in the + future. + + We can achieve the same behavior (namely that clicking the Quit button quits + the state machine, regardless of which state the state machine is in) by + grouping states \c s1, \c s2 and \c s3. This is done by creating a new + top-level state and making the three original states children of the new + state. The following diagram shows the new state machine. + + \image statemachine-button-nested.png + \omit + \caption This is a caption + \endomit + + The three original states have been renamed \c s11, \c s12 and \c s13 to + reflect that they are now children of the new top-level state, \c s1. Child + states implicitly inherit the transitions of their parent state. This means + it is now sufficient to add a single transition from \c s1 to the final + state \c s2. New states added to \c s1 will also automatically inherit this + transition. + + All that's needed to group states is to specify the proper parent when the + state is created. You also need to specify which of the child states is the + initial one (i.e. which child state the state machine should enter when the + parent state is the target of a transition). + + \snippet statemachine/main2.cpp 0 + + \snippet statemachine/main2.cpp 1 + + In this case we want the application to quit when the state machine is + finished, so the machine's finished() signal is connected to the + application's quit() slot. + + A child state can override an inherited transition. For example, the + following code adds a transition that effectively causes the Quit button to + be ignored when the state machine is in state \c s12. + + \snippet statemachine/main2.cpp 2 + + A transition can have any state as its target, i.e. the target state does + not have to be on the same level in the state hierarchy as the source state. + + \section1 Using History States to Save and Restore the Current State + + Imagine that we wanted to add an "interrupt" mechanism to the example + discussed in the previous section; the user should be able to click a button + to have the state machine perform some non-related task, after which the + state machine should resume whatever it was doing before (i.e. return to the + old state, which is one of \c s11, \c s12 and \c s13 in this case). + + Such behavior can easily be modeled using \e{history states}. A history + state (QHistoryState object) is a pseudo-state that represents the child + state that the parent state was in the last time the parent state was + exited. + + A history state is created as a child of the state for which we wish to + record the current child state; when the state machine detects the presence + of such a state at runtime, it automatically records the current (real) + child state when the parent state is exited. A transition to the history + state is in fact a transition to the child state that the state machine had + previously saved; the state machine automatically "forwards" the transition + to the real child state. + + The following diagram shows the state machine after the interrupt mechanism + has been added. + + \image statemachine-button-history.png + \omit + \caption This is a caption + \endomit + + The following code shows how it can be implemented; in this example we + simply display a message box when \c s3 is entered, then immediately return + to the previous child state of \c s1 via the history state. + + \snippet statemachine/main2.cpp 3 + + \section1 Using Parallel States to Avoid a Combinatorial Explosion of States + + Assume that you wanted to model a set of mutually exclusive properties of a + car in a single state machine. Let's say the properties we are interested in + are Clean vs Dirty, and Moving vs Not moving. It would take four mutually + exclusive states and eight transitions to be able to represent and freely + move between all possible combinations. + + \image statemachine-nonparallel.png + \omit + \caption This is a caption + \endomit + + If we added a third property (say, Red vs Blue), the total number of states + would double, to eight; and if we added a fourth property (say, Enclosed vs + Convertible), the total number of states would double again, to 16. + + Using parallel states, the total number of states and transitions grows + linearly as we add more properties, instead of exponentially. Furthermore, + states can be added to or removed from the parallel state without affecting + any of their sibling states. + + \image statemachine-parallel.png + \omit + \caption This is a caption + \endomit + + To create a parallel state group, pass QState::ParallelStates to the QState + constructor. + + \snippet statemachine/main3.cpp 0 + + When a parallel state group is entered, all its child states will be + simultaneously entered. Transitions within the individual child states + operate normally. However, any of the child states may take a transition which exits the parent + state. When this happens, the parent state and all of its child states are exited. + + The parallelism in the State Machine framework follows an interleaved semantics. All parallel + operations will be executed in a single, atomic step of the event processing, so no event can + interrupt the parallel operations. However, events will still be processed sequentially, since + the machine itself is single threaded. As an example: Consider the situation where there are two + transitions that exit the same parallel state group, and their conditions become true + simultaneously. In this case, the event that is processed last of the two will not have any + effect, since the first event will already have caused the machine to exit from the parallel + state. + + \section1 Detecting that a Composite State has Finished + + A child state can be final (a QFinalState object); when a final child state + is entered, the parent state emits the QState::finished() signal. The + following diagram shows a composite state \c s1 which does some processing + before entering a final state: + + \image statemachine-finished.png + \omit + \caption This is a caption + \endomit + + When \c s1 's final state is entered, \c s1 will automatically emit + finished(). We use a signal transition to cause this event to trigger a + state change: + + \snippet statemachine/main3.cpp 1 + + Using final states in composite states is useful when you want to hide the + internal details of a composite state; i.e. the only thing the outside world + should be able to do is enter the state, and get a notification when the + state has completed its work. This is a very powerful abstraction and + encapsulation mechanism when building complex (deeply