It wasn't that hard as I thought to add linearGradient and radialGradient after getting gradientPaint() to work. One may think that gradientPaint and linearGradient are pretty much the same but there are 3 differences

1. linearGradient supports more than twp colors at a time.
2. linearGradient supports 3 cycle modes.
3. linearGradient is only available since jdk6.

Because of #1 both linearGradient and radialGradient require a nested set of stop operations (at least 2 or they will bomb, watch out for that). Let's revisit the previous examples of gradients but this time with linearGradient



The code is a little more verbose this time, but because builders allow any groovy code we can take advantage of variables and looping costructs to trim some lines
def stops = { def offsets = [0,0.5,1] def colors = ['black','red','blue'] (0..2).each{ stop( offset: offsets[it], color: colors[it] ) } } rect( x: 0, y: 0, width: 100, height: 100 ){ linearGradient( x1: 0, y1: 0, x2: 50, y2: 50 ){ stops() } } rect( x: 100, y: 0, width: 100, height: 100 ){ linearGradient( x1: 50, y1: 0, x2: 0, y2: 50 ){ stops() } } rect( x: 0, y: 100, width: 100, height: 100 ){ linearGradient( x1: 0, y1: 50, x2: 50, y2: 0 ){ stops() } } rect( x: 100, y: 100, width: 100, height: 100 ){ linearGradient( x1: 50, y1: 50, x2: 0, y2: 0 ){ stops() } }
As with gradialPaint this operation also allows fit and stretch; cycle may have 3 different values ['nocycle','reflect','repeat']

fit = true	fit = false
stretch = true
cycle = reflect	cycle = repeat

Similar to other gradient paints, radialGradient will transform the paint according to the shape's bounds, in this case it will translate the center (cx,cy) and the focus (fx,fy) unless absolute=true is specified. Let's see a quick example



Produced with the following code
def stops = { def offsets = [0,0.5,1] def colors = ['black','red','blue'] (0..2).each{ stop( offset: offsets[it], color: colors[it] ) } } rect( x: 0, y: 0, width: 100, height: 100 ){ radialGradient( cx: 25, cy: 25, radius: 75 ){ stops() } } rect( x: 25, y: 100, width: 100, height: 100 ){ radialGradient( cx: 25, cy: 125, radius: 75, absolute: true ){ stops() } }
Notice that the second square is moved 25 pixels to the right but the gradient is not, because it has been marked with absolute=true.

The code is already available at the svn repo, more to come in the following days.

Keep on Groovying!