ZOO.Geometry.Collection

A Collection is exactly what it sounds like: A collection of different Geometries. These are stored in the local parameter components (which can be passed as a parameter to the constructor).

As new geometries are added to the collection, they are NOT cloned. When removing geometries, they need to be specified by reference (ie you have to pass in the exact geometry to be removed).

The <getArea> and getLength functions here merely iterate through the components, summing their respective areas and lengths.

Create a new instance with the ZOO.Geometry.Collection constructor.

Inherits from

• ZOO.Geometry

Properties

NAME	DESCRIPTION
components	{Array(ZOO.Geometry)} The component parts of this geometry
componentTypes	{Array(String)} An array of class names representing the types of components that the collection can include.

Functions

NAME	DESCRIPTION
ZOO.Geometry.Collection	Creates a Geometry Collection – a list of geoms.
destroy	Destroy this geometry.
clone	Clone this geometry.
getComponentsString	Get a string representing the components for this collection.
calculateBounds	Recalculate the bounds by iterating through the components and calling extendBounds() on each item.
addComponent	Add a new component (geometry) to the collection.
removeComponents	Remove components from this geometry.
removeComponent	Remove a component from this geometry.
getLength	Calculate the length of this geometry.
getCentroid	{ZOO.Geometry.Point} The centroid of the collection.
getGeodesicLength	Calculate the approximate length of the geometry were it projected onto the earth.
move	Moves a geometry by the given displacement along positive x and y axes.
rotate	Rotate a geometry around some origin.
resize	Resize a geometry relative to some origin.
equals	Determine whether another geometry is equivalent to this one.
transform	Reproject the components geometry from source to dest.
intersects	Determine if the input geometry intersects this one.
getVertices	Return a list of all points in this geometry.

Properties

components

{Array(ZOO.Geometry)} The component parts of this geometry

componentTypes

{Array(String)} An array of class names representing the types of components that the collection can include. A null value means the component types are not restricted.

Functions

ZOO.Geometry.Collection

Creates a Geometry Collection – a list of geoms.

Parameters

components {Array(ZOO.Geometry)} Optional array of geometries

destroy

destroy: function ()

Destroy this geometry.

clone

clone: function()

Clone this geometry.

Returns

{ZOO.Geometry.Collection} An exact clone of this collection.

getComponentsString

getComponentsString: function()

Get a string representing the components for this collection.

Returns

{String} A string representation of the components of this geometry.

calculateBounds

calculateBounds: function()

Recalculate the bounds by iterating through the components and calling extendBounds() on each item.

addComponent

addComponent: function(component,index)

Add a new component (geometry) to the collection. If this.componentTypes is set, then the component class name must be in the componentTypes array. The bounds cache is reset.

Parameters

component {ZOO.Geometry} A geometry to add

index {int} Optional index into the array to insert the component

Returns

{Boolean} The component geometry was successfully added

removeComponents

removeComponents: function(components)

Remove components from this geometry.

Parameters

components {Array(ZOO.Geometry)} The components to be removed

removeComponent

removeComponent: function(component)

Remove a component from this geometry.

Parameters

component {ZOO.Geometry}

getLength

getLength: function()

Calculate the length of this geometry

Returns

{Float} The length of the geometry

getCentroid

getCentroid: function()

Returns

{ZOO.Geometry.Point} The centroid of the collection

getGeodesicLength

getGeodesicLength: function(projection)

Calculate the approximate length of the geometry were it projected onto the earth.

Parameters

projection {ZOO.Projection} The spatial reference system for the geometry coordinates. If not provided, Geographic/WGS84 is assumed.

Returns

{Float} The appoximate geodesic length of the geometry in meters.

move

move: function(x,y)

Moves a geometry by the given displacement along positive x and y axes. This modifies the position of the geometry and clears the cached bounds.

Parameters

x {Float} Distance to move geometry in positive x direction.

y {Float} Distance to move geometry in positive y direction.

rotate

rotate: function(angle,origin)

Rotate a geometry around some origin

Parameters

angle {Float} Rotation angle in degrees (measured counterclockwise from the positive x-axis)

origin {ZOO.Geometry.Point} Center point for the rotation

resize

resize: function(scale,origin,ratio)

Resize a geometry relative to some origin. Use this method to apply a uniform scaling to a geometry.

Parameters

scale {Float} Factor by which to scale the geometry. A scale of 2 doubles the size of the geometry in each dimension (lines, for example, will be twice as long, and polygons will have four times the area).

origin {ZOO.Geometry.Point} Point of origin for resizing

ratio {Float} Optional x:y ratio for resizing. Default ratio is 1.

Returns

{ZOO.Geometry} The current geometry.

equals

equals: function(geometry)

Determine whether another geometry is equivalent to this one. Geometries are considered equivalent if all components have the same coordinates.

Parameters

geom {ZOO.Geometry} The geometry to test.

Returns

{Boolean} The supplied geometry is equivalent to this geometry.

transform

transform: function(source,dest)

Reproject the components geometry from source to dest.

Parameters

source {ZOO.Projection}

dest {ZOO.Projection}

Returns

{ZOO.Geometry}

intersects

intersects: function(geometry)

Determine if the input geometry intersects this one.

Parameters

geometry {ZOO.Geometry} Any type of geometry.

Returns

{Boolean} The input geometry intersects this one.

getVertices

getVertices: function(nodes)

Return a list of all points in this geometry.

Parameters

nodes {Boolean} For lines, only return vertices that are endpoints. If false, for lines, only vertices that are not endpoints will be returned. If not provided, all vertices will be returned.

Returns

{Array} A list of all vertices in the geometry.