added null pointer check and assert

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

\section{\class{wxBitmapButton}}\label{wxbitmapbutton}

A bitmap button is a control that contains a bitmap.
It may be placed on a \helpref{dialog box}{wxdialog} or \helpref{panel}{wxpanel}, or indeed
almost any other window.


\wxheading{Derived from}

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


\wxheading{Include files}

<wx/bmpbuttn.h>

\wxheading{Library}

\helpref{wxCore}{librarieslist}


\wxheading{Remarks}

A bitmap button can be supplied with a single bitmap, and wxWidgets will draw
all button states using this bitmap. If the application needs more control, additional bitmaps for
the selected state, unpressed focused state, and greyed-out state may be supplied.


\wxheading{Button states}

This class supports bitmaps for several different states:

\twocolwidtha{5cm}
\begin{twocollist}\itemsep=0pt
\twocolitem{\windowstyle{normal}}{This is the bitmap shown in the default state,
it must be always valid while all the other bitmaps are optional and don't have
to be set.}
\twocolitem{\windowstyle{disabled}}{Bitmap shown when the button is disabled.}
\twocolitem{\windowstyle{selected}}{Bitmap shown when the button is pushed
(e.g. while the user keeps the mouse button pressed on it)}
\twocolitem{\windowstyle{focus}}{Bitmap shown when the button has keyboard
focus but is not pressed.}
\twocolitem{\windowstyle{hover}}{Bitmap shown when the mouse is over the
button (but it is not pressed). Notice that if hover bitmap is not specified
but the current platform UI uses hover images for the buttons (such as Windows
XP or GTK+), then the focus bitmap is used for hover state as well. This makes
it possible to set focus bitmap only to get reasonably good behaviour on all
platforms.}
\end{twocollist}


\wxheading{Window styles}

\twocolwidtha{5cm}
\begin{twocollist}\itemsep=0pt
\twocolitem{\windowstyle{wxBU\_AUTODRAW}}{If
this is specified, the button will be drawn automatically using the label bitmap only, providing
a 3D-look border. If this style is not specified, the button will be drawn without borders and using all
provided bitmaps. WIN32 only.}
\twocolitem{\windowstyle{wxBU\_LEFT}}{Left-justifies the bitmap label. WIN32 only.}
\twocolitem{\windowstyle{wxBU\_TOP}}{Aligns the bitmap label to the top of the button. WIN32 only.}
\twocolitem{\windowstyle{wxBU\_RIGHT}}{Right-justifies the bitmap label. WIN32 only.}
\twocolitem{\windowstyle{wxBU\_BOTTOM}}{Aligns the bitmap label to the bottom of the button. WIN32 only.}
\end{twocollist}

Note that \windowstyle{wxBU\_EXACTFIT} supported by 
\helpref{wxButton}{wxbutton} is \emph{not} used by this class as bitmap buttons
don't have any minimal standard size by default.

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{wxButton}{wxbutton}



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


\membersection{wxBitmapButton::wxBitmapButton}\label{wxbitmapbuttonctor}

\func{}{wxBitmapButton}{\void}

Default constructor.

\func{}{wxBitmapButton}{
\param{wxWindow* }{parent}, 
\param{wxWindowID }{id}, 
\param{const wxBitmap\& }{bitmap},\rtfsp
\param{const wxPoint\& }{pos = wxDefaultPosition}, 
\param{const wxSize\& }{size = wxDefaultSize},\rtfsp
\param{long }{style = wxBU\_AUTODRAW}, 
\param{const wxValidator\& }{validator = wxDefaultValidator}, 
\param{const wxString\& }{name = ``button"}}

Constructor, creating and showing a button.

\wxheading{Parameters}

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

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

\docparam{bitmap}{Bitmap to be displayed.}

\docparam{pos}{Button position.}

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

\docparam{style}{Window style. See \helpref{wxBitmapButton}{wxbitmapbutton}.}

\docparam{validator}{Window validator.}

\docparam{name}{Window name.}

\wxheading{Remarks}

The {\it bitmap} parameter is normally the only bitmap you need to provide, and wxWidgets will
draw the button correctly in its different states. If you want more control, call
any of the functions \helpref{wxBitmapButton::SetBitmapSelected}{wxbitmapbuttonsetbitmapselected},\rtfsp
\helpref{wxBitmapButton::SetBitmapFocus}{wxbitmapbuttonsetbitmapfocus},\rtfsp
\helpref{wxBitmapButton::SetBitmapDisabled}{wxbitmapbuttonsetbitmapdisabled}.

Note that the bitmap passed is smaller than the actual button created.

\wxheading{See also}

\helpref{wxBitmapButton::Create}{wxbitmapbuttoncreate}, \helpref{wxValidator}{wxvalidator}


\membersection{wxBitmapButton::\destruct{wxBitmapButton}}\label{wxbitmapbuttondtor}

\func{}{\destruct{wxBitmapButton}}{\void}

Destructor, destroying the button.


\membersection{wxBitmapButton::Create}\label{wxbitmapbuttoncreate}

\func{bool}{Create}{\param{wxWindow* }{parent}, \param{wxWindowID}{ id}, \param{const wxBitmap\& }{bitmap},\rtfsp
\param{const wxPoint\& }{pos}, \param{const wxSize\& }{size = wxDefaultSize},\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{wxBitmapButton::wxBitmapButton}{wxbitmapbuttonctor}.


\membersection{wxBitmapButton::GetBitmapDisabled}\label{wxbitmapbuttongetbitmapdisabled}

\constfunc{const wxBitmap\&}{GetBitmapDisabled}{\void}
\func{wxBitmap\&}{GetBitmapDisabled}{\void}

Returns the bitmap for the disabled state, may be invalid.

