X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/36c9828f702fb504b07968703bcd82f04196070a..4e15d1caa03346c126015019c1fdf093033ef40b:/docs/doxygen/overviews/xrc.h diff --git a/docs/doxygen/overviews/xrc.h b/docs/doxygen/overviews/xrc.h index 2cfddd9936..31ea4378da 100644 --- a/docs/doxygen/overviews/xrc.h +++ b/docs/doxygen/overviews/xrc.h @@ -1,646 +1,540 @@ ///////////////////////////////////////////////////////////////////////////// -// Name: xrc +// Name: xrc.h // Purpose: topic overview // Author: wxWidgets team // RCS-ID: $Id$ -// Licence: wxWindows license +// Licence: wxWindows licence ///////////////////////////////////////////////////////////////////////////// -/*! - - @page xrc_overview XML-based resource system overview - - Classes: #wxXmlResource, #wxXmlResourceHandler - 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 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. - - - Recompiling and linking an application is not necessary if the - resources change. - 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. - You can choose between different alternative resource files at run time, if necessary. - The XRC format uses sizers for flexibility, allowing dialogs to be resizable - and highly portable. - The XRC format is a wxWidgets standard, - and can be generated or postprocessed by any program that understands it. As it is based - on the XML standard, existing XML editors can be used for simple editing purposes. - - - XRC was written by Vaclav Slavik. - @ref xrcconcepts_overview - @ref binaryresourcefiles_overview - @ref embeddedresource_overview - @ref xrccppsample_overview - @ref xrcsample_overview - @ref xrcfileformat_overview - @ref xrccppheader_overview - @ref newresourcehandlers_overview - - - @section xrcconcepts XRC concepts - - These are the typical steps for using XRC files in your application. - - - Include the appropriate headers: normally "wx/xrc/xmlres.h" will suffice; - If you are going to use @ref binaryresourcefiles_overview, install - wxFileSystem archive handler first with @c wxFileSystem::AddHandler(new wxArchiveFSHandler); - call @c wxXmlResource::Get()-InitAllHandlers() from your wxApp::OnInit function, - and then call @c wxXmlResource::Get()-Load("myfile.xrc") to load the resource file; - to create a dialog from a resource, create it using the default constructor, and then - load it using for example @c wxXmlResource::Get()-LoadDialog(dlg, this, "dlg1"); - set up event tables as usual but use the @c XRCID(str) macro to translate from XRC string names - to a suitable integer identifier, for example @c EVT_MENU(XRCID("quit"), MyFrame::OnQuit). - - - To create an XRC file, you can use one of the following methods. - - - Create the file by hand; - use #wxDesigner, a commercial dialog designer/RAD tool; - use #DialogBlocks, a commercial dialog editor; - use #XRCed, a wxPython-based - dialog editor that you can find in the @c wxPython/tools subdirectory of the wxWidgets - CVS archive; - use #wxGlade, a GUI designer written in wxPython. At the moment it can generate Python, C++ and XRC; - - - A complete list of third-party tools that write to XRC can be found at #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. - You can use wxXmlResource::Load in a number of ways. - You can pass an XRC file (XML-based text resource file) - or a @ref binaryresourcefiles_overview (extension ZIP or XRS) containing other XRC. - You can also use @ref embeddedresource_overview - - @section binaryresourcefiles Using binary resource files - - To compile binary resource files, use the command-line wxrc utility. It takes one or more file parameters - (the input XRC files) and the following switches and options: - - - -h (--help): show a help message - -v (--verbose): show verbose logging information - -c (--cpp-code): write C++ source rather than a XRS file - -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) - -u (--uncompressed): do not compress XML files (C++ only) - -g (--gettext): output underscore-wrapped strings that poEdit or gettext can scan. Outputs to stdout, or a file if -o is used - -n (--function) name: specify C++ function name (use with -c) - -o (--output) filename: specify the output file, such as resource.xrs or resource.cpp - -l (--list-of-handlers) filename: