86 lines
3.4 KiB
Plaintext
86 lines
3.4 KiB
Plaintext
/****************************************************************************
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**
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** Copyright (C) 2016 The Qt Company Ltd.
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** Contact: https://www.qt.io/licensing/
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**
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** This file is part of the documentation of the Qt Toolkit.
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**
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** $QT_BEGIN_LICENSE:FDL$
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** Commercial License Usage
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** Licensees holding valid commercial Qt licenses may use this file in
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** accordance with the commercial license agreement provided with the
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** Software or, alternatively, in accordance with the terms contained in
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** a written agreement between you and The Qt Company. For licensing terms
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** and conditions see https://www.qt.io/terms-conditions. For further
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** information use the contact form at https://www.qt.io/contact-us.
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**
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** GNU Free Documentation License Usage
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** Alternatively, this file may be used under the terms of the GNU Free
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** Documentation License version 1.3 as published by the Free Software
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** Foundation and appearing in the file included in the packaging of
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** this file. Please review the following information to ensure
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** the GNU Free Documentation License version 1.3 requirements
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** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
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** $QT_END_LICENSE$
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**
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****************************************************************************/
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/*!
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\example statemachine/eventtransitions
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\title Event Transitions Example
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\brief The Event Transitions example shows how to use event transitions,
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a feature of \l{The State Machine Framework}.
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The Event Transitions Example illustrates how states change when a
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user enters or leaves the area of a button. The states are handled by
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a QStateMachine object. The screen consists of a QVBoxLayout with a
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central button.
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When the mouse is outside the button, the text in the button displays
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"Outside". When the mouse enters the button, it displays "Inside".
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\borderedimage transitions.png
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\snippet statemachine/eventtransitions/main.cpp 0
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The \c Window class's constructors begins by creating a button.
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This button is added to \c layout, which is a QVBoxLayout object.
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Then two states are created: \c s1 is the state
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"Outside", and \c s2 is the state "Inside".
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\snippet statemachine/eventtransitions/main.cpp 1
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State \c s1 is the state "Outside" and state \c s2 is state "Inside".
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\snippet statemachine/eventtransitions/main.cpp 2
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When the button receives an event of type QEvent::Enter and the state
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machine is in state \c s1, the machine will transition to state \c s2.
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\snippet statemachine/eventtransitions/main.cpp 3
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When the button receives an event of type QEvent::Leave and the state
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machine is in state \c s2, the machine will transition back to state \c
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s1.
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\snippet statemachine/eventtransitions/main.cpp 4
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Next, state \c s3 is created. \c s3 will be entered when the button
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receives an event of type QEvent::MouseButtonPress and the state machine
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is in state \c s2. When the button receives an event of type
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QEvent::MouseButtonRelease and the state machine is in state \c s3, the
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machine will revert to state \c s2.
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\snippet statemachine/eventtransitions/main.cpp 5
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Finally, the states are added to the machine as top-level states, the
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initial state is set to be \c s1 ("Outside"), and the machine is started.
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\snippet statemachine/eventtransitions/main.cpp 6
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The main() function constructs a Window object that displays the QVBoxLayout
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object \c layout with its \c button.
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*/
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