ArcGIS Runtime SDK for iOS: AGSLayer Class Reference
ArcGIS Runtime SDK for iOS  100.12
AGSLayer Class Reference

Description

An abstract base class for all layers.

AGSLayer is the base class for all layer types. A layer is a representation of geographic data portrayed using symbols and text labels. Multiple layers can be 'stacked' to enhance the information displayed. Layers are displayed in an AGSMap inside an AGSMapView control. Layers are drawn bottom-to-top, so the first layer in a map's layer collection is drawn first (on the bottom) and each subsequent layer is drawn on top of it.

Layer type 2D/3D Time-aware Online/offline Sources
Annotation layer (AGSAnnotationLayer) 2D No Both ArcGIS feature service, portal item, mobile map package (.mmpk)
ArcGIS map image layer (AGSArcGISMapImageLayer) Both Yes Online ArcGIS map service
ArcGIS scene layer (AGSArcGISSceneLayer) 3D No Both Scene service or scene package
ArcGIS tiled layer (AGSArcGISTiledLayer) Both No Both ArcGIS tile service, tile package (.tpk/.tpkx)
ArcGIS vector tiled layer (AGSArcGISVectorTiledLayer) 2D No Both ArcGIS vector tile service, vector tile package (.vtpk)
Bing maps layer (AGSBingMapsLayer) Both No Online Bing maps
ENC layer (AGSENCLayer) 2D No Offline ENC exchange set, ENC cell
Feature collection layer (AGSFeatureCollectionLayer) Both No Both Portal item, web map, feature set / query result
Feature layer (AGSFeatureLayer) Both Yes Both ArcGIS feature service, WFS, shapefile, GeoPackage, geodatabase, OGC API Features
Group layer (AGSGroupLayer) Both No Both Other layers and group layers
KML layer (AGSKMLLayer) Both Yes Both KML file (.kml, .kmz)
Integrated mesh layer (AGSIntegratedMeshLayer) 3D No Both Scene layer package (.slpk)
Mobile basemap layer (AGSMobileBasemapLayer) 2D No Offline Mobile map package (.mmpk)
OpenStreetMap layer (AGSOpenStreetMapLayer) Both No Online OpenStreetMap.org
Point cloud layer (AGSPointCloudLayer) 3D No Both Portal item, scene layer package (.slpk)
Raster layer (AGSRasterLayer) Both Yes Both GeoPackage, raster file, ArcGIS Image service
Subtype feature layer (AGSSubtypeFeatureLayer) 2D No Both ArcGIS feature service, geodatabase
Web tiled layer (AGSWebTiledLayer) Both No Online Web tile service
WMS layer (AGSWMSLayer) Both Yes Online WMS service
WMTS layer (AGSWMTSLayer) Both No Online WMTS service
Since
100
Inheritance diagram for AGSLayer:
AGSLoadableBase <AGSLayerContent> AGSObject <AGSLoadable> AGSAnnotationLayer AGSArcGISSceneLayer AGSArcGISVectorTiledLayer AGSENCLayer AGSFeatureCollectionLayer AGSFeatureLayer AGSGroupLayer AGSImageAdjustmentLayer AGSIntegratedMeshLayer AGSKMLLayer AGSMobileBasemapLayer AGSPointCloudLayer AGSUnknownLayer AGSUnsupportedLayer

Instance Methods

(void) - cancelLoad
 
(void) - doCancelLoading
 
(void) - doStartLoading:
 
(id< AGSCancelable >) - fetchLegendInfosWithCompletion:
 
(BOOL) - isEqualToLayer:
 
(BOOL) - isVisibleAtScale:
 
(void) - loadDidFinishWithError:
 
(void) - loadWithCompletion:
 
(void) - onLoadStatusChanged
 
(void) - retryLoadWithCompletion:
 

