openlayers/doc/ol3.md

CLASS HIERARCHY

goog.math.Coordinate // Simple 2D point

goog.math.Coordinate3 | +- TileCoord

goog.math.Box | +- TileBounds // A range of tiles in two dimensions, integer coordinates, z not stored | +- Extent // The extent of a single object in two dimensions, projection not stored | +- Bounds // A range of objects in two dimensions

Projection

goog.events.EventTarget | +- MVCObject | | | +- Camera | | | +- Control | | | | | +- ? | | | +- Layer | | | | | +- TileLayer | | | | | | | +- TMSTileLayer | | | | | | | +- WMTSTileLayer | | | | | | | +- XYZTileLayer / OSMTileLayer | | | | | +- VectorLayer | | | | | +- ImageLayer | | | +- LayerRenderer | | | +- LayerView | | | +- Map | | | +- MapRenderer | | | | | +- HTMLMapRenderer | | | | | +- WebGLMapRenderer | | | +- MVCArray | | | | | +- ControlArray | | | | | +- LayerViewArray | | +- TileQueue | +- Tile

Layer renderer hierarchy

goog.events.EventTarget | +- MVCObject | +- LayerRenderer | +- SingleTileLayerRenderer | | | +- HTMLSingleTileLayerRenderer | | | +- WebGLSingleTileLayerRenderer | +- TileLayerRenderer | | | +- HTMLTileLayerRenderer | | | +- WebGLTileLayerRenderer | +- VectorLayerRenderer | | | +- HTMLVectorLayerRenderer | | | | | +- SVGHTMLVectorLayerRenderer | | | | | +- Canvas2DHTMLVectorLayerRenderer | | | | | +- VMLHTMLVectorLayerRenderer | | | +- WebGLVectorLayerRenderer

OBJECT PROPERTIES AND METHODS

Notation: property type // property with type, trailing ? indicates unsure // getters and setters are assumed to exist f(args) -> type // function taking args returning type f(args) -> type = something // f is a trivial wrapper around something fires 'x' // fires events of type 'x'

Principles: All non-trivial objects inherit from MVCObject All non-trivial collections are either MVCArrays or a child class thereof Resolutions are Array., infinitely scalable resoueces (e.g. vectore layers) have resolutions == null

MVCObject as Google Maps MVCObject freeze() unfreeze()

TileCoord getHash() -> number

Tile tileCoord TileCoord url string state UNLOADED | LOADING | LOADED fires 'loaded' // when loaded fires 'aborted' // when loading is aborted

Camera center goog.math.Coordinate resolution number rotation number

Layer projections Array. extent Extent ? getResolutions() -> Array.|null fires 'change' // when data changes

LayerArray getResolutions() -> Array.|null getMaxResolution() = this.getResolutions()[0] | null

LayerView layer Layer visible boolean opacity number brightness number color number hue number saturation number

Map projection Projection renderer Renderer layers LayerArray addLayer(layer) = layers.push(layer) getExtent() -> Extent getMaxResolution() = layers.getMaxResolution()

TileGrid resolutions Array. extent Extent corner TOP_LEFT | BOTTOM_LEFT origin(s) Coord|Array. tileSize goog.math.Size getTileBounds(z, extent) -> TileBounds getTileCoordCenter(tileCoord) -> goog.math.Coordinate getTileCoord(coordinate) -> TileCoord getTileCoordExtent(tileCoord) -> Extent getZForResolution(resolution) -> number yieldTileCoordChildren(tileCoord, function(z, TileBounds)) yieldTileCoordParents(tileCoord, function(z, TileBounds))

TileLayer tileGrid TileGrid tileUrl function(tileCoord) -> string getTileCoordUrl(tileCoord) -> string = this.tileUrl(tileCoord)

TileQueue camera Camera // or maybe MVCArray. ? getTileCoordPriority(tileCoord) -> number // private enqueueTile(Tile)

VectorLayer yieldFeatures(resolution, extent, projection, function(Feature))

Renderer target HTMLDivElement map Map camera Camera getCapabilities() -> Array. // maybe ?

Question: store tile layer extent in TileLayer or in TileGrid? (not clear) Question: who determines "best" resolution? (static function?)

Todo: if tile layer extent stored in TileLayer rather than TileGrid then extent will occasionally need to be passed to TileGrid functions for cropping

DESIGN ASSERTIONS

• A map has a renderer (the map renderer).

• A map has a camera.

• Multiple maps can share the same camera.

• A map has a layer list.

• A layer view stores view-related states for a layer.

• View-related states include visibility, opacity, saturation, hue, etc.

• A layer view has a layer.

• Multiple layer views can share the same layer.

• In other words a layer can be viewed in different manners.

• The map renderer responds to events.

• The map renderer receives events from the camera.

• The map renderer creates layer renderers.

• A layer can have multiple projections (the supported projections).

• A layer advertizes the projections it supports.

• A layer returns no data if asked data for an unsupported projection.

• A control may listen to map events.

• A control may listen to camera events.

• A map navigation control acts on the camera.

• Types can be described in MVC terms.

• Models don't know what rendering means.

• Maps are models.

• Layers are models.

• Layer views are models (sorry!).

• Cameras are models.

• Layer lists are collections.

• Renderers are views.

• Controls are views or controllers or both.

• An attribution control is a view.

• A map navigation control is a controller.

• A zoom slider control is both a view and a controller.