Class FeaturePainter

An object that determines how features are visualized in a FeatureLayer.

You will need to reassign the paintBody method since its default implementation only throws an error. This object does not have a paintLabel method as it is optional.

  const featurePainter = new FeaturePainter();
  //Use a custom paintBody implementation
  featurePainter.paintBody = function(geoCanvas, feature, shape, layer, map, paintState) {
    geoCanvas.drawShape(shape, {
      stroke: {
        color: "rgb(0,0,255)",
        width: 5
      },
      fill: {color: "rgba(0,0,255,0.5)"}
    });
  };

  // Sub-classing FeaturePainter
  class CustomPainter extends FeaturePainter {
    strokeStyle: ShapeStyle;
    constructor() {
      super();
      this.strokeStyle = {
        stroke: { color: "rgb(0,0,255)", width: 5 },
        fill: {color: "rgba(0,0,255,0.5)"}
      }
    }
    paintBody(geoCanvas: GeoCanvas, feature: Feature, shape: Shape, layer: Layer, map: RIAMap, paintState: PaintState) {
      geoCanvas.drawShape(shape, this.strokeStyle);
    }
  }
  const painter = new CustomPainter();

To use a basic painter, see BasicFeaturePainter.

Hierarchy (View Summary)

Implements

Constructors

constructor

Accessors

density

Methods

getDetailLevelScales invalidate invalidateAll invalidateById paintBody paintLabel?

Events

InvalidateAll Invalidate InvalidateById

Constructors

Accessors

  • get density(): DensitySettings | null

    Set or get the density painting settings on this painter. Use null to disable density painting.

    The setting affects all features in the layer associated with this painter.

    The density settings object has one property: colorMap, the color map used to map density values to color.

    The density at a particular location is the sum of the value of alpha channel for all overlapping objects. So for a single opaque object you would get a density value of 1.0, for 2 opaque objects 2.0, etc.

    Example:

      var painter = new FeaturePainter();
      painter.paintBody = ... // customize painter as usual
      painter.density = {
        colorMap: ColorMap.createGradientColorMap([
          {level:  0, color: "rgba(  0,   0,   0, 0.0)"}, // no objects       -> Transparent
          {level:  1, color: "rgba(  0, 255,   0, 0.5)"}, // 1 opaque object  -> Transparent green
          {level: 10, color: "rgba(255, 255, 255, 1.0)"}  //10 opaque objects -> White
        ])
      };

    Notes when using density painting:

    • Density painting works for all kinds of objects: points/icons, lines and areas.
    • The color aspect of the styling provided in paintBody is ignored. The alpha value of the color is used as a per-feature weight.
    • If you paint icons, you can leave out the icon image. You will automatically get a gradient icon. You can still adapt the size with the width and height style properties.

    Returns DensitySettings | null

  • set density(value: DensitySettings | null): void

    Parameters

    Returns void

Methods

  • Returns an array of map scales that define when to switch between levels of detail.

    This method allows the painter to support multiple visual representations (levels-of-detail, or LOD) for the same feature depending on the map's current scale. The map determines the active level and passes it to the painter via the paintState.level property during rendering. If the level changes due to map navigation (such as zooming, panning, or fitting), the map will call the paintBody and paintLabel methods with the corresponding level.

    By default, this method returns null, indicating that level-of-detail is not used. Override this method to enable scale-based LOD behavior.

    Parameters

    • Optionallayer: FeatureLayer

      The feature layer for which level-of-detail scales are requested.

    • Optionalmap: RIAMap

      The map instance for which the scales apply.

    Returns number[] | null

    An array of scales at which to switch to the next detail level, or null if LOD is not used.

      // The example below illustrates how switching scales map to paint levels.
      // It uses 3 switching points, resulting in 4 distinct paint levels:
      //
      // Scale:         1 : 100 000     1 : 10 000      1 : 1000
      // (zoomed out) --- | ------------- | ------------- | --- (zoomed in)
      //       level 0    |    level 1    |    level 2    |    level 3

      painter.getDetailLevelScales = (): number[] => {
        return [ 1 / 100_000, 1 / 10_000, 1 / 1_000 ];
      }

  • Invalidates this painter for a specific feature. Call this method when any state that affects the rendering of the given feature has changed. This method refreshes the associated layer and ensures that FeaturePainter.paintBody and FeaturePainter.paintLabel will be called for the specified feature during the next map render.

