Class: ImageCanvasSource

ol/source/ImageCanvas~ImageCanvasSource 


import ImageCanvasSource from 'ol/source/ImageCanvas';

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

new ImageCanvasSource(opt_options)

source/ImageCanvas.js, line 53
Name Type Description
options

ImageCanvas options.

Name Type Description
attributions module:ol/source/Source~AttributionLike

Attributions.
canvasFunction module:ol/source/ImageCanvas~FunctionType

Canvas function. The function returning the canvas element used by the source as an image. The arguments passed to the function are: {module:ol/extent~Extent} the image extent, {number} the image resolution, {number} the pixel ratio of the map, {module:ol/size~Size} the image size, and {module:ol/proj/Projection~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 changed should be called on the source for the source to invalidate the current cached image. See: module:ol/Observable~Observable#changed
imageSmoothing boolean (defaults to true)

Enable image smoothing.
projection module:ol/proj~ProjectionLike

Projection. Default is the view projection.
ratio number (defaults to 1.5)

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.
resolutions Array.<number>

Resolutions. If specified, new canvases will be created for these resolutions
state module:ol/source/State

Source state.
Fires:

Extends

Methods

changed() inherited

Observable.js, line 70

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

dispatchEvent(event){boolean|undefined} inherited

events/Target.js, line 85

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 module:ol/events/Event~BaseEvent | string

Event object.
Returns:
false if anyone called preventDefault on the event object or if any of the listeners returned false.

get(key){*} inherited

Object.js, line 135

Gets a value.

Name Type Description
key string

Key name.
Returns:
Value.

getKeys(){Array.<string>} inherited

Object.js, line 148

Get a list of object property names.

Returns:
List of property names.

getProjection(){module:ol/proj/Projection~Projection} inherited

source/Source.js, line 115

Get the projection of the source.

Returns:
Projection.

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

Object.js, line 157

Get an object of all property names and values.

Returns:
Object.

getRevision(){number} inherited

Observable.js, line 81

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

Returns:
Revision.

getState(){module:ol/source/State} inherited

source/Source.js, line 132

Get the state of the source, see module:ol/source/State~State for possible states.

Returns:
State.

on(type, listener){module:ol/events~EventsKey|Array.<module:ol/events~EventsKey>} inherited

Observable.js, line 155

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.
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){module:ol/events~EventsKey|Array.<module:ol/events~EventsKey>} inherited

Observable.js, line 167

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.
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

source/Source.js, line 154

Refreshes the source. The source will be cleared, and data from the server will be reloaded.

set(key, value, opt_silent) inherited

Object.js, line 203

Sets a value.

Name Type Description
key string

Key name.
value *

Value.
silent boolean

Update without triggering an event.

setAttributions(attributions) inherited

source/Source.js, line 165

Set the attributions of the source.

Name Type Description
attributions module:ol/source/Source~AttributionLike | undefined

Attributions. Can be passed as string, Array<string>, module:ol/source/Source~Attribution, or undefined.

setProperties(values, opt_silent) inherited

Object.js, line 223

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) inherited

Observable.js, line 176

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.

unset(key, opt_silent) inherited

Object.js, line 247

Unsets a property.

Name Type Description
key string

Key name.
silent boolean

Unset without triggering an event.