@allmaps/leaflet

Allmaps plugin for Leaflet. This plugin allows displaying georeferenced IIIF images on a Leaflet map. The plugin works by loading Georeference Annotations and uses WebGL to transform images from a IIIF image server to overlay them on their correct geographical position. See allmaps.org for more information.

The development of the Allmaps plugin for Leaflet was funded by CLARIAH-VL. The development of the Allmaps plugin for Leaflet was funded by CLARIAH-VL.

Examples:

• Observable notebook
• Observable notebook

How it works

This plugin exports the class WarpedMapLayer that extends L.Layer. You can add one or multiple Georeference Annotations (or AnnotationPages that contain multiple Georeference Annotations) to a WarpedMapLayer, and add the WarpedMapLayer to your Leaflet map. This will render all georeferenced maps defined by the Georeference Annotations.

To understand what happens under the hood for each georeferenced map, see the @allmaps/render package.

Installation

This package works in browsers and in Node.js as an ESM or an UMD module.

Install with pnpm:

npm install @allmaps/leaflet

You can optionally build this package locally by running:

pnpm run build

Usage

Built for Leaflet 1.9, but should work with earlier versions as well.

Loading a Georeference Annotation

Creating a WarpedMapLayer and adding it to a map looks like this:

import { WarpedMapLayer } from '@allmaps/leaflet'

const map = L.map('map', {
  center: [51.0518, 3.7278],
  zoom: 14,
  // Zoom animations for more than one zoom level are
  // currently not supported by the Allmaps plugin for Leaflet
  zoomAnimationThreshold: 1
})
L.tileLayer('https://tile.openstreetmap.org/{z}/{x}/{y}.png', {
  attribution:
    '&copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors'
}).addTo(map)

const annotationUrl =
  'https://annotations.allmaps.org/manifests/8f9faeba73d67031'
const warpedMapLayer = new WarpedMapLayer(annotationUrl).addTo(map)

When adding this WarpedMapLayer to the Leaflet map, the georeferenced map specified in the Georeference Annotation will be rendered on the Leaflet map.

Specifying a the URL Georeference Annotation when creating a WarpedMapLayer (as is done above) is optional. A Georeference Annotation can also be added at a later stage using the addGeoreferenceAnnotation and addGeoreferenceAnnotationByUrl functions:

fetch(annotationUrl)
  .then((response) => response.json())
  .then((annotation) => warpedMapLayer.addGeoreferenceAnnotation(annotation))

Or:

await warpedMapLayer.addGeoreferenceAnnotationByUrl(annotationUrl)

WarpedMapLayer API and Events

See the @allmaps/warpedmaplayer package for the API documentation of the methods inherited from the WarpedMapLayer class (shared by all Allmaps plugins). It includes a list of all options that can be set on instances of the class and all events which are passed to the native map instance hosting the layer instance.

You can set options on the entire layer, or on a specific map on the layer (overwriting layer options):

warpedMapLayer.setLayerOptions({ visible: true })
warpedMapLayer.setMapOptions(mapId, { visible: true })

You can listen to events in the typical way:

map.on('warpedmapadded', (event) => {
  console.log(event.mapIds)
})

License

MIT

API

LeafletWarpedMapLayerOptions

Type

SpecificLeafletWarpedMapLayerOptions & Partial<WebGL2RenderOptions>

new WarpedMapEvent(type, data)

Parameters

• type (WarpedMapEventType)
• data? (Partial<WarpedMapEventData> | undefined)

Returns

WarpedMapEvent.

Extends

• Event

WarpedMapEvent#data?

Type

{
  mapIds?: Array<string> | undefined
  tileUrl?: string | undefined
  optionKeys?: Array<string> | undefined
  spritesInfo?: SpritesInfo | undefined
}

new WarpedMapLayer(annotationOrAnnotationUrl, options)

Creates a WarpedMapLayer

Parameters

• annotationOrAnnotationUrl (unknown)
  • Georeference Annotation or URL of a Georeference Annotation
• options? (Partial<LeafletWarpedMapLayerOptions> | undefined)
  • Options for the layer

Returns

WarpedMapLayer.

