ShapeCollection (Spatial4J 0.5 API)

java.lang.Object
- java.util.AbstractCollection<E>
- - java.util.AbstractList<S>
  - - com.spatial4j.core.shape.ShapeCollection<S>

All Implemented Interfaces:

Shape, Iterable<S>, Collection<S>, List<S>
```
public class ShapeCollection<S extends Shape>
extends AbstractList<S>
implements Shape
```
A collection of Shape objects, analogous to an OGC GeometryCollection. The implementation demands a List (with random access) so that the order can be retained if an application requires it, although logically it's treated as an unordered Set, mostly.
Ideally, relate(Shape) should return the same result no matter what the shape order is, although the default implementation can be order dependent when the shapes overlap; see relateContainsShortCircuits(). To improve performance slightly, the caller could order the shapes by largest first so that relate() will have a greater chance of short-circuit'ing sooner. As the Shape contract states; it may return intersects when the best answer is actually contains or within. If any shape intersects the provided shape then that is the answer.
This implementation is not optimized for a large number of shapes; relate is O(N). A more sophisticated implementation might do an R-Tree based on bbox'es, for example.

Field Summary

Fields
Modifier and Type Field and Description

protected Rectangle bbox

protected SpatialContext ctx

protected List<S> shapes
- Fields inherited from class java.util.AbstractList
  modCount

Fields
Modifier and Type	Field and Description
`protected Rectangle`	`bbox`
`protected SpatialContext`	`ctx`
`protected List<S>`	`shapes`

Constructor Summary

Constructors
Constructor and Description

ShapeCollection(List<S> shapes, SpatialContext ctx)
WARNING: shapes is copied by reference.

Constructors
Constructor and Description
`ShapeCollection(List<S> shapes, SpatialContext ctx)` WARNING: `shapes` is copied by reference.

Method Summary

Methods
Modifier and Type	Method and Description
`protected Rectangle`	`computeBoundingBox(Collection<? extends Shape> shapes, SpatialContext ctx)`
`protected static boolean`	`computeMutualDisjoint(List<? extends Shape> shapes)` Computes whether the shapes are mutually disjoint.
`boolean`	`equals(Object o)` The sub-classes of Shape generally implement the same contract for `Object.equals(Object)` and `Object.hashCode()` amongst the same sub-interface type.
`S`	`get(int index)`
`double`	`getArea(SpatialContext ctx)` Calculates the area of the shape, in square-degrees.
`Rectangle`	`getBoundingBox()` Get the bounding box for this Shape.
`ShapeCollection`	`getBuffered(double distance, SpatialContext ctx)` Returns a buffered version of this shape.
`Point`	`getCenter()` Returns the center point of this shape.
`SpatialContext`	`getContext()` Get the SpatialContext that created the Shape
`List<S>`	`getShapes()`
`boolean`	`hasArea()` Does the shape have area? This will be false for points and lines.
`int`	`hashCode()`
`SpatialRelation`	`relate(Shape other)` Describe the relationship between the two objects.
`protected boolean`	`relateContainsShortCircuits()` Called by relate() to determine whether to return early if it finds CONTAINS, instead of checking the remaining shapes.
`int`	`size()`
`String`	`toString()`

Methods inherited from class java.util.AbstractList
add, add, addAll, clear, indexOf, iterator, lastIndexOf, listIterator, listIterator, remove, removeRange, set, subList

Methods inherited from class java.util.AbstractCollection
addAll, contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.spatial4j.core.shape.Shape
isEmpty

Methods inherited from interface java.util.List
addAll, contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray

- Field Detail
  - ctx
```
protected final SpatialContext ctx
```
  - shapes
```
protected final List<S extends Shape> shapes
```
  - bbox
```
protected final Rectangle bbox
```
- Constructor Detail
  - ShapeCollection
```
public ShapeCollection(List<S> shapes,
               SpatialContext ctx)
```
    WARNING: shapes is copied by reference.
    
    Parameters:
    shapes - Copied by reference! (make a defensive copy if caller modifies)
    ctx -
- Method Detail
  - computeBoundingBox
```
protected Rectangle computeBoundingBox(Collection<? extends Shape> shapes,
                           SpatialContext ctx)
```
  - getShapes
```
public List<S> getShapes()
```
  - get
```
public S get(int index)
```
    Specified by:
    
    get in interface List<S extends Shape>
    
    Specified by:
    
    get in class AbstractList<S extends Shape>
  - size
```
public int size()
```
    Specified by:
    
    size in interface Collection<S extends Shape>
    
    Specified by:
    
    size in interface List<S extends Shape>
    
    Specified by:
    
    size in class AbstractCollection<S extends Shape>
  - getBoundingBox
```
public Rectangle getBoundingBox()
```
    Description copied from interface: Shape
    
    Get the bounding box for this Shape. This means the shape is within the bounding box and that it touches each side of the rectangle.
    Postcondition: this.getBoundingBox().relate(this) == CONTAINS
    
    Specified by:
    
    getBoundingBox in interface Shape
  - getCenter
```
public Point getCenter()
```
    Description copied from interface: Shape
    
    Returns the center point of this shape. This is usually the same as getBoundingBox().getCenter() but it doesn't have to be.
    Postcondition: this.relate(this.getCenter()) == CONTAINS
    
    Specified by:
    
    getCenter in interface Shape
  - hasArea
```
public boolean hasArea()
```
    Description copied from interface: Shape
    
    Does the shape have area? This will be false for points and lines. It will also be false for shapes that normally have area but are constructed in a degenerate case as to not have area (e.g. a circle with 0 radius or rectangle with no height or no width).
    
