By default, horizontal and vertical layouts expand to fill their parent
in their on-axis direction (horizontally for horizontal layouts), but
fit to their child views in their off-axis.
Flexible space views take advantage of auto-expansion, pushing sibling
views such that the grandparent view is filled on the parent view's
on-axis, and the parent view is filled by the space in the parent view's
off-axis. Flexible views currently have a background fill, allowing them
to provide background filling of the overall view with minimal overdraw
(ancestor views don't need to have any fill at all).
I had forgotten that Hash_NewTable checked the hashctx parameter, so
calling Hash_NewTable in the struct initializer meant the hasctx was
uninitialized.
This takes care of element order stability. It did need reworking the
mouse tracking code (including adding an active flag to views), but now
buttons seem to work correctly.
It's there for a reason :P. Fixes most of the really bad behavior after
disabling some widgets (re-layout isn't working at all, though, and
adding the widgets back again puts them in the wrong place).
Using label + key_offset in both imui_state_getkey and the call to
Hash_Find greatly simplifies the logic of using the correct key. Fixes
an ever-growing set of buttons when using separators (hmm, I think this
means pruning isn't working correctly).
TextContent seems redundant at this stage since a text view is always
sized to its content, and PercentOfParent doesn't work yet. Pixels
definitely works and Null seems to work in that it does no sizing or
positioning. Vertical layout is supported but not yet tested, similar
for ChildrenSum, but I can have two buttons side by side.
Text_StringView sets the view bounds to the bounds of the glyphs in the
view. This has its advantages, but is not suitable for automatic UI
sizing. However, the view is positioned correctly, so nothing needs to
be done there. Now full height glyphs (eg, C) look balanced in the view,
and glyphs with descenders (g) brush the bottom of the view.
