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Diffstat (limited to 'examples/widgets/doc/src/sliders.qdoc')
| -rw-r--r-- | examples/widgets/doc/src/sliders.qdoc | 117 |
1 files changed, 48 insertions, 69 deletions
diff --git a/examples/widgets/doc/src/sliders.qdoc b/examples/widgets/doc/src/sliders.qdoc index eb9a932c76..9bfb4abdc4 100644 --- a/examples/widgets/doc/src/sliders.qdoc +++ b/examples/widgets/doc/src/sliders.qdoc @@ -1,33 +1,10 @@ -/**************************************************************************** -** -** Copyright (C) 2016 The Qt Company Ltd. -** Contact: https://www.qt.io/licensing/ -** -** This file is part of the documentation of the Qt Toolkit. -** -** $QT_BEGIN_LICENSE:FDL$ -** Commercial License Usage -** Licensees holding valid commercial Qt licenses may use this file in -** accordance with the commercial license agreement provided with the -** Software or, alternatively, in accordance with the terms contained in -** a written agreement between you and The Qt Company. For licensing terms -** and conditions see https://www.qt.io/terms-conditions. For further -** information use the contact form at https://www.qt.io/contact-us. -** -** GNU Free Documentation License Usage -** 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. Please review the following information to ensure -** the GNU Free Documentation License version 1.3 requirements -** will be met: https://www.gnu.org/licenses/fdl-1.3.html. -** $QT_END_LICENSE$ -** -****************************************************************************/ +// Copyright (C) 2016 The Qt Company Ltd. +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only /*! \example widgets/sliders \title Sliders Example + \examplecategory {User Interface Components} \ingroup examples-widgets \brief The Sliders example shows how to use the different types of sliders available in Qt: QSlider, QScrollBar and QDial. @@ -41,7 +18,8 @@ manipulated through their properties. The example also demonstrates how signals and slots can be used to - synchronize the behavior of two or more widgets. + synchronize the behavior of two or more widgets, and how to override + \l{QWidget::}{resizeEvent()} to implement a responsive layout. \borderedimage sliders-example.png \caption Screenshot of the Sliders example @@ -54,10 +32,8 @@ 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. + SlidersGroup. The QGroupBox contains several widgets that control + the behavior of the slider-like widgets. \endlist @@ -79,28 +55,14 @@ \snippet 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. + In the constructor we first create the \c SlidersGroup widget + that displays the slider widgets. With \c createControls() we + create the controlling widgets, and connect those to to the + sliders. \snippet widgets/sliders/window.cpp 1 - \snippet 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 + We put the groups of control widgets and the sliders 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 @@ -108,15 +70,14 @@ minimum and maximum values propagate through the connections we created with \c createControls(). + \snippet widgets/sliders/window.cpp 2 \snippet widgets/sliders/window.cpp 3 - \snippet 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. + is composed by two checkboxes, and three spin boxes with labels. After creating the labels, we create the two checkboxes. Checkboxes are typically used to represent features in an @@ -154,8 +115,8 @@ bindings are inverted by default: \uicontrol PageDown increases the current value, and \uicontrol PageUp decreases it. + \snippet widgets/sliders/window.cpp 4 \snippet widgets/sliders/window.cpp 5 - \snippet 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 \uicontrol @@ -164,14 +125,15 @@ 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 widgets/sliders/window.cpp 6 - \snippet widgets/sliders/window.cpp 7 - \snippet widgets/sliders/window.cpp 8 + Then we connect the \c slidersGroup and the \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 synchronize the behavior of the control widgets and the slider widgets through their signals and slots. We connect each control @@ -181,6 +143,17 @@ lay out the control widgets in a QGridLayout within the \c controlsGroup group box. + \snippet widgets/sliders/window.cpp 7 + + Lastly, we override resizeEvent() from QWidget. We guard against + dividing by zero, and otherwise compute the aspect ratio of the + widget. If the window has a portrait format, then we set the + layout to organize the groups of control widgets and sliders + vertically, and we give the sliders a horizontal orientation. + If the window has a landscape format, then we change the layout + to show the sliders and controlling widgets side by side, and + give the sliders a vertical orientation. + \section1 SlidersGroup Class Definition \snippet widgets/sliders/slidersgroup.h 0 @@ -193,7 +166,8 @@ 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. + widgets' appearance as well as key bindings, and set the + orientation. \section1 SlidersGroup Class Implementation @@ -206,24 +180,21 @@ focus. The Qt::StrongFocus policy means that the widget accepts focus by both tabbing and clicking. + \snippet widgets/sliders/slidersgroup.cpp 1 + Then we connect the widgets with each other, so that they will stay synchronized when the current value of one of them changes. - \snippet widgets/sliders/slidersgroup.cpp 1 - \snippet 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 widgets/sliders/slidersgroup.cpp 3 \codeline \snippet 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. + Finally, we create the layout for the slider widgets within the + group box. We start with a horizontal arrangement of the sliders. \snippet widgets/sliders/slidersgroup.cpp 5 \snippet widgets/sliders/slidersgroup.cpp 6 @@ -256,4 +227,12 @@ \l{QAbstractSlider::invertedAppearance}{invertedAppearance} and \l{QAbstractSlider::invertedControls}{invertedControls} properties. + + \snippet widgets/sliders/slidersgroup.cpp 15 + + The setOrientation() slot controls the direction of the layout + and the orientation of the sliders. In a horizontal group, the + sliders have a horizontal orientation, and are laid out on top + of each other. In a vertical group, the sliders have a vertical + orientation, and are laid out next to each other. */ |