8 new toolbar buttons (Align L/R/T/B, Center H/V, Distribute H/V)
plus a Select All button. Each operation takes the current
selection and applies a pure-function transform to the (x, y)
positions, then commits each result via store.moveNode().
Architecture:
- src/flowchart/flowchart-align.js: pure module with 8 helpers
+ nodeWidth / nodeHeight utility. UMD wrapper for browser
global + CommonJS, same pattern as the other pure modules.
- src/renderer/flowchart-bundle.js: pure module inlined so the
standalone window doesn't need a separate bundle build; the
inlined functions are exposed as window.FlowchartAlign for
jsdom tests.
- Bundle's _selectedNodeIds Set tracks the alignment selection.
Empty by default; populated by Select All or by future
canvas-side shift+click (item 1: multi-select).
- Each align button no-ops with a status hint if fewer than 2
nodes are selected. Distribute needs 3+.
- Each moveNode call creates its own undo snapshot, which is
fine for typical 2-10 node selections and lets the user undo
a misalignment one node at a time.
Tests: 14 new (1376 total) covering all 8 functions plus
immutability, no-op for insufficient nodes, and unsorted-input
sorting for distribute.
Amit Haridas
