CopperSpice API  1.8.1

The QGradient class is used in combination with QBrush to specify gradient fills. More...

Inheritance diagram for QGradient:

## Public Types

enum  CoordinateMode

enum  Type

## Public Methods

CoordinateMode coordinateMode () const

InterpolationMode interpolationMode () const

void setColorAt (qreal position, const QColor &color)

void setCoordinateMode (CoordinateMode mode)

void setInterpolationMode (InterpolationMode mode)

void setStops (const QVector< QPair< qreal, QColor >> &stops)

QVector< QPair< qreal, QColor > > stops () const

Type type () const

class QBrush

## Detailed Description

The QGradient class is used in combination with QBrush to specify gradient fills.

CopperSpice currently supports three types of gradient fills:

• Linear gradients interpolate colors between start and end points.
• Simple radial gradients interpolate colors between a focal point and end points on a circle surrounding it.
• Extended radial gradients interpolate colors between a center and a focal circle.
• Conical gradients interpolate colors around a center point.

A gradient's type can be retrieved using the type() function. Each of the types is represented by a subclass of QGradient:

The colors in a gradient are defined using stop points of the QGradientStop type; i.e., a position and a color. Use the setColorAt() function to define a single stop point. Alternatively, use the setStops() function to define several stop points in one go. Note that the latter function replaces the current set of stop points.

It is the gradient's complete set of stop points (accessible through the stops() function) that describes how the gradient area should be filled. If no stop points have been specified, a gradient of black at 0 to white at 1 is used.

A diagonal linear gradient from black at (100, 100) to white at (200, 200) could be specified like this:

A gradient can have an arbitrary number of stop points. The following would create a radial gradient starting with red in the center, blue and then green on the edges:

It is possible to repeat or reflect the gradient outside its area by specifying the spread method using the setSpread() function. The default is to pad the outside area with the color at the closest stop point. The currently set spread method can be retrieved using the spread() function. The QGradient::Spread enum defines three different methods:

Note that the setSpread() function only has effect for linear and radial gradients. The reason is that the conical gradient is closed by definition, i.e. the conical gradient fills the entire circle from 0 - 360 degrees, while the boundary of a radial or a linear gradient can be specified through its radius or final stop points, respectively.

The gradient coordinates can be specified in logical coordinates, relative to device coordinates, or relative to object bounding box coordinates. The coordinate mode can be set using the setCoordinateMode() function. The default is LogicalMode, where the gradient coordinates are specified in the same way as the object coordinates. To retrieve the currently set coordinate mode use coordinateMode().

QBrush

## Member Enumeration Documentation

This enum specifies how gradient coordinates map to the paint device on which the gradient is used.

ConstantValueDescription
QGradient::LogicalMode0 This is the default mode. The gradient coordinates are specified logical space just like the object coordinates.
QGradient::StretchToDeviceMode1 In this mode the gradient coordinates are relative to the bounding rectangle of the paint device, with (0,0) in the top left corner, and (1,1) in the bottom right corner of the paint device.
QGradient::ObjectBoundingMode2 In this mode the gradient coordinates are relative to the bounding rectangle of the object being drawn, with (0,0) in the top left corner, and (1,1) in the bottom right corner of the object's bounding rectangle.

Specifies how the area outside the gradient area should be filled.

ConstantValueDescription
QGradient::PadSpread0 The area is filled with the closest stop color. This is the default.
QGradient::RepeatSpread2 The gradient is repeated outside the gradient area.
QGradient::ReflectSpread1 The gradient is reflected outside the gradient area.

Specifies the type of gradient.

ConstantValueDescription
QGradient::LinearGradient 0Interpolates colors between start and end points (QLinearGradient).
QGradient::RadialGradient1 Interpolate colors between a focal point and end points on a circle surrounding it (QRadialGradient).
QGradient::ConicalGradient2 Interpolate colors around a center point (QConicalGradient).
QGradient::NoGradient3 No gradient is used.
type()

## Method Documentation

 CoordinateMode QGradient::coordinateMode ( ) const

Returns the coordinate mode of this gradient. The default mode is LogicalMode.

setCoordinateMode()
 InterpolationMode QGradient::interpolationMode ( ) const

Returns the value of the property.

inline

Returns true if the gradient is the same as the other gradient specified, otherwise returns false.

operator==()

Returns true if the gradient is the same as the other gradient specified, otherwise returns false.

operator!=()
 void QGradient::setColorAt ( qreal position, const QColor & color )

Creates a stop point at the given position with the given color. The position must be in the range 0 to 1.

setStops(), stops()
 void QGradient::setCoordinateMode ( CoordinateMode mode )

Sets the coordinate mode of this gradient to mode. The default mode is LogicalMode.

coordinateMode()
 void QGradient::setInterpolationMode ( InterpolationMode mode )

Sets the value of the property to mode.

inline

Specifies the spreadType which should be used for this gradient. This spreadType only matters for linear and radial gradients.

 void QGradient::setStops ( const QVector< QPair< qreal, QColor >> & stops )

Replaces the current set of stop points with the given stops. The positions of the points must be in the range 0 to 1, and must be sorted with the lowest point first.

setColorAt(), stops()
inline