Package org.mapsforge.poi.storage

Class DoubleLinkedPoiCategory

  • All Implemented Interfaces:
    PoiCategory
    public class DoubleLinkedPoiCategory
extends java.lang.Object
implements PoiCategory
    A POI category representation that stores a node, its parent node and its child nodes.

    • Constructor Detail

      • DoubleLinkedPoiCategory

        public DoubleLinkedPoiCategory​(java.lang.String title,
                               PoiCategory parent)
        Creates a new category without knowing its position in the final category tree. If all categories have been created you have to call calculateCategoryIDs(DoubleLinkedPoiCategory, int) to assign the IDs.
        Parameters:
        title - The category's unique title.
        parent - The category's parent category. For creating a root node, set the parent to null.

      • DoubleLinkedPoiCategory

        public DoubleLinkedPoiCategory​(java.lang.String title,
                               PoiCategory parent,
                               int id)
        Creates a new category. This constructor should only be called from PoiCategoryManager when reading a category configuration from a database or XML file. Otherwise call DoubleLinkedPoiCategory(String, PoiCategory).
        Parameters:
        title - The category's unique title.
        parent - The category's parent category. For creating a root node, set the parent to null.
        id - The category's position in the tree determined by left-order-dfs-traversal.

    • Method Detail

      • calculateCategoryIDs

        public static int calculateCategoryIDs​(DoubleLinkedPoiCategory rootNode,
                                       int maxValue)
        This method calculates a unique ID for all nodes in the tree. For each node's 'n' ID named 'ID_'n at depth 'd' the following invariants must be true:
        • ID > max(ID of all child nodes)
        • All nodes' IDs left of n must be < ID_n.
        • All nodes' IDs right of n must be > ID_n.
        Parameters:
        rootNode - The tree's root node. (Any other node will result in invalid IDs!)
        maxValue - Global maximum ID.
        Returns:
        The root node's ID.

      • deepChildren

        public java.util.Collection<PoiCategory> deepChildren()
        Specified by:
        deepChildren in interface PoiCategory
        Returns:
        All child categories of the category, including their children.

      • getChildren

        public java.util.Collection<PoiCategory> getChildren()
        Specified by:
        getChildren in interface PoiCategory
        Returns:
        All child categories of the category.

      • getGraphVizString

        public static java.lang.String getGraphVizString​(DoubleLinkedPoiCategory rootNode)
        Generates a GraphViz source representation as a tree having the current node as its root.
        Parameters:
        rootNode - The resulting graph's root node. (You can use any sub node to get a sub-graph).
        Returns:
        a GraphViz source representation as a tree having the current node as its root.

      • getParent

        public PoiCategory getParent()
        Specified by:
        getParent in interface PoiCategory
        Returns:
        The parent category of this category or null if this category has no parent.

      • getTitle

        public java.lang.String getTitle()
        Specified by:
        getTitle in interface PoiCategory
        Returns:
        The title of this category.

      • setParent

        public void setParent​(PoiCategory parent)
        Sets the category's parent category.
        Specified by:
        setParent in interface PoiCategory
        Parameters:
        parent - The category to be set as parent.

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object