For what it's worth, I think enabling this is a really good idea. The starting point is StyleConverter.java - it currently just hard codes all available converters. Making that pluggable won't be too difficult. If you (or anyone else) is interested in looking into this, we can discuss further.
-- Jonathan Sent from a touch device. Please excuse my brevity. On 4 September 2015 17:17:14 GMT+12:00, Michael Ennen <mike.en...@gmail.com> wrote: >I am trying to mentally digest the CSS API, but I am having trouble >answering the question of whether or not the following scenario is now >possible (using only public APIs). Imagine one wanted to create a new >class >that was analogous to DeriveColorConverter.java, and that it worked >"all >the way down" in terms of being parsed from CSS into a >StyleableProperty<Color>. For concreteness, say one wanted to implement >a >fadein function: > >fadein >fadein( <color> , <number>% ) > >The fadein function takes a color and computes a more opaque version of >that color. >The second parameter is the opacity, ranging from 0% to 100%. Has no >effect >on >fully opaque colors. > >Does the API allow for a way to hook this new function up into the CSS >parser? If one implemented FadeInColorConverter extends >StyleConverter<ParsedValue[], Color> that worked according to the above >specs, how would one hook this fadein function into the parser, so that >one >can write CSS such as: > >my-awesome-color: fadein(my-semi-transparent-color, 30%); > >and have a StyleableObjectProperty<Color> come out the other side? > >If this is possible using the new APIs, then this makes those APIs very >powerful in terms of the possibilities of extending the built-in CSS >capabilities in very powerful and interesting ways. If it is not >possible, >would it be feasible to make it so in the scope of this JEP? > >Thanks very much, >-- >Michael Ennen
