ExportedIDLookup class

Used to look up what part of a ScalableImage is clicked on within a ScalableImageWidget.

An SVG node can have a name in its id attribute. When an SVG is read, or converted to an SI, these ID values can be marked as exported. This can be done by listing the IDs, or by using a regular expression. For example, to build an SI where all ID values are exported, you can specify -x '.*' to svg_to_si. Each exported ID does add some overhead, so in production, it's best to only export the ones you need.

A ScalableImageWidget can have an ExportedIDLookup instance associated with it. This can be used, for example, to determine which node(s) are under a mouse click (or other tap event).

Usage:

class _GlorpState extends State<GlorpWidget> {
    final ExportedIDLookup _idLookup = ExportedIDLookup();
    ...
    @override
    Widget build() => ...
        GestureDetector(
          onTapDown: _handleTapDown,
          child: ScalableImageWidget(
            ...
            lookup: _idLookup))
      ...;

  void _handleTapDown(TapDownDetails event) {
    final Set<String> hits = _idLookup.hits(event.localPosition);
    print('Tap down at ${event.localPosition}:  $hits');
  }
}

See example/lib/animation.dart and demo/lib/main.dart for more complete examples.

Constructors

ExportedIDLookup.new()

Properties

exportedIDs → Set<ExportedID>
Get the exported IDs from the underlying ScalableImage instance, if it has been loaded. The ExportedIDs will be in the coordinate system of the ScalableImage. See also scalingTransform.
no setter
hashCode → int
The hash code for this object.
no setterinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
scalingTransform → ScalingTransform
Get the ScalingTransform needed to convert coordinates between the coordinate system of the ScalableImage's exportedIDs and the containing ScalableImageWidget.
no setter

Methods

hits(Offset p) → Set<String>
Return the set of node IDs whose bounding rectangles contain p.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited