RasterColormapRenderer | API Reference | ArcGIS Maps SDK for JavaScript 4.30

The RasterColormapRenderer defines the symbology to display raster data based on specific colors, aiding in visual analysis of the data. For example, a forestry commission may want to quickly visualize areas above and below the treeline occurring at a known elevation on a raster containing elevation values. They could overlay a transparent colormap set to color those areas below the treeline elevation green, and those above white.

The RasterColormapRenderer is only available if a color map is present in an ImageryLayer or ImageryTileLayer. Otherwise, you can use the UniqueValueRenderer to apply colors to your layer.

Constructors

RasterColormapRenderer Constructor new RasterColormapRenderer(properties)

Parameter

properties Object

optional

See the properties for a list of all the properties that may be passed into the constructor.

Examples

// create a new RasterColormapRenderer from provided the colormap array
const renderer = RasterColormapRenderer.createFromColormap(colors);

// create a new RasterColormapRenderer
const renderer = new RasterColormapRenderer({
 colormapInfos: colormapInfos
});

Property Overview

Any properties can be set, retrieved or listened to. See the Working with Properties topic.

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Type	Summary	Class
ColormapInfo []	A colormap info array containing mappings for pixel and RGB color values.	RasterColormapRenderer
String	The name of the class.	Accessor
String	The type of Renderer.	RasterColormapRenderer

Property Details

colormapInfos Property colormapInfos ColormapInfo[]autocast

A colormap info array containing mappings for pixel and RGB color values. Colormaps contain a set of values that are associated with colors and pixel values, and are used to display a single-band raster consistently with the same colors.

declaredClass Inherited Property declaredClass Stringreadonly Inherited from Accessor

The name of the class. The declared class name is formatted as esri.folder.className.

type Property type Stringreadonly

The type of Renderer.

For RasterColormapRenderer the type is always "raster-colormap".

Method Overview

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Return Type	Summary	Class
	Adds one or more handles which are to be tied to the lifecycle of the object.	Accessor
RasterColormapRenderer	Creates a deep clone of the renderer.	RasterColormapRenderer
RasterColormapRenderer	Creates a new instance RasterColormapRenderer from an array of color maps where pixel values with its corresponding RGB color values specified.	RasterColormapRenderer
*	Creates a new instance of this class and initializes it with values from a JSON object generated from an ArcGIS product.	RasterColormapRenderer
Boolean	Returns true if a named group of handles exist.	Accessor
	Removes a group of handles owned by the object.	Accessor
Object	Converts an instance of this class to its ArcGIS portal JSON representation.	RasterColormapRenderer

Method Details

addHandles Inherited Method addHandles(handleOrHandles, groupKey) Inherited from Accessor Since: ArcGIS Maps SDK for JavaScript 4.25 Accessor since 4.0, addHandles added at 4.25.

Adds one or more handles which are to be tied to the lifecycle of the object. The handles will be removed when the object is destroyed.

// Manually manage handles
const handle = reactiveUtils.when(
  () => !view.updating,
  () => {
    wkidSelect.disabled = false;
  },
  { once: true }
);

this.addHandles(handle);

// Destroy the object
this.destroy();

Parameters

handleOrHandles WatchHandle|WatchHandle []

Handles marked for removal once the object is destroyed.

groupKey *

optional

Key identifying the group to which the handles should be added. All the handles in the group can later be removed with Accessor.removeHandles(). If no key is provided the handles are added to a default group.

clone Method clone(){RasterColormapRenderer}

Creates a deep clone of the renderer.

Returns

Type	Description
RasterColormapRenderer	A deep clone of the object that invoked this method.

Example

// Creates a deep clone of the first layer's renderer
let renderer = view.map.layers.at(0).renderer.clone();

createFromColormap Method createFromColormap(colormap){RasterColormapRenderer}static

Creates a new instance RasterColormapRenderer from an array of color maps where pixel values with its corresponding RGB color values specified.

Parameter

colormap Number [][]

RGB color representation of pixel values. Each item in the colormap array has an array of the pixel value and red, green, and blue values.

Returns

Type	Description
RasterColormapRenderer	Returns a new instance RasterColormapRenderer based on provided colormap.

Example

// create a color map where values 0-199 are pink and 200-250 are light blue.
let colors = [];
for (let i = 0; i <= 250; i++) {
  if (i < 200) {
    colors.push([i, 250, 0, 128]);
  } else {
    colors.push([i, 0, 128, 250]);
  }
}

// create a RasterColormapRenderer from the colors array
const renderer = RasterColormapRenderer.createFromColormap(colors);

fromJSON Method fromJSON(json){*}static

Creates a new instance of this class and initializes it with values from a JSON object generated from an ArcGIS product. The object passed into the input json parameter often comes from a response to a query operation in the REST API or a toJSON() method from another ArcGIS product. See the Using fromJSON() topic in the Guide for details and examples of when and how to use this function.

Parameter

json Object

A JSON representation of the instance in the ArcGIS format. See the ArcGIS REST API documentation for examples of the structure of various input JSON objects.

Returns

Type	Description
*	Returns a new instance of this class.

hasHandles Inherited Method hasHandles(groupKey){Boolean} Inherited from Accessor Since: ArcGIS Maps SDK for JavaScript 4.25 Accessor since 4.0, hasHandles added at 4.25.

Returns true if a named group of handles exist.

Parameter

groupKey *

optional

A group key.

Returns

Type	Description
Boolean	Returns `true` if a named group of handles exist.

Example

// Remove a named group of handles if they exist.
if (obj.hasHandles("watch-view-updates")) {
  obj.removeHandles("watch-view-updates");
}

removeHandles Inherited Method removeHandles(groupKey) Inherited from Accessor Since: ArcGIS Maps SDK for JavaScript 4.25 Accessor since 4.0, removeHandles added at 4.25.

Removes a group of handles owned by the object.

Parameter

groupKey *

optional

A group key or an array or collection of group keys to remove.

Example

obj.removeHandles(); // removes handles from default group

obj.removeHandles("handle-group");
obj.removeHandles("other-handle-group");

toJSON Method toJSON(){Object}

Converts an instance of this class to its ArcGIS portal JSON representation. See the Using fromJSON() guide topic for more information.

Returns

Type	Description
Object	The ArcGIS portal JSON representation of an instance of this class.