// Copyright (C) 2017 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only

/*!
    \page qtquickcontrols-universal.html
    \title Universal Style

    The Universal Style is based on the Microsoft Universal Design Guidelines.
    \l {detailed-desc-universal}{More...}

    \styleimport {QtQuick.Controls.Universal 2.12} {Qt 5.7}

    \section1 Attached Properties

    \list
        \li \l {universal-accent-attached-prop}{\b accent} : color
        \li \l {universal-background-attached-prop}{\b background} : color
        \li \l {universal-foreground-attached-prop}{\b foreground} : color
        \li \l {universal-theme-attached-prop}{\b theme} : enumeration
    \endlist

    \section1 Attached Methods

    \list
        \li color \l {color-attached-method}{\b color}(enumeration predefined)
    \endlist

    \section1 Detailed Description
    \target detailed-desc-universal

    The Universal style is a device-agnostic style based on the
    \l {https://dev.windows.com/design}{Microsoft Universal Design Guidelines}.
    The Universal style has been designed to look good on all devices, from
    phones and tablets to PCs.

    \include style-screenshots.qdocinc {file} {Universal} {universal}

    To run an application with the Universal style, see
    \l {Using Styles in Qt Quick Controls}.

    \note The Universal style is not a native Windows 10 style. The Universal
    style is a 100% cross-platform Qt Quick Controls style implementation that
    follows the Microsoft Universal Design Guidelines. The style runs on any
    platform, and looks more or less identical everywhere. Minor differences
    may occur due to differences in available system fonts and font rendering
    engines.

    \section2 Customization

    The Universal style allows customizing four attributes, \l {universal-theme-attached-prop}{theme},
    \l {universal-accent-attached-prop}{accent}, \l {universal-foreground-attached-prop}{foreground}, and
    \l {universal-background-attached-prop}{background}.

    \image qtquickcontrols-universal-attributes.png

    Both attributes can be specified for any window or item, and they automatically
    propagate to children in the same manner as \l {Control::font}{fonts}. In the
    following example, the window and all three radio buttons appear in the dark
    theme using a violet accent color:

    \table
        \row
            \li
                \qml
                import QtQuick 2.12
                import QtQuick.Controls 2.12
                import QtQuick.Controls.Universal 2.12

                ApplicationWindow {
                    visible: true

                    Universal.theme: Universal.Dark
                    Universal.accent: Universal.Violet

                    Column {
                        anchors.centerIn: parent

                        RadioButton { text: qsTr("Small") }
                        RadioButton { text: qsTr("Medium");  checked: true }
                        RadioButton { text: qsTr("Large") }
                    }
                }
                \endqml
            \li
                \image qtquickcontrols-universal-violet.png
    \endtable

    In addition to specifying the attributes in QML, it is also possible to
    specify them via environment variables or in a configuration file. Attributes
    specified in QML take precedence over all other methods.

    \section3 Configuration File

    \include qquickuniversalstyle.qdocinc conf

    See \l {Qt Quick Controls Configuration File} for more details about the
    configuration file.

    \section3 Environment Variables

    \include qquickuniversalstyle.qdocinc env

    See \l {Supported Environment Variables in Qt Quick Controls} for the full
    list of supported environment variables.

    \section2 Dependency

    The Universal style must be separately imported to gain access to the
    attributes that are specific to the Universal style. It should be noted
    that regardless of the references to the Universal style, the same
    application code runs with any other style. Universal-specific attributes
    only have an effect when the application is run with the Universal style.

    If the Universal style is imported in a QML file that is always loaded, the
    Universal style must be deployed with the application in order to be able
    to run the application regardless of which style the application is run with.
    By using \l {Using File Selectors with Qt Quick Controls}{file selectors},
    style-specific tweaks can be applied without creating a hard dependency to
    a style.

