pub struct Gradient<'a> { /* private fields */ }
Expand description
Notice these docs are heavy WIP and not very relevent yet
Qt 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:
-
QLinearGradient
-
QRadialGradient
-
QConicalGradient
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 specifiying 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().
See also: {painting/gradients}{The Gradients Example} QBrush
Licence
The documentation is an adoption of the original Qt Documentation and provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation.
Implementations
sourceimpl<'a> Gradient<'a>
impl<'a> Gradient<'a>
pub fn new() -> Gradient<'a>
sourcepub fn set_spread(&self, spread: Spread) -> &Self
pub fn set_spread(&self, spread: Spread) -> &Self
Specifies the spread method that should be used for this gradient.
Note that this function only has effect for linear and radial gradients.
See also: spread()
sourcepub fn spread(&self) -> Spread
pub fn spread(&self) -> Spread
Returns the spread method use by this gradient. The default is PadSpread.
See also: setSpread()
sourcepub fn set_color_at<C: ColorTrait<'a>>(&self, pos: f32, color: &C) -> &Self
pub fn set_color_at<C: ColorTrait<'a>>(&self, pos: f32, color: &C) -> &Self
Creates a stop point at the given position with the given color. The given position must be in the range 0 to 1.
See also: setStops() stops()
sourcepub fn coordinate_mode(&self) -> CoordinateMode
pub fn coordinate_mode(&self) -> CoordinateMode
Returns the coordinate mode of this gradient. The default mode is LogicalMode.
sourcepub fn set_coordinate_mode(&self, mode: CoordinateMode) -> &Self
pub fn set_coordinate_mode(&self, mode: CoordinateMode) -> &Self
Sets the coordinate mode of this gradient to mode. The default mode is LogicalMode.