include/wx/app.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        app.h
   3 // Purpose:     wxAppBase class and macros used for declaration of wxApp
   4 //              derived class in the user code
   5 // Author:      Julian Smart
   6 // Modified by:
   7 // Created:     01/02/97
   8 // RCS-ID:      $Id$
   9 // Copyright:   (c) Julian Smart and Markus Holzem
  10 // Licence:     wxWindows licence
  11 /////////////////////////////////////////////////////////////////////////////
  12
  13 #ifndef _WX_APP_H_BASE_
  14 #define _WX_APP_H_BASE_
  15
  16 #ifdef __GNUG__
  17     #pragma interface "appbase.h"
  18 #endif
  19
  20 // ----------------------------------------------------------------------------
  21 // typedefs
  22 // ----------------------------------------------------------------------------
  23
  24 #ifdef __WXMSW__
  25     class WXDLLEXPORT wxApp;
  26     typedef wxApp* (*wxAppInitializerFunction)();
  27 #else
  28     // returning wxApp* won't work with gcc
  29     #include "wx/object.h"
  30
  31     typedef wxObject* (*wxAppInitializerFunction)();
  32 #endif
  33
  34 // ----------------------------------------------------------------------------
  35 // headers we have to include here
  36 // ----------------------------------------------------------------------------
  37
  38 #include "wx/event.h"       // for the base class
  39
  40 #include "wx/window.h"      // for wxTopLevelWindows
  41
  42 #if wxUSE_LOG
  43     #include "wx/log.h"
  44 #endif
  45
  46 // ----------------------------------------------------------------------------
  47 // constants
  48 // ----------------------------------------------------------------------------
  49
  50 static const int wxPRINT_WINDOWS = 1;
  51 static const int wxPRINT_POSTSCRIPT = 2;
  52
  53 // ----------------------------------------------------------------------------
  54 // the common part of wxApp implementations for all platforms
  55 // ----------------------------------------------------------------------------
  56
  57 class WXDLLEXPORT wxAppBase : public wxEvtHandler
  58 {
  59 public:
  60     // the virtual functions which may/must be overridden in the derived class
  61     // -----------------------------------------------------------------------
  62
  63         // called during the program initialization, returning FALSE from here
  64         // prevents the program from continuing - it's a good place to create
  65         // the top level program window and return TRUE.
  66         //
  67         // Override: always.
  68     virtual bool OnInit() { return FALSE; };
  69
  70         // a platform-dependent version of OnInit(): the code here is likely to
  71         // depend on the toolkit. default version does nothing.
  72         //
  73         // Override: rarely.
  74     virtual bool OnInitGui() { return TRUE; }
  75
  76         // called to start program execution - the default version just enters
  77         // the main GUI loop in which events are received and processed until
  78         // the last window is not deleted (if GetExitOnFrameDelete) or
  79         // ExitMainLoop() is called.
  80         //
  81         // Override: rarely.
  82     virtual int OnRun() { return MainLoop(); };
  83
  84         // called after the main loop termination. This is a good place for
  85         // cleaning up (it may be too late in dtor) and is also useful if you
  86         // want to return some non-default exit code - this is just the return
  87         // value of this method.
  88         //
  89         // Override: often.
  90     virtual int OnExit() { return 0; }
  91
  92         // called when a fatal exception occurs, this function should take care
  93         // not to do anything which might provoke a nested exception! It may be
  94         // overridden if you wish to react somehow in non-default way (core
  95         // dump under Unix, application crash under Windows) to fatal program
  96         // errors, however extreme care should be taken if you don't want this
  97         // function to crash.
  98         //
  99         // Override: rarely.
 100     virtual void OnFatalException() { }
 101
 102     // the worker functions - usually not used directly by the user code
 103     // -----------------------------------------------------------------
 104
 105         // execute the main GUI loop, the function returns when the loop ends
 106     virtual int MainLoop() = 0;
 107
 108         // exit the main GUI loop during the next iteration (i.e. it does not
 109         // stop the program immediately!)