output a list of necessary handlers to this file - - - For example: - - @code - % wxrc resource.xrc - % wxrc resource.xrc -o resource.xrs - % wxrc resource.xrc -v -c -o resource.cpp - @endcode - - @b Note - 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 the #wxFileSystem archive handler first! It is a simple - thing to do: - - @code - #include wx/filesys.h - #include wx/fs_arc.h - ... - wxFileSystem::AddHandler(new wxArchiveFSHandler); - @endcode - - - @section embeddedresource Using embedded resources - - It is sometimes useful to embed resources in the executable itself instead - 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. - Use the @c -c switch to - @c wxrc utility to produce C++ file with embedded resources. This file will - contain a function called @e InitXmlResource (unless you override this with - a command line switch). Use it to load the resource: - - @code - extern void InitXmlResource(); // defined in generated file - ... - wxXmlResource::Get()-InitAllHandlers(); - InitXmlResource(); - ... - @endcode - - - @section xrccppsample XRC C++ sample - - This is the C++ source file (xrcdemo.cpp) for the XRC sample. - - @code - #include "wx/wx.h" - #include "wx/image.h" - #include "wx/xrc/xmlres.h" - - // the application icon - #if defined(__WXGTK__) || defined(__WXMOTIF__) || defined(__WXMAC__) - #include "rc/appicon.xpm" - #endif - - // ---------------------------------------------------------------------------- - // private classes - // ---------------------------------------------------------------------------- - - // Define a new application type, each program should derive a class from wxApp - class MyApp : public wxApp - { - public: - // override base class virtuals - // ---------------------------- - - // this one is called on application startup and is a good place for the app - // initialization (doing it here and not in the ctor allows to have an error - // return: if OnInit() returns @false, the application terminates) - virtual bool OnInit(); - }; - - // Define a new frame type: this is going to be our main frame - class MyFrame : public wxFrame - { - public: - // ctor(s) - MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size); - - // event handlers (these functions should _not_ be virtual) - void OnQuit(wxCommandEvent& event); - void OnAbout(wxCommandEvent& event); - void OnDlg1(wxCommandEvent& event); - void OnDlg2(wxCommandEvent& event); - - private: - // any class wishing to process wxWidgets events must use this macro - DECLARE_EVENT_TABLE() - }; - - // ---------------------------------------------------------------------------- - // event tables and other macros for wxWidgets - // ---------------------------------------------------------------------------- - - BEGIN_EVENT_TABLE(MyFrame, wxFrame) - EVT_MENU(XRCID("menu_quit"), MyFrame::OnQuit) - EVT_MENU(XRCID("menu_about"), MyFrame::OnAbout) - EVT_MENU(XRCID("menu_dlg1"), MyFrame::OnDlg1) - EVT_MENU(XRCID("menu_dlg2"), MyFrame::OnDlg2) - END_EVENT_TABLE() - - IMPLEMENT_APP(MyApp) - - // ---------------------------------------------------------------------------- - // the application class - // ---------------------------------------------------------------------------- - - // 'Main program' equivalent: the program execution "starts" here - bool MyApp::OnInit() - { - wxImage::AddHandler(new wxGIFHandler); - wxXmlResource::Get()-InitAllHandlers(); - wxXmlResource::Get()-Load("rc/resource.xrc"); - - MyFrame *frame = new MyFrame("XML resources demo", - wxPoint(50, 50), wxSize(450, 340)); - frame-Show(@true); - return @true; - } - - // ---------------------------------------------------------------------------- - // main frame - // ---------------------------------------------------------------------------- - - // frame constructor - MyFrame::MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size) - : wxFrame((wxFrame *)@NULL, -1, title, pos, size) - { - SetIcon(wxICON(appicon)); - - SetMenuBar(wxXmlResource::Get()-LoadMenuBar("mainmenu")); - SetToolBar(wxXmlResource::Get()-LoadToolBar(this, "toolbar")); - } - - // event handlers - void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event)) - { - // @true is to force the frame to close - Close(@true); - } - - void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event)) - { - wxString msg; - msg.Printf( _T("This is the about dialog of XML resources demo.