Extends

• BaseWarpedMapLayer

WarpedMapLayer#_animateZoom(e)

Parameters

• e (L.ZoomAnimEvent)

Returns

void.

WarpedMapLayer#_annotationOrAnnotationUrl

Type

unknown

WarpedMapLayer#_initGl()

Parameters

There are no parameters.

Returns

void.

WarpedMapLayer#_resized(entries)

Parameters

• entries (Array<ResizeObserverEntry>)

Returns

void.

WarpedMapLayer#_unload()

Parameters

There are no parameters.

Returns

void.

WarpedMapLayer#_update()

Parameters

There are no parameters.

Returns

HTMLDivElement | undefined.

WarpedMapLayer#_updateZIndex()

Parameters

There are no parameters.

Returns

void.

WarpedMapLayer#addEventListeners()

Parameters

There are no parameters.

Returns

void.

WarpedMapLayer#addGeoreferenceAnnotation(annotation, mapOptions)

Adds a Georeference Annotation

Parameters

• annotation (unknown)
  • Georeference Annotation
• mapOptions? (Partial<WebGL2WarpedMapOptions> | undefined)
  • Map options

Returns

Map IDs of the maps that were added, or an error per map (Promise<Array<string | Error>>).

WarpedMapLayer#addGeoreferenceAnnotationByUrl(annotationUrl, mapOptions)

Adds a Georeference Annotation by URL

Parameters

• annotationUrl (string)
  • URL of a Georeference Annotation
• mapOptions? (Partial<WebGL2WarpedMapOptions> | undefined)
  • Map options

Returns

Map IDs of the maps that were added, or an error per map (Promise<Array<string | Error>>).

WarpedMapLayer#addGeoreferencedMap(georeferencedMap, mapOptions)

Adds a Georeferenced Map

Parameters

• georeferencedMap (unknown)
  • Georeferenced Map
• mapOptions? (Partial<WebGL2WarpedMapOptions> | undefined)
  • Map options

Returns

Map ID of the map that was added, or an error (Promise<string | Error>).

WarpedMapLayer#addImageInfos(imageInfos)

Adds image information to the WarpedMapList's image information cache

Parameters

• imageInfos (Array<unknown>)
  • Image informations

Returns

Image IDs of the image informations that were added (Array<string>).

WarpedMapLayer#addSprites(sprites, imageUrl, imageSize)

Adds sprites to the Renderer's sprite tile cache

This adds tiles from sprites to warped maps in WarpedMapList. Load maps before running this function. This uses the image info of related maps. When using addImageInfos(), call it before calling this function.

Parameters

• sprites (Array<Sprite>)
  • Sprites
• imageUrl (string)
  • Image url
• imageSize ([number, number])
  • Image size

Returns

Promise<void>.

WarpedMapLayer#bringMapsForward(mapIds)

Bring maps forward

Parameters

• mapIds (Iterable<string>)
  • IDs of the maps

Returns

void.

WarpedMapLayer#bringMapsToFront(mapIds)

Bring maps to front

Parameters

• mapIds (Iterable<string>)
  • IDs of the maps

Returns

void.

WarpedMapLayer#bringToBack()

Brings the layer to the back of other overlays (in the same map pane).

Parameters

There are no parameters.

Returns

this.

WarpedMapLayer#bringToFront()

Brings the layer in front of other overlays (in the same map pane).

Parameters

There are no parameters.

Returns

this.

WarpedMapLayer#canvas?

Type

HTMLCanvasElement

WarpedMapLayer#clear()

Removes all warped maps from the layer

Parameters

There are no parameters.

Returns

void.

WarpedMapLayer#container?

Type

HTMLDivElement

WarpedMapLayer#contextLost(event)

Parameters

• event (Event)

Returns

void.

