fixed another return FALSE in a function returning a pointer (patch 545046)

[wxWidgets.git] / docs / latex / wx / combobox.tex

\section{\class{wxComboBox}}\label{wxcombobox}

A combobox is like a combination of an edit control and a listbox. It can be
displayed as static list with editable or read-only text field; or a drop-down list with
text field; or a drop-down list without a text field.

A combobox permits a single selection only. Combobox items are numbered from zero.

\wxheading{Derived from}

\helpref{wxChoice}{wxchoice}\\
\helpref{wxControl}{wxcontrol}\\
\helpref{wxWindow}{wxwindow}\\
\helpref{wxEvtHandler}{wxevthandler}\\
\helpref{wxObject}{wxobject}

\wxheading{Include files}

<wx/combobox.h>

\wxheading{Window styles}

\begin{twocollist}\itemsep=0pt
\twocolitem{\windowstyle{wxCB\_SIMPLE}}{Creates a combobox with a permanently displayed list. Windows only. }
\twocolitem{\windowstyle{wxCB\_DROPDOWN}}{Creates a combobox with a drop-down list.}
\twocolitem{\windowstyle{wxCB\_READONLY}}{Same as wxCB\_DROPDOWN but only the
strings specified as the combobox choices can be selected, it is impossible to
select (even from a program) a string which is not in the choices list.}
\twocolitem{\windowstyle{wxCB\_SORT}}{Sorts the entries in the list alphabetically.}
\end{twocollist}

See also \helpref{window styles overview}{windowstyles}.

\wxheading{Event handling}

\twocolwidtha{7cm}
\begin{twocollist}\itemsep=0pt
\twocolitem{{\bf EVT\_COMBOBOX(id, func)}}{Process a wxEVT\_COMMAND\_COMBOBOX\_SELECTED event,
when an item on the list is selected.}
\twocolitem{{\bf EVT\_TEXT(id, func)}}{Process a wxEVT\_COMMAND\_TEXT\_UPDATED event,
when the combobox text changes.}
\end{twocollist}

\wxheading{See also}

\helpref{wxListBox}{wxlistbox}, \helpref{wxTextCtrl}{wxtextctrl}, \helpref{wxChoice}{wxchoice},
\rtfsp\helpref{wxCommandEvent}{wxcommandevent}

\latexignore{\rtfignore{\wxheading{Members}}}

\membersection{wxComboBox::wxComboBox}\label{wxcomboboxconstr}

\func{}{wxComboBox}{\void}

Default constructor.

\func{}{wxComboBox}{\param{wxWindow*}{ parent}, \param{wxWindowID}{ id},\rtfsp
\param{const wxString\& }{value = ``"}, \param{const wxPoint\&}{ pos = wxDefaultPosition}, \param{const wxSize\&}{ size = wxDefaultSize},\rtfsp
\param{int}{ n}, \param{const wxString }{choices[]},\rtfsp
\param{long}{ style = 0}, \param{const wxValidator\& }{validator = wxDefaultValidator}, \param{const wxString\& }{name = ``comboBox"}}

Constructor, creating and showing a combobox.

\wxheading{Parameters}

\docparam{parent}{Parent window. Must not be NULL.}

\docparam{id}{Window identifier. A value of -1 indicates a default value.}

\docparam{pos}{Window position.}

\docparam{size}{Window size. If the default size (-1, -1) is specified then the window is sized
appropriately.}

\docparam{n}{Number of strings with which to initialise the control.}

\docparam{choices}{An array of strings with which to initialise the control.}

\docparam{style}{Window style. See \helpref{wxComboBox}{wxcombobox}.}

\docparam{validator}{Window validator.}

\docparam{name}{Window name.}

\wxheading{See also}

\helpref{wxComboBox::Create}{wxcomboboxcreate}, \helpref{wxValidator}{wxvalidator}

\pythonnote{The wxComboBox constructor in wxPython reduces the {\tt n}
and {\tt choices} arguments are to a single argument, which is
a list of strings.}

\perlnote{In wxPerl there is just an array reference in place of {\tt n}
and {\tt choices}.}

\membersection{wxComboBox::\destruct{wxComboBox}}

\func{}{\destruct{wxComboBox}}{\void}

Destructor, destroying the combobox.

