OpenLayers

Class: ImageCanvas

ol.source.ImageCanvas

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

new ol.source.ImageCanvas(options)

src/ol/source/imagecanvas.js, line 18
Name Type Description
options

Constructor options.

Name Type Description
attributions ol.AttributionLike | 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. Required.
logo string | olx.LogoOptions | undefined

Logo.
projection ol.ProjectionLike

Projection.
ratio number | undefined

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

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

Source state.
Fires:

Subclasses

Extends

Methods

changed() inherited

src/ol/observable.js, line 58

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

dispatchEvent(event) inherited

src/ol/observable.js, line 75

Dispatches an event and calls all listeners listening for events of this type. The event parameter can either be a string or an Object with a type property.

Name Type Description
event Object | ol.events.Event | string

Event object.

get(key){*} inherited

src/ol/object.js, line 101

Gets a value.

Name Type Description
key string

Key name.
Returns:
Value.

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

src/ol/source/source.js, line 113

Get the attributions of the source.

Returns:
Attributions.

getKeys(){Array.<string>} inherited

src/ol/object.js, line 115

Get a list of object property names.

Returns:
List of property names.

getLogo(){string|olx.LogoOptions|undefined} inherited

src/ol/source/source.js, line 123

Get the logo of the source.

Returns:
Logo.

getProjection(){ol.proj.Projection} inherited

src/ol/source/source.js, line 133

Get the projection of the source.

Returns:
Projection.

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

src/ol/object.js, line 125

Get an object of all property names and values.

Returns:
Object.

getRevision(){number} inherited

src/ol/observable.js, line 84

Get the version number for this object. Each time the object is modified, its version number will be incremented.

Returns:
Revision.

getState(){ol.source.State} inherited

src/ol/source/source.js, line 150

Get the state of the source, see ol.source.State for possible states.

Returns:
State.

on(type, listener, opt_this){ol.EventsKey|Array.<ol.EventsKey>} inherited

src/ol/observable.js, line 99

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. If called with an array of event types as the first argument, the return will be an array of keys.

once(type, listener, opt_this){ol.EventsKey|Array.<ol.EventsKey>} inherited

src/ol/observable.js, line 124

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. If called with an array of event types as the first argument, the return will be an array of keys.

refresh() inherited

src/ol/source/source.js, line 167

Refreshes the source and finally dispatches a 'change' event.

set(key, value, opt_silent) inherited

src/ol/object.js, line 150

Sets a value.

Name Type Description
key string

Key name.
value *

Value.
silent boolean

Update without triggering an event.

setAttributions(attributions) inherited

src/ol/source/source.js, line 179

Set the attributions of the source.

Name Type Description
attributions ol.AttributionLike | undefined

Attributions. Can be passed as string, Array<string>, ol.Attribution, Array<ol.Attribution> or undefined.

setProperties(values, opt_silent) inherited

src/ol/object.js, line 170

Sets a collection of key-value pairs. Note that this changes any existing properties and adds new ones (it does not remove any existing properties).

Name Type Description
values Object.<string, *>

Values.
silent boolean

Update without triggering an event.

un(type, listener, opt_this) inherited

src/ol/observable.js, line 147

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.

unset(key, opt_silent) inherited

src/ol/object.js, line 184

Unsets a property.

Name Type Description
key string

Key name.
silent boolean

Unset without triggering an event.