Properties

NSString * attribution
 
BOOL canChangeVisibility
 
AGSEnvelopefullExtent
 
BOOL identifyEnabled
 
AGSItemitem
 
NSString * layerDescription
 
NSString * layerID
 
NSError * loadError
 
AGSLoadStatus loadStatus
 
double maxScale
 
double minScale
 
NSString * name
 
float opacity
 
BOOL showInLegend
 
AGSSpatialReferencespatialReference
 
NSArray< id< AGSLayerContent > > * subLayerContents
 
void(^ subLayerContentsChangedHandler )(void)
 
BOOL visible
 

Method Documentation

◆ cancelLoad

- (void) cancelLoad
requiredinherited

Cancels loading if it is in progress, otherwise it does nothing. This should be called carefully because other objects could be waiting for loadWithCompletion: or retryLoadWithCompletion: to complete and this will call them all back with the error of NSUserCancelledError

Since
100

◆ doCancelLoading

- (void) doCancelLoading

Never call this method directly. The framework calls this method on a background thread when cancelLoad (AGSLoadable-p) is called. It is meant to be overriden by subclasses. Subclasses should override this method to cancel loading their data and call loadDidFinishWithError: (AGSLoadableBase(ForSubclassEyesOnly)) at the end passing in an error representing NSUserCancelledError.

Since
100

Provided by category AGSLoadableBase(ForSubclassEyesOnly).

◆ doStartLoading:

- (void) doStartLoading: (BOOL)  retrying

Never call this method directly. The framework calls this method on a background thread when loadWithCompletion: (AGSLoadable-p) or retryLoadWithCompletion: (AGSLoadable-p) is called. It is meant to be overriden by subclasses. Subclasses should override this method to load their data and call loadDidFinishWithError: (AGSLoadableBase(ForSubclassEyesOnly)) upon completion, passing in the error if any.

Parameters
retryingflag that is true if this method was called from retryLoadWithCompletion: (AGSLoadable-p).
Since
100

Provided by category AGSLoadableBase(ForSubclassEyesOnly).

◆ fetchLegendInfosWithCompletion:

- (id<AGSCancelable>) fetchLegendInfosWithCompletion: (void(^)(NSArray< AGSLegendInfo * > *__nullable legendInfos, NSError *__nullable error))  completion

Fetches the array of legend infos (AGSLegendInfo) for this layer.

Since
100

◆ isEqualToLayer:

- (BOOL) isEqualToLayer: (AGSLayer *)  other

◆ isVisibleAtScale:

- (BOOL) isVisibleAtScale: (double)  scale

Check whether this layer is visible at a given scale.

Since
100

◆ loadDidFinishWithError:

- (void) loadDidFinishWithError: (nullable NSError *)  error

Only subclasses should call this method in doStartLoading: (AGSLoadableBase(ForSubclassEyesOnly)) and doCancelLoading (AGSLoadableBase(ForSubclassEyesOnly)) when done loading or failed to load.

Since
100

Provided by category AGSLoadableBase(ForSubclassEyesOnly).

◆ loadWithCompletion:

- (void) loadWithCompletion: (nullable void(^)(NSError *__nullable error))  completion
requiredinherited

Loads data for the object asynchronously. The completion block is invoked upon completion.

You can call this method any number of times, however only one attempt is made to load the data. If it is already loading, it will just continue to load (i.e. not force a reload). If it has already loaded successfully, the completion block will be invoked right away. If it has already failed to load, the completion block will be invoked right away with error previously encountered. This method supports multiple callers and will call them all back on completion. However, each caller's completion block will be invoked once and only once.

Parameters
completionblock that is invoked when object loads successfully or fails to load. An error is passed to the block if the object fails to load.
Note
The completion block is always invoked on the main thread.
Since
100
See also
- cancelLoad to cancel loading
- retryLoadWithCompletion: to force reload

◆ onLoadStatusChanged

- (void) onLoadStatusChanged

Never call this method directly. The framework calls this method on a background thread when AGSLoadable::loadStatus changes is called. Subclasses can optionally implement this to know when their loading status has changed.

Since
100

Provided by category AGSLoadableBase(ForSubclassEyesOnly).

