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List Processing¶

Synopsis¶

This section contains various definitions related to list processing using doubly-linked nodes.

FT_List¶

Defined in FT_TYPES_H (freetype/fttypes.h).

  typedef struct FT_ListRec_*  FT_List;

A handle to a list record (see FT_ListRec).

FT_ListNode¶

Defined in FT_TYPES_H (freetype/fttypes.h).

  typedef struct FT_ListNodeRec_*  FT_ListNode;

Many elements and objects in FreeType are listed through an FT_List record (see FT_ListRec). As its name suggests, an FT_ListNode is a handle to a single list element.

FT_ListRec¶

Defined in FT_TYPES_H (freetype/fttypes.h).

  typedef struct  FT_ListRec_
  {
    FT_ListNode  head;
    FT_ListNode  tail;

  } FT_ListRec;

A structure used to hold a simple doubly-linked list. These are used in many parts of FreeType.

fields

head	The head (first element) of doubly-linked list.
tail	The tail (last element) of doubly-linked list.

FT_ListNodeRec¶

Defined in FT_TYPES_H (freetype/fttypes.h).

  typedef struct  FT_ListNodeRec_
  {
    FT_ListNode  prev;
    FT_ListNode  next;
    void*        data;

  } FT_ListNodeRec;

A structure used to hold a single list element.

fields

prev	The previous element in the list. `NULL` if first.
next	The next element in the list. `NULL` if last.
data	A typeless pointer to the listed object.

FT_List_Add¶

Defined in FT_LIST_H (freetype/ftlist.h).

  FT_EXPORT( void )
  FT_List_Add( FT_List      list,
               FT_ListNode  node );

Append an element to the end of a list.

inout

list	A pointer to the parent list.
node	The node to append.

FT_List_Insert¶

Defined in FT_LIST_H (freetype/ftlist.h).

  FT_EXPORT( void )
  FT_List_Insert( FT_List      list,
                  FT_ListNode  node );

Insert an element at the head of a list.

inout

list	A pointer to parent list.
node	The node to insert.

FT_List_Find¶

Defined in FT_LIST_H (freetype/ftlist.h).

  FT_EXPORT( FT_ListNode )
  FT_List_Find( FT_List  list,
                void*    data );

Find the list node for a given listed object.

input

list	A pointer to the parent list.
data	The address of the listed object.

return

List node. NULL if it wasn't found.

FT_List_Remove¶

Defined in FT_LIST_H (freetype/ftlist.h).

  FT_EXPORT( void )
  FT_List_Remove( FT_List      list,
                  FT_ListNode  node );

Remove a node from a list. This function doesn't check whether the node is in the list!

input

node	The node to remove.

inout

list	A pointer to the parent list.

FT_List_Up¶

Defined in FT_LIST_H (freetype/ftlist.h).

  FT_EXPORT( void )
  FT_List_Up( FT_List      list,
              FT_ListNode  node );

Move a node to the head/top of a list. Used to maintain LRU lists.

inout

list	A pointer to the parent list.
node	The node to move.

FT_List_Iterate¶

Defined in FT_LIST_H (freetype/ftlist.h).

  FT_EXPORT( FT_Error )
  FT_List_Iterate( FT_List           list,
                   FT_List_Iterator  iterator,
                   void*             user );

Parse a list and calls a given iterator function on each element. Note that parsing is stopped as soon as one of the iterator calls returns a non-zero value.

input

list	A handle to the list.
iterator	An iterator function, called on each node of the list.
user	A user-supplied field that is passed as the second argument to the iterator.

return

The result (a FreeType error code) of the last iterator call.

FT_List_Iterator¶

Defined in FT_LIST_H (freetype/ftlist.h).

  typedef FT_Error
  (*FT_List_Iterator)( FT_ListNode  node,
                       void*        user );

An FT_List iterator function that is called during a list parse by FT_List_Iterate.

input

node	The current iteration list node.
user	A typeless pointer passed to `FT_List_Iterate`. Can be used to point to the iteration's state.

FT_List_Finalize¶

Defined in FT_LIST_H (freetype/ftlist.h).

  FT_EXPORT( void )
  FT_List_Finalize( FT_List             list,
                    FT_List_Destructor  destroy,
                    FT_Memory           memory,
                    void*               user );

Destroy all elements in the list as well as the list itself.

input

list	A handle to the list.
destroy	A list destructor that will be applied to each element of the list. Set this to `NULL` if not needed.
memory	The current memory object that handles deallocation.
user	A user-supplied field that is passed as the last argument to the destructor.

note

This function expects that all nodes added by FT_List_Add or FT_List_Insert have been dynamically allocated.

FT_List_Destructor¶

Defined in FT_LIST_H (freetype/ftlist.h).

  typedef void
  (*FT_List_Destructor)( FT_Memory  memory,
                         void*      data,
                         void*      user );

An FT_List iterator function that is called during a list finalization by FT_List_Finalize to destroy all elements in a given list.

input

system	The current system object.
data	The current object to destroy.
user	A typeless pointer passed to `FT_List_Iterate`. It can be used to point to the iteration's state.