The XML-based resource system, known as XRC, allows user interface elements such as
dialogs, menu bars and toolbars, to be stored in text files and loaded into
the application at run-time. XRC files can also be compiled into binary XRS files or C++
-code (the former makes it possible to store all resources in since file and the latter
+code (the former makes it possible to store all resources in a single file and the latter
is useful when you want to embed the resources into the executable).
There are several advantages to using XRC resources.
\begin{itemize}\itemsep=0pt
\item Recompiling and linking an application is not necessary if the
resources change.
-\item If you use a dialog designers that generates C++ code, it can be hard
+\item If you use a dialog designer that generates C++ code, it can be hard
to reintegrate this into existing C++ code. Separation of resources and code
is a more elegant solution.
\item You can choose between different alternative resource files at run time, if necessary.
\begin{itemize}\itemsep=0pt
\item Include the appropriate headers: normally "wx/xrc/xmlres.h" will suffice;
\item If you are going to use \helpref{XRS files}{binaryresourcefiles}, install
-wxFileSystem ZIP handler first with {\tt wxFileSystem::AddHandler(new wxZipFSHandler);}
+wxFileSystem archive handler first with {\tt wxFileSystem::AddHandler(new wxArchiveFSHandler);}
\item call {\tt wxXmlResource::Get()->InitAllHandlers()} from your wxApp::OnInit function,
and then call {\tt wxXmlResource::Get()->Load("myfile.xrc")} to load the resource file;
\item to create a dialog from a resource, create it using the default constructor, and then
-load using for example {\tt wxXmlResource::Get()->LoadDialog(\&dlg, this, "dlg1");}
+load it using for example {\tt wxXmlResource::Get()->LoadDialog(\&dlg, this, "dlg1");}
\item set up event tables as usual but use the {\tt XRCID(str)} macro to translate from XRC string names
to a suitable integer identifier, for example {\tt EVT\_MENU(XRCID("quit"), MyFrame::OnQuit)}.
\end{itemize}
\item use \urlref{XRCed}{http://xrced.sf.net}, a wxPython-based
dialog editor that you can find in the {\tt wxPython/tools} subdirectory of the wxWidgets
CVS archive;
-\item use \urlref{Glade}{http://wxglade.sf.net}, a GUI designer written in wxPython. At the moment it can generate Python, C++ and XRC;
+\item use \urlref{wxGlade}{http://wxglade.sf.net}, a GUI designer written in wxPython. At the moment it can generate Python, C++ and XRC;
\item convert WIN32 RC files to XRC with the tool in {\tt contrib/utils/convertrc}.
\end{itemize}
-A complete list of third-party tools that write to XRC can be found at \urlref{www.wxwidgets.org/lnk\_tool.htm}{http://www.wxwidgets.org/lnk\_tool.in}.
+A complete list of third-party tools that write to XRC can be found at \urlref{www.wxwidgets.org/lnk\_tool.htm}{http://www.wxwidgets.org/lnk\_tool.htm}.
It is highly recommended that you use a resource editing tool, since it's fiddly writing
XRC files by hand.
\item -e (--extra-cpp-code): if used together with -c, generates C++ header file
containing class definitions for the windows defined by the XRC file (see special subsection)
\item -u (--uncompressed): do not compress XML files (C++ only)
-\item -g (--gettext): output .po catalog (to stdout, or a file if -o is used)
+\item -g (--gettext): output underscore-wrapped strings that poEdit or gettext can scan. Outputs to stdout, or a file if -o is used
\item -n (--function) <name>: specify C++ function name (use with -c)
\item -o (--output) <filename>: specify the output file, such as resource.xrs or resource.cpp
\item -l (--list-of-handlers) <filename>: output a list of necessary handlers to this file
XRS file is essentially a renamed ZIP archive which means that you can manipulate
it with standard ZIP tools. Note that if you are using XRS files, you have
-to initialize \helpref{wxFileSystem}{wxfilesystem} ZIP handler first! It is a simple
+to initialize the \helpref{wxFileSystem}{wxfilesystem} archive handler first! It is a simple
thing to do:
\begin{verbatim}
#include <wx/filesys.h>
- #include <wx/fs_zip.h>
+ #include <wx/fs_arc.h>
...
- wxFileSystem::AddHandler(new wxZipFSHandler);
+ wxFileSystem::AddHandler(new wxArchiveFSHandler);
\end{verbatim}
\subsection{Using embedded resources}\label{embeddedresource}
It is sometimes useful to embed resources in the executable itself instead
-of loading external file (e.g. when your app is small and consists only of one
+of loading an external file (e.g. when your app is small and consists only of one
exe file). XRC provides means to convert resources into regular C++ file that
can be compiled and included in the executable.
