Add a color picker widget

[ilankri]

The code is imported from ocsigen-widgets; it was just tweaked (to try) to match the conventions of ocsigen-toolkit. As a side effect, these changes should normally close the issue ocsigen/ocsigen.github.io#10.

[vasilisp]

There is a competing PR: #141. Can you take a look at the feedback for that one and possibly adjust your code?

[ilankri]

Thank you @vasilisp. I saw it, but it seems that there were two kinds of color picker in ocsigen-widgets; one with a table and another one with hue and saturation selection. This pull request is for the latter and the one you mentioned is for the former.

[sagotch]

I think that same feedback still apply to this PR. The way these widgets has been written in ocsigen-widget is really weird, especially regarding the rest of the code.

Code from oscigen-widget can not only be imported as is.

The strange style used in ocsigen-widget is a reason why ocsigen-toolkit has been created.

[sagotch]

You would prefer a widget with signature such as:

unit -> [> `Div ] Eliom_content.Html.elt * (int * int * int) React.S.t

[sagotch]

Also, the type and these funtion

val append_at : Dom_html.element Js.t -> t -> unit
val init_handler : t -> unit
val get_rgb : t -> int * int * int

are not needed

[ilankri]

Thanks for the feedback, I will try to work on it.

[chrismamo1]

@ilankri have you made much progress on this? I'm trying to update Graffiti for the tutorial, and it uses the OW color picker widget.

[ilankri]

Not at all @chrismamo1, unfortunately, I have never had the opportunity to rework on it.

[chrismamo1]

@ilankri Ok I'll try and pick up where you left off, and address the concerns brought up in this PR as well as the other one.

[jrochel]

superseded by: #175