No need to use a TextLayout here, we can just count the number of lines
and multiply that by the font's preferred line height.
In addition to being much simpler, it also fixes a bug where labels were
got too tall if we calculated their preferred height before assigning
a final width to them.
This is achieved by simplifying the logic in TextLayout. We get rid
of all the various ways that the layout bounding rect can get cropped.
Then we make sure to use the right pixel metrics.
Finally we use the font's own line gap metrics instead of hard-coding 4.
The end result is that text painted with vector fonts now gets pretty
reasonable vertical alignment in most cases.
The height of a line or column doesn't change unless the font changes,
and we were already caching the line height. This patch extends it so
we also cache the column width.
When changing the font size, we now resize the terminal widget *before*
setting the font. This ensures that we keep the same logical terminal
size after the font change.
Instead of indicating which individual cards should be highlighted, card
games now indicate which stack is highlighted. This lets the stack draw
empty stacks with a highlight (e.g. the Foundation stack in Solitaire).
If the stack is non-empty, the stack can delegate highlighting to the
top-most card.
Currently, the outside of the card highlight has rounded corners, but
the inside has square corners. It looks a bit more polished if they are
both rounded.
Change column distribution to take in account is_length() and
is_percentage() width values instead of treating all cells like
they have auto width by implementing it in the way described
in CSS Tables 3 spec:
https://www.w3.org/TR/css-tables-3/#width-distribution-algorithm
distribute_width_to_column() is structured to follow schema:
w3.org/TR/css-tables-3/images/CSS-Tables-Column-Width-Assignment.svg
It is not possible to use width of containing block to resolve
cells width because by the time compute_table_measures() is
called row width is not known yet.
ThrowableStringBuilder is a thin wrapper around StringBuilder to map
results from the try_* methods to a throw completion. This will let us
try to throw on OOM conditions rather than just blowing up.
For example, in Solitaire, when dragging a card around, it's common for
other implementations to highlight the card underneath the dragged card
if that other card is a valid drop target. This implementation will draw
a rounded rectangle within the edges of the highlighted card, using a
rudimentary complementary color of the board background color.