nested) state + machines. (In the above example, you could of course create a transition + directly from \c s1 's \c done state rather than relying on \c s1 's + finished() signal, but with the consequence that implementation details of + \c s1 are exposed and depended on). + + For parallel state groups, the QState::finished() signal is emitted when \e + all the child states have entered final states. + + \section1 Targetless Transitions + + A transition need not have a target state. A transition without a target can + be triggered the same way as any other transition; the difference is that + when a targetless transition is triggered, it doesn't cause any state + changes. This allows you to react to a signal or event when your machine is + in a certain state, without having to leave that state. Example: + + \code + QStateMachine machine; + QState *s1 = new QState(&machine); + + QPushButton button; + QSignalTransition *trans = new QSignalTransition(&button, SIGNAL(clicked())); + s1->addTransition(trans); + + QMessageBox msgBox; + msgBox.setText("The button was clicked; carry on."); + QObject::connect(trans, SIGNAL(triggered()), &msgBox, SLOT(exec())); + + machine.setInitialState(s1); + \endcode + + The message box will be displayed each time the button is clicked, but the + state machine will remain in its current state (s1). If the target state + were explicitly set to s1, however, s1 would be exited and re-entered each + time (e.g. the QAbstractState::entered() and QAbstractState::exited() + signals would be emitted). + + \section1 Events, Transitions and Guards + + A QStateMachine runs its own event loop. For signal transitions + (QSignalTransition objects), QStateMachine automatically posts a + QStateMachine::SignalEvent to itself when it intercepts the corresponding + signal; similarly, for QObject event transitions (QEventTransition objects) + a QStateMachine::WrappedEvent is posted. + + You can post your own events to the state machine using + QStateMachine::postEvent(). + + When posting a custom event to the state machine, you typically also have + one or more custom transitions that can be triggered from events of that + type. To create such a transition, you subclass QAbstractTransition and + reimplement QAbstractTransition::eventTest(), where you check if an event + matches your event type (and optionally other criteria, e.g. attributes of + the event object). + + Here we define our own custom event type, \c StringEvent, for posting + strings to the state machine: + + \snippet statemachine/main4.cpp 0 + + Next, we define a transition that only triggers when the event's string + matches a particular string (a \e guarded transition): + + \snippet statemachine/main4.cpp 1 + + In the eventTest() reimplementation, we first check if the event type is the + desired one; if so, we cast the event to a StringEvent and perform the + string comparison. + + The following is a statechart that uses the custom event and transition: + + \image statemachine-customevents.png + \omit + \caption This is a caption + \endomit + + Here's what the implementation of the statechart looks like: + + \snippet statemachine/main4.cpp 2 + + Once the machine is started, we can post events to it. + + \snippet statemachine/main4.cpp 3 + + An event that is not handled by any relevant transition will be silently + consumed by the state machine. It can be useful to group states and provide + a default handling of such events; for example, as illustrated in the + following statechart: + + \image statemachine-customevents2.png + \omit + \caption This is a caption + \endomit + + For deeply nested statecharts, you can add such "fallback" transitions at + the level of granularity that's most appropriate. + + \section1 Using Restore Policy To Automatically Restore Properties + + In some state machines it can be useful to focus the attention on assigning properties in states, + not on restoring them when the state is no longer active. If you know that a property should + always be restored to its initial value when the machine enters a state that does not explicitly + give the property a value, you can set the global restore policy to + QStateMachine::RestoreProperties. + + \code + QStateMachine machine; + machine.setGlobalRestorePolicy(QStateMachine::RestoreProperties); + \endcode + + When this restore policy is set, the machine will automatically restore all properties. If it + enters a state where a given property is not set, it will first search the hierarchy of ancestors + to see if the property is defined there. If it is, the property will be restored to the value + defined by the closest ancestor. If not, it will be restored to its initial value (i.e. the + value of the property before any property assignments in states were executed.) + + Take the following code: + + \snippet statemachine/main5.cpp 0 + + Lets say the property \c fooBar is 0.0 when the machine starts. When the machine is in state + \c s1, the property will be 1.0, since the state explicitly assigns this value to it. When the + machine is in state \c s2, no value is explicitly defined for the property, so it will implicitly + be restored to 0.0. + + If we are using nested states, the parent defines a value for the property which is inherited by + all descendants that do not explicitly assign a value to the property. + + \snippet statemachine/main5.cpp 2 + + Here \c s1 has two children: \c s2 and \c s3. When \c s2 is entered, the property \c fooBar + will have the value 2.0, since this is explicitly defined for the state. When the machine is in + state \c s3, no value is defined for the state, but \c s1 defines the property to be 1.0, so this + is the value that will be assigned to \c fooBar. + + \section1 Animating Property Assignments + + The State Machine API connects with the Animation API in Qt to allow automatically animating + properties as they are assigned in states. + + Say we have the following code: + + \snippet statemachine/main5.cpp 3 + + Here we define two states of a user interface. In \c s1 the \c button is small, and in \c s2 + it is bigger. If we click the button to transition from \c s1 to \c s2, the geometry of the button + will be set immediately when a given state has been entered. If we want the transition to be + smooth, however, all we need to do is make a QPropertyAnimation and add this to the transition + object. + + \snippet statemachine/main5.cpp 4 + + Adding an animation for the property in question means that the property assignment will no + longer take immediate effect when the state has been entered. Instead, the animation