\membersection{wxComboBox::Append}\label{wxcomboboxappend}

\func{void}{Append}{\param{const wxString\& }{item}}

Adds the item to the end of the combobox.

\func{void}{Append}{\param{const wxString\& }{ item}, \param{void* }{clientData}}

Adds the item to the end of the combobox, associating the given data
with the item.

\wxheading{Parameters}

\docparam{item}{The string to add.}

\docparam{clientData}{Client data to associate with the item.}

\membersection{wxComboBox::Clear}\label{wxcomboboxclear}

\func{void}{Clear}{\void}

Clears all strings from the combobox.

\membersection{wxComboBox::Create}\label{wxcomboboxcreate}

\func{bool}{Create}{\param{wxWindow*}{ parent}, \param{wxWindowID}{ id},\rtfsp
\param{const wxString\& }{value = ``"}, \param{const wxPoint\&}{ pos = wxDefaultPosition}, \param{const wxSize\&}{ size = wxDefaultSize},\rtfsp
\param{int}{ n}, \param{const wxString }{choices[]},\rtfsp
\param{long}{ style = 0}, \param{const wxValidator\& }{validator = wxDefaultValidator}, \param{const wxString\& }{name = ``comboBox"}}

Creates the combobox for two-step construction. Derived classes
should call or replace this function. See \helpref{wxComboBox::wxComboBox}{wxcomboboxconstr}\rtfsp
for further details.

\membersection{wxComboBox::Copy}\label{wxcomboboxcopy}

\func{void}{Copy}{\void}

Copies the selected text to the clipboard.

\membersection{wxComboBox::Cut}\label{wxcomboboxcut}

\func{void}{Cut}{\void}

Copies the selected text to the clipboard and removes the selection.

\membersection{wxComboBox::Delete}\label{wxcomboboxdelete}

\func{void}{Delete}{\param{int}{ n}}

Deletes an item from the combobox.

\wxheading{Parameters}

\docparam{n}{The item to delete, starting from zero.}

\membersection{wxComboBox::FindString}\label{wxcomboboxfindstring}

\func{int}{FindString}{\param{const wxString\& }{string}}

Finds a choice matching the given string.

\wxheading{Parameters}

\docparam{string}{The item to find.}

\wxheading{Return value}

The position if found, or -1 if not found.

\membersection{wxComboBox::GetClientData}\label{wxcomboboxgetclientdata}

\constfunc{void*}{GetClientData}{\param{int}{ n}}

Returns a pointer to the client data associated with the given item (if any).

\wxheading{Parameters}

\docparam{n}{An item, starting from zero.}

\wxheading{Return value}

A pointer to the client data, or NULL if the item was not found.

\membersection{wxComboBox::GetCount}\label{wxcomboboxgetcount}

\constfunc{int}{GetCount}{\void}

Returns the number of items in the combobox.

\membersection{wxComboBox::GetInsertionPoint}\label{wxcomboboxgetinsertionpoint}

\constfunc{long}{GetInsertionPoint}{\void}

Returns the insertion point for the combobox's text field.

\membersection{wxComboBox::GetLastPosition}\label{wxcomboboxgetlastposition}

\constfunc{long}{GetLastPosition}{\void}

Returns the last position in the combobox text field.

\membersection{wxComboBox::GetSelection}\label{wxcomboboxgetselection}

\constfunc{int}{GetSelection}{\void}

Gets the position of the selected string, or -1 if there is no selection.

\membersection{wxComboBox::GetString}\label{wxcomboboxgetstring}

\constfunc{wxString}{GetString}{\param{int}{ n}}

Returns the string at position {\it n}.

\wxheading{Parameters}

\docparam{n}{The item position, starting from zero.}

\wxheading{Return value}

The string if the item is found, otherwise the empty string.

