Updated wxBitmap overview

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@18848 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
This commit is contained in:
Julian Smart
2003-01-21 08:58:30 +00:00
parent 63a76696df
commit e7b6ce1cf9

View File

@@ -18,18 +18,16 @@ version of the graphic which appears on the main window.
See \helpref{wxMemoryDC}{wxmemorydc} for an example of drawing onto a bitmap.
The following shows the conditional compilation required to load a
bitmap under Unix and in Windows. The alternative is to use the string
version of the bitmap constructor, which loads a file under Unix and a
resource or file under Windows, but has the disadvantage of requiring the
XPM icon file to be available at run-time.
All wxWindows platforms support XPMs for small bitmaps and icons.
You may include the XPM inline as below, since it's C code, or you
can load it at run-time.
\begin{verbatim}
#if defined(__WXGTK__) || defined(__WXMOTIF__)
#include "mondrian.xpm"
#endif
\end{verbatim}
Sometimes you wish to use a .ico resource on Windows, and XPMs on
other platforms (for example to take advantage of Windows' support for multiple icon resolutions).
A macro, \helpref{wxICON}{wxiconmacro}, is available which creates an icon using an XPM
on the appropriate platform, or an icon resource on Windows.
@@ -68,8 +66,9 @@ wxBitmap bmp(wxBITMAP(bmpname));
\end{verbatim}
You should always use wxICON and wxBITMAP macros because they work for any
platform (unlike the code above which doesn't deal with wxMac, wxBe, ...) and
are more short and clear than versions with {\tt \#ifdef}s.
platform (unlike the code above which doesn't deal with wxMac, wxX11, ...) and
are more short and clear than versions with {\tt \#ifdef}s. Even better,
use the same XPMs on all platforms.
\subsection{Supported bitmap file formats}\label{supportedbitmapformats}
@@ -101,7 +100,7 @@ Under wxGTK, wxBitmap may load the following formats:
\item All formats that are supported by the \helpref{wxImage}{wximage} class.
\end{itemize}
Under wxMotif, wxBitmap may load the following formats:
Under wxMotif and wxX11, wxBitmap may load the following formats:
\begin{itemize}\itemsep=0pt
\item XBM data and file (wxBITMAP\_TYPE\_XBM)
@@ -126,12 +125,12 @@ Under wxGTK, wxIcon may load the following formats:
\item All formats that are supported by the \helpref{wxImage}{wximage} class.
\end{itemize}
Under wxMotif, wxIcon may load the following formats:
Under wxMotif and wxX11, wxIcon may load the following formats:
\begin{itemize}\itemsep=0pt
\item XBM data and file (wxBITMAP\_TYPE\_XBM)
\item XPM data and file (wxBITMAP\_TYPE\_XPM)
\item All formats that are supported by the \helpref{wxImage}{wximage} class (?).
\item All formats that are supported by the \helpref{wxImage}{wximage} class.
\end{itemize}
\wxheading{wxCursor}
@@ -152,7 +151,7 @@ to stock cursors):
\item None (stock cursors only).
\end{itemize}
Under wxMotif, wxCursor may load the following formats:
Under wxMotif and wxX11, wxCursor may load the following formats:
\begin{itemize}\itemsep=0pt
\item XBM data and file (wxBITMAP\_TYPE\_XBM)
@@ -168,27 +167,8 @@ have special requirements, you may wish to initialise the wxBitmap class with
some extra handlers which you write yourself or receive from a third party.
To add a handler object to wxBitmap, your application needs to include the header which implements it, and
then call the static function \helpref{wxBitmap::AddHandler}{wxbitmapaddhandler}. For example:
then call the static function \helpref{wxBitmap::AddHandler}{wxbitmapaddhandler}.
{\small
\begin{verbatim}
#include <wx/xpmhand.h>
...
// Initialisation
wxBitmap::AddHandler(new wxXPMFileHandler);
wxBitmap::AddHandler(new wxXPMDataHandler);
...
\end{verbatim}
}
Assuming the handlers have been written correctly, you should now be able to load and save
XPM files using the usual wxBitmap API.
{\bf Note:} bitmap handlers are not implemented on all platforms. Currently, the above is only necessary on
Windows, to save the extra overhead of formats that may not be necessary (if you don't use them, they
are not linked into the executable). Unix platforms have XPM capability built-in (where supported).
Also, just because a handler (such as a PNG handler) is not present does not mean that
wxBitmap does not support that file format. If wxBitmap fails to find a suitable handler,
the file-loading capabilities of wxImage are used instead.
{\bf Note:} bitmap handlers are not implemented on all platforms, and new ones rarely need
to be implemented since wxImage can be used for loading most formats, as noted earlier.