## com.vividsolutions.jts.index.strtree
Class AbstractSTRtree

    java.lang.Object
      com.vividsolutions.jts.index.strtree.AbstractSTRtree

Direct Known Subclasses:
  SIRtree, STRtree

public abstract class AbstractSTRtree
extends java.lang.Object

Base class for STRtree and SIRtree. STR-packed R-trees are described in: P. Rigaux, Michel Scholl and Agnes Voisard. Spatial Databases With Application To GIS. Morgan Kaufmann, San Francisco, 2002.

This implementation is based on Boundables rather than just AbstractNodes, because the STR algorithm operates on both nodes and data, both of which are treated here as Boundables.

Version:
  1.7
See Also:
  `STRtree`, `SIRtree`

Nested Class Summary
`protected static interface` `AbstractSTRtree.IntersectsOp` A test for intersection between two bounds, necessary because subclasses of AbstractSTRtree have different implementations of bounds.

Field Summary
`protected AbstractNode` `root`

Constructor Summary
`AbstractSTRtree(int nodeCapacity)` Constructs an AbstractSTRtree with the specified maximum number of child nodes that a node may have

Method Summary
`protected java.util.List` `boundablesAtLevel(int level)`
`void` `build()` Creates parent nodes, grandparent nodes, and so forth up to the root node, for the data that has been inserted into the tree.
`protected int` `compareDoubles(double a, double b)`
`protected abstract AbstractNode` `createNode(int level)`
`protected java.util.List` `createParentBoundables(java.util.List childBoundables, int newLevel)` Sorts the childBoundables then divides them into groups of size M, where M is the node capacity.
`protected int` `depth()`
`protected int` `depth(AbstractNode node)`
`protected abstract java.util.Comparator` `getComparator()`
`protected abstract AbstractSTRtree.IntersectsOp` `getIntersectsOp()`
`int` `getNodeCapacity()` Returns the maximum number of child nodes that a node may have
`AbstractNode` `getRoot()`
`protected void` `insert(java.lang.Object bounds, java.lang.Object item)`
`java.util.List` `itemsTree()` Gets a tree structure (as a nested list) corresponding to the structure of the items and nodes in this tree.
`protected AbstractNode` `lastNode(java.util.List nodes)`
`protected java.util.List` `query(java.lang.Object searchBounds)` Also builds the tree, if necessary.
`protected void` `query(java.lang.Object searchBounds, ItemVisitor visitor)` Also builds the tree, if necessary.
`protected boolean` `remove(java.lang.Object searchBounds, java.lang.Object item)` Removes an item from the tree.
`protected int` `size()`
`protected int` `size(AbstractNode node)`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Field Detail

### root

    protected AbstractNode root

Constructor Detail

### AbstractSTRtree

    public AbstractSTRtree(int nodeCapacity)

  Constructs an AbstractSTRtree with the specified maximum number of child nodes that a node may have

Method Detail

### build

    public void build()

  Creates parent nodes, grandparent nodes, and so forth up to the root node, for the data that has been inserted into the tree. Can only be called once, and thus can be called only after all of the data has been inserted into the tree.

### createNode

    protected abstract AbstractNode createNode(int level)

### createParentBoundables

    protected java.util.List createParentBoundables(java.util.List childBoundables,
                                                    int newLevel)

  Sorts the childBoundables then divides them into groups of size M, where M is the node capacity.

### lastNode

    protected AbstractNode lastNode(java.util.List nodes)

### compareDoubles

    protected int compareDoubles(double a,
                                 double b)

### getRoot

    public AbstractNode getRoot()

### getNodeCapacity

    public int getNodeCapacity()

  Returns the maximum number of child nodes that a node may have

### size

    protected int size()

### size

    protected int size(AbstractNode node)

### depth

    protected int depth()

### depth

    protected int depth(AbstractNode node)

### insert

    protected void insert(java.lang.Object bounds,
                          java.lang.Object item)

### query

    protected java.util.List query(java.lang.Object searchBounds)

  Also builds the tree, if necessary.

### query

    protected void query(java.lang.Object searchBounds,
                         ItemVisitor visitor)

  Also builds the tree, if necessary.

### getIntersectsOp

    protected abstract AbstractSTRtree.IntersectsOp getIntersectsOp()

  Returns:
    a test for intersection between two bounds, necessary because subclasses of AbstractSTRtree have different implementations of bounds.
  See Also:
    `AbstractSTRtree.IntersectsOp`

### itemsTree

    public java.util.List itemsTree()

  Gets a tree structure (as a nested list) corresponding to the structure of the items and nodes in this tree.

  The returned `List`s contain either `Object` items, or Lists which correspond to subtrees of the tree Subtrees which do not contain any items are not included.

  Builds the tree if necessary.

  Returns:
    a List of items and/or Lists

### remove

    protected boolean remove(java.lang.Object searchBounds,
                             java.lang.Object item)

  Removes an item from the tree. (Builds the tree, if necessary.)

### boundablesAtLevel

    protected java.util.List boundablesAtLevel(int level)

### getComparator

    protected abstract java.util.Comparator getComparator()