While wxList class in the previous versions of wxWindows only could contain
elements of type wxObject and had essentially untyped interface (thus allowing
you to put apples in the list and read back oranges from it), the new wxList
-classes family may contain elements of any type and has much more stricter type
+classes family may contain elements of any type and has much more strict type
checking. Unfortunately, it also requires an additional line to be inserted in
your program for each list class you use (which is the only solution short of
using templates which is not done in wxWindows because of portability issues).
that they can only be used from derived classes which, in turn, expose a type
safe interface. With this approach a new wxList-like class must be defined for
each list type (i.e. list of ints, of wxStrings or of MyObjects). This is done
-with {\it WX\_DECLARE\_LIST} and {\it WX\_IMPLEMENT\_LIST} macros like this
+with {\it WX\_DECLARE\_LIST} and {\it WX\_DEFINE\_LIST} macros like this
(notice the similarity with WX\_DECLARE\_OBJARRAY and WX\_IMPLEMENT\_OBJARRAY
macros):
\wxheading{Example}
-{\small%
\begin{verbatim}
// this part might be in a header or source (.cpp) file
class MyListElement
// declare our list class: this macro declares and partly implements MyList
// class (which derives from wxListBase)
- WX_DECLARE_LIST(MyListElement, MyList)
+ WX_DECLARE_LIST(MyListElement, MyList);
...
// usually it will be found in the source file and not in the header
#include <wx/listimpl.cpp>
- WX_DEFINE_LIST(MyList)
+ WX_DEFINE_LIST(MyList);
// now MyList class may be used as a usual wxList, but all of its methods
// will take/return the objects of the right (i.e. MyListElement) type. You
// also have MyList::Node type which is the type-safe version of wxNode.
MyList list;
MyListElement element;
- list.Add(element); // ok
- list.Add(17); // error: incorrect type
+ list.Append(element); // ok
+ list.Append(17); // error: incorrect type
// let's iterate over the list
for ( MyList::Node *node = list.GetFirst(); node; node = node->GetNext() )
...process the current element...
}
\end{verbatim}
-}
For compatibility with previous versions wxList and wxStringList classes are
still defined, but their usage is deprecated and they will disappear in the
-future versions completely.
+future versions completely. The use of the latter is especially discouraged as
+it is not only unsafe but is also much less efficient than
+\helpref{wxArrayString}{wxarraystring} class.
+
+In the documentation of the list classes below, you should replace wxNode with
+wxListName::Node and wxObject with the list element type (i.e. the first
+parameter of WX\_DECLARE\_LIST) for the template lists.
\wxheading{Derived from}
\helpref{wxObject}{wxobject}
+\wxheading{Include files}
+
+<wx/list.h>
+
\wxheading{Example}
It is very common to iterate on a list as follows:
wxNode *node = SomeList.GetFirst();
while (node)
{
- wxWindow *win = (wxWindow *)node->Data();
+ wxWindow *win = node->GetData();
...
- node = node->Next();
+ node = node->GetNext();
}
\end{verbatim}
\begin{verbatim}
...
- node = node->Next();
+ node = node->GetNext();
...
\end{verbatim}
See \helpref{wxNode}{wxnode} for members that retrieve the data associated with a node, and
members for getting to the next or previous node.
-Note that a cast is required when retrieving the data from a node. Although a
-node is defined to store objects of type {\bf wxObject} and derived types, other
-types (such as char*) may be used with appropriate casting.
-
\wxheading{See also}
\helpref{wxNode}{wxnode}, \helpref{wxStringList}{wxstringlist},
Destroys the list. Also destroys any remaining nodes, but does not destroy
client data held in the nodes.
-\membersection{wxList::Append}
+\membersection{wxList::Append}\label{wxlistappend}
\func{wxNode *}{Append}{\param{wxObject *}{object}}
The key string is copied and stored by the list implementation.
-\membersection{wxList::Clear}
+\membersection{wxList::Clear}\label{wxlistclear}
\func{void}{Clear}{\void}
-Clears the list (but does not delete the client data stored with each node).
+Clears the list (but does not delete the client data stored with each node
+unless you called DeleteContents(TRUE), in which case it deletes data).
\membersection{wxList::DeleteContents}\label{wxlistdeletecontents}
If {\it destroy} is TRUE, instructs the list to call {\it delete} on the client contents of
a node whenever the node is destroyed. The default is FALSE.
-\membersection{wxList::DeleteNode}
+\membersection{wxList::DeleteNode}\label{wxlistdeletenode}
\func{bool}{DeleteNode}{\param{wxNode *}{node}}
Deletes the given node from the list, returning TRUE if successful.