will start + playing when the state has been entered and smoothly animate the property assignment. Since we + do not set the start value or end value of the animation, these will be set implicitly. The + start value of the animation will be the property's current value when the animation starts, and + the end value will be set based on the property assignments defined for the state. + + If the global restore policy of the state machine is set to QStateMachine::RestoreProperties, + it is possible to also add animations for the property restorations. + + \section1 Detecting That All Properties Have Been Set In A State + + When animations are used to assign properties, a state no longer defines the exact values that a + property will have when the machine is in the given state. While the animation is running, the + property can potentially have any value, depending on the animation. + + In some cases, it can be useful to be able to detect when the property has actually been assigned + the value defined by a state. + + Say we have the following code: + + \snippet statemachine/main5.cpp 5 + + When \c button is clicked, the machine will transition into state \c s2, which will set the + geometry of the button, and then pop up a message box to alert the user that the geometry has + been changed. + + In the normal case, where animations are not used, this will operate as expected. However, if + an animation for the \c geometry of \c button is set on the transition between \c s1 and \c s2, + the animation will be started when \c s2 is entered, but the \c geometry property will not + actually reach its defined value before the animation is finished running. In this case, the + message box will pop up before the geometry of the button has actually been set. + + To ensure that the message box does not pop up until the geometry actually reaches its final + value, we can use the state's propertiesAssigned() signal. The propertiesAssigned() signal will be + emitted when the property is assigned its final value, whether this is done immediately or + after the animation has finished playing. + + \snippet statemachine/main5.cpp 6 + + In this example, when \c button is clicked, the machine will enter \c s2. It will remain in state + \c s2 until the \c geometry property has been set to \c QRect(0, 0, 50, 50). Then it will + transition into \c s3. When \c s3 is entered, the message box will pop up. If the transition into + \c s2 has an animation for the \c geometry property, then the machine will stay in \c s2 until the + animation has finished playing. If there is no such animation, it will simply set the property and + immediately enter state \c s3. + + Either way, when the machine is in state \c s3, you are guaranteed that the property \c geometry + has been assigned the defined value. + + If the global restore policy is set to QStateMachine::RestoreProperties, the state will not emit + the propertiesAssigned() signal until these have been executed as well. + + \section1 What Happens If A State Is Exited Before The Animation Has Finished + + If a state has property assignments, and the transition into the state has animations for the + properties, the state can potentially be exited before the properties have been assigned to the + values defines by the state. This is true in particular when there are transitions out from the + state that do not depend on the propertiesAssigned signal, as described in the previous section. + + The State Machine API guarantees that a property assigned by the state machine either: + \list + \li Has a value explicitly assigned to the property. + \li Is currently being animated into a value explicitly assigned to the property. + \endlist + + When a state is exited prior to the animation finishing, the behavior of the state machine depends + on the target state of the transition. If the target state explicitly assigns a value to the + property, no additional action will be taken. The property will be assigned the value defined by + the target state. + + If the target state does not assign any value to the property, there are two + options: By default, the property will be assigned the value defined by the state it is leaving + (the value it would have been assigned if the animation had been permitted to finish playing). If + a global restore policy is set, however, this will take precedence, and the property will be + restored as usual. + + \section1 Default Animations + + As described earlier, you can add animations to transitions to make sure property assignments + in the target state are animated. If you want a specific animation to be used for a given property + regardless of which transition is taken, you can add it as a default animation to the state + machine. This is in particular useful when the properties assigned (or restored) by specific + states is not known when the machine is constructed. + + \code + QState *s1 = new QState(); + QState *s2 = new QState(); + + s2->assignProperty(object, "fooBar", 2.0); + s1->addTransition(s2); + + QStateMachine machine; + machine.setInitialState(s1); + machine.addDefaultAnimation(new QPropertyAnimation(object, "fooBar")); + \endcode + + When the machine is in state \c s2, the machine will play the default animation for the + property \c fooBar since this property is assigned by \c s2. + + Note that animations explicitly set on transitions will take precedence over any default + animation for the given property. + + \section1 Nesting State Machines + + QStateMachine is a subclass of QState. This allows for a state machine to be a child state of + another machine. QStateMachine reimplements QState::onEntry() and calls QStateMachine::start(), + so that when the child state machine is entered, it will automatically start running. + + The parent state machine treats the child machine as an \e atomic state in the state machine + algorithm. The child state machine is self-contained; it maintains its own event queue and + configuration. In particular, note that the \l{QStateMachine::configuration()}{configuration} + of the child machine is not part of the parent machine's configuration (only the child machine + itself is). + + States of the child state machine cannot be specified as targets of transitions in the parent + state machine; only the child state machine itself can. Conversely, states of the parent state + machine cannot be specified as targets of transitions in the child state machine. The child + state machine's \l{QState::finished()}{finished}() signal can be used to trigger a transition + in the parent machine. +*/ -- cgit v1.2.3