InterfaceContainer (Java UNO Runtime Reference)

com.sun.star.lib.uno.helper

## Class InterfaceContainer

- java.lang.Object
- - com.sun.star.lib.uno.helper.InterfaceContainer

- All Implemented Interfaces:
    Cloneable

      public class InterfaceContainer
      extends Object
      implements Cloneable

  This class is a container for interfaces. It is intended to be used as storage for UNO interface of a specific type. The client has to ensure that the container contains only elements of the same type. If one needs to store different types, then one uses OMultiTypeInterfaceContainer. When the client calls disposeAndClear, the contained objects are queried for com.sun.star.lang.XEventListener and disposing is called. Afterwards the list cannot be used anymore. This list does not allow null values. All methods are thread-safe. The same holds true for iterators, issued by this class. Several iterators can exist at the same time and can also be modified (java.util.ListIterator.add, java.util.ListIterator.remove etc.). To make this work, the InterfaceContainer provides the iterators with copies of the list's data. The add and remove calls on the iterator modify the data in the iterator's list as well as in InterfaceContainer. Modification on InterfaceContainer, however, are not synchronized with existing iterators. For example

       InterfaceContainer cont= new InterfaceContainer();
       ListIterator it= cont.listIterator();

       cont.add( someInterface);
       // one cannot obtain someInterface through iterator it,
       // instead get a new iterator
       it= cont.listIterator();
       // it now keeps a fresh copy of cont and hence contains someInterface

       // Adding an interface on the iterator will cause the interface also to be added
       // to InterfaceContainer
       it.add( someOtherInterface);
       // someOtherInterface is now in it and cont
       ListIterator it2= cont.listIterator();
       //someOtherInterface can also be obtained by all newly created iterators, e.g. it2.

  The add and remove methods of an iterator work on a particular location within a list, dependent on what the value of the iterator's cursor is. After the call the value at the appropriate position has been modified. Since the iterator received a copy of InterfaceContainer's data, InterfaceContainer may have been modified (by List methods or through other iterators). Therefore both data sets may not contain the same elements anymore. Consequently, a List method that modifies data, does not modify InterfaceContainer's data at a certain index (according to the iterators cursor). Instead, new elements are added at the end of list. When Iterator.remove is called, then the first occurrence of that element in InterfaceContainer is removed. ListIterator.set is not supported. A lot of methods resemble those of the to java.util.List interface, although this class does not implement it. However, the list iterators returned, for example by the listIterator method implement the java.util.ListIterator interface. Implementing the List interface would mean to support all none - optional methods as prescribed by the interface declaration. Among those is the subList method which returns a range of values of the list's data wrapped in a List implementation. Changes to the sub list have to cause changes in the main list. This is a problem, since this class is to be used in a multi-threaded environment. The sub list could work on a copy as the iterators do, but all the functions which work on an given index could not be properly supported. Unfortunately, the List interface documentation states that all optional methods implemented by the list have to be implemented in the sub list. That would mean to do without all those critical methods, although they might work well in the "main list" (as opposed to sub list).

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `InterfaceContainer()` Creates a new instance of InterfaceContainer
    `InterfaceContainer(int initialCapacity)` Constructs an empty list with the specified initial capacity.