WarpedMapLayer#contextRestored(event)

Parameters

• event (Event)

Returns

void.

WarpedMapLayer#defaultSpecificWarpedMapLayerOptions

Type

{
  interactive: boolean
  className: string
  pane: string
  zIndex?: number
}

WarpedMapLayer#getBounds()

Returns the bounds of all visible maps (inside or outside of the Viewport), in latitude/longitude coordinates.

Parameters

There are no parameters.

Returns

Array<Array<number>> | undefined.

• L.LatLngBounds in array form of all visible maps

WarpedMapLayer#getDefaultOptions()

Get the default options the layer

Parameters

There are no parameters.

Returns

SpecificLeafletWarpedMapLayerOptions & Partial<WebGL2RenderOptions> & object & SpecificWarpedMapListOptions & Partial<...> & SpecificWebGL2WarpedMapOptions & SpecificTriangulatedWarpedMapOptions & WarpedMapOptions.

WarpedMapLayer#getLayerOptions()

Get the layer options

Parameters

There are no parameters.

Returns

{ interactive?: boolean | undefined; className?: string | undefined; pane?: string | undefined; zIndex?: number | undefined; createRTree?: boolean | undefined; rtreeUpdatedOptions?: Array<string> | undefined; ... 62 more ...; distortionMeasure?: DistortionMeasure | undefined; }.

WarpedMapLayer#getMapDefaultOptions(mapId)

Get the default options of a map

These come from the default option settings for WebGL2WarpedMaps and the map's georeferenced map proporties

Parameters

• mapId (string)
  • Map ID for which the options apply

Returns

WebGL2WarpedMapOptions | undefined.

WarpedMapLayer#getMapIds()

Get mapIds for selected maps

Note: more selection options are available on this function of WarpedMapList

Parameters

There are no parameters.

Returns

Array<string>.

WarpedMapLayer#getMapMapOptions(mapId)

Get the map-specific options of a map

Parameters

• mapId (string)
  • Map ID for which the options apply

Returns

Partial<WebGL2WarpedMapOptions> | undefined.

WarpedMapLayer#getMapOptions(mapId)

Get the options of a map

These options are the result of merging the default, georeferenced map, layer and map-specific options of that map.

Parameters

• mapId (string)
  • Map ID for which the options apply

Returns

WebGL2WarpedMapOptions | undefined.

WarpedMapLayer#getMapZIndex(mapId)

Get the z-index of a map

Parameters

• mapId (string)
  • Map ID for which to get the z-index

Returns

The z-index of a map (number | undefined).

WarpedMapLayer#getMapsBbox(mapIds, projectionOptions)

Get the bounding box of the maps

By default the result is returned in the list's projection, which is EPSG:3857 by default Use {definition: 'EPSG:4326'} to request the result in lon-lat EPSG:4326

Note: more selection options are available on this function of WarpedMapList

Parameters

• mapIds (Array<string>)
  • Map IDs
• projectionOptions? (ProjectionOptions | undefined)

Returns

The bbox of all selected maps, in the chosen projection, or undefined if there were no maps matching the selection (Bbox | undefined).

WarpedMapLayer#getMapsCenter(mapIds, projectionOptions)

Get the center of the bounding box of the maps

By default the result is returned in the list's projection, which is EPSG:3857 by default Use {definition: 'EPSG:4326'} to request the result in lon-lat EPSG:4326

Note: more selection options are available on this function of WarpedMapList

Parameters

• mapIds (Array<string>)
  • Map IDs
• projectionOptions? (ProjectionOptions | undefined)

Returns

The center of the bbox of all selected maps, in the chosen projection, or undefined if there were no maps matching the selection (Point | undefined).

WarpedMapLayer#getMapsConvexHull(mapIds, projectionOptions)

Get the convex hull of the maps

By default the result is returned in the list's projection, which is EPSG:3857 by default Use {definition: 'EPSG:4326'} to request the result in lon-lat EPSG:4326

Note: more selection options are available on this function of WarpedMapList

Parameters

• mapIds (Array<string>)
  • Map IDs
• projectionOptions? (ProjectionOptions | undefined)

Returns

The convex hull of all selected maps, in the chosen projection, or undefined if there were no maps matching the selection (Ring | undefined).

