Add Image support

[novakov-alexey-zz]

No description provided.

[novakov-alexey-zz]

@alexarchambault Documentation tests seem not relevant for Image Trace due to outdated documentation fork. plotly-scala would require to update documentation to the latest Plotly.js state. However, Image trace is working fine:

import plotly.element.HoverInfo
import plotly.element.HoverInfo._

val z = Seq(
    Seq(Seq(0, 33, 50), Seq(0, 66, 50), Seq(0, 100, 50)),
    Seq(Seq(90, 33, 50), Seq(90, 66, 50), Seq(90, 100, 50)),
    Seq(Seq(180, 33, 50), Seq(180, 66, 50), Seq(180, 100, 50)),
    Seq(Seq(270, 33, 50), Seq(270, 66, 50), Seq(270, 100, 50)))

Image(
    z = z,
    x0=Some(0.05),
    y0=Some(0.05),
    hoverinfo = Some(HoverInfo(X, Y, Z)),
    colormodel = Some("rgb")
).plot()

[alexarchambault]

@novakov-alexey Thanks for opening this! I'm about to update the documentation sub-module, I should open a PR for it, either later today or in the coming days. That should allow to add tests for this.

Just ping me if I forget to come back here once it's done.

[novakov-alexey-zz]

Great, looking forward to that!

[alexarchambault]

I only left some minor comments.

I also updated the documentation sub-module in master, feel free to rebase, and enable relevant tests for images.

[alexarchambault]

Can this be added in a separate commit, to make the git history cleaner?

[alexarchambault]

Same as above, let's edit the README in a separate commit too.

[novakov-alexey-zz]

There is a small problem that I do not know how to resolve on JSON encoding level.

If we want to support 3-channel and 4 channel color models like RGB and RGBA, we might need to model colors in z property as some case classes. For example:

abstract class ZColor with ....
Color3(c1: Int, c2: Int, c3: Int) extends ZColor
// note that last property is Double, all other are Ints
Color4(c1: Int, c2: Int, c3: Int, alpha: Double) extends ZColor 

I tried to implement it, but failed to render these case classes without class name in the resulting JSON string. Currently, Trace encoder renders every type by printing all nested property type names/keys. That breaks z property. Expected JavaScript format of z is z: [[ [123,123,123], [.....] ]]

Latets API I came up with:

import plotly.element.HoverInfo._
import plotly.element.ColorModel._
import plotly.element.Element._

val colors = Seq(
    Seq(Seq(0d, 33d, 50d), Seq(0d, 66, 50), Seq(0d, 100, 50)),
    Seq(Seq(90d, 33d, 50d), Seq(90d, 66, 50), Seq(90d, 100, 50)),
    Seq(Seq(180d, 33d, 50d), Seq(180d, 66, 50), Seq(180d, 100, 50)),
    Seq(Seq(270d, 33d, 50d), Seq(270d, 66, 50), Seq(270d, 100, 50)))

Image(z = colors)
  .withX0(0.05)
  .withY0(0.05)
  .withHoverinfo(HoverInfo(X, Y, Z, HoverInfo.Color))
  .withColormodel(RGB)
  .plot()

It works, but requires Double numbers for RGB, which is weird.

[novakov-alexey-zz]

New PR is here: #274