    Specified by:
    
    hasArea in interface Shape
  - getBuffered
```
public ShapeCollection getBuffered(double distance,
                          SpatialContext ctx)
```
    Description copied from interface: Shape
    
    Returns a buffered version of this shape. The buffer is usually a rounded-corner buffer, although some shapes might buffer differently. This is an optional operation.
    
    Specified by:
    
    getBuffered in interface Shape
    
    Returns:
    Not null, and the returned shape should contain the current shape.
  - relate
```
public SpatialRelation relate(Shape other)
```
    Description copied from interface: Shape
    Describe the relationship between the two objects. For example
    - this is WITHIN other
    - this CONTAINS other
    - this is DISJOINT other
    - this INTERSECTS other
    Note that a Shape implementation may choose to return INTERSECTS when the true answer is WITHIN or CONTAINS for performance reasons. If a shape does this then it must document when it does. Ideally the shape will not do this approximation in all circumstances, just sometimes.
    If the shapes are equal then the result is CONTAINS (preferred) or WITHIN.
    Specified by:
    
    relate in interface Shape
  - relateContainsShortCircuits
```
protected boolean relateContainsShortCircuits()
```
    Called by relate() to determine whether to return early if it finds CONTAINS, instead of checking the remaining shapes. It will do so without calling this method if the "other" shape is a Point. If a remaining shape finds INTERSECTS, then INTERSECTS will be returned. The only problem with this returning true is that if some of the shapes overlap, it's possible that the result of relate() could be dependent on the order of the shapes, which could be unexpected / wrong depending on the application. The default implementation returns true because it probably doesn't matter. If it does, a subclass could add a boolean flag that this method could return. That flag could be initialized to true only if the shapes are mutually disjoint.
    
    See Also:
    .
  - computeMutualDisjoint
```
protected static boolean computeMutualDisjoint(List<? extends Shape> shapes)
```
    Computes whether the shapes are mutually disjoint. This is a utility method offered for use by a subclass implementing relateContainsShortCircuits(). Beware: this is an O(N^2) algorithm.. Consequently, consider safely assuming non-disjoint if shapes.size() > 10 or something. And if all shapes are a Point then the result of this method doesn't ultimately matter.
  - getArea
```
public double getArea(SpatialContext ctx)
```
    Description copied from interface: Shape
    
    Calculates the area of the shape, in square-degrees. If ctx is null then simple Euclidean calculations will be used. This figure can be an estimate.
    
    Specified by:
    
    getArea in interface Shape
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class AbstractCollection<S extends Shape>
  - equals
```
public boolean equals(Object o)
```
    Description copied from interface: Shape
    
    The sub-classes of Shape generally implement the same contract for Object.equals(Object) and Object.hashCode() amongst the same sub-interface type. This means, for example, that multiple Point implementations of different classes are equal if they share the same x & y.
    
    Specified by:
    
    equals in interface Shape
    
    Specified by:
    
    equals in interface Collection<S extends Shape>
    
    Specified by:
    
    equals in interface List<S extends Shape>
    
    Overrides:
    
    equals in class AbstractList<S extends Shape>
  - hashCode
```
public int hashCode()
```
    Specified by:
    
    hashCode in interface Collection<S extends Shape>
    
    Specified by:
    
    hashCode in interface List<S extends Shape>
    
    Overrides:
    
    hashCode in class AbstractList<S extends Shape>
  - getContext
```
public SpatialContext getContext()
```
    Description copied from interface: Shape
    
    Get the SpatialContext that created the Shape
    
    Specified by:
    
    getContext in interface Shape

Class ShapeCollection<S extends Shape>

Field Summary

Fields inherited from class java.util.AbstractList

Constructor Summary

Method Summary

Methods inherited from class java.util.AbstractList

Methods inherited from class java.util.AbstractCollection

Methods inherited from class java.lang.Object

Methods inherited from interface com.spatial4j.core.shape.Shape

Methods inherited from interface java.util.List

Field Detail

ctx

shapes

bbox

Constructor Detail

ShapeCollection

Method Detail

computeBoundingBox

getShapes

get

size

getBoundingBox

getCenter

hasArea

getBuffered

relate

relateContainsShortCircuits

computeMutualDisjoint

getArea

toString

equals

hashCode

getContext