\n") - _T("Welcome to %s"), wxVERSION_STRING); - - wxMessageBox(msg, "About XML resources demo", wxOK | wxICON_INFORMATION, this); - } - - void MyFrame::OnDlg1(wxCommandEvent& WXUNUSED(event)) - { - wxDialog dlg; - wxXmlResource::Get()-LoadDialog(, this, "dlg1"); - dlg.ShowModal(); - } - - void MyFrame::OnDlg2(wxCommandEvent& WXUNUSED(event)) - { - wxDialog dlg; - wxXmlResource::Get()-LoadDialog(, this, "dlg2"); - dlg.ShowModal(); - } - @endcode - - - @section xrcsample XRC resource file sample - - This is the XML file (resource.xrc) for the XRC sample. - - @code - ?xml version="1.0"? - resource version="2.3.0.1" - object class="wxMenuBar" name="mainmenu" - stylewxMB_DOCKABLE/style - object class="wxMenu" name="menu_file" - label_File/label - stylewxMENU_TEAROFF/style - object class="wxMenuItem" name="menu_about" - label_About.../label - bitmapfilesave.gif/bitmap - /object - object class="separator"/ - object class="wxMenuItem" name="menu_dlg1" - labelDialog 1/label - /object - object class="wxMenuItem" name="menu_dlg2" - labelDialog 2/label - /object - object class="separator"/ - object class="wxMenuItem" name="menu_quit" - labelE_xit\tAlt-X/label - /object - /object - /object - object class="wxToolBar" name="toolbar" - stylewxTB_FLAT|wxTB_DOCKABLE/style - margins2,2/margins - object class="tool" name="menu_open" - bitmapfileopen.gif/bitmap - tooltipOpen catalog/tooltip - /object - object class="tool" name="menu_save" - bitmapfilesave.gif/bitmap - tooltipSave catalog/tooltip - /object - object class="tool" name="menu_update" - bitmapupdate.gif/bitmap - tooltipUpdate catalog - synchronize it with sources/tooltip - /object - separator/ - object class="tool" name="menu_quotes" - bitmapquotes.gif/bitmap - toggle1/toggle - tooltipDisplay quotes around the string?/tooltip - /object - object class="separator"/ - object class="tool" name="menu_fuzzy" - bitmapfuzzy.gif/bitmap - tooltipToggled if selected string is fuzzy translation/tooltip - toggle1/toggle - /object - /object - object class="wxDialog" name="dlg1" - object class="wxBoxSizer" - object class="sizeritem" - object class="wxBitmapButton" - bitmapfuzzy.gif/bitmap - focusfileopen.gif/focus - /object - /object - object class="sizeritem" - object class="wxPanel" - object class="wxStaticText" - labelfdgdfgdfgdfg/label - /object - stylewxBORDER\_SUNKEN/style - /object - flagwxALIGN_CENTER/flag - /object - object class="sizeritem" - object class="wxButton" - labelButtonek/label - /object - border10d/border - flagwxALL/flag - /object - object class="sizeritem" - object class="wxHtmlWindow" - htmlcodeh1Hi,/h1man/htmlcode - size100,45d/size - /object - /object - object class="sizeritem" - object class="wxNotebook" - object class="notebookpage" - object class="wxPanel" - object class="wxBoxSizer" - object class="sizeritem" - object class="wxHtmlWindow" - htmlcodeHello, we are inside a uNOTEBOOK/u.../htmlcode - size50,50d/size - /object - option1/option - /object - /object - /object - labelPage/label - /object - object class="notebookpage" - object class="wxPanel" - object class="wxBoxSizer" - object class="sizeritem" - object class="wxHtmlWindow" - htmlcodeHello, we are inside a uNOTEBOOK/u.../htmlcode - size50,50d/size - /object - /object - /object - /object - labelPage 2/label - /object - usenotebooksizer1/usenotebooksizer - /object - flagwxEXPAND/flag - /object - orientwxVERTICAL/orient - /object - /object - object class="wxDialog" name="dlg2" - object class="wxBoxSizer" - orientwxVERTICAL/orient - object class="sizeritem" name="dfgdfg" - object class="wxTextCtrl" - size200,200d/size - stylewxTE_MULTILINE|wxBORDER_SUNKEN/style - valueHello, this is an ordinary multiline\n textctrl..../value - /object - option1/option - flagwxEXPAND|wxALL/flag - border10/border - /object - object class="sizeritem" - object class="wxBoxSizer" - object class="sizeritem" - object class="wxButton" name="wxID_OK" - labelOk/label - default1/default - /object - /object - object class="sizeritem" - object class="wxButton" name="wxID_CANCEL" - labelCancel/label - /object - border10/border - flagwxLEFT/flag - /object - /object - flagwxLEFT|wxRIGHT|wxBOTTOM|wxALIGN_RIGHT/flag - border10/border - /object - /object - titleSecond testing dialog/title - /object - /resource - @endcode - - - @section xrcfileformat XRC file format - - Please see Technical Note 14 (docs/tech/tn0014.txt) in your wxWidgets - distribution. - - @section xrccppheader C++ header file generation - - Using the @c -e switch together with @c -c, a C++ header file is written - containing class definitions for the GUI windows defined in the XRC file. - This code generation can make it easier to use XRC and automate program - development. - The classes can be used as basis for development, freeing the - programmer from dealing with most of the XRC specifics (e.g. @c XRCCTRL). - For each top level window defined in the XRC file a C++ class definition is - generated, containing as class members the named widgets of the window. - A default constructor for each class is also generated. Inside the constructor - all XRC loading is done and all class members representing widgets are initialized. - A simple example will help understand how the scheme works. Suppose you have - a XRC file defining a top level window @c TestWnd_Base, which subclasses @c wxFrame (any - other class like @c wxDialog will do also), and has subwidgets @c wxTextCtrl A and @c wxButton B. - The XRC file and corresponding class definition in the header file will be something like: - - @code - ?xml version="1.0"? - resource version="2.3.0.1" - object class="wxFrame" name="TestWnd_Base" - size-1,-1/size - titleTest/title - object class="wxBoxSizer" - orientwxHORIZONTAL/orient - object class="sizeritem" - object class="wxTextCtrl" name="A" - labelTest label/label - /object - /object - object class="sizeritem" - object class="wxButton" name="B" - labelTest button/label - /object - /object - /object - /object - /resource - - - class TestWnd_Base : public wxFrame { - protected: - wxTextCtrl* A; - wxButton* B; - - private: - void InitWidgetsFromXRC(){ - wxXmlResource::Get()-LoadObject(this,@NULL,"TestWnd","wxFrame"); - A = XRCCTRL(*this,"A",wxTextCtrl); - B = XRCCTRL(*this,"B",wxButton); - } - public: - TestWnd::TestWnd(){ - InitWidgetsFromXRC(); - } - }; - @endcode - - 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 - @c XRCCTRL every time you wish to reference them (note that they are @c protected class members), - though you must still use @c XRCID to refer to widget IDs in the event - table. - Example: - - @code - #include "resource.h" - - class TestWnd : public TestWnd_Base { - public: - TestWnd(){ - // A, B already initialised at this point - A-SetValue("Updated in TestWnd::TestWnd"); - B-SetValue("Nice :)"); - } - void OnBPressed(wxEvent& event){ - Close(); - } - DECLARE_EVENT_TABLE(); - }; - - BEGIN_EVENT_TABLE(TestWnd,TestWnd_Base) - EVT_BUTTON(XRCID("B"),TestWnd::OnBPressed) - END_EVENT_TABLE() - @endcode - - It is also possible to access the wxSizerItem of a sizer that is part of - a resource. This can be done using @c XRCSIZERITEM as shown. The - resource file can have something like this for a sizer item. - - @code - object class="spacer" name="area" - size400, 300/size - /object - @endcode - - The code can then access the sizer item by using @c XRCSIZERITEM and - @c XRCID together. - - @code - wxSizerItem* item = XRCSIZERITEM(*this, "area"); - @endcode - - - @section newresourcehandlers Adding new resource handlers - - Adding a new resource handler is pretty easy. - Typically, to add an handler for the @c MyControl class, you'll want to create - the @c xh_mycontrol.h @c xh_mycontrol.cpp files. - The header needs to contains the @c MyControlXmlHandler class definition: - - @code - 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) - }; - @endcode - - The implementation of your custom XML handler will typically look as: - - @code - // Register with wxWidgets' dynamic class subsystem. - IMPLEMENT_DYNAMIC_CLASS(MyControlXmlHandler, wxXmlResourceHandler) - - MyControlXmlHandler::MyControlXmlHandler() - { - // this call adds support for all wxWindows class styles - // (e.g. wxBORDER_SIMPLE, wxBORDER_SUNKEN, 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 , const wxPoint , - // const wxBitmap , const wxPoint , - // const wxString , const wxFont , - // const wxPoint , const wxSize , - // long style = MYCONTROL_DEFAULT_STYLE, - // const wxString = wxT("MyControl")); - // - // then the XRC for your component should look like: - // - // object class="MyControl" name="some_name" - // first-bitmapfirst.xpm/first-bitmap - // second-bitmaptext.xpm/second-bitmap - // first-pos3,3/first-pos - // second-pos4,4/second-pos - // the-titlea 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")); - } - @endcode - - You may want to check the #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. - - */ - - +/** + +@page overview_xrc XML Based Resource System (XRC) + +@tableofcontents + +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 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: + +@li Recompiling and linking an application is not necessary if the resources + change. +@li 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. +@li You can choose between different alternative resource files at run time, if + necessary. +@li The XRC format uses sizers for flexibility, allowing dialogs to be + resizable and highly portable. +@li The XRC format is a wxWidgets standard, and can be generated or + postprocessed by any program that understands it. As it is based on the XML + standard, existing XML editors can be used for simple editing purposes. + +XRC was written by Vaclav Slavik. + +@see wxXmlResource, wxXmlResourceHandler, @ref overview_xrcformat + + + +@section overview_xrc_gettingstarted Getting Started with XRC + + Creating an XRC file + +You will need to write an XRC file. Though this @e can be done by hand in a +text editor, for all but the smallest files it is advisable to use a +specialised tool. Examples of these include: + +@e Non-free: +@li wxDesigner , a commercial dialog + designer/RAD tool. +@li DialogBlocks , a commercial + dialog editor. + +@e Free: +@li XRCed , a wxPython-based dialog editor that you + can find in the wxPython/tools subdirectory of the wxWidgets SVN archive. +@li wxFormBuilder , a C++-based dialog editor that + can output C++, XRC or python. + +There's a more complete list at + +This small demonstration XRC file contains a simple dialog: +@code + + + + Simple dialog + + wxVERTICAL + + + + wxALL|wxEXPAND + 10 + + + + + + + + wxRIGHT + 10 + + + + + + wxLEFT + 10 + + wxHORIZONTAL + + wxALL|wxALIGN_CENTRE + 10 + + + + +@endcode + +You can keep all your XRC elements together in one file, or split them between +several. + + Loading XRC files + +Before you can use XRC in an app, it must first be loaded. This code fragment +shows how to load a single XRC file "resource.xrc" from the current working +directory, plus all the *.xrc files contained in the subdirectory "rc". + +@code +#include "wx/xrc/xmlres.h" + +bool MyApp::OnInit() +{ + ... + wxXmlResource::Get()->InitAllHandlers(); + + wxXmlResource::Get()->Load("resource.xrc"); + wxXmlResource::Get()->LoadAllFiles("rc"); + ... +} +@endcode + +It's normal to load any XRC files at the beginning of an app. Though it is +possible to unload a file later, it's seldom necessary. + + + Using an XRC item + +The XRC file(s) are now loaded into the app's virtual filesystem. From there, +you must do another sort of load when you want to use an individual object. +Yes, it's confusingly named, but you first Load() the file, and later load each +top-level object when its needed. + +This is how you would use the above simple dialog in your code. + +@code +void MyClass::ShowDialog() +{ + wxDialog dlg; + if (wxXmlResource::Get()->LoadDialog(&dlg, NULL, "SimpleDialog")) + dlg.ShowModal(); +} +@endcode + +See how simple the code is. All the instantiation is done invisibly by the XRC +system. + +Though you'll most often use wxXmlResource::LoadDialog, there are also +equivalents that load a frame, a menu etc; and the generic +wxXmlResource::LoadObject. See wxXmlResource for more details. + + Accessing XRC child controls + +The last section showed how to load top-level windows like dialogs, but what +about child windows like the wxTextCtrl named "text" that the dialog contains? +You can't 'load' an individual child control in the same way. Instead you use +the XRCCTRL macro to get a pointer to the child. To expand the previous code: + +@code +void MyClass::ShowDialog() +{ + wxDialog dlg; + if (!wxXmlResource::Get()->LoadDialog(&dlg, NULL, "SimpleDialog")) + return; + + wxTextCtrl* pText = XRCCTRL(dlg, "text", wxTextCtrl); + if (pText) + pText->ChangeValue("This is a simple dialog"); + + dlg.ShowModal(); +} +@endcode + +XRCCTRL takes a reference to the parent container and uses wxWindow::FindWindow +to search inside it for a wxWindow with the supplied name (here "text"). It +returns a pointer to that control, cast to the type in the third parameter; so +a similar effect could be obtained by writing: + +@code +pText = (wxTextCtrl*)(dlg.FindWindowByName("text")); +@endcode + + XRC and IDs + +The ID of a control is often needed, e.g. for use in an event table +or with wxEvtHandler::Bind. It can easily be found by passing the name of the +control to the XRCID macro: + +@code +void MyClass::ShowDialog() +{ + wxDialog dlg; + if (!wxXmlResource::Get()->LoadDialog(&dlg, NULL, "SimpleDialog")) + return; + + XRCCTRL(dlg, "text", wxTextCtrl)->Bind(wxEVT_COMMAND_TEXT_UPDATED, + wxTextEventHandler(MyClass::OnTextEntered), this, XRCID("text")); + + XRCCTRL(dlg, "clickme_btn", wxButton)->Bind(wxEVT_COMMAND_BUTTON_CLICKED, + wxCommandEventHandler(MyClass::OnClickme), this, XRCID("clickme_btn")); + + dlg.ShowModal(); +} +@endcode + +A few points to note: +@li The value of the int returned by XRCID("foo") is guaranteed to be unique +within an app. +@li However that value isn't predictable, and you shouldn't rely on it being +consistent between runs. It certainly won't be the same in different apps. +@li @ref page_stockitems such as wxID_OK work correctly without requiring XRCID +(because, internally, XRCID("wxID_OK") is mapped to wxID_OK). +@li Both XRCID and XRCCTRL use the 'name' of the control (as in +wxWindow::GetName). This is different from the label that the user sees on +e.g. a wxButton. + + Subclassing in XRC + +You will often want to use subclassed wx controls in your code. There are three +ways to do this from XRC: +@li Very rarely you might need to +@ref overview_xrcformat_extending_custom "create your own wxXmlResourceHandler" +@li Occasionally wxXmlResource::AttachUnknownControl may be best. See +@ref overview_xrcformat_extending_unknown +@li Usually though, the simple 'subclass' keyword will suffice. + +Suppose you wanted the wxTextCtrl named "text" to be created as your derived +class MyTextCtrl. The only change needed in the XRC file would be in this line: + +@code + +@endcode + +The only change in your code would be to use MyTextCtrl in XRCCTRL. However for +the subclass to be created successfully, it's important to ensure that it uses +wxWidget's RTTI mechanism: see @ref overview_xrcformat_extending_subclass for +the details. + + + +@section overview_xrc_xrcsample The XRC sample + +A major resource for learning how to use XRC is the @sample{xrc}. This +demonstrates all of the standard uses of XRC, and some of the less common ones. +It is strongly suggested that you run it, and look at the well-commented +source code to see how it works. + + +@section overview_xrc_binaryresourcefiles Binary Resource Files + +To compile binary resource files, use the command-line @c wxrc utility. It +takes one or more file parameters (the input XRC files) and the following +switches and options: + +@li -h (--help): Show a help message. +@li -v (--verbose): Show verbose logging information. +@li -c (--cpp-code): Write C++ source rather than a XRS file. +@li -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). +@li -u (--uncompressed): Do not compress XML files (C++ only). +@li -g (--gettext): Output underscore-wrapped strings that poEdit or gettext + can scan. Outputs to stdout, or a file if -o is used. +@li -n (--function) @: Specify C++ function name (use with -c). +@li -o (--output) @: Specify the output file, such as resource.xrs + or resource.cpp. +@li -l (--list-of-handlers) @: Output a list of necessary handlers + to this file. + +For example: + +@code +$ wxrc resource.xrc +$ wxrc resource.xrc -o resource.xrs +$ wxrc resource.xrc -v -c -o resource.cpp +@endcode + +@note 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 the wxFileSystem archive handler first! It is a simple +thing to do: + +@code +#include +#include +... +wxFileSystem::AddHandler(new wxArchiveFSHandler); +@endcode + + +@section overview_xrc_embeddedresource Using Embedded Resources + +It is sometimes useful to embed resources in the executable itself instead 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. + +Use the @c -c switch to @c wxrc utility to produce C++ file with embedded +resources. This file will contain a function called @c InitXmlResource (unless +you override this with a command line switch). Use it to load the resource: + +@code +extern void InitXmlResource(); // defined in generated file +... +wxXmlResource::Get()->InitAllHandlers(); +InitXmlResource(); +... +@endcode + + +@section overview_xrc_cppheader C++ header file generation + +Using the @c -e switch together with @c -c, a C++ header file is written +containing class definitions for the GUI windows defined in the XRC file. This +code generation can make it easier to use XRC and automate program development. +The classes can be used as basis for development, freeing the programmer from +dealing with most of the XRC specifics (e.g. @c XRCCTRL). + +For each top level window defined in the XRC file a C++ class definition is +generated, containing as class members the named widgets of the window. A +default constructor for each class is also generated. Inside the constructor +all XRC loading is done and all class members representing widgets are +initialized. + +A simple example will help understand how the scheme works. Suppose you have a +XRC file defining a top level window @c TestWnd_Base, which subclasses wxFrame +(any other class like @c wxDialog will do also), and has subwidgets wxTextCtrl A +and wxButton B. + +The XRC file and corresponding class definition in the header file will be +something like: + +@code + + + + -1,-1 + Test + + wxHORIZONTAL + + + + + + + + + + + + + + + +class TestWnd_Base : public wxFrame +{ +protected: + wxTextCtrl* A; + wxButton* B; + +private: + void InitWidgetsFromXRC() + { + wxXmlResource::Get()->LoadObject(this, NULL, "TestWnd", "wxFrame"); + A = XRCCTRL(*this, "A", wxTextCtrl); + B = XRCCTRL(*this, "B", wxButton); + } +public: + TestWnd::TestWnd() + { + InitWidgetsFromXRC(); + } +}; +@endcode + +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 +@c XRCCTRL every time you wish to reference them (note that they are +@c protected class members), though you must still use @c XRCID to refer to +widget IDs in the event table. + +Example: + +@code +#include "resource.h" + +class TestWnd : public TestWnd_Base +{ +public: + TestWnd() + { + // A, B already initialised at this point + A->SetValue("Updated in TestWnd::TestWnd"); + B->SetValue("Nice :)"); + } + void OnBPressed(wxEvent& event) + { + Close(); + } + DECLARE_EVENT_TABLE(); +}; + +BEGIN_EVENT_TABLE(TestWnd,TestWnd_Base) + EVT_BUTTON(XRCID("B"), TestWnd::OnBPressed) +END_EVENT_TABLE() +@endcode + +It is also possible to access the wxSizerItem of a sizer that is part of a +resource. This can be done using @c XRCSIZERITEM as shown. + +The resource file can have something like this for a sizer item. + +@code + + 400, 300 + +@endcode + +The code can then access the sizer item by using @c XRCSIZERITEM and @c XRCID +together. + +@code +wxSizerItem* item = XRCSIZERITEM(*this, "area"); +@endcode + + +@section overview_xrc_newresourcehandlers Adding New Resource Handlers + +Adding a new resource handler is pretty easy. + +Typically, to add an handler for the @c MyControl class, you'll want to create +the @c xh_mycontrol.h and @c xh_mycontrol.cpp files. + +The header needs to contains the @c MyControlXmlHandler class definition: + +@code +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) +}; +@endcode + +The implementation of your custom XML handler will typically look as: + +@code +// Register with wxWidgets' dynamic class subsystem. +IMPLEMENT_DYNAMIC_CLASS(MyControlXmlHandler, wxXmlResourceHandler) + +MyControlXmlHandler::MyControlXmlHandler() +{ + // this call adds support for all wxWindows class styles + // (e.g. wxBORDER_SIMPLE, wxBORDER_SUNKEN, 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: + // + // + // first.xpm + // text.xpm + // 3,3 + // 4,4 + // a title + // + // + // + // + // + // + // 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 tags + return IsOfClass(node, wxT("MyControl")); +} +@endcode + +You may want to check the 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. + +*/