The sweep the ghost/accent/danger fix implied: navuser, poprow, panechip,
chiptoggle and choice each set VerticalContentAlignment now, because each set
everything else about how its content sits and left that one to Avalonia's
Stretch default.
None of them was misbehaving. Every one is content-sized everywhere it is used
today, so Stretch and Center agreed and this moves nothing — 113 buttons across
29 screens and cards measured byte-identical before and after, the strips that
have no height of their own included. What it buys is that the day one of them
is given a height, it is already right rather than quietly drawing its label in
the top third.
flat and cat are deliberately NOT swept in, and the reasoning that would sweep
them is exactly the trap. flat carries the titlebar's search pill, a
Border.searchpill with no height of its own that is meant to fill all 35 pixels
of its button — the usage states HorizontalContentAlignment="Stretch" and takes
the vertical default to match. cat carries the keychain rail's accent strip, a
Border.rowmark whose style sets Width="2" and no height at all, "at full row
height" by its own remark. Centring either from the style shrinks a pill and a
strip that are correct today. AStretchingShapeStillFillsItsButton pins both, and
fails when flat is centred.
ButtonCaptionTests covers the five new shapes on the existing rule. Its
stretch-fill assertion reads the content slot off the presenter rather than
recomputing it from the button's Padding: the shapes differ in whether their
presenter also draws a border, and a hand-rolled sum was two pixels out on
Button.cat for that reason.
App.axaml's Button.ghost, Button.accent, Button.danger rule set
VerticalAlignment and never VerticalContentAlignment. The first places the
button in its parent; the second places the caption in the button, and its
default is Stretch — so on any of these given a fixed Height the content
presenter stretched the caption TextBlock to the whole content box, and a
TextBlock draws its line at the top of whatever it is given. Measured on the
hosts toolbar, whose three buttons are 40 pixels: nine above the ink and
twenty below it. Every box was the height it declared, which is why this read
as one of them being the wrong height — nothing was mis-sized, the labels sat
in the top third.
Center rather than a hand-tuned Padding, because the gap is the difference
between the line box and the content box and moves with the font size: these
carry 11.5 by default and the primary action overrides it to 13.5. It is the
three shapes that were missed rather than a new idiom — navseg, sesstab,
headerghost, sidebarrow, fieldrow and paneicon all state it already, as does
every one of the phone head's own button classes. 134 buttons carry these
three classes; the ones that show it are those with an explicit Height, which
is both toolbars, the drawer's Save/Cancel pair, and the import screen. A
button sized to its own caption was already right and is untouched.
HorizontalContentAlignment is deliberately left alone: it is Stretch too and
invisible on a self-sized button, and the flyout rows that are stretched wide
ask for Left themselves.
ButtonCaptionTests measures a bare Button, since Application.Styles is global
and a screen-level test would pin one toolbar and leave the rest to the same
defect. It measures the laid-out line rather than the TextBlock's arranged
bounds, and that distinction is the test: under Stretch those bounds fill the
content box and so are symmetrical whether or not the ink in them is. The
first draft asserted on them and passed against the defect; the calibration
test caught it, and against the old markup all three shapes now fail naming
their own gap.
jaap-jan