    Note: If the layer is currently invisible, the invalidation is deferred and will be applied when the layer becomes visible again.

    Parameters

    • feature: Feature

      the model feature whose representation has changed

    Returns void

  • Invalidates this painter for all features. Call this method when any state that affects the rendering of features has changed. This method refreshes the associated layer and ensures that FeaturePainter.paintBody and FeaturePainter.paintLabel will be called for all features in the layer during the next map render.

    Note: If the layer is currently invisible, the invalidation is deferred and will be applied when the layer becomes visible again.

    Note that this is called automatically whenever RIAMap.displayScale changes.

    Returns void

  • Invalidates this painter for a specific feature identified by its id. Call this method when any state that affects the rendering of the given feature has changed. This method refreshes the associated layer and ensures that FeaturePainter.paintBody and FeaturePainter.paintLabel will be called for the specified feature during the next map render.

    Note: If the layer is currently invisible, the invalidation is deferred and will be applied when the layer becomes visible again.

    Parameters

    Returns void

  • Renders a model object on the map.

    This method is called by the map for each (feature, paintState) combination. The result of the rendering is cached by the system, so this method is called only once per combination unless it is explicitly invalidated.

    To invalidate a cached result, call one of the invalidate methods on the painter instance.

    Rendering can vary depending on the paintState, which includes:

    • selected: a boolean value indicating whether the feature is currently selected.
    • hovered: a boolean value indicating whether the feature is currently hovered over
    • level: the current level of detail, where `0` is the least detailed

    Note For quick dataset visualization, you can use BasicFeaturePainter. If you need more advanced or customized styling logic, implement this method yourself. The default implementation will throw an error.

    Parameters

    • geoCanvas: GeoCanvas

      The rendering target.

    • feature: Feature

      The feature to be rendered.

    • shape: Shape

      The shape of the feature. This shape may be provided by a ShapeProvider associated with the layer.

    • layer: Layer

      The layer that contains the given feature.

    • map: RIAMap

      The map on which the layer is displayed.

    • paintState: PaintState

      The current state describing how the feature should be rendered.

    Returns void

  • Renders a label for a model object on the map.

    This method is invoked by the map for each (feature, paintState) combination. The result is cached by the system, so the method is called only once per combination unless explicitly invalidated.

    To invalidate a cached result, call one of the invalidate methods on the painter instance.

    Rendering can vary depending on the paintState, which includes

    • selected: a boolean value indicating whether the feature is currently selected.
    • hovered: a boolean value indicating whether the feature is currently hovered over
    • level: the current level of detail, where `0` is the least detailed

    Note: This method is not implemented by default. If label rendering is required, you must provide a custom implementation.

    Parameters

    • labelCanvas: LabelCanvas

      the render target

    • feature: Feature

      the feature that is being rendered

    • shape: Shape

      the shape to render

    • layer: Layer

      the layer containing the given feature

    • map: RIAMap

      the map containing the layer

    • paintState: PaintState

      an object describing the current paint state

    Returns void

Events

  • Registers a callback function for the "InvalidateAll" event, that notifies a listener that the all features are invalidated.

    Parameters

    • event: "InvalidateAll"

      Always set to "InvalidateAll" for this event type.

    • callback: () => void

      The callback function to be executed when the event is emitted

    • Optionalcontext: any

      The context in which the function should be invoked.

      "InvalidateAll"

    Returns Handle

    2020.1

  • Registers a callback function for the "Invalidate" event, that notifies a listener that a given feature is invalidated.

    Parameters

    • event: "Invalidate"

      Always set to "Invalidate" for this event type.

    • callback: (feature: Feature) => void

      The callback function to be executed when the event is emitted

    • Optionalcontext: any

      The context in which the function should be invoked.

      "Invalidate"

    Returns Handle

    2020.1

  • Registers a callback function for the "InvalidateById" event, that notifies a listener that a feature with the given id is invalidated.

    Parameters

    • event: "InvalidateById"

      Always set to "InvalidateById" for this event type.

    • callback: (id: FeatureId) => void

      The callback function to be executed when the event is emitted

    • Optionalcontext: any

      The context in which the function should be invoked.

      "InvalidateById"

    Returns Handle

    2020.1

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