Stage
Stage
symfony-stage: a surface the pointer moves and elements laid on it — picked, dragged onto a grid, linked, removed, every change undone and done again. The stage draws the elements the page hands it and knows nothing of what they mean: each one here is one of its figures (stage-shape) — a box for a step, a circle for an event, a diamond for a choice.
A timeline
The surface moves along its line only (axis x), as a process reads. Drag the surface to move it, a card to move it; Shift and drag picks several; the arrows move the picked ones, Delete removes them, Ctrl+Z undoes and Ctrl+Shift+Z does again.