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/*!
    \page qtlabscontrols-index.html
    \title Qt Labs Controls

    \brief Provides a set of UI controls for Qt Quick.

    Qt Labs Controls provides a set of controls that can be used
    to build complete interfaces in Qt Quick.

    \section1 QML Types

    \section2 Qt.labs.controls Module
    \generatelist {qmltypesbymodule Qt.labs.controls}

    \section2 Qt.labs.calendar Module
    \generatelist {qmltypesbymodule Qt.labs.calendar}

    \section1 Differences between Qt Quick Controls

    Qt Quick Controls were originally developed to support desktop platforms,
    with mobile and embedded support coming shortly afterwards. They have a
    very broad scope, in that they provide a styling system flexible enough to
    allow the development of applications that have either a platform-dependent
    or platform-independent style.

    On embedded systems, where the hardware has limited resources, this approach
    can be inefficient. Qt Labs Controls were designed to solve this problem,
    using
    \l {https://blog.qt.io/blog/2015/03/31/qt-quick-controls-for-embedded/}{benchmarks}
    to guide the development.

    \section2 C++ and QML

    In many cases, the internal state of a control can be more efficiently
    processed in C++. For example, handling input events in C++ makes a
    difference for controls that would otherwise need to create internal
    MouseAreas and attached Keys objects.

    \section2 Styles

    Not only does handling events and logic in C++ increase performance, but it
    allows the visual QML layer to be a simple, declarative layer on top. This
    is reflected in the structure of the controls project: all visual
    implementations sit in the \e imports folder, so that users who want to
    create their own complete style can copy the folder and start tweaking.
    Read more about implementing a style plugin \l {TODO}{here}.

    In Qt Labs Controls, styles no longer provide components that are
    dynamically instantiated by controls, but controls themselves consist of
    item delegates that can be replaced. In effect, this means that delegates
    are Qt Quick items that are instantiated on the spot, as properties of the
    control, and are simply parented to the control.

    Control-specific style objects have been replaced by a Theme object that
    offers a simple set of themable attributes. Basic color adjustments can be
    made by setting a few properties that are automatically inherited by the
    hierarchy of children.

    \section2 Modularity and Simplicity

    When it comes to more complex controls, it is sometimes better to split
    them up into separate building blocks. As an example, the complex
    ScrollView control:

    \qml
    ScrollView {
        horizontalScrollBarPolicy: Qt.ScrollBarAlwaysOff
        Flickable {
            // ...
        }
    }
    \endqml

    Is replaced with simple ScrollBar/ScrollIndicator controls that can be
    attached to any Flickable:

    \qml
    Flickable {
        // ...
        ScrollBar.vertical: ScrollBar { }
    }
    \endqml

    The API of Qt Labs Controls aims to be clean and simple. Common
    operations are easy, and more advanced ones are liberally documented with
    snippets that can be copied into your code.

    \section2 Feature Comparison Table

    \table
    \header
        \li
        \li Qt Quick Controls
        \li Qt Labs Controls
    \row
        \li Stylable delegates
        \li Yes
        \li Yes
    \row
        \li Pre-built native styles
        \li Yes
        \li No
    \row
        \li Runtime style changes
        \li Yes
        \li Yes
    \row
        \li Can be used on Desktop
        \li Yes
        \li Yes \b *
    \row
        \li Can be used on Mobile
        \li Yes
        \li Yes
    \row
        \li Can be used on Embedded
        \li Yes
        \li Yes
    \row
        \li Internal event handling
        \li QML
        \li C++
    \endtable

    \b {* No hover support}

    \section2 Porting Qt Quick Controls Code

    The API of Qt Labs Controls is very similar to Qt Quick Controls, but it
    does come with some changes necessary to facilitate the improvements. The
    majority of changes are to do with styling; all of a control's delegates
    are now accessible in the control itself, instead of in a separate style
    object.

    For example, to style a button in Qt Quick Controls:

    \badcode
    Button {
        style: ButtonStyle {
            label: Label {
                // ...
            }
        }
    }
    \endcode

    To style a button in Qt Labs Controls:

    \qml
    Button {
        label: Label {
            // ...
        }
    }
    \endqml

    \section3 Preparing for Migration

    With this in mind, a good way to prepare for a migration to Qt Quick
    Labs is to place each control that you have a custom style for in its
    own QML file. For example, the Qt Quick Controls button above could be moved to a
    file named Button.qml, and used in the following manner:

    \badcode
    import "controls" as Controls

    Controls.Button {
        ...
    }
    \endcode

    This works with both modules, and will reduce the amount of work needed
    when the migration begins.

