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(options)

Name Type Description
attributions AttributionLike | undefined

Attributions.

canvasFunction FunctionType | undefined

Canvas function. The function returning the canvas element used by the source as an image. The arguments passed to the function are: Extent the image extent, {number} the image resolution, {number} the pixel ratio of the map, Size the image size, and 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: changed

interpolate boolean (defaults to true)

Use interpolated values when resampling. By default, linear interpolation is used when resampling. Set to false to use the nearest neighbor instead.

projection ProjectionLike | undefined

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> | undefined

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

state State | undefined

Source state.

Fires:

Extends

Methods

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

dispatchEvent(event){boolean | undefined} inherited

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 BaseEvent | string

Event object.

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

Gets a value.

Name Type Description
key string

Key name.

Returns:
Value.

Get the attribution function for the source.

Returns:
Attribution function.

getAttributionsCollapsible(){boolean} inherited

Returns:
Attributions are collapsible.

getKeys(){Array.<string>} inherited

Get a list of object property names.

Returns:
List of property names.

getProjection(){Projection | null} inherited

Get the projection of the source.

Returns:
Projection.

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

Get an object of all property names and values.

Returns:
Object.

getRevision(){number} inherited

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

Returns:
Revision.

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

Returns:
State.

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

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){EventsKey | Array<EventsKey>} inherited

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.

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

set(key, value, silent) inherited

Sets a value.

Name Type Description
key string

Key name.

value *

Value.

silent boolean | undefined

Update without triggering an event.

setAttributions(attributions) inherited

Set the attributions of the source.

Name Type Description
attributions AttributionLike | undefined

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

setProperties(values, silent) inherited

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 | undefined

Update without triggering an event.

un(type, listener) inherited

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, silent) inherited

Unsets a property.

Name Type Description
key string

Key name.

silent boolean | undefined

Unset without triggering an event.