\membersection{wxComboBox::GetStringSelection}\label{wxcomboboxgetstringselection}

\constfunc{wxString}{GetStringSelection}{\void}

Gets the selected string.

\membersection{wxComboBox::GetValue}\label{wxcomboboxgetvalue}

\constfunc{wxString}{GetValue}{\void}

Returns the current value in the combobox text field.

\membersection{wxComboBox::Number}\label{wxcomboboxnumber}

\constfunc{int}{Number}{\void}

{\bf Obsolescence note:} This method is obsolete and was replaced with 
\helpref{GetCount}{wxcomboboxgetcount}, please use the new method in the new
code. This method is only available if wxWindows was compiled with 
{\tt WXWIN\_COMPATIBILITY\_2\_2} defined and will disappear completely in
future versions.

Returns the number of items in the combobox list.

\membersection{wxComboBox::Paste}\label{wxcomboboxpaste}

\func{void}{Paste}{\void}

Pastes text from the clipboard to the text field.

\membersection{wxComboBox::Replace}\label{wxcomboboxreplace}

\func{void}{Replace}{\param{long}{ from}, \param{long}{ to}, \param{const wxString\& }{text}}

Replaces the text between two positions with the given text, in the combobox text field.

\wxheading{Parameters}

\docparam{from}{The first position.}

\docparam{to}{The second position.}

\docparam{text}{The text to insert.}

\membersection{wxComboBox::Remove}\label{wxcomboboxremove}

\func{void}{Remove}{\param{long}{ from}, \param{long}{ to}}

Removes the text between the two positions in the combobox text field.

\wxheading{Parameters}

\docparam{from}{The first position.}

\docparam{to}{The last position.}

\membersection{wxComboBox::SetClientData}\label{wxcomboboxsetclientdata}

\func{void}{SetClientData}{\param{int}{ n}, \param{void* }{data}}

Associates the given client data pointer with the given item.

\wxheading{Parameters}

\docparam{n}{The zero-based item.}

\docparam{data}{The client data.}

\membersection{wxComboBox::SetInsertionPoint}\label{wxcomboboxsetinsertionpoint}

\func{void}{SetInsertionPoint}{\param{long}{ pos}}

Sets the insertion point in the combobox text field.

\wxheading{Parameters}

\docparam{pos}{The new insertion point.}

\membersection{wxComboBox::SetInsertionPointEnd}\label{wxcomboboxsetinsertionpointend}

\func{void}{SetInsertionPointEnd}{\void}

Sets the insertion point at the end of the combobox text field.

\membersection{wxComboBox::SetSelection}\label{wxcomboboxsetselection}

\func{void}{SetSelection}{\param{int}{ n}}

Selects the given item in the combobox list. This does not cause a
wxEVT\_COMMAND\_COMBOBOX\_SELECTED event to get emitted.

\func{void}{SetSelection}{\param{long}{ from}, \param{long}{ to}}

Selects the text between the two positions, in the combobox text field.

\wxheading{Parameters}

\docparam{n}{The zero-based item to select.}

\docparam{from}{The first position.}

\docparam{to}{The second position.}

\pythonnote{The second form of this method is called {\tt SetMark} in
wxPython.}

\membersection{wxComboBox::SetString}\label{wxcomboboxsetstring}

\func{void}{SetString}{\param{int }{n}, \param{const wxString\& }{text}}

Replaces the specified string in the control with another one.

\wxheading{Parameters}

\docparam{n}{The zero-based index of the string to replace}

\docparam{text}{The new value for this item}

{\bf NB:} This method is currently not implemented in wxGTK.

\membersection{wxComboBox::SetValue}\label{wxcomboboxsetvalue}

\func{void}{SetValue}{\param{const wxString\& }{text}}

Sets the text for the combobox text field.

{\bf NB:} For a combobox with {\tt wxCB\_READONLY} style the string must be in
the combobox choices list, otherwise the call to SetValue() is ignored.

\wxheading{Parameters}

\docparam{text}{The text to set.}