First step in background erase optimization

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

\section{\class{wxButton}}\label{wxbutton}

A button is a control that contains a text string,
and is one of the commonest elements of a GUI. It may be placed on a
\rtfsp\helpref{dialog box}{wxdialog} or \helpref{panel}{wxpanel}, or indeed
almost any other window.

\wxheading{Derived from}

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

\wxheading{Include files}

<wx/button.h>

\wxheading{Window styles}

\twocolwidtha{5cm}%
\begin{twocollist}\itemsep=0pt
\twocolitem{\windowstyle{wxBU\_LEFT}}{Left-justifies the label. Windows and GTK+ only.}
\twocolitem{\windowstyle{wxBU\_TOP}}{Aligns the label to the top of the button. Windows and GTK+ only.}
\twocolitem{\windowstyle{wxBU\_RIGHT}}{Right-justifies the bitmap label. Windows and GTK+ only.}
\twocolitem{\windowstyle{wxBU\_BOTTOM}}{Aligns the label to the bottom of the button. Windows and GTK+ only.}
\twocolitem{\windowstyle{wxBU\_EXACTFIT}}{Creates the button as small as possible instead of making it of the standard size (which is the default behaviour ).}
\twocolitem{\windowstyle{wxNO\_BORDER}}{Creates a flat button. Windows and GTK+ only.}
\end{twocollist}

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

\wxheading{Event handling}

\twocolwidtha{7cm}%
\begin{twocollist}\itemsep=0pt
\twocolitem{{\bf EVT\_BUTTON(id, func)}}{Process a wxEVT\_COMMAND\_BUTTON\_CLICKED event,
when the button is clicked.}
\end{twocollist}

\wxheading{See also}

\helpref{wxBitmapButton}{wxbitmapbutton}

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

\membersection{wxButton::wxButton}\label{wxbuttonconstr}

\func{}{wxButton}{\void}

Default constructor.

\func{}{wxButton}{\param{wxWindow* }{parent}, \param{wxWindowID}{ id}, \param{const wxString\& }{label},\rtfsp
\param{const wxPoint\& }{pos}, \param{const wxSize\& }{size = wxDefaultSize},\rtfsp
\param{long}{ style = 0}, \param{const wxValidator\& }{validator}, \param{const wxString\& }{name = ``button"}}

\func{}{wxButton}{\param{wxWindow* }{parent}, \param{wxWindowID}{ id},
\param{wxStockItemID}{ stock},\rtfsp
\param{const wxString\& }{descriptiveLabel = wxEmptyString},\rtfsp
\param{const wxPoint\& }{pos},\rtfsp
\param{long}{ style = 0}, \param{const wxValidator\& }{validator}, \param{const wxString\& }{name = ``button"}}

Constructor, creating and showing a button.

The second form is used to create {\em stock} button. Stock buttons are
commonly used buttons such as OK or Cancel. They have standard label and
dimensions and may have different appearance on some platforms (e.g. GTK+ 2
decorates them with icons). Using this from is preferred way of creating
standard buttons.

\wxheading{Parameters}

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

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

\docparam{label}{Text to be displayed on the button.}

\docparam{pos}{Button position.}

\docparam{size}{Button size. If the default size (-1, -1) is specified then the button is sized
appropriately for the text.}

\docparam{style}{Window style. See \helpref{wxButton}{wxbutton}.}

\docparam{validator}{Window validator.}

\docparam{name}{Window name.}

\docparam{stock}{Stock ID of the stock button to create. See the
\helpref{list of possible values}{stockitems}.}

\docparam{descriptiveLabel}{Optional label to be used on platforms where
standard buttons have descriptive rather than generic labels. Mac is one such
platforms, well-behaved Mac apps should use descriptive labels (e.g. "Save"
and "Don't Save" instead of "OK" and "Cancel"). This argument is ignored on
other platforms.}

\wxheading{See also}

\helpref{wxButton::Create}{wxbuttoncreate}, \helpref{wxValidator}{wxvalidator}

\membersection{wxButton::\destruct{wxButton}}

\func{}{\destruct{wxButton}}{\void}

Destructor, destroying the button.

\membersection{wxButton::Create}\label{wxbuttoncreate}

\func{bool}{Create}{\param{wxWindow* }{parent}, \param{wxWindowID}{ id}, \param{const wxString\& }{label},\rtfsp
\param{const wxPoint\& }{pos}, \param{const wxSize\& }{size = wxDefaultSize},\rtfsp
\param{long}{ style = 0}, \param{const wxValidator\& }{validator}, \param{const wxString\& }{name = ``button"}}

\func{bool}{Create}{\param{wxWindow* }{parent}, \param{wxWindowID}{ id},
\param{wxStockItemID}{ stock},\rtfsp
\param{const wxString\& }{descriptiveLabel = wxEmptyString},\rtfsp
\param{const wxPoint\& }{pos},\rtfsp
\param{long}{ style = 0}, \param{const wxValidator\& }{validator}, \param{const wxString\& }{name = ``button"}}

Button creation function for two-step creation. For more details, see
\helpref{wxButton::wxButton}{wxbuttonconstr}.

\membersection{wxButton::GetLabel}\label{wxbuttongetlabel}

\constfunc{wxString}{GetLabel}{\void}

Returns the string label for the button.

\wxheading{Return value}

The button's label.

\wxheading{See also}

\helpref{wxButton::SetLabel}{wxbuttonsetlabel}

\membersection{wxButton::GetDefaultSize}\label{wxbuttongetdefaultsize}

\func{wxSize}{GetDefaultSize}{\void}

Returns the default size for the buttons. It is advised to make all the dialog
buttons of the same size and this function allows to retrieve the (platform and
current font dependent size) which should be the best suited for this.

\membersection{wxButton::SetDefault}\label{wxbuttonsetdefault}

\func{void}{SetDefault}{\void}

This sets the button to be the default item for the panel or dialog
box.

\wxheading{Remarks}

Under Windows, only dialog box buttons respond to this function.  As
normal under Windows and Motif, pressing return causes the default button to
be depressed when the return key is pressed. See also \helpref{wxWindow::SetFocus}{wxwindowsetfocus}\rtfsp
which sets the keyboard focus for windows and text panel items,\rtfsp
and \helpref{wxPanel::SetDefaultItem}{wxpanelsetdefaultitem}.

Note that under Motif, calling this function immediately after
creation of a button and before the creation of other buttons
will cause misalignment of the row of buttons, since default
buttons are larger. To get around this, call {\it SetDefault}\rtfsp
after you have created a row of buttons: wxWidgets will
then set the size of all buttons currently on the panel to
the same size.

\membersection{wxButton::SetLabel}\label{wxbuttonsetlabel}

\func{void}{SetLabel}{\param{const wxString\& }{label}}

Sets the string label for the button.

\wxheading{Parameters}

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

\wxheading{See also}

\helpref{wxButton::GetLabel}{wxbuttongetlabel}