Class: ImageCanvas

ol.source.ImageCanvas

Base class for image sources where a canvas element is the image.

new ol.source.ImageCanvas(options) experimental

src/ol/source/imagecanvassource.js, line 19
Name Type Description
options
Name Type Description
attributions Array.<ol.Attribution> | undefined experimental

Attributions.

canvasFunction ol.CanvasFunctionType experimental

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.

logo string | olx.LogoOptions | undefined experimental

Logo.

projection ol.proj.ProjectionLike experimental

Projection.

ratio number | undefined experimental

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 experimental

Resolutions. If specified, new canvases will be created for these resolutions only.

state ol.source.State | string | undefined experimental

Source state.

Fires:
  • change experimental - Triggered when the state of the source changes.
  • propertychange (ol.ObjectEvent) experimental - Triggered when a property is changed.

Subclasses

Extends

Methods

bindTo(key, target, opt_targetKey){ol.ObjectAccessor} inherited experimental

src/ol/object.js, line 326

The bindTo method allows you to set up a two-way binding between a source and target object. The method returns an object with a transform method that you can use to provide from and to functions to transform values on the way from the source to the target and on the way back.

For example, if you had two map views (sourceView and targetView) and you wanted the target view to have double the resolution of the source view, you could transform the resolution on the way to and from the target with the following:

sourceView.bindTo('resolution', targetView)
  .transform(
    function(sourceResolution) {
      // from sourceView.resolution to targetView.resolution
      return 2 * sourceResolution;
    },
    function(targetResolution) {
      // from targetView.resolution to sourceView.resolution
      return targetResolution / 2;
    }
  );
Name Type Description
key string

Key name.

target ol.Object

Target.

targetKey string

Target key.

changed() inherited experimental

src/ol/observable.js, line 52

Increases the revision counter and disptches a 'change' event.

Fires:
  • change experimental

get(key){*} inherited experimental

src/ol/object.js, line 354

Gets a value.

Name Type Description
key string

Key name.

Returns:
Value.

getAttributions(){Array.<ol.Attribution>} inherited

src/ol/source/source.js, line 96
Returns:
Attributions.

getKeys(){Array.<string>} inherited experimental

src/ol/object.js, line 373

Get a list of object property names.

Returns:
List of property names.
src/ol/source/source.js, line 105
Returns:
Logo.

getProjection(){ol.proj.Projection} inherited experimental

src/ol/source/source.js, line 114
Returns:
Projection.

getProperties(){Object.<string, *>} inherited experimental

src/ol/object.js, line 405

Get an object of all property names and values.

Returns:
Object.

getRevision(){number} inherited experimental

src/ol/observable.js, line 62
Returns:
Revision.

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

src/ol/source/source.js, line 129
Returns:
State.

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

src/ol/observable.js, line 75

Listen for a certain type of event.

Name Type Description
type string | Array.<string>

The event type or array of event types.

listener function

The listener function.

this Object

The object to use as this in listener.

Returns:
Unique key for the listener.

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

src/ol/observable.js, line 88

Listen once for a certain type of event.

Name Type Description
type string | Array.<string>

The event type or array of event types.

listener function

The listener function.

this Object

The object to use as this in listener.

Returns:
Unique key for the listener.

set(key, value) inherited experimental

src/ol/object.js, line 437

Sets a value.

Name Type Description
key string

Key name.

value *

Value.

setProperties(values) inherited experimental

src/ol/object.js, line 456

Sets a collection of key-value pairs.

Name Type Description
values Object.<string, *>

Values.

un(type, listener, opt_this) inherited

src/ol/observable.js, line 101

Unlisten for a certain type of event.

Name Type Description
type string | Array.<string>

The event type or array of event types.

listener function

The listener function.

this Object

The object which was used as this by the listener.

unbind(key) inherited experimental

src/ol/object.js, line 470

Removes a binding. Unbinding will set the unbound property to the current value. The object will not be notified, as the value has not changed.

Name Type Description
key string

Key name.

unbindAll() inherited experimental

src/ol/object.js, line 487

Removes all bindings.

unByKey(key) inherited

src/ol/observable.js, line 114

Removes an event listener using the key returned by on() or once(). Note that using the ol.Observable.unByKey static function is to be preferred.

Name Type Description
key goog.events.Key

The key returned by on() or once().