add ColorModel, use Double for z array to support RGB(A) alpha channel

Author: novakov-alexey

core/shared/src/main/scala/plotly/Trace.scala

@@ -153,23 +153,24 @@ object Box {
 }
 
 @data(optionSetters = true) class Image(
+  z: Seq[Seq[Seq[Double]]],
+  @since
+  x0: Option[Element] = None,
+  y0: Option[Element] = None,
   name: Option[String] = None,
   text: Option[Seq[String]] = None,
   opacity: Option[Double] = None,
   ids: Option[Seq[String]] = None,
-  x0: Option[Element] = None,
   dx: Option[Double] = None,
-  y0: Option[Element] = None,
   dy: Option[Double] = None,
-  z: Seq[Seq[Seq[Int]]],
   source: Option[String] = None,
   hoverinfo: Option[HoverInfo] = None,
   hovertemplate: Option[Seq[String]] = None,
   meta: Option[String] = None,
   customdata: Option[Seq[String]] = None,
   xaxis: Option[AxisReference] = None,
   yaxis: Option[AxisReference] = None,
-  colormodel: Option[String] = None,
+  colormodel: Option[ColorModel] = None,
   zmax: Option[Seq[Int]] = None,
   zmin: Option[Seq[Int]] = None,
   hoverlabel: Option[HoverLabel] = None

core/shared/src/main/scala/plotly/element/ColorModel.scala

@@ -0,0 +1,11 @@
+package plotly.element
+
+sealed abstract class ColorModel(val label: String) extends Product with Serializable
+
+object ColorModel {
+  case object RGB extends ColorModel("rgb")
+  case object RGBA extends ColorModel("rgba")
+  case object RGBA256 extends ColorModel("rgba256")
+  case object HSL extends ColorModel("hsl")
+  case object HSLA extends ColorModel("hsla")
+}