jet_cad_2d_flutter 0.7.2

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. The snippet uses both packages, so add both: dart pub add jet_cad_2d jet_cad_2d_flutter.

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

final canvas = 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.

Screenshots

The same drawing on the dark canvas: canvasResolverFor and ChromePalette.dark re-tone the colours for a dark theme.

A few entities selected, each with its grips, and one entity highlighted under the pointer.

A crossing band, dragged right to left, mid-drag: it selects what it touches, not only what it encloses.

SymbolGallery: a furniture library in collapsible categories of thumbnails, the Bathroom category open.

These pictures are made by tool/screenshots in the repository, with the app's own theme.

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 (0.7.3) does not.

The jet-cad packages

Package	What it is	Depends on
jet_cad_floor_plan	The embeddable floor planner and its host API	the renderer and the engine
jet_cad_2d_flutter	Flutter rendering and interaction	the engine
jet_cad_2d	The pure-Dart engine and document model	nothing of jet-cad

A host that embeds the planner adds only jet_cad_floor_plan; the other two come with it, and a host should not also depend on them directly unless it uses their API itself.

Embedding the floor planner in an app is walked through in the host guide.

Support

If jet-cad is useful to you, you can support its development through GitHub Sponsors or Buy Me a Coffee.

License

Apache License 2.0. See LICENSE.