 110     virtual void ExitMainLoop() = 0;
 111
 112         // returns TRUE if the program is initialized
 113     virtual bool Initialized() = 0;
 114
 115         // returns TRUE if there are unprocessed events in the event queue
 116     virtual bool Pending() = 0;
 117
 118         // process the first event in the event queue (blocks until an event
 119         // apperas if there are none currently)
 120     virtual void Dispatch() = 0;
 121
 122     // application info: name, description, vendor
 123     // -------------------------------------------
 124
 125     // NB: all these should be set by the application itself, there are no
 126     //     reasonable default except for the application name which is taken to
 127     //     be argv[0]
 128
 129         // set/get the application name
 130     wxString GetAppName() const
 131     {
 132         if ( !m_appName )
 133             return m_className;
 134         else
 135             return m_appName;
 136     }
 137     void SetAppName(const wxString& name) { m_appName = name; }
 138
 139         // set/get the app class name
 140     wxString GetClassName() const { return m_className; }
 141     void SetClassName(const wxString& name) { m_className = name; }
 142
 143         // set/get the vendor name
 144     const wxString& GetVendorName() const { return m_vendorName; }
 145     void SetVendorName(const wxString& name) { m_vendorName = name; }
 146
 147     // top level window functions
 148     // --------------------------
 149
 150         // set the "main" top level window
 151     void SetTopWindow(wxWindow *win) { m_topWindow = win; }
 152
 153         // return the "main" top level window (if it hadn't been set previously
 154         // with SetTopWindow(), will return just some top level window and, if
 155         // there are none, will return NULL)
 156     wxWindow *GetTopWindow() const
 157     {
 158         if (m_topWindow)
 159             return m_topWindow;
 160         else if (wxTopLevelWindows.GetCount() > 0)
 161             return wxTopLevelWindows.GetFirst()->GetData();
 162         else
 163             return (wxWindow *)NULL;
 164     }
 165
 166         // control the exit behaviour: by default, the program will exit the
 167         // main loop (and so, usually, terminate) when the last top-level
 168         // program window is deleted. Beware that if you disabel this (with
 169         // SetExitOnFrameDelete(FALSE)), you'll have to call ExitMainLoop()
 170         // explicitly from somewhere.
 171     void SetExitOnFrameDelete(bool flag) { m_exitOnFrameDelete = flag; }
 172     bool GetExitOnFrameDelete() const { return m_exitOnFrameDelete; }
 173
 174     // miscellaneous customization functions
 175     // -------------------------------------
 176
 177 #if wxUSE_LOG
 178         // override this function to create default log target of arbitrary
 179         // user-defined class (default implementation creates a wxLogGui
 180         // object) - this log object is used by default by all wxLogXXX()
 181         // functions.
 182     virtual wxLog *CreateLogTarget() { return new wxLogGui; }
 183 #endif // wxUSE_LOG
 184
 185
 186         // get the standard icon used by wxWin dialogs - this allows the user
 187         // to customize the standard dialogs. The 'which' parameter is one of
 188         // wxICON_XXX values
 189     virtual wxIcon GetStdIcon(int which) const = 0;
 190
 191         // VZ: what does this do exactly?
 192     void SetWantDebugOutput( bool flag ) { m_wantDebugOutput = flag; }
 193     bool GetWantDebugOutput() const { return m_wantDebugOutput; }
 194
 195         // set/get printing mode: see wxPRINT_XXX constants.
 196         //
 197         // default behaviour is the normal one for Unix: always use PostScript
 198         // printing.
