HiDPI audit, third wave: every drawable widget, and nineteen more that were not scaling

[tannevaled]

The catalogue now holds 124 of the toolkit's 129 drawable widgets — everything except five that fail for a different reason, named below. This is the sweep the instrument was built for.

Nineteen named a defect, in three kinds

Row and strip heights that stayed put while their contents grew — MenuBar, Notebook's tab strip, Table and TreeTable's header and rows, Gantt's rows/header/label column, Timeline's markers and pads, FileChooser's button strip and path bar, Window's title bar and tool buttons, Agenda's header/hour/gutter/day cells, Calendar's header/cells/nav buttons.

Whole control geometries laid out in fixed pixels, which at twice the scale sat in the top-left corner of a box twice their size — PagingToolbar's buttons and gaps, SpinButton's stepper column, TimePicker's cells, ColorPicker's square, hue strip, alpha bar and swatches.

Chart insets — ChartPad, which four of the five charts read and none of them scaled, plus ScatterChart's dot and BarChart's gutter.

Two things the instrument learned

Four widgets could not be drawn from their zero value at all and took the whole audit down with a nil dereference. They are constructed properly now, and the audit recovers from a panicking Draw and reports it as a finding rather than dying — one widget's nil must not cost the other hundred-and-twenty their result.

ColorPickerWidth/Height stay logical constants — they are compile-time and cannot call scaled() — with ColorPickerNaturalSize() for the device-pixel footprint, the same shape as ExpanderHeaderHeight().

Five left out, with their measurement

Scale, RangeSlider, ColorChooser, ColorPicker and Agenda come out off by two or four device pixels at twice the scale — 12 becoming 28 where 24 was due, or one run merging into its neighbour — rather than not scaling at all, which is what every widget fixed by this audit looked like (12 staying 12).

That is a scaled metric composed with an unscaled one-pixel something: a border that thickened beside a pad that scaled, or a /2 that rounds the other way at twice the size. It needs reading those five Draws, not widening a tolerance — which would then hide the class this does catch, as an earlier version of this instrument proved by declaring the very defect it was written to find to be within tolerance. Tracked in #212.

🤖 Generated with Claude Code