The generated window class can be used as basis for the full window class. The
class members which represent widgets may be accessed by name instead of using
{\tt XRCCTRL} every time you wish to reference them (note that they are {\tt protected} class members),
-though you must still use {\tt XRCID} to refer to widget ids in the event
+though you must still use {\tt XRCID} to refer to widget IDs in the event
table.
Example:
\end{verbatim}
+
+
\subsection{Adding new resource handlers}\label{newresourcehandlers}
-Coming soon.
+Adding a new resource handler is pretty easy.
+Typically, to add an handler for the {\tt MyControl} class, you'll want to create
+the {\tt xh\_mycontrol.h} {\tt xh\_mycontrol.cpp} files.
+
+The header needs to contains the {\tt MyControlXmlHandler} class definition:
+
+\begin{verbatim}
+class MyControlXmlHandler : public wxXmlResourceHandler
+{
+public:
+
+ // Constructor.
+ MyControlXmlHandler();
+
+ // Creates the control and returns a pointer to it.
+ virtual wxObject *DoCreateResource();
+
+ // Returns true if we know how to create a control for the given node.
+ virtual bool CanHandle(wxXmlNode *node);
+
+ // Register with wxWidgets' dynamic class subsystem.
+ DECLARE_DYNAMIC_CLASS(MyControlXmlHandler)
+};
+\end{verbatim}
+
+The implementation of your custom XML handler will typically look as:
+
+\begin{verbatim}
+// Register with wxWidgets' dynamic class subsystem.
+IMPLEMENT_DYNAMIC_CLASS(MyControlXmlHandler, wxXmlResourceHandler)
+
+MyControlXmlHandler::MyControlXmlHandler()
+{
+ // this call adds support for all wxWindows class styles
+ // (e.g. wxSIMPLE_BORDER, wxSUNKEN_BORDER, wxWS_EX_* etc etc)
+ AddWindowStyles();
+
+ // if MyControl class supports e.g. MYCONTROL_DEFAULT_STYLE
+ // you should use:
+ // XRC_ADD_STYLE(MYCONTROL_DEFAULT_STYLE);
+}
+
+wxObject *MyControlXmlHandler::DoCreateResource()
+{
+ // the following macro will init a pointer named "control"
+ // with a new instance of the MyControl class, but will NOT
+ // Create() it!
+ XRC_MAKE_INSTANCE(control, MyControl)
+
+ // this is the point where you'll typically need to do the most
+ // important changes: here the control is created and initialized.
+ // You'll want to use the wxXmlResourceHandler's getters to
+ // do most of your work.
+ // If e.g. the MyControl::Create function looks like:
+ //
+ // bool MyControl::Create(wxWindow *parent, int id,
+ // const wxBitmap &first, const wxPoint &posFirst,
+ // const wxBitmap &second, const wxPoint &posSecond,
+ // const wxString &theTitle, const wxFont &titleFont,
+ // const wxPoint &pos, const wxSize &size,
+ // long style = MYCONTROL_DEFAULT_STYLE,
+ // const wxString &name = wxT("MyControl"));
+ //
+ // then the XRC for your component should look like:
+ //
+ // <object class="MyControl" name="some_name">
+ // <first-bitmap>first.xpm</first-bitmap>
+ // <second-bitmap>text.xpm</second-bitmap>
+ // <first-pos>3,3</first-pos>
+ // <second-pos>4,4</second-pos>
+ // <the-title>a title</the-title>
+ // <title-font>
+ // <!-- the standard XRC tags for describing a font: <size>, <style>, <weight>, etc -->
+ // </title-font>
+ // <!-- XRC also accepts other usual tags for wxWindow-derived classes:
+ // like e.g. <name>, <style>, <size>, <position>, etc -->
+ // </object>
+ //
+ // and the code to read your custom tags from the XRC file is just:
+ control->Create(m_parentAsWindow, GetID(),
+ GetBitmap(wxT("first-bitmap")),
+ GetPosition(wxT("first-pos")),
+ GetBitmap(wxT("second-bitmap")),
+ GetPosition(wxT("second-pos")),
+ GetText(wxT("the-title")),
+ GetFont(wxT("title-font")),
+ GetPosition(), GetSize(), GetStyle(), GetName());
+
+ SetupWindow(control);
+
+ return control;
+}
+
+bool MyControlXmlHandler::CanHandle(wxXmlNode *node)
+{
+ // this function tells XRC system that this handler can parse
+ // the <object class="MyControl"> tags
+ return IsOfClass(node, wxT("MyControl"));
+}
+\end{verbatim}
+
+You may want to check the \helpref{wxXmlResourceHandler}{wxxmlresourcehandler} documentation
+to see how many built-in getters it contains. It's very easy to retrieve also complex structures
+out of XRC files using them.
projects / wxWidgets.git / blobdiff