WarpedMapLayer#getOpacity()

Get the layer opacity

Returns a number between 0 and 1 (the default)

Parameters

There are no parameters.

Returns

number.

WarpedMapLayer#getWarpedMap(mapId)

Get the WarpedMap instance for a map

Parameters

• mapId (string)
  • Map ID of the requested WarpedMap instance

Returns

WebGL2WarpedMap | undefined.

WarpedMapLayer#getWarpedMapList()

Get the WarpedMapList object that contains a list of the warped maps of all loaded maps

Parameters

There are no parameters.

Returns

WarpedMapList<WebGL2WarpedMap>.

WarpedMapLayer#getWarpedMaps(mapIds)

Get the WarpedMap instances for selected maps

Note: more selection options are available on this function of WarpedMapList

Parameters

• mapIds? (Array<string> | undefined)
  • Map IDs

Returns

Iterable<WebGL2WarpedMap>.

WarpedMapLayer#getZIndex()

Gets the z-index of the layer.

Parameters

There are no parameters.

Returns

number | undefined.

WarpedMapLayer#gl

Type

WebGL2RenderingContext | null | undefined

WarpedMapLayer#initialize(annotationOrAnnotationUrl, options)

Parameters

• annotationOrAnnotationUrl (unknown)
• options? (Partial<LeafletWarpedMapLayerOptions> | undefined)

Returns

void.

WarpedMapLayer#nativePassWarpedMapEvent(event)

Parameters

• event (Event)

Returns

void.

WarpedMapLayer#nativeUpdate()

Parameters

There are no parameters.

Returns

void.

WarpedMapLayer#onAdd(map)

Contains all code code that creates DOM elements for the layer and adds them to map panes where they belong.

Parameters

• map (L.Map)

Returns

this.

WarpedMapLayer#onRemove(map)

Contains all cleanup code that removes the layer's elements from the DOM.

Parameters

• map (L.Map)

Returns

this.

WarpedMapLayer#options

Type

SpecificLeafletWarpedMapLayerOptions & Partial<WebGL2RenderOptions>

WarpedMapLayer#removeEventListeners()

Parameters

There are no parameters.

Returns

void.

WarpedMapLayer#removeGeoreferenceAnnotation(annotation)

Removes a Georeference Annotation

Parameters

• annotation (unknown)
  • Georeference Annotation

Returns

Map IDs of the maps that were removed, or an error per map (Promise<Array<string | Error>>).

WarpedMapLayer#removeGeoreferenceAnnotationByUrl(annotationUrl)

Removes a Georeference Annotation by URL

Parameters

• annotationUrl (string)
  • URL of a Georeference Annotation

Returns

Map IDs of the maps that were removed, or an error per map (Promise<Array<string | Error>>).

WarpedMapLayer#removeGeoreferencedMap(georeferencedMap)

Removes a Georeferenced Map

Parameters

• georeferencedMap (unknown)
  • Georeferenced Map

Returns

Map ID of the map that was removed, or an error (Promise<string | Error>).

WarpedMapLayer#removeGeoreferencedMapById(mapId)

Removes a Georeferenced Map by its ID

Parameters

• mapId (string)
  • Map ID of the georeferenced map to remove

Returns

Map ID of the map that was removed, or an error (Promise<string | Error | undefined>).

WarpedMapLayer#renderer?

Type

WebGL2Renderer

WarpedMapLayer#resetLayerOptions(layerOptionKeys, animationOptions)

Reset the layer options

An empty array resets all options, undefined resets no options. Doesn't reset render options or specific warped map layer options

Parameters

• layerOptionKeys? (Array<string> | undefined)
  • Keys of the options to reset
• animationOptions? (Partial<AnimationOptions> | undefined)
  • Animation options

Returns

void.

