node_flow 0.2.2

React Flow-style node editor canvas for Flutter: pan/zoom viewport, draggable nodes, drag-to-connect edges, marquee selection, snap guides, and a minimap.

Changelog

0.2.2

• Added node tap, double-tap, and context-menu callbacks for app-owned detail views while retaining selection and child-widget gesture behavior.

• The Editing demo opens a Flutter details dialog from node double-click or right-click.

• Added optional NodeFlow.isValidConnection for normalized application rules during connection hover and drop; rejected ports are not highlighted.

• The Connect demo uses that predicate to reject occupied inputs before drop.

• The editing demo now demonstrates focusing a node and updating an application-owned status; API and example docs describe current behavior.

• Added FlowController.updateNodeData for typed application-data updates while preserving node geometry, selection, ports, lock state, and connections.

• centerOnNode now accepts an omitted canvas size, using the last size reported by a mounted canvas. Existing explicit-size calls are unchanged.

• Hardened NodeFlow controller replacement: listener ownership now follows the active controller, transform state re-syncs on replacement, and borrowed controllers remain usable after the canvas is disposed.

• Interaction teardown is resilient to pointer cancellation and application callback errors, so marquee, connection, and node-drag state return to idle.

• Controller invariants now normalize initial selection, make same-instance node replacement safe, and validate/clamp viewport zoom state.

• Static edges and the minimap now repaint from the node geometry they consume, including programmatic position and measured-size changes.

• Bezier hit testing now covers same-side curves that overshoot an endpoint along the endpoint chord.

• Initial fitViewOnLoad waits for the first node measurement pass instead of fitting against placeholder sizes.

• Documentation now distinguishes rendered edge features from application-owned metadata and clarifies the 0.2.x onConnect return-value compatibility.

• CI now analyzes and tests the runnable example package as well as the library.

0.2.1

• Fixed alignment snapping pinning dragged nodes: the snap correction was fed back into the node position, so escaping a guide required a single fast pointer event larger than the threshold — slow, precise drags could never break free, and the swallowed travel left the node drifting away from the cursor. Node drags now track the raw pointer offset from drag start and compute snapping as a pure function of it: a guide holds while the raw position is within the threshold and releases exactly when it travels past, with the node always landing back under the cursor.
• The guide capture radius is now a constant screen distance: the new FlowController.snapGuideThreshold (default 8 logical pixels, mutable at runtime) is divided by the current zoom, so the magnet feels the same at every zoom level. Previously it was 6 graph units, which grew stronger the further you zoomed in. Note the graph-unit radius now grows when zoomed out (8 px at zoom 0.5 is 16 graph units), so drags can align — and commit off-grid — across slightly larger distances than before.
• FlowController.cancelNodeDrag() aborts an in-flight drag and restores the dragged nodes to their drag-start positions; the node gesture wires it to the recognizer's cancel callback, so a system takeover mid-drag no longer strands the drag session or the interaction mode.
• Mid-drag edge cases hardened: replaceNode and a mid-drag commitMove re-anchor the live drag (their positions stick instead of being reverted by the next pointer event), a node locked and unlocked mid-drag stays where it stopped instead of teleporting, releasing a drag on a node locked mid-drag commits instead of leaving the canvas stuck, and stale guides are cleared when snapping is disabled mid-drag.
• FlowNode.boundsAt(origin) returns the node's bounds at a hypothetical position; resolveAlignmentSnap's default threshold is now 8.0 to match the controller's default.

0.2.0

• Per-edge accent colors: FlowEdge.accent (also settable in the constructor) paints one edge in its own color instead of FlowTheme.edge, so an app can highlight a traversed path, a failing branch, or a data type without borrowing selection for it.
• FlowController.setEdgeAccent(id, color) and FlowController.clearEdgeAccents() apply accents and repaint the edge layers through the new FlowController.edgeAccentVersion notifier, leaving the edge selection — and edgeSelectionVersion — untouched.
• Painting precedence is selected > accent > theme default: a selected edge still paints selected (and heavier) whatever its accent, and accents compose with the animated flowing dash unchanged.

0.1.1

• No functional changes. Infrastructure release: CI and automated publishing from GitHub Actions.

0.1.0

Initial release.

• NodeFlow<T, E> canvas widget: infinite pan/zoom viewport, dotted background grid, app-defined node visuals via nodeBuilder.
• FlowController<T, E>: nodes, edges, selection, marquee, viewport operations (fitView, zoomTo, centerOnNode), and callback seams for app-owned undo/persistence (onMoveCommitted, onDeleted, onEdgesDeleted).
• Node dragging with multi-selection, locked nodes, grid snap on commit, and Figma-style alignment snap guides.
• Ports and drag-to-connect with compatible-port detection, connection preview, and normalized onConnect requests.
• Edge styles: bezier, smoothstep, and straight, with optional animated flowing-dash rendering, hit-testing, and selection.
• Pannable minimap overlay with viewport indicator.
• Zero-dependency theming: explicit FlowTheme, ThemeData extension lookup, or built-in dark defaults.