org.osgl.util

Interface C.List.Cursor<T>

Type Parameters:

T -

Enclosing interface:

C.List<T>

public static interface C.List.Cursor<T>

A cursor points to an element of a List. It performs like ListIterator but differs in the following way:

• Add insert, append method
• Support method chain calling style for most methods
• A clear get() method to get the element the cursor point to
• Unlike next/previous method, the new forward/backward method returns a Cursor reference

Method Summary

Modifier and Type	Method and Description
C.List.Cursor<T>	append(T t) Add an element after the element this cursor points to.
C.List.Cursor<T>	backward() Move the cursor backward to make it point to the previous element to the current element
C.List.Cursor<T>	drop() Remove the current element this cursor points to.
C.List.Cursor<T>	forward() Move the cursor forward to make it point to the next element to the current element
T	get() Returns the element this cursor points to.
boolean	hasNext() Returns if the cursor can be moved forward to get the next element
boolean	hasPrevious() Returns if the cursor can be moved backward to get the previous element
int	index() Returns the index of the element to which the cursor pointed
boolean	isDefined() Returns true if the cursor is not obsolete and points to an element in the list
C.List.Cursor<T>	parkLeft() Park the cursor at the position before the first element.
C.List.Cursor<T>	parkRight() Park the cursor at the position after the last element
C.List.Cursor<T>	prepend(T t) Add an element in front of the element this cursor points to.
C.List.Cursor<T>	set(T t) Replace the element this cursor points to with the new element specified.

Method Detail

isDefined

boolean isDefined()

Returns true if the cursor is not obsolete and points to an element in the list

Returns:

true if this cursor is not obsolete and point to an element

index

int index()

Returns the index of the element to which the cursor pointed

Returns:

the cursor index

hasNext

boolean hasNext()

Returns if the cursor can be moved forward to get the next element

Returns:

true if there are element after the cursor in the underline list

hasPrevious

boolean hasPrevious()

Returns if the cursor can be moved backward to get the previous element

Returns:

true if there are element before the cursor in the underline list

forward

C.List.Cursor<T> forward()
                  throws UnsupportedOperationException

Move the cursor forward to make it point to the next element to the current element

Returns:

the cursor points to the next element

Throws:

UnsupportedOperationException - if cannot move forward anymore

backward

C.List.Cursor<T> backward()
                   throws UnsupportedOperationException

Move the cursor backward to make it point to the previous element to the current element

Returns:

the cursor points to the previous element

Throws:

UnsupportedOperationException - if cannot move backward anymore

parkLeft

C.List.Cursor<T> parkLeft()

Park the cursor at the position before the first element.

After calling this method, isDefined() shall return false

Returns:

this cursor

parkRight

C.List.Cursor<T> parkRight()

Park the cursor at the position after the last element

After calling this method, isDefined() shall return false

Returns:

this cursor

get

T get()
throws NoSuchElementException

Returns the element this cursor points to. If the cursor isn’t point to any element, calling to this method will trigger NoSuchElementException been thrown out. The only case the cursor doesn’t point to any element is when it is initialized in which case the cursor index is -1

Returns:

the current element

Throws:

NoSuchElementException - if the cursor isn’t point to any element

set

C.List.Cursor<T> set(T t)
              throws IndexOutOfBoundsException,
                     NullPointerException

Replace the element this cursor points to with the new element specified.

Parameters:

t - the new element to be set to this cursor

Returns:

the cursor itself

Throws:

IndexOutOfBoundsException - if the cursor isn’t point to any element

NullPointerException - if when passing null value to this method and the underline list does not allow null value

drop

C.List.Cursor<T> drop()
               throws NoSuchElementException,
                      UnsupportedOperationException

Remove the current element this cursor points to. After the element is removed, the cursor points to the next element if there is next, or if there isn’t next element, the cursor points to the previous element, or if there is previous element neither, then the cursor points to -1 position and the current element is not defined

Returns:

the cursor itself

Throws:

UnsupportedOperationException - if the operation is not supported by the underline container does not support removing elements

NoSuchElementException - if the cursor is parked either left or right

prepend

C.List.Cursor<T> prepend(T t)
                  throws IndexOutOfBoundsException

Add an element in front of the element this cursor points to. After added, the cursor should still point to the current element

Parameters:

t - the element to be inserted

Returns:

this cursor which is still pointing to the current element

Throws:

IndexOutOfBoundsException - if the current element is undefined

append

C.List.Cursor<T> append(T t)

Add an element after the element this cursor points to. After added, the cursor should still point to the current element

Parameters:

t - the element to be added

Returns:

this cursor which is still pointing to the current element