\wxheading{Return value}

A reference to the disabled state bitmap.

\wxheading{See also}

\helpref{wxBitmapButton::SetBitmapDisabled}{wxbitmapbuttonsetbitmapdisabled}


\membersection{wxBitmapButton::GetBitmapFocus}\label{wxbitmapbuttongetbitmapfocus}

\constfunc{const wxBitmap\&}{GetBitmapFocus}{\void}
\func{wxBitmap\&}{GetBitmapFocus}{\void}

Returns the bitmap for the focused state, may be invalid.

\wxheading{Return value}

A reference to the focused state bitmap.

\wxheading{See also}

\helpref{wxBitmapButton::SetBitmapFocus}{wxbitmapbuttonsetbitmapfocus}


\membersection{wxBitmapButton::GetBitmapHover}\label{wxbitmapbuttongetbitmaphover}

\constfunc{const wxBitmap\&}{GetBitmapHover}{\void}
\func{wxBitmap\&}{GetBitmapHover}{\void}

Returns the bitmap used when the mouse is over the button, may be invalid.

\wxheading{See also}

\helpref{wxBitmapButton::SetBitmapHover}{wxbitmapbuttonsetbitmaphover}


\membersection{wxBitmapButton::GetBitmapLabel}\label{wxbitmapbuttongetbitmaplabel}

\constfunc{const wxBitmap\&}{GetBitmapLabel}{\void}
\func{wxBitmap\&}{GetBitmapLabel}{\void}

Returns the label bitmap (the one passed to the constructor), always valid.

\wxheading{Return value}

A reference to the button's label bitmap.

\wxheading{See also}

\helpref{wxBitmapButton::SetBitmapLabel}{wxbitmapbuttonsetbitmaplabel}


\membersection{wxBitmapButton::GetBitmapSelected}\label{wxbitmapbuttongetbitmapselected}

\constfunc{wxBitmap\&}{GetBitmapSelected}{\void}

Returns the bitmap for the selected state.

\wxheading{Return value}

A reference to the selected state bitmap.

\wxheading{See also}

\helpref{wxBitmapButton::SetBitmapSelected}{wxbitmapbuttonsetbitmapselected}


\membersection{wxBitmapButton::SetBitmapDisabled}\label{wxbitmapbuttonsetbitmapdisabled}

\func{void}{SetBitmapDisabled}{\param{const wxBitmap\& }{bitmap}}

Sets the bitmap for the disabled button appearance.

\wxheading{Parameters}

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

\wxheading{See also}

\helpref{wxBitmapButton::GetBitmapDisabled}{wxbitmapbuttongetbitmapdisabled},\rtfsp
\helpref{wxBitmapButton::SetBitmapLabel}{wxbitmapbuttonsetbitmaplabel},\rtfsp
\helpref{wxBitmapButton::SetBitmapSelected}{wxbitmapbuttonsetbitmapselected},\rtfsp
\helpref{wxBitmapButton::SetBitmapFocus}{wxbitmapbuttonsetbitmapfocus}


\membersection{wxBitmapButton::SetBitmapFocus}\label{wxbitmapbuttonsetbitmapfocus}

\func{void}{SetBitmapFocus}{\param{const wxBitmap\& }{bitmap}}

Sets the bitmap for the button appearance when it has the keyboard focus.

\wxheading{Parameters}

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

\wxheading{See also}

\helpref{wxBitmapButton::GetBitmapFocus}{wxbitmapbuttongetbitmapfocus},\rtfsp
\helpref{wxBitmapButton::SetBitmapLabel}{wxbitmapbuttonsetbitmaplabel},\rtfsp
\helpref{wxBitmapButton::SetBitmapSelected}{wxbitmapbuttonsetbitmapselected},\rtfsp
\helpref{wxBitmapButton::SetBitmapDisabled}{wxbitmapbuttonsetbitmapdisabled}


\membersection{wxBitmapButton::SetBitmapHover}\label{wxbitmapbuttonsetbitmaphover}

\func{void}{SetBitmapHover}{\param{const wxBitmap\& }{bitmap}}

Sets the bitmap to be shown when the mouse is over the button.

\newsince{2.7.0} and the hover bitmap is currently only supported in wxMSW. 

\wxheading{See also}

\helpref{wxBitmapButton::GetBitmapHover}{wxbitmapbuttongetbitmaphover}

\membersection{wxBitmapButton::SetBitmapLabel}\label{wxbitmapbuttonsetbitmaplabel}

\func{void}{SetBitmapLabel}{\param{const wxBitmap\& }{bitmap}}

Sets the bitmap label for the button.

\wxheading{Parameters}

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

\wxheading{Remarks}

This is the bitmap used for the unselected state, and for all other states
if no other bitmaps are provided.

\wxheading{See also}

\helpref{wxBitmapButton::GetBitmapLabel}{wxbitmapbuttongetbitmaplabel}


\membersection{wxBitmapButton::SetBitmapSelected}\label{wxbitmapbuttonsetbitmapselected}

\func{void}{SetBitmapSelected}{\param{const wxBitmap\& }{bitmap}}

Sets the bitmap for the selected (depressed) button appearance.

\wxheading{Parameters}

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

\wxheading{See also}

\helpref{wxBitmapButton::GetBitmapSelected}{wxbitmapbuttongetbitmapselected},\rtfsp
\helpref{wxBitmapButton::SetBitmapLabel}{wxbitmapbuttonsetbitmaplabel},\rtfsp
\helpref{wxBitmapButton::SetBitmapFocus}{wxbitmapbuttonsetbitmapfocus},\rtfsp
\helpref{wxBitmapButton::SetBitmapDisabled}{wxbitmapbuttonsetbitmapdisabled}