Closes#60
Stepping in sliders is a compromise due to the flexibility of the
current slider implementation. I don't want to force types to implement
Add, and I don't like forcing types to require a Step (ie, what's the
appropriate value for f32 to specify as its next value?). Using a
percentage combined with lerp keeps the implementation fairly
straightfoward, although I remember experiencing this type of
configuration in another UI framework a long time ago and thinking it
was a little annoying to work with.
Ultimately, setting actual step boundaries can be done by customizing
the type that the slider is operating over. I feel like that's a much
more powerful design than I've experienced in previous frameworks, so
I'm hoping this percent step behavior is a reasonable compromise.
This also fixes some inconsistencies that arose when the focus widget
was "stuck" on a removed widget. Button previously handled it hackily in
a redraw function, but now Gooey handles it automatically without
needing to wait for a repaint.
Introducing two new colors:
- ColorTheme::color_dim, for dimmed/disabled primary colors
- SurfaceTheme::opaque_widget, for buttons.
In material design, a button's background color uses the Highest
Container role, which seems incorrect because then buttons wouldn't have
a different color when placed inside of the highest level container.
Rather than remove a container level, I added one more tone using the
neutral variant.
Other changes are just gut feelings to have a slightly richer dark
theme. I feel like material is a little muddy in dark mode.
Scroll was previously taking the graphics region as its control size as
opposed to the constraints. This was due to this code originally living
in redraw. This fixes scroll areas being able to scroll their contents
fully when sharing window space with other widgts.
This also means that if an animation is animating over discrete values
and the actual value has not changed, the Dynamic will no longer detect
a change because it's now using update instead of set.