-\membersection{wxList::DeleteObject}
+\membersection{wxList::DeleteObject}\label{wxlistdeleteobject}
\func{bool}{DeleteObject}{\param{wxObject *}{object}}
Finds the given client {\it object} and deletes the appropriate node from the list, returning
TRUE if successful. The application must delete the actual object separately.
-\membersection{wxList::Find}
+\membersection{wxList::Find}\label{wxlistfind}
\func{wxNode *}{Find}{\param{long}{ key}}
Returns the node whose stored key matches {\it key}. Use on a keyed list only.
-\membersection{wxList::GetFirst}
+\membersection{wxList::GetCount}\label{wxlistgetcount}
+
+\constfunc{size\_t}{GetCount}{\void}
+
+Returns the number of elements in the list.
+
+\membersection{wxList::GetFirst}\label{wxlistgetfirst}
\func{wxNode *}{GetFirst}{\void}
Returns the first node in the list (NULL if the list is empty).
-\membersection{wxList::IndexOf}
+\membersection{wxList::GetLast}\label{wxlistgetlast}
+
+\func{wxNode *}{GetLast}{\void}
+
+Returns the last node in the list (NULL if the list is empty).
+
+\membersection{wxList::IndexOf}\label{wxlistindexof}
\func{int}{IndexOf}{\param{wxObject*}{ obj }}
-Returns the index of {\it obj} within the list or NOT\_FOUND if {\it obj}
+Returns the index of {\it obj} within the list or wxNOT\_FOUND if {\it obj}
is not found in the list.
-\membersection{wxList::Insert}
+\membersection{wxList::Insert}\label{wxlistinsert}
\func{wxNode *}{Insert}{\param{wxObject *}{object}}
Insert object at front of list.
-\func{wxNode *}{Insert}{\param{wxNode *}{position}, \param{wxObject *}{object}}
+\func{wxNode *}{Insert}{\param{size\_t }{position}, \param{wxObject *}{object}}
-Insert object before {\it position}.
+Insert object before {\it position}, i.e. the index of the new item in the
+list will be equal to {\it position}. {\it position} should be less than or
+equal to \helpref{GetCount}{wxlistgetcount}; if it is equal to it, this is the
+same as calling \helpref{Append}{wxlistappend}.
+\func{wxNode *}{Insert}{\param{wxNode *}{node}, \param{wxObject *}{object}}
-\membersection{wxList::GetLast}
+Inserts the object before the given {\it node}.
-\func{wxNode *}{GetLast}{\void}
+\membersection{wxList::Item}\label{wxlistitem}
-Returns the last node in the list (NULL if the list is empty).
+\constfunc{wxNode *}{Item}{\param{size\_t }{index}}
+
+Returns the node at given position in the list.
-\membersection{wxList::Member}
+\membersection{wxList::Member}\label{wxlistmember}
\func{wxNode *}{Member}{\param{wxObject *}{object}}
+{\bf NB:} This function is deprecated, use \helpref{Find}{wxlistfind} instead.
+
Returns the node associated with {\it object} if it is in the list, NULL otherwise.
-\membersection{wxList::Nth}
+\membersection{wxList::Nth}\label{wxlistnth}
\func{wxNode *}{Nth}{\param{int}{ n}}
+{\bf NB:} This function is deprecated, use \helpref{Item}{wxlistitem} instead.
+
Returns the {\it nth} node in the list, indexing from zero (NULL if the list is empty
or the nth node could not be found).
-\membersection{wxList::Number}
+\membersection{wxList::Number}\label{wxlistnumber}
\func{int}{Number}{\void}
+{\bf NB:} This function is deprecated, use \helpref{GetCount}{wxlistgetcount} instead.
+
Returns the number of elements in the list.
-\membersection{wxList::Sort}
+\membersection{wxList::Sort}\label{wxlistsort}
\func{void}{Sort}{\param{wxSortCompareFunction}{ compfunc}}
Allows the sorting of arbitrary lists by giving
a function to compare two list elements. We use the system {\bf qsort} function
-for the actual sorting process. The sort function receives pointers to wxObject pointers (wxObject **),
-so be careful to dereference appropriately.
+for the actual sorting process.
+
+If you use untyped wxList the sort function receives pointers to wxObject
+pointers (wxObject **), so be careful to dereference appropriately - but,
+of course, a better solution is to use list of appropriate type defined with
+{\tt WX\_DECLARE\_LIST}.
Example:
}
\end{verbatim}
-
projects / wxWidgets.git / blobdiff