class PArrayObjects

An array of objects.

Inheritance:


Public Methods

[more] Construction
[more] Overrides from class PObject
[more] Overrides from class PContainer
[more] Overrides from class PCollection


Inherited from PCollection:

Public Methods

Common functions for collections


Inherited from PContainer:

Public Methods

Common functions for containers

Protected Methods

ovirtual void DestroyContents()
ovirtual void AssignContents(const PContainer & c)
ovoid CopyContents(const PContainer & c)
ovoid CloneContents(const PContainer* src)
ovoid Destruct()


Inherited from PObject:

Public Methods

Run Time Type functions

I/O functions

Miscellaneous functions

Public Members

Comparison functions


Documentation

An array of objects. This class is a collection of objects which are descendents of the PObject class. It is implemeted as a dynamic, linear array of pointers to the objects.

The implementation of an array allows very fast random access to items in the collection, but has severe penalties for inserting and deleting objects as all other objects must be moved to accommodate the change.

An array of objects may have "gaps" in it. These are array entries that contain NULL as the object pointer.

The PArrayObjects class would very rarely be descended from directly by the user. The PARRAY macro would normally be used to create a class. That will instantiate the template based on PArray or directly declare and define the class (using inline functions) if templates are not being used.

The PArray class or PARRAY macro will define the correctly typed operators for pointer access (operator const T *) and subscript access (operator[]).

o Construction

oPINLINE PArrayObjects( PINDEX initialSize = 0 )
Create a new array of objects. The array is initially set to the specified size with each entry having NULL as is pointer value.

Note that by default, objects placed into the list will be deleted when removed or when all references to the list are destroyed.

Parameters:
initialSize - Initial number of objects in the array.

o Overrides from class PObject

ovirtual Comparison Compare( const PObject & obj ) const
Get the relative rank of the two arrays. The following algorithm is employed for the comparison:
EqualTo
if the two array memory blocks are identical in length and each objects values, not pointer, are equal.

LessThan
if the instances object value at an ordinal position is less than the corresponding objects value in the obj parameters array.

This is also returned if all objects are equal and the instances array length is less than the obj parameters array length.

GreaterThan
if the instances object value at an ordinal position is greater than the corresponding objects value in the obj parameters array.

This is also returned if all objects are equal and the instances array length is greater than the obj parameters array length.

Parameters:
obj - Other PAbstractArray to compare against.
Returns:
comparison of the two objects, EqualTo for same, LessThan for obj logically less than the object and GreaterThan for obj logically greater than the object.

o Overrides from class PContainer

ovirtual PINDEX GetSize() const
Get size of array

ovirtual BOOL SetSize( PINDEX newSize )
Set the size of the array in objects. A new array may be allocated to accomodate the new number of objects. If the array increases in size then the new object pointers are initialised to NULL. If the array is made smaller then the data beyond the new size is lost.

Parameters:
newSize - New size of the array in objects.
Returns:
TRUE if the memory for the array was allocated successfully.

o Overrides from class PCollection

ovirtual PINDEX Append( PObject* obj )
Append a new object to the collection. This will increase the size of the array by one and place the new object at that position.

Parameters:
obj - New object to place into the collection.
Returns:
index of the newly added object.

ovirtual PINDEX Insert( const PObject & before, PObject* obj )
Insert a new object immediately before the specified object. If the object to insert before is not in the collection then the equivalent of the Append() function is performed.

All objects, including the before object are shifted up one in the array.

Note that the object values are compared for the search of the before parameter, not the pointers. So the objects in the collection must correctly implement the PObject::Compare() function.

Parameters:
before - Object value to insert before.
obj - New object to place into the collection.
Returns:
index of the newly inserted object.

ovirtual PINDEX InsertAt( PINDEX index, PObject* obj )
Insert a new object at the specified ordinal index. If the index is greater than the number of objects in the collection then the equivalent of the Append() function is performed.

All objects, including the index position object are shifted up one in the array.

Parameters:
index - Index position in collection to place the object.
obj - New object to place into the collection.
Returns:
index of the newly inserted object.

ovirtual BOOL Remove( const PObject* obj )
Remove the object from the collection. If the AllowDeleteObjects option is set then the object is also deleted.

All objects are shifted down to fill the vacated position.

Parameters:
obj - Existing object to remove from the collection.
Returns:
TRUE if the object was in the collection.

ovirtual PObject* RemoveAt( PINDEX index )
Remove the object at the specified ordinal index from the collection. If the AllowDeleteObjects option is set then the object is also deleted.

All objects are shifted down to fill the vacated position.

Note if the index is beyond the size of the collection then the function will assert.

Parameters:
index - Index position in collection to place the object.
Returns:
pointer to the object being removed, or NULL if it was deleted.

ovirtual BOOL SetAt( PINDEX index, PObject* val )
Set the object at the specified ordinal position to the new value. This will overwrite the existing entry. If the AllowDeleteObjects option is set then the old object is also deleted.

Parameters:
index - Index position in collection to set.
val - New value to place into the collection.
Returns:
TRUE if the object was successfully added.

ovirtual PObject* GetAt( PINDEX index ) const
Get the object at the specified ordinal position. If the index was greater than the size of the collection then NULL is returned.

Parameters:
index - Index position in the collection of the object.
Returns:
pointer to object at the specified index.

ovirtual PINDEX GetObjectsIndex( const PObject* obj ) const
Search the collection for the specific instance of the object. The object pointers are compared, not the values. A simple linear search from ordinal position zero is performed.

Parameters:
obj - Object to find.
Returns:
ordinal index position of the object, or P_MAX_INDEX.

ovirtual PINDEX GetValuesIndex( const PObject & obj ) const
Search the collection for the specified value of the object. The object values are compared, not the pointers. So the objects in the collection must correctly implement the PObject::Compare() function. A simple linear search from ordinal position zero is performed.

Returns:
ordinal index position of the object, or P_MAX_INDEX.

ovirtual void RemoveAll()
Remove all of the elements in the collection. This operates by continually calling RemoveAt() until there are no objects left.

The objects are removed from the last, at index (GetSize()-1) toward the first at index zero.


Direct child classes:
PArray

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