Problem

Handles were drawn inside the zoomed view transform, so every length they emitted — grab dots, gizmo reach (arrows/circle/box), and stroke width — got multiplied by the view scale. Zooming in made the handles grow instead of just repositioning them; at high zoom the grab dots became huge and strokes thickened.

Approach

Refactor handles to operate in screen space, the way every vector editor draws its overlay layer:

• Handles receive the full view transform via setViewTransform(viewX, viewY, viewScale) and project the document coordinates they operate on through toScreen().
• Decorations (dots, knobs, arrows, strokes) are drawn at a constant pixel size — no scale math.
• Only genuine document measurements scale with the view: the four-point bounding box, the circle radius, the snap grid spacing.
• Hit-testing projects both the handle position and the cursor to screen space and compares with a constant pixel tolerance.
• Drag value math stays in document space and is unchanged — a point dragged to document coord X is still X.

The result: viewScale collapses from "defensively divide every size everywhere" to a single seam (toScreen) plus the handful of real measurements that multiply by it. No / viewScale anywhere.

Viewer

• Draws the handle layer outside the view transform (screen space).
• Sizes the handle canvas to the viewport — Canvas.draw clips to its bounds, and the old 1000×1000 canvas was clipping handles near the document edges at high zoom.
• Refreshes the handle transform at paint time (covers the first-paint setViewPosition path that doesn't fire onViewTransformChanged).

Bonus: translate handle affordance

The whole axis line is now draggable (with a padded grab band), not just the arrow tip — drag a line to constrain movement to that axis.

Tests

• AbstractHandleTest — screen-space projection and grab-area constancy across 0.1×–10× and under pan.
• ScaleHandleTest — drag response is identical for equal on-screen drags at any zoom.
• TranslateHandleTest — axis-line grab regions constrain to the right axis; center moves both; off-axis starts no drag.

Full suite: 322 tests, 0 failures. Verified all built-in nodes' handles by hand, plus a Jython smoke test for the ReflectHandle projection path.

🤖 Generated with Claude Code