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `add(int index, Object element)` Inserts the specified element at the specified position in this list.
    `boolean` | `add(Object o)` Appends the specified element to the end of this list.
    `boolean` | `addAll(Collection c)` Appends all of the elements in the specified Collection to the end of this list, in the order that they are returned by the specified Collection's Iterator.
    `boolean` | `addAll(int index, Collection c)` Inserts all of the elements in the specified Collection into this list, starting at the specified position.
    `void` | `clear()` Removes all of the elements from this list.
    `Object` | `clone()` Returns a shallow copy of this `ArrayList` instance.
    `boolean` | `contains(Object elem)` Returns `true` if this list contains the specified element.
    `boolean` | `containsAll(Collection collection)`
    `void` | `disposeAndClear(EventObject evt)`
    `void` | `ensureCapacity(int minCapacity)` Increases the capacity of this `ArrayList` instance, if necessary, to ensure that it can hold at least the number of elements specified by the minimum capacity argument.
    `Object` | `get(int index)` Returns the element at the specified position in this list.
    `int` | `indexOf(Object elem)` Searches for the first occurrence of the given argument, testing for equality using the `equals` method.
    `boolean` | `isEmpty()` Tests if this list has no elements.
    `Iterator` | `iterator()`
    `int` | `lastIndexOf(Object elem)` Returns the index of the last occurrence of the specified object in this list.
    `ListIterator` | `listIterator()`
    `ListIterator` | `listIterator(int index)` The iterator keeps a copy of the list.
    `Object` | `remove(int index)` Removes the element at the specified position in this list.
    `boolean` | `remove(Object obj)` Parameter obj may
    `boolean` | `removeAll(Collection collection)`
    `boolean` | `retainAll(Collection collection)`
    `Object` | `set(int index, Object element)` Not supported.
    `int` | `size()` Returns the number of elements in this list.
    `Object[]` | `toArray()` Returns an array containing all of the elements in this list in the correct order.
    `Object[]` | `toArray(Object[] a)` Returns an array containing all of the elements in this list in the correct order.
    `void` | `trimToSize()` Trims the capacity of this `ArrayList` instance to be the list's current size.

    - ### Methods inherited from class java.lang.Object

      `equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### InterfaceContainer

          public InterfaceContainer()

      Creates a new instance of InterfaceContainer

    - #### InterfaceContainer

          public InterfaceContainer(int initialCapacity)

      Constructs an empty list with the specified initial capacity.
      Parameters:
        `initialCapacity` - the initial capacity of the list.
      Throws:
        `IllegalArgumentException` - if the specified initial capacity is negative

  - ### Method Detail

    - #### trimToSize

          public void trimToSize()

      Trims the capacity of this `ArrayList` instance to be the list's current size. An application can use this operation to minimize the storage of an `ArrayList` instance.

    - #### ensureCapacity

          public void ensureCapacity(int minCapacity)

      Increases the capacity of this `ArrayList` instance, if necessary, to ensure that it can hold at least the number of elements specified by the minimum capacity argument.
      Parameters:
        `minCapacity` - the desired minimum capacity.

    - #### add

          public boolean add(Object o)

      Appends the specified element to the end of this list.
      Parameters:
        `o` - element to be appended to this list.
      Returns:
        `true` (as per the general contract of Collection.add).

    - #### add

          public void add(int index,
                 Object element)

      Inserts the specified element at the specified position in this list. Shifts the element currently at that position (if any) and any subsequent elements to the right (adds one to their indices).
      Parameters:
        `index` - index at which the specified element is to be inserted.
        `element` - element to be inserted.
      Throws:
        `IndexOutOfBoundsException` - if index is out of range `(index < 0 || index > size())`.

    - #### addAll

          public boolean addAll(Collection c)

      Appends all of the elements in the specified Collection to the end of this list, in the order that they are returned by the specified Collection's Iterator. The behavior of this operation is undefined if the specified Collection is modified while the operation is in progress. (This implies that the behavior of this call is undefined if the specified Collection is this list, and this list is nonempty.)
      Parameters:
        `c` - the elements to be inserted into this list.
      Throws:
        `IndexOutOfBoundsException` - if index out of range `(index < 0 || index > size())`.

    - #### addAll

          public boolean addAll(int index,
                       Collection c)

      Inserts all of the elements in the specified Collection into this list, starting at the specified position. Shifts the element currently at that position (if any) and any subsequent elements to the right (increases their indices). The new elements will appear in the list in the order that they are returned by the specified Collection's iterator.
      Parameters:
        `index` - index at which to insert first element from the specified collection.
        `c` - elements to be inserted into this list.
      Throws:
        `IndexOutOfBoundsException` - if index out of range `(index < 0 || index > size())`.

