/*!
    \class QskAspect QskAspect.h
    \ingroup theming

    \brief Lookup key for a QskSkinHintTable

    Used by the \ref qskskinning "skin engine" to determine how a given aspect
    of a control is drawn. While Aspect is simply a 64-bit unsigned integer, it
    is composed of smaller enum bitfields which can be ORed together to
    describe a more specific part of the user interface.

    For example, the border colors of a QskPushButton while pressed is
    defined by combining the State (QskAbstractButton::Pressed) with the
    Subcontrol (QskPushButton::Panel), the Primitive (Border),
    and the Type (Color) as so:

        auto aspect = QskPushButton::Panel | QskAbstractButton::Pressed | QskAspect::Color | QskAspect::Border

    \sa QskSkinnable::effectiveSkinHint(), QskSkin::skinHint()
 */

/*!
    \enum QskAspect::Type

    \brief Represents the type of the Aspect. 

    The type categorizes the aspect to be a metric, color or "something else".

    Often primitives are related to a specific category. F.e QskAspect::Alignment will
    probably always be a QskAspect::Flag, while QskAspect::Border will usually
    be combined with QskAspect::Color and QskAspect::Metric.

    Smooth transitions can be set up depending on these categories. F.e when
    changing from daylight to darkness color schemem only values of QskAspect::Color
    aspects need to be considered. But when changing the Look&Feel of the 
    application all type of aspects need to be considered.

    \var QskAspect::Type QskAspect::Flag

    Flags are all sort of attributes that are no metrics or colors - f.e
    an alignment. A reasonable subset of possible flags is offered as
    QskAspect::FlagPrimitive

    \var QskAspect::Type QskAspect::Metric

    Metrics are related to geometries in most cases corresponding to pixel distances.
    Examples are the margin/padding. A reasonable subset of possible metrics
    is offered as QskAspect::MetricPrimitive.

    \var QskAspect::Type QskAspect::Color

    Colors are all sort of color values, like fill gradients, border colors.
 */

/*!
    \enum QskAspect::FlagPrimitive

    \var QskAspect::FlagPrimitive QskAspect::NoFlagPrimitive
    \var QskAspect::FlagPrimitive QskAspect::Alignment
    \var QskAspect::FlagPrimitive QskAspect::Direction
    \var QskAspect::FlagPrimitive QskAspect::Style
    \var QskAspect::FlagPrimitive QskAspect::Decoration
    \var QskAspect::FlagPrimitive QskAspect::GraphicRole
    \var QskAspect::FlagPrimitive QskAspect::FontRole
 */

/*!
    \enum QskAspect::MetricPrimitive

    \var QskAspect::MetricPrimitive QskAspect::NoMetricPrimitive
    \var QskAspect::MetricPrimitive QskAspect::StrutSize
    \var QskAspect::MetricPrimitive QskAspect::Size
    \var QskAspect::MetricPrimitive QskAspect::Position
    \var QskAspect::MetricPrimitive QskAspect::Margin
    \var QskAspect::MetricPrimitive QskAspect::Padding
    \var QskAspect::MetricPrimitive QskAspect::Shadow
    \var QskAspect::MetricPrimitive QskAspect::Spacing
    \var QskAspect::MetricPrimitive QskAspect::Shape
    \var QskAspect::MetricPrimitive QskAspect::Border
 */

/*!
    \enum QskAspect::ColorPrimitive

    \var QskAspect::ColorPrimitive QskAspect::NoColorPrimitive
    \var QskAspect::ColorPrimitive QskAspect::TextColor
    \var QskAspect::ColorPrimitive QskAspect::StyleColor
    \var QskAspect::ColorPrimitive QskAspect::LinkColor
 */
    
/*! For use within the rendering of a specific QskSkinnable. While the Default
    value applies to any control (and can be used as a fallback), specifying a
    Subcontrol limits the aspect's scope to that sub-component (or \em subcontrol)
    of the control. For example, the Subcontrol type QskPushButton::Panel refers
    to the background panel of a push button. */
enum Subcontrol : std::uint32_t
{
    Default =           0x00000000,
    FirstSubcontrol =   0x00100000,
    LastSubcontrol =    0xFFF00000
};

/*! Applies to a given aspect when the control is in a given state.
    QskSkinnable subclasses (typically QskControl subclasses) can define UI
    states, as denoted by any OR combination of State flags. For example, a
    checked QskPushButton has the QskPushButton::Checked state flag set when
    it is checked. */
enum State : std::uint64_t
{
    FirstSystemState =  0x0000000100000000, ///< The first state bit reserved for framework use
    FirstUserState =    0x0000001000000000, ///< The first state bit reserved for application use
    LastUserState =     0x0000080000000000, ///< The last state bit reserved for applicaiton use
    LastSystemState =   0x0000800000000000, ///< The last state bit reserved for framework use
    Automatic =         0x0000000000000000, ///< No specified state (the default)
    NoState =           0x0000FFFF00000000  ///< Empty state, explicitly specified. Useful in some types of animators.
};