    \section2 Pre-defined Universal Colors

    Available pre-defined colors:
    \value Universal.Lime \stylecolor {#A4C400} {}
    \value Universal.Green \stylecolor {#60A917} {}
    \value Universal.Emerald \stylecolor {#008A00} {}
    \value Universal.Teal \stylecolor {#00ABA9} {}
    \value Universal.Cyan \stylecolor {#1BA1E2} {}
    \value Universal.Cobalt \stylecolor {#3E65FF} {(default accent)}
    \value Universal.Indigo \stylecolor {#6A00FF} {}
    \value Universal.Violet \stylecolor {#AA00FF} {}
    \value Universal.Pink \stylecolor {#F472D0} {}
    \value Universal.Magenta \stylecolor {#D80073} {}
    \value Universal.Crimson \stylecolor {#A20025} {}
    \value Universal.Red \stylecolor {#E51400} {}
    \value Universal.Orange \stylecolor {#FA6800} {}
    \value Universal.Amber \stylecolor {#F0A30A} {}
    \value Universal.Yellow \stylecolor {#E3C800} {}
    \value Universal.Brown \stylecolor {#825A2C} {}
    \value Universal.Olive \stylecolor {#6D8764} {}
    \value Universal.Steel \stylecolor {#647687} {}
    \value Universal.Mauve \stylecolor {#76608A} {}
    \value Universal.Taupe \stylecolor {#87794E} {}

    \b {See also} \l {Basic Style}, \l {Material Style}

    \section1 Attached Property Documentation

    \styleproperty {Universal.accent} {color}
    \target universal-accent-attached-prop
    This attached property holds the accent color of the theme. The property
    can be attached to any window or item. The value is propagated to children.

    The default value is \c Universal.Cobalt.

    In the following example, the accent color of the highlighted button is
    changed to \c Universal.Orange:

    \table
        \row
            \li
                \snippet qtquickcontrols-universal-accent.qml 1
            \li
                \image qtquickcontrols-universal-accent.png
    \endtable

    \note Even though the accent can be any \l {colorvaluetypedocs}{color}, it is
    recommended to use one of the \l {pre-defined Universal colors} that have been
    designed to work well with the rest of the Universal style palette.

    \endstyleproperty

    \styleproperty {Universal.background} {color}
    \target universal-background-attached-prop
    This attached property holds the background color of the theme. The property
    can be attached to any window or item. The value is propagated to children.

    The default value is theme-specific (light or dark).

    In the following example, the background color of the pane is changed to
    \c Universal.Steel:

    \table
        \row
            \li
                \snippet qtquickcontrols-universal-background.qml 1
            \li
                \image qtquickcontrols-universal-background.png
    \endtable

    \endstyleproperty

    \styleproperty {Universal.foreground} {color}
    \target universal-foreground-attached-prop
    This attached property holds the foreground color of the theme. The property
    can be attached to any window or item. The value is propagated to children.

    The default value is theme-specific (light or dark).

    In the following example, the foreground color of the button is set to \c
    Universal.Pink:

    \table
        \row
            \li
                \snippet qtquickcontrols-universal-foreground.qml 1
            \li
                \image qtquickcontrols-universal-foreground.png
    \endtable

    \styleproperty {Universal.theme} {enumeration}
    \target universal-theme-attached-prop
    This attached property holds whether the theme is light or dark. The property
    can be attached to any window or item. The value is propagated to children.

    Available themes:
    \value Universal.Light Light theme (default)
    \value Universal.Dark Dark theme
    \value Universal.System System theme

    Setting the theme to \c System chooses either the light or dark theme based
    on the system theme colors. However, when reading the value of the theme
    property, the value is never \c System, but the actual theme.

    In the following example, the theme for both the pane and the button is set
    to \c Universal.Dark:

    \table
        \row
            \li
                \snippet qtquickcontrols-universal-theme.qml 1
            \li
                \image qtquickcontrols-universal-theme.png
    \endtable

    \endstyleproperty

    \section1 Attached Method Documentation

    \stylemethod {color} {color} {enumeration} {predefined}
    \target color-attached-method
    This attached method returns the effective color value of the specified
    \l {pre-defined Universal colors}{pre-defined Universal color}.

    \qml
    Rectangle {
        color: Universal.color(Universal.Red)
    }
    \endqml

    \endstylemethod

    \section1 Related Information

    \list
      \li \l{Styling Qt Quick Controls}
    \endlist
*/