◆ retryLoadWithCompletion:

- (void) retryLoadWithCompletion: (nullable void(^)(NSError *__nullable error))  completion
requiredinherited

Tries to reload when an object has failed to load. This method should be called judiciously. It should be called when:

  1. you didn't have network connectivity earlier when it failed and you want to retry now that you have connectivity
  2. the server was down earlier when it failed and you want to retry
  3. the request is taking too long and you want to cancel it and retry, in which case you will first call cancelLoad and then this method

If the data hasn't started loading, it will start loading. If it is already loading, it will just continue to load. If it has already loaded successfully, calls back right away. If it has already failed to load, tries again. This method supports multiple callers and will call them all back on completion. However, each caller's completion block will be invoked once and only once.

Parameters
completionblock that is invoked when object loads successfully or fails to load. An error is passed to the block if the object fails to load.
Note
The completion block is always invoked on the main thread.
Since
100

Property Documentation

◆ attribution

- (NSString*) attribution
readnonatomiccopy

Attribution information of the layer.

Since
100

◆ canChangeVisibility

- (BOOL) canChangeVisibility
readrequirednonatomicassigninherited

Denotes whether the layer can change visibility or not.

Since
100

◆ fullExtent

- (AGSEnvelope*) fullExtent
readnonatomicstrong

Full extent of the layer.

Since
100

◆ identifyEnabled

- (BOOL) identifyEnabled
readnonatomicassign

Specifies whether the layer supports identify.

Since
100

◆ item

- (AGSItem*) item
readnonatomicstrong

The item the layer has been created from.

Since
100

◆ layerDescription

- (NSString*) layerDescription
readwritenonatomiccopy

The layer's description.

Since
100

◆ layerID

- (NSString*) layerID
readwritenonatomiccopy

The layer's ID specified in the web map item of ArcGIS Online or an on-premises portal.

Since
100

◆ loadError

- (NSError*) loadError
readnonatomicstronginherited

The error that was encountered during the most recent load operation. Will be nil if the operation succeeded.

Since
100

◆ loadStatus

- (AGSLoadStatus) loadStatus
readrequirednonatomicassigninherited

Status of the load operation.

Since
100

◆ maxScale

- (double) maxScale
readwritenonatomicassign

The maximum scale at which this layer is visible. If the map or scene is zoomed in beyond this scale, the layer will not be visible. A value of 0 means there is no maximum scale threshold and the layer will be visible at the smallest scale available for the map or scene.

Since
100

◆ minScale

- (double) minScale
readwritenonatomicassign

The minimum scale at which this layer is visible. If the map or scene is zoomed out. beyond this scale, the layer will not be visible. A value of 0 means there is no minimum scale threshold and the layer will be visible at the largest scale available for the map or scene.

Since
100

◆ name

- (NSString*) name
readwritenonatomiccopy

The name of the layer.

Since
100

◆ opacity

- (float) opacity
readwritenonatomicassign

The opacity of this layer as a value between 0 (fully transparent) and 1 (fully opaque). Default value is 1.

Since
100

◆ showInLegend

- (BOOL) showInLegend
readwritenonatomicassigninherited

Indicates whether to show legend information.

Since
100

◆ spatialReference

- (AGSSpatialReference*) spatialReference
readnonatomicstrong

The spatial reference of the layer.

Since
100

◆ subLayerContents

- (NSArray<id<AGSLayerContent> >*) subLayerContents
readnonatomiccopyinherited

This layer's sub-layers.

Since
100

◆ subLayerContentsChangedHandler

- (void(^ subLayerContentsChangedHandler) (void))
readwritenonatomiccopyinherited

Block that is invoked when the sub layer contents changes.

Note
The block will be invoked on the same thread on which the event occured, which could be any arbitrary thread. You need to dispatch any UI related work to the main thread.
Since
100

◆ visible

- (BOOL) visible
readwritenonatomicassigninherited

Denotes whether the layer is visible or not. The visibility changes can be monitored using Key-Value Observing (KVO).

Since
100