TimeGridGeometry

The integer pixel grid that time-series widgets share, so their strips scroll by whole pixels and line up.

Detailed description

The owning activity computes one geometry and gives it to every graph it stacks (compute-graph-fidelity §CG-G). Each sample is exactly pxPerSample pixels wide, and the strip moves left by that amount on each tick. Widgets with the same leftGutter, rightLive and pxPerSample draw a sample of one age at the same x.

A widget with no valid grid (isValid() is false) draws as it did before, fitted to its width: the grid is opt-in (§CG-G-6).

See also StackedAreaChartWidget, HistoryStripListWidget.