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diff --git a/doc/src/examples/sliders.qdoc b/doc/src/examples/sliders.qdoc deleted file mode 100644 index 383efc6140..0000000000 --- a/doc/src/examples/sliders.qdoc +++ /dev/null @@ -1,255 +0,0 @@ -/**************************************************************************** -** -** 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. -** -** -** -** -** -** $QT_END_LICENSE$ -** -****************************************************************************/ - -/*! - \example widgets/sliders - \title Sliders Example - - Qt provides three types of slider-like widgets: QSlider, - QScrollBar and QDial. They all inherit most of their - functionality from QAbstractSlider, and can in theory replace - each other in an application since the differences only concern - their look and feel. This example shows what they look like, how - they work and how their behavior and appearance can be - manipulated through their properties. - - The example also demonstrates how signals and slots can be used to - synchronize the behavior of two or more widgets. - - \image sliders-example.png Screenshot of the Sliders example - - The Sliders example consists of two classes: - - \list - - \li \c SlidersGroup is a custom widget. It combines a QSlider, a - QScrollBar and a QDial. - - \li \c Window is the main widget combining a QGroupBox and a - QStackedWidget. In this example, the QStackedWidget provides a - stack of two \c SlidersGroup widgets. The QGroupBox contain - several widgets that control the behavior of the slider-like - widgets. - - \endlist - - First we will review the \c Window class, then we - will take a look at the \c SlidersGroup class. - - \section1 Window Class Definition - - \snippet examples/widgets/sliders/window.h 0 - - The \c Window class inherits from QWidget. It displays the slider - widgets and allows the user to set their minimum, maximum and - current values and to customize their appearance, key bindings - and orientation. We use a private \c createControls() function to - create the widgets that provide these controlling mechanisms and - to connect them to the slider widgets. - - \section1 Window Class Implementation - - \snippet examples/widgets/sliders/window.cpp 0 - - In the constructor we first create the two \c SlidersGroup - widgets that display the slider widgets horizontally and - vertically, and add them to the QStackedWidget. QStackedWidget - provides a stack of widgets where only the top widget is visible. - With \c createControls() we create a connection from a - controlling widget to the QStackedWidget, making the user able to - choose between horizontal and vertical orientation of the slider - widgets. The rest of the controlling mechanisms is implemented by - the same function call. - - \snippet examples/widgets/sliders/window.cpp 1 - \snippet examples/widgets/sliders/window.cpp 2 - - Then we connect the \c horizontalSliders, \c verticalSliders and - \c valueSpinBox to each other, so that the slider widgets and the - control widget will behave synchronized when the current value of - one of them changes. The \c valueChanged() signal is emitted with - the new value as argument. The \c setValue() slot sets the - current value of the widget to the new value, and emits \c - valueChanged() if the new value is different from the old one. - - We put the group of control widgets and the stacked widget in a - horizontal layout before we initialize the minimum, maximum and - current values. The initialization of the current value will - propagate to the slider widgets through the connection we made - between \c valueSpinBox and the \c SlidersGroup widgets. The - minimum and maximum values propagate through the connections we - created with \c createControls(). - - \snippet examples/widgets/sliders/window.cpp 3 - \snippet examples/widgets/sliders/window.cpp 4 - - In the private \c createControls() function, we let a QGroupBox - (\c controlsGroup) display the control widgets. A group box can - provide a frame, a title and a keyboard shortcut, and displays - various other widgets inside itself. The group of control widgets - is composed by two checkboxes, three spin boxes (with labels) and - one combobox. - - After creating the labels, we create the two checkboxes. - Checkboxes are typically used to represent features in an - application that can be enabled or disabled. When \c - invertedAppearance is enabled, the slider values are inverted. - The table below shows the appearance for the different - slider-like widgets: - - \table - \header \li \li{2,1} QSlider \li{2,1} QScrollBar \li{2,1} QDial - \header \li \li Normal \li Inverted \li Normal \li Inverted \li Normal \li Inverted - \row \li Qt::Horizontal \li Left to right \li Right to left \li Left to right \li Right to left \li Clockwise \li Counterclockwise - \row \li Qt::Vertical \li Bottom to top \li Top to bottom \li Top to bottom \li Bottom to top \li Clockwise \li Counterclockwise - \endtable - - It is common to invert the appearance of a vertical QSlider. A - vertical slider that controls volume, for example, will typically - go from bottom to top (the non-inverted appearance), whereas a - vertical slider that controls the position of an object on