    \section3 Type Changes

    \table
    \header
        \li Qt Quick Controls
        \li Qt Labs Controls
    \row
        \li \l [QtQuickControls] {Action}
        \li No equivalent; see \l [QtQuick] {Shortcut} instead.
    \row
        \li \l [QtQuickControls] {ApplicationWindow}
        \li \l [QtLabsControls] {ApplicationWindow}
    \row
        \li \l [QtQuickControls] {BusyIndicator}
        \li \l [QtLabsControls] {BusyIndicator}
    \row
        \li \l [QtQuickControls] {Button}
        \li \l [QtLabsControls] {Button}
    \row
        \li \l [QtQuickControls] {Calendar}
        \li No equivalent; see \l [QML] {CalendarView} instead.
    \row
        \li \l [QtQuickControls] {CheckBox}
        \li \l [QtLabsControls] {CheckBox}
    \row
        \li \l [QtQuickControls] {ExclusiveGroup}
        \li \l [QtLabsControls] {ExclusiveGroup}
    \row
        \li \l [QtQuickControls] {GroupBox}

        \li \l [QtLabsControls] {GroupBox}, or \l [QtLabsControls] {Frame}
            if a title is not required.

    \row
        \li \l [QtQuickControls] {Label}
        \li \l [QtLabsControls] {Label}
    \row
        \li \l [QtQuickControls] {ProgressBar}
        \li \l [QtLabsControls] {ProgressBar}
    \row
        \li \l [QtQuickControls] {RadioButton}
        \li \l [QtLabsControls] {RadioButton}
    \row
        \li \l [QtQuickControls] {ScrollView}
        \li \l [QtLabsControls] {ScrollBar},
            \l [QtLabsControls] {ScrollIndicator}
    \row
        \li \l [QtQuickControls] {Slider}
        \li \l [QtLabsControls] {Slider}
    \row
        \li \l [QtQuickControls] {SpinBox}
        \li No equivalent; see \l [QtLabsControls] {Tumbler} instead.
    \row
        \li \l [QtQuickControls] {Stack},
            \l [QtQuickControls] {StackView},
            \l [QtQuickControls] {StackViewDelegate}
        \li \l [QtLabsControls] {StackView}
    \row
        \li \l [QtQuickControls] {StatusBar}
        \li No equivalent
    \row
        \li \l [QtQuickControls] {Switch}
        \li \l [QtLabsControls] {Switch}
    \row
        \li \l [QtQuickControls] {Tab},
            \l [QtQuickControls] {TabView}
        \li \l [QtLabsControls] {TabBar} in combination with, for example,
            \l [QtLabsControls] {SwipeView}.
    \row
        \li \l [QtQuickControls] {TableView}
        \li No equivalent
    \row
        \li \l [QtQuickControls] {TextArea}
        \li \l [QtLabsControls] {TextArea}
    \row
        \li \l [QtQuickControls] {TextField}
        \li \l [QtLabsControls] {TextField}
    \row
        \li \l [QtQuickControls] {ToolBar}
        \li \l [QtLabsControls] {ToolBar}
    \row
        \li \l [QtQuickControls] {ToolButton}
        \li \l [QtLabsControls] {ToolButton}
    \row
        \li \l [QtQuickControls] {TreeView}
        \li No equivalent
    \endtable

    \section1 Getting Started

    A basic example of a QML file that makes use of controls is shown here:

    \snippet basic-example.qml 0

    \section1 Setting Up Controls from C++

    Although QQuickView has traditionally been used to display QML files in a
    C++ application, doing this means you can only set window properties from
    C++.

    With Qt Labs Controls, declare an ApplicationWindow as the root item of
    your application and launch it by using QQmlApplicationEngine instead.
    This ensures that you can control top level window properties from QML.

    A basic example of a source file that makes use of controls is shown here:

    \code
    #include <QApplication>
    #include <QQmlApplicationEngine>

    int main(int argc, char *argv[])
    {
        QGuiApplication app(argc, argv);
        QQmlApplicationEngine engine("main.qml");
        return app.exec();
    }
    \endcode

    \section2 Using C++ Data From QML

    If you need to register a C++ class to use from QML, you can call
    qmlRegisterType() before declaring your QQmlApplicationEngine.
    See \l [QtQml] {Defining QML Types from C++} for more information.

    If you need to expose data to QML components, you need to make them
    available to the context of the current QML engine. See QQmlContext for
    more information.

    \section2 Deploying Qt Labs Controls

    TODO

    \section1 Related Information

    \list
      \li \l{Qt Quick}
      \li \l{Qt Quick Layouts}
      \li \l{Qt Labs Calendar}
      \li \l{Qt Labs Controls QML Types}{Qt Labs Controls QML Types}
    \endlist
*/