ImageryLayerCollection

Members

layerAdded :Event

An event that is raised when a layer is added to the collection. Event handlers are passed the layer that was added and the index at which it was added.

Default Value:

• Event()

layerMoved :Event

An event that is raised when a layer changes position in the collection. Event handlers are passed the layer that was moved, its new index after the move, and its old index prior to the move.

Default Value:

• Event()

layerRemoved :Event

An event that is raised when a layer is removed from the collection. Event handlers are passed the layer that was removed and the index from which it was removed.

Default Value:

• Event()

layerShownOrHidden :Event

An event that is raised when a layer is shown or hidden by setting the ImageryLayer#show property. Event handlers are passed a reference to this layer, the index of the layer in the collection, and a flag that is true if the layer is now shown or false if it is now hidden.

Default Value:

• Event()

Methods

add

Adds a layer to the collection.

Parameters:

Name	Type	Argument	Description
layer	ImageryLayer		the layer to add.
index	Number	<optional>	the index to add the layer at. If omitted, the layer will added on top of all existing layers.

Throws:

• DeveloperError : layer is required.
• DeveloperError : index, if supplied, must be greater than or equal to zero and less than or equal to the number of the layers.

addImageryProvider

Creates a new layer using the given ImageryProvider and adds it to the collection.

Parameters:

Name	Type	Argument	Description
imageryProvider	ImageryProvider		the imagery provider to create a new layer for.
index	Number	<optional>	the index to add the layer at. If omitted, the layer will added on top of all existing layers.

Throws:

DeveloperError : imageryProvider is required.

Returns:

ImageryLayer The newly created layer.

contains

Checks to see if the collection contains a given layer.

Parameters:

Name	Type	Description
layer	ImageryLayer	the layer to check for.

Returns:

Boolean true if the collection contains the layer, false otherwise.

destroy

Destroys the WebGL resources held by all layers in this collection. Explicitly destroying this object allows for deterministic release of WebGL resources, instead of relying on the garbage collector.

Once this object is destroyed, it should not be used; calling any function other than isDestroyed will result in a DeveloperError exception. Therefore, assign the return value (undefined) to the object as done in the example.

Throws:

DeveloperError : This object was destroyed, i.e., destroy() was called.

Returns:

Example

layerCollection = layerCollection && layerCollection.destroy();

See:

• ImageryLayerCollection#isDestroyed

get

Gets a layer by index from the collection.

Parameters:

Name	Type	Description
index	Number	the index to retrieve.

Throws:

• DeveloperError : index is required.
• DeveloperError : This object was destroyed, i.e., destroy() was called.

getLength

Gets the number of layers in this collection.

Throws:

DeveloperError : This object was destroyed, i.e., destroy() was called.

indexOf

Determines the index of a given layer in the collection.

Parameters:

Name	Type	Description
layer	ImageryLayer	The layer to find the index of.

Returns:

Number The index of the layer in the collection, or -1 if the layer does not exist in the collection.

isDestroyed

Returns true if this object was destroyed; otherwise, false.

If this object was destroyed, it should not be used; calling any function other than isDestroyed will result in a DeveloperError exception.

Returns:

Boolean true if this object was destroyed; otherwise, false.

See:

• ImageryLayerCollection#destroy

lower

Lowers a layer down one position in the collection.

Parameters:

Name	Type	Description
layer	ImageryLayer	the layer to move.

Throws:

• DeveloperError : layer is not in this collection.
• DeveloperError : This object was destroyed, i.e., destroy() was called.

lowerToBottom

Lowers a layer to the bottom of the collection.

Parameters:

Name	Type	Description
layer	ImageryLayer	the layer to move.

Throws:

• DeveloperError : layer is not in this collection.
• DeveloperError : This object was destroyed, i.e., destroy() was called.

raise

Raises a layer up one position in the collection.

Parameters:

Name	Type	Description
layer	ImageryLayer	the layer to move.

Throws:

• DeveloperError : layer is not in this collection.
• DeveloperError : This object was destroyed, i.e., destroy() was called.

raiseToTop

Raises a layer to the top of the collection.

Parameters:

Name	Type	Description
layer	ImageryLayer	the layer to move.

Throws:

• DeveloperError : layer is not in this collection.
• DeveloperError : This object was destroyed, i.e., destroy() was called.

remove

Removes a layer from this collection, if present.

Parameters:

Name	Type	Argument	Default	Description
layer	ImageryLayer			The layer to remove.
destroy	Boolean	<optional>	true	whether to destroy the layers in addition to removing them.

Returns:

Boolean true if the layer was in the collection and was removed, false if the layer was not in the collection.

removeAll

Removes all layers from this collection.

Parameters:

Name	Type	Argument	Default	Description
destroy	Boolean	<optional>	true	whether to destroy the layers in addition to removing them.