OpenLayers 3 API Documentation

Class: ImageCanvas

ol.source. ImageCanvas

experimental new ol.source.ImageCanvas(options)

src/ol/source/imagecanvassource.js, line 16
Name Type Description
options
Name Type Description
attributions Array.<ol.Attribution> | undefined

Attributions.
canvasFunction ol.CanvasFunctionType

Canvas function. The function returning the canvas element used by the source as an image. The arguments passed to the function are: {ol.Extent} the image extent, {number} the image resolution, {number} the device pixel ratio, {ol.Size} the image size, and {ol.proj.Projection} the image projection. The canvas returned by this function is cached by the source. If the value returned by the function is later changed then dispatchChangeEvent should be called on the source for the source to invalidate the current cached image.
extent ol.Extent | undefined

Extent.
logo string | undefined

Logo.
projection ol.proj.ProjectionLike

Projection.
ratio number | undefined

Ratio. 1 means canvases are the size of the map viewport, 2 means twice the size of the map viewport, and so on. Default is 1.5.
resolutions Array.<number> | undefined

Resolutions. If specified, new canvases will be created for these resolutions only.
state ol.source.State | string | undefined

Source state.
Fires:
  • change

Subclasses

Extends

Methods

experimental inherited dispatchChangeEvent()

src/ol/observable.js, line 39

Dispatches a change event. Register a listener for this event to get notified of changes.

Fires:
  • change

experimental inherited getState(){ol.source.State}

src/ol/source/source.js, line 137

experimental inherited on(type, listener, opt_this){goog.events.Key}

src/ol/observable.js, line 61

Listen for a certain type of event.

Name Type Argument Description
type string | Array.<string>

The event type or array of event types.
listener function

The listener function.
this Object <optional>
 optional

The object to use as this in listener.
Returns:
key for the listener.

experimental inherited once(type, listener, opt_this){goog.events.Key}

src/ol/observable.js, line 74

Listen once for a certain type of event.

Name Type Argument Description
type string | Array.<string>

The event type or array of event types.
listener function

The listener function.
this Object <optional>
 optional

The object to use as this in listener.
Returns:
key for the listener.

experimental inherited un(type, listener, opt_this)

src/ol/observable.js, line 86

Unlisten for a certain type of event.

Name Type Argument Description
type string | Array.<string>

The event type or array of event types.
listener function

The listener function.
this Object <optional>
 optional

The object to use as this in listener.

experimental inherited unByKey(key)

src/ol/observable.js, line 96

Removes an event listener using the key returned by on() or once().

Name Type Description
key goog.events.Key

Key.