WarpedMapLayer#resetMapsOptions(mapIds, mapOptionKeys, layerOptionKeys, animationOptions)

Reset the map-specific options of maps (and the layer options)

An empty array resets all options, undefined resets no options. Doesn't reset render options or specific warped map layer options

Parameters

• mapIds (Array<string>)
  • Map IDs for which to reset the options
• mapOptionKeys? (Array<string> | undefined)
  • Keys of the map-specific options to reset
• layerOptionKeys? (Array<string> | undefined)
  • Keys of the layer options to reset
• animationOptions? (Partial<AnimationOptions> | undefined)
  • Animation options

Returns

void.

WarpedMapLayer#resetMapsOptionsByMapId(mapOptionkeysByMapId, layerOptionKeys, animationOptions)

Reset the map-specific options of maps by map ID (and the layer options)

An empty array or map resets all options (for all maps), undefined resets no options. Doesn't reset render options or specific warped map layer options

Parameters

• mapOptionkeysByMapId (Map<string, Array<string>>)
  • Keys of map-specific options to reset by map ID
• layerOptionKeys? (Array<string> | undefined)
  • Keys of the layer options to reset
• animationOptions? (Partial<AnimationOptions> | undefined)
  • Animation options

Returns

void.

WarpedMapLayer#resizeObserver

Type

ResizeObserver | undefined

WarpedMapLayer#sendMapsBackward(mapIds)

Send maps backward

Parameters

• mapIds (Iterable<string>)
  • IDs of the maps

Returns

void.

WarpedMapLayer#sendMapsToBack(mapIds)

Send maps to back

Parameters

• mapIds (Array<string>)
  • IDs of the maps

Returns

void.

WarpedMapLayer#setLayerOptions(layerOptions, animationOptions)

Set the layer options

Parameters

• layerOptions (Partial<WebGL2RenderOptions> | Partial<LeafletWarpedMapLayerOptions>)
  • Layer options to set
• animationOptions? (Partial<AnimationOptions> | undefined)
  • Animation options

Returns

void.

Examples

warpedMapLayer.setLayerOptions({ transformationType: 'thinPlateSpline' })

WarpedMapLayer#setMapGcps(mapId, gcps, animationOptions)

Set the GCPs of a map

This only sets the map-specific gcps option of the map (or more specifically of the warped map used for rendering), overwriting the original GCPs inferred from the Georeference Annotation.

The original GCPs can be reset by resetting the map-specific GCPs option, and stay accessible in the warped map's map property.

Parameters

• mapId (string)
  • Map ID for which to set the options
• gcps (Array<Gcp>)
  • GCPs to set
• animationOptions? (Partial<AnimationOptions> | undefined)
  • Animation options

Returns

void.

WarpedMapLayer#setMapOptions(mapId, mapOptions, layerOptions, animationOptions)

Set the map-specific options of a map (and the layer options)

In general setting a map-specific option also sets the corresponding option of the map, since these are the result of merging the default, georeferenced map, layer and map-specific options of that map.

A special case is setting a map-specific option to undefined: then the corresponding option is derived from the default, georeferenced map or layer option. This is equivalent to using the reset function for map-specific option.

Parameters

• mapId (string)
  • Map ID for which to set the options
• mapOptions ({ renderMaps?: boolean | undefined; renderLines?: boolean | undefined; renderPoints?: boolean | undefined; renderGcps?: boolean | undefined; renderGcpsColor?: string | undefined; renderGcpsSize?: number | undefined; renderGcpsBorderColor?: string | undefined; ... 54 more ...; distortionMeasure?: DistortionMeasure | ...)
  • Map-specific options to set
• layerOptions? ( | Partial<WebGL2RenderOptions> | Partial<LeafletWarpedMapLayerOptions> | undefined)
  • Layer options to set
• animationOptions? (Partial<AnimationOptions> | undefined)
  • Animation options

Returns

void.

