jet_cad_2d_flutter 0.7.1

Flutter rendering and interaction for the jet_cad_2d engine: a CAD canvas with camera, rulers, selection and snapping, and PDF and PNG export.

jet_cad_2d_flutter

Flutter rendering and interaction for the pure-Dart jet_cad_2d engine. It draws a DraftDocument on a canvas, with a camera, rulers, selection and snapping, and writes a page of it out as a vector PDF or a PNG. The engine stays free of dart:ui; everything that needs Flutter is here.

What it holds

• DraftCanvas: the widget that paints a document and repaints on camera and document changes and on nothing else.
• CameraController and ViewportTransform: pan, zoom and the world-to-screen transform, with zoom-to-fit.
• RulerFrame: rulers around a canvas.
• InteractionLayer and ToolController: the pointer layer over a canvas, which routes mouse, touch and keyboard input to the active Tool: SelectTool (selection and grips) or one of the drawing tools (LineTool, PolylineTool, RectangleTool, CircleTool, ArcTool, TextTool). Object snapping is configured with SnapSettings and drawn by drawSnapMarker.
• PDF and PNG export: exportPagePdf and exportPagePng write a page of a document to bytes.

Example

DraftCanvas borrows its document, its spatial index and its camera: the application creates them and disposes of them. The document must carry a FlutterTextMeasurer, which is how its text is measured.

final document = DraftDocument.empty(measurer: FlutterTextMeasurer());
final index = SpatialIndex(document);
final camera = CameraController(
    ViewportTransform.fit(document.extents.expandedBy(20), size));

DraftCanvas(document: document, index: index, camera: camera)

A complete app, which draws a line and a circle and frames them, is example/lib/main.dart. Run it from the package directory with flutter run -t example/lib/main.dart.

The API

package:jet_cad_2d_flutter/jet_cad_2d_flutter.dart is the API. Nothing under src/ is. package:jet_cad_2d_flutter/export_testing.dart is a test instrument for this repository's own suites; it is not API and may change in any release.

While the version is 0.x, a minor release (0.8.0) may break the API, and a patch release (0.7.2) does not.

Where it comes from

This package is the rendering layer of jet-cad, a parametric floor planner; jet_cad_floor_plan builds on it.

License

Apache License 2.0. See LICENSE.