    - #### clear

          public void clear()

      Removes all of the elements from this list. The list will be empty after this call returns.

    - #### contains

          public boolean contains(Object elem)

      Returns `true` if this list contains the specified element.
      Parameters:
        `elem` - element whose presence in this List is to be tested.

    - #### containsAll

          public boolean containsAll(Collection collection)

    - #### get

          public Object get(int index)

      Returns the element at the specified position in this list.
      Parameters:
        `index` - index of element to return.
      Returns:
        the element at the specified position in this list.
      Throws:
        `IndexOutOfBoundsException` - if index is out of range `(index < 0 || index >= size())`.

    - #### indexOf

          public int indexOf(Object elem)

      Searches for the first occurrence of the given argument, testing for equality using the `equals` method.
      Parameters:
        `elem` - an object.
      Returns:
        the index of the first occurrence of the argument in this list; returns `-1` if the object is not found.
      See Also:
        `Object.equals(Object)`

    - #### isEmpty

          public boolean isEmpty()

      Tests if this list has no elements.
      Returns:
        `true` if this list has no elements; `false` otherwise.

    - #### iterator

          public Iterator iterator()

    - #### lastIndexOf

          public int lastIndexOf(Object elem)

      Returns the index of the last occurrence of the specified object in this list.
      Parameters:
        `elem` - the desired element.
      Returns:
        the index of the last occurrence of the specified object in this list; returns -1 if the object is not found.

    - #### clone

          public Object clone()

      Returns a shallow copy of this `ArrayList` instance. The contained references are copied but the objects not.
      Overrides:
        `clone` in class `Object`
      Returns:
        a clone of this `List` instance.

    - #### listIterator

          public ListIterator listIterator()

    - #### listIterator

          public ListIterator listIterator(int index)

      The iterator keeps a copy of the list. Changes to InterfaceContainer do not affect the data of the iterator. Conversely, changes to the iterator are effect InterfaceContainer.

    - #### remove

          public Object remove(int index)

      Removes the element at the specified position in this list. Shifts any subsequent elements to the left (subtracts one from their indices).
      Parameters:
        `index` - the index of the element to removed.
      Returns:
        the element that was removed from the list.
      Throws:
        `IndexOutOfBoundsException` - if index out of range `(index < 0 || index >= size())`.

    - #### remove

          public boolean remove(Object obj)

      Parameter obj may

    - #### removeAll

          public boolean removeAll(Collection collection)

    - #### retainAll

          public boolean retainAll(Collection collection)

    - #### set

          public Object set(int index,
                   Object element)

      Not supported.
      Parameters:
        `index` - index of element to replace.
        `element` - element to be stored at the specified position.
      Returns:
        the element previously at the specified position.
      Throws:
        `IndexOutOfBoundsException` - if index out of range `(index < 0 || index >= size())`.

    - #### size

          public int size()

      Returns the number of elements in this list.
      Returns:
        the number of elements in this list.

    - #### toArray

          public Object[] toArray()

      Returns an array containing all of the elements in this list in the correct order.
      Returns:
        an array containing all of the elements in this list in the correct order.

    - #### toArray

          public Object[] toArray(Object[] a)

      Returns an array containing all of the elements in this list in the correct order. The runtime type of the returned array is that of the specified array. If the list fits in the specified array, it is returned therein. Otherwise, a new array is allocated with the runtime type of the specified array and the size of this list.

      If the list fits in the specified array with room to spare (i.e., the array has more elements than the list), the element in the array immediately following the end of the collection is set to `null`. This is useful in determining the length of the list only if the caller knows that the list does not contain any `null` elements.

      Parameters:
        `a` - the array into which the elements of the list are to be stored, if it is big enough; otherwise, a new array of the same runtime type is allocated for this purpose.
      Returns:
        an array containing the elements of the list.
      Throws:
        `ArrayStoreException` - if the runtime type of a is not a supertype of the runtime type of every element in this list.

    - #### disposeAndClear

          public void disposeAndClear(EventObject evt)