screen - might go from top to bottom, because screen coordinates go from - top to bottom. - - When the \c invertedKeyBindings option is enabled (corresponding - to the QAbstractSlider::invertedControls property), the slider's - wheel and key events are inverted. The normal key bindings mean - that scrolling the mouse wheel "up" or using keys like page up - will increase the slider's current value towards its maximum. - Inverted, the same wheel and key events will move the value - toward the slider's minimum. This can be useful if the \e - appearance of a slider is inverted: Some users might expect the - keys to still work the same way on the value, whereas others - might expect \uicontrol PageUp to mean "up" on the screen. - - Note that for horizontal and vertical scroll bars, the key - bindings are inverted by default: \uicontrol PageDown increases the - current value, and \uicontrol PageUp decreases it. - - \snippet examples/widgets/sliders/window.cpp 5 - \snippet examples/widgets/sliders/window.cpp 6 - - Then we create the spin boxes. QSpinBox allows the user to choose - a value by clicking the up and down buttons or pressing the \key - Up and \uicontrol Down keys on the keyboard to modify the value - currently displayed. The user can also type in the value - manually. The spin boxes control the minimum, maximum and current - values for the QSlider, QScrollBar, and QDial widgets. - - We create a QComboBox that allows the user to choose the - orientation of the slider widgets. The QComboBox widget is a - combined button and popup list. It provides a means of presenting - a list of options to the user in a way that takes up the minimum - amount of screen space. - - \snippet examples/widgets/sliders/window.cpp 7 - \snippet examples/widgets/sliders/window.cpp 8 - - We synchronize the behavior of the control widgets and the slider - widgets through their signals and slots. We connect each control - widget to both the horizontal and vertical group of slider - widgets. We also connect \c orientationCombo to the - QStackedWidget, so that the correct "page" is shown. Finally, we - lay out the control widgets in a QGridLayout within the \c - controlsGroup group box. - - \section1 SlidersGroup Class Definition - - \snippet examples/widgets/sliders/slidersgroup.h 0 - - The \c SlidersGroup class inherits from QGroupBox. It provides a - frame and a title, and contains a QSlider, a QScrollBar and a - QDial. - - We provide a \c valueChanged() signal and a public \c setValue() - slot with equivalent functionality to the ones in QAbstractSlider - and QSpinBox. In addition, we implement several other public - slots to set the minimum and maximum value, and invert the slider - widgets' appearance as well as key bindings. - - \section1 SlidersGroup Class Implementation - - \snippet examples/widgets/sliders/slidersgroup.cpp 0 - - First we create the slider-like widgets with the appropriate - properties. In particular we set the focus policy for each - widget. Qt::FocusPolicy is an enum type that defines the various - policies a widget can have with respect to acquiring keyboard - focus. The Qt::StrongFocus policy means that the widget accepts - focus by both tabbing and clicking. - - Then we connect the widgets with each other, so that they will - stay synchronized when the current value of one of them changes. - - \snippet examples/widgets/sliders/slidersgroup.cpp 1 - \snippet examples/widgets/sliders/slidersgroup.cpp 2 - - We connect \c {dial}'s \c valueChanged() signal to the - \c{SlidersGroup}'s \c valueChanged() signal, to notify the other - widgets in the application (i.e., the control widgets) of the - changed value. - - \snippet examples/widgets/sliders/slidersgroup.cpp 3 - \codeline - \snippet examples/widgets/sliders/slidersgroup.cpp 4 - - Finally, depending on the \l {Qt::Orientation}{orientation} given - at the time of construction, we choose and create the layout for - the slider widgets within the group box. - - \snippet examples/widgets/sliders/slidersgroup.cpp 5 - \snippet examples/widgets/sliders/slidersgroup.cpp 6 - - The \c setValue() slot sets the value of the QSlider. We don't - need to explicitly call - \l{QAbstractSlider::setValue()}{setValue()} on the QScrollBar and - QDial widgets, since QSlider will emit the - \l{QAbstractSlider::valueChanged()}{valueChanged()} signal when - its value changes, triggering a domino effect. - - \snippet examples/widgets/sliders/slidersgroup.cpp 7 - \snippet examples/widgets/sliders/slidersgroup.cpp 8 - \codeline - \snippet examples/widgets/sliders/slidersgroup.cpp 9 - \snippet examples/widgets/sliders/slidersgroup.cpp 10 - - The \c setMinimum() and \c setMaximum() slots are used by the \c - Window class to set the range of the QSlider, QScrollBar, and - QDial widgets. - - \snippet examples/widgets/sliders/slidersgroup.cpp 11 - \snippet examples/widgets/sliders/slidersgroup.cpp 12 - \codeline - \snippet examples/widgets/sliders/slidersgroup.cpp 13 - \snippet examples/widgets/sliders/slidersgroup.cpp 14 - - The \c invertAppearance() and \c invertKeyBindings() slots - control the child widgets' - \l{QAbstractSlider::invertedAppearance}{invertedAppearance} and - \l{QAbstractSlider::invertedControls}{invertedControls} - properties. -*/ |