Examples

warpedMapLayer.setMapOptions(myMapId, { transformationType: 'thinPlateSpline' })

WarpedMapLayer#setMapResourceMask(mapId, resourceMask, animationOptions)

Set the resource mask of a map

This only sets the map-specific resourceMask option of the map (or more specifically of the warped map used for rendering), overwriting the original resource mask inferred from the Georeference Annotation.

The original resource mask can be reset by resetting the map-specific resource mask option, and stays accessible in the warped map's map property.

Parameters

• mapId (string)
  • Map ID for which to set the options
• resourceMask (Array<Point>)
  • Resource mask to set
• animationOptions? (Partial<AnimationOptions> | undefined)
  • Animation options

Returns

void.

WarpedMapLayer#setMapTransformationType(mapId, transformationType, animationOptions)

Set the transformation type of a map

This only sets the map-specific transformationType option of the map (or more specifically of the warped map used for rendering), overwriting the original transformation type inferred from the Georeference Annotation.

The original transformation type can be reset by resetting the map-specific transformation type option, and stays accessible in the warped map's map property.

Parameters

• mapId (string)
  • Map ID for which to set the options
• transformationType ( | 'straight' | 'helmert' | 'polynomial' | 'polynomial1' | 'polynomial2' | 'polynomial3' | 'thinPlateSpline' | 'projective' | 'linear')
  • Transformation type to set
• animationOptions? (Partial<AnimationOptions> | undefined)
  • Animation options

Returns

void.

WarpedMapLayer#setMapsOptions(mapIds, mapOptions, layerOptions, animationOptions)

Set the map-specific options of maps (and the layer options)

In general setting a map-specific option also sets the corresponding option of the map, since these are the result of merging the default, georeferenced map, layer and map-specific options of that map.

A special case is setting a map-specific option to undefined: then the corresponding option is derived from the default, georeferenced map or layer option. This is equivalent to using the reset function for map-specific option.

Parameters

• mapIds (Array<string>)
  • Map IDs for which to set the options
• mapOptions ({ renderMaps?: boolean | undefined; renderLines?: boolean | undefined; renderPoints?: boolean | undefined; renderGcps?: boolean | undefined; renderGcpsColor?: string | undefined; renderGcpsSize?: number | undefined; renderGcpsBorderColor?: string | undefined; ... 54 more ...; distortionMeasure?: DistortionMeasure | ...)
  • Map-specific options to set
• layerOptions? ( | Partial<WebGL2RenderOptions> | Partial<LeafletWarpedMapLayerOptions> | undefined)
  • Layer options to set
• animationOptions? (Partial<AnimationOptions> | undefined)
  • Animation options

Returns

void.

Examples

warpedMapLayer.setMapsOptions([myMapId], { transformationType: 'thinPlateSpline' })

WarpedMapLayer#setMapsOptionsByMapId(mapOptionsByMapId, layerOptions, animationOptions)

Set the map-specific options of maps by map ID (and the layer options)

In general setting a map-specific option also sets the corresponding option of the map, since these are the result of merging the default, georeferenced map, layer and map-specific options of that map.

A special case is setting a map-specific option to undefined: then the corresponding option is derived from the default, georeferenced map or layer option. This is equivalent to using the reset function for map-specific option.

Parameters

• mapOptionsByMapId (Map<string, Partial<WebGL2WarpedMapOptions>>)
  • Map-specific options to set by map ID
• layerOptions? ( | Partial<WebGL2RenderOptions> | Partial<LeafletWarpedMapLayerOptions> | undefined)
  • Layer options to set
• animationOptions? (Partial<AnimationOptions> | undefined)
  • Animation options

Returns

void.

WarpedMapLayer#setOpacity(opacity)

Set the layer opacity

Parameters

• opacity (number)
  • Layer opacity to set

Returns

void.

WarpedMapLayer#setZIndex(value)

Changes the z-index of the layer.

Parameters

• value (number)
  • z-index

Returns

this.