Class PageIndex

  • All Implemented Interfaces:
    java.io.Serializable, Sortable

    public class PageIndex
    extends java.lang.Object
    implements java.io.Serializable, Sortable
    A sorted array of integers, the positions of the first characters of each line. To facilitate processing the first element should be maintained at position 0. Facilities to add, remove, search and determine row and column are provided. This class provides similar functionality to a Vector but does not incur the overhead of an Integer object per element.
    See Also:
    Serialized Form
    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected int mCount
      The number of valid elements.
      protected int mIncrement
      Increment for allocations.
      protected int[] mIndices
      The elements.
      protected Page mPage
      The page associated with this index.
      protected static int mStartIncrement
      Starting increment for allocations.
    • Constructor Summary

      Constructors 
      Constructor Description
      PageIndex​(Page page)
      Create an empty index.
      PageIndex​(Page page, int cursor)
      Create an index with the one element given.
      PageIndex​(Page page, int[] cursors)
      Create an index with the elements given.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      int add​(int cursor)
      Add an element to the list
      int add​(Cursor cursor)
      Add an element to the list
      protected int bsearch​(int cursor)
      Binary search for the element.
      protected int bsearch​(int cursor, int first, int last)
      Binary search for the element.
      int capacity()
      Get the capacity for elements without reallocation.
      int column​(int cursor)
      Get the column number for a position.
      int column​(Cursor cursor)
      Get the column number for a cursor.
      int elementAt​(int index)
      Get an element from the list.
      Ordered fetch​(int index, Ordered reuse)
      Fetch the object at the given index.
      int first()
      Returns the first index of the Sortable.
      int[] get()
      Get the elements as an array of int.
      Page getPage()
      Get this index's page.
      protected void insertElementAt​(int cursor, int index)
      Inserts an element into the list.
      int last()
      Returns the last index of the Sortable.
      void remove​(int cursor)
      Remove an element from the list
      void remove​(Cursor cursor)
      Remove an element from the list
      protected void removeElementAt​(int index)
      Remove an element from the list.
      int row​(int cursor)
      Get the line number for a position.
      int row​(Cursor cursor)
      Get the line number for a cursor.
      int size()
      Get the count of elements.
      void swap​(int i, int j)
      Swaps the elements at the given indicies.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • mStartIncrement

        protected static final int mStartIncrement
        Starting increment for allocations.
        See Also:
        Constant Field Values
      • mIncrement

        protected int mIncrement
        Increment for allocations.
      • mCount

        protected int mCount
        The number of valid elements.
      • mIndices

        protected int[] mIndices
        The elements.
      • mPage

        protected Page mPage
        The page associated with this index.
    • Constructor Detail

      • PageIndex

        public PageIndex​(Page page)
        Create an empty index.
        Parameters:
        page - The page associated with this index.
      • PageIndex

        public PageIndex​(Page page,
                         int cursor)
        Create an index with the one element given.
        Parameters:
        page - The page associated with this index.
        cursor - The single element for the new index.
      • PageIndex

        public PageIndex​(Page page,
                         int[] cursors)
        Create an index with the elements given.
        Parameters:
        page - The page associated with this index.
        cursors - The initial elements of the index. NOTE: The list must be sorted in ascending order.
    • Method Detail

      • getPage

        public Page getPage()
        Get this index's page.
        Returns:
        The page associated with this index.
      • size

        public int size()
        Get the count of elements.
        Returns:
        The number of valid elements.
      • capacity

        public int capacity()
        Get the capacity for elements without reallocation.
        Returns:
        The number of spaces for elements.
      • add

        public int add​(Cursor cursor)
        Add an element to the list
        Parameters:
        cursor - The element to add.
        Returns:
        The position at which the element was inserted or the index of the existing element if it is a duplicate.
      • add

        public int add​(int cursor)
        Add an element to the list
        Parameters:
        cursor - The element to add.
        Returns:
        The position at which the element was inserted or the index of the existing element if it is a duplicate.
      • remove

        public void remove​(Cursor cursor)
        Remove an element from the list
        Parameters:
        cursor - The element to remove.
      • remove

        public void remove​(int cursor)
        Remove an element from the list
        Parameters:
        cursor - The element to remove.
      • elementAt

        public int elementAt​(int index)
        Get an element from the list.
        Parameters:
        index - The index of the element to get.
        Returns:
        The element.
      • row

        public int row​(Cursor cursor)
        Get the line number for a cursor.
        Parameters:
        cursor - The character offset into the page.
        Returns:
        The line number the character is in.
      • row

        public int row​(int cursor)
        Get the line number for a position.
        Parameters:
        cursor - The character offset into the page.
        Returns:
        The line number the character is in.
      • column

        public int column​(Cursor cursor)
        Get the column number for a cursor.
        Parameters:
        cursor - The character offset into the page.
        Returns:
        The character offset into the line this cursor is on.
      • column

        public int column​(int cursor)
        Get the column number for a position.
        Parameters:
        cursor - The character offset into the page.
        Returns:
        The character offset into the line this cursor is on.
      • get

        public int[] get()
        Get the elements as an array of int.
        Returns:
        A new array containing the elements, i.e. a snapshot of the index.
      • bsearch

        protected int bsearch​(int cursor)
        Binary search for the element.
        Parameters:
        cursor - The element to search for.
        Returns:
        The index at which the element was found or is to be inserted.
      • bsearch

        protected int bsearch​(int cursor,
                              int first,
                              int last)
        Binary search for the element.
        Parameters:
        cursor - The element to search for.
        first - The index to start at.
        last - The index to stop at.
        Returns:
        The index at which the element was found or is to be inserted.
      • insertElementAt

        protected void insertElementAt​(int cursor,
                                       int index)
        Inserts an element into the list. The index must be a value greater than or equal to 0 and less than or equal to the current size of the array.
        Parameters:
        cursor - The element to insert.
        index - The index in the list to insert it at.
      • removeElementAt

        protected void removeElementAt​(int index)
        Remove an element from the list.
        Parameters:
        index - The index of the item to remove.
      • first

        public int first()
        Returns the first index of the Sortable.
        Specified by:
        first in interface Sortable
        Returns:
        The index of the first element.
      • last

        public int last()
        Returns the last index of the Sortable.
        Specified by:
        last in interface Sortable
        Returns:
        The index of the last element. If this were an array object this would be (object.length - 1). For an empty index this will return -1.
      • fetch

        public Ordered fetch​(int index,
                             Ordered reuse)
        Fetch the object at the given index.
        Specified by:
        fetch in interface Sortable
        Parameters:
        index - The item number to get.
        reuse - If this argument is not null, it is an object acquired from a previous fetch that is no longer needed and may be returned as the result if it makes mores sense to alter and return it than to fetch or create a new element. That is, the reuse object is garbage and may be used to avoid allocating a new object if that would normally be the strategy.
        Returns:
        The Ordered object at that index.
      • swap

        public void swap​(int i,
                         int j)
        Swaps the elements at the given indicies.
        Specified by:
        swap in interface Sortable
        Parameters:
        i - One index.
        j - The other index.