 199     virtual void SetPrintMode(int WXUNUSED(mode)) { }
 200     int GetPrintMode() const { return wxPRINT_POSTSCRIPT; }
 201
 202     // implementation only from now on
 203     // -------------------------------
 204
 205     // helpers for dynamic wxApp construction
 206     static void SetInitializerFunction(wxAppInitializerFunction fn)
 207         { m_appInitFn = fn; }
 208     static wxAppInitializerFunction GetInitializerFunction()
 209         { return m_appInitFn; }
 210
 211     // access to the command line arguments
 212     int      argc;
 213     wxChar **argv;
 214
 215 //private:
 216 protected:
 217     // function used for dynamic wxApp creation
 218     static wxAppInitializerFunction m_appInitFn;
 219
 220     // application info (must be set from the user code)
 221     wxString m_vendorName,      // vendor name (ACME Inc)
 222              m_appName,         // app name
 223              m_className;       // class name
 224
 225     // if TRUE, exit the main loop when the last top level window is deleted
 226     bool m_exitOnFrameDelete;
 227
 228     // TRUE if the application wants to get debug output
 229     bool m_wantDebugOutput;
 230
 231     // the main top level window - may be NULL
 232     wxWindow *m_topWindow;
 233 };
 234
 235 // ----------------------------------------------------------------------------
 236 // now include the declaration of the real class
 237 // ----------------------------------------------------------------------------
 238
 239 #if defined(__WXMSW__)
 240     #include "wx/msw/app.h"
 241 #elif defined(__WXMOTIF__)
 242     #include "wx/motif/app.h"
 243 #elif defined(__WXQT__)
 244     #include "wx/qt/app.h"
 245 #elif defined(__WXGTK__)
 246     #include "wx/gtk/app.h"
 247 #elif defined(__WXMAC__)
 248     #include "wx/mac/app.h"
 249 #elif defined(__WXPM__)
 250     #include "wx/os2/app.h"
 251 #elif defined(__WXSTUBS__)
 252     #include "wx/stubs/app.h"
 253 #endif
 254
 255 // ----------------------------------------------------------------------------
 256 // the global data
 257 // ----------------------------------------------------------------------------
 258
 259 // the one and only application object - use of wxTheApp in application code
 260 // is discouraged, consider using DECLARE_APP() after which you may call
 261 // wxGetApp() which will return the object of the correct type (i.e. MyApp and
 262 // not wxApp)
 263 WXDLLEXPORT_DATA(extern wxApp*) wxTheApp;
 264
 265 // ----------------------------------------------------------------------------
 266 // global functions
 267 // ----------------------------------------------------------------------------
 268
 269 // Force an exit from main loop
 270 void WXDLLEXPORT wxExit();
 271
 272 // Yield to other apps/messages
 273 bool WXDLLEXPORT wxYield();
 274
 275 // ----------------------------------------------------------------------------
 276 // macros for dynamic creation of the application object
 277 // ----------------------------------------------------------------------------
 278
 279 // Having a global instance of this class allows wxApp to be aware of the app
 280 // creator function. wxApp can then call this function to create a new app
 281 // object. Convoluted, but necessary.
 282
 283 class WXDLLEXPORT wxAppInitializer
 284 {
 285 public:
 286     wxAppInitializer(wxAppInitializerFunction fn)
 287         { wxApp::SetInitializerFunction(fn); }
 288 };
 289
 290 // Here's a macro you can use if your compiler really, really wants main() to
 291 // be in your main program (e.g. hello.cpp). Now IMPLEMENT_APP should add this
 292 // code if required.
 293
 294 #if defined(__AIX__) || defined(__HPUX__)
 295     #define IMPLEMENT_WXWIN_MAIN \
 296         extern int wxEntry( int argc, char *argv[] ); \
 297         int main(int argc, char *argv[]) { return wxEntry(argc, argv); }
 298 #elif defined(__WXMSW__) && defined(WXUSINGDLL)
 299     // NT defines APIENTRY, 3.x not
 300     #if !defined(WXAPIENTRY)
 301         #ifdef __WATCOMC__
 302             #define WXAPIENTRY PASCAL
 303         #else
 304             #define WXAPIENTRY FAR PASCAL
 305         #endif
 306     #endif
 307
 308     #define IMPLEMENT_WXWIN_MAIN \
 309         int WXAPIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,\
 310                                LPSTR m_lpCmdLine, int nCmdShow )\
 311         {\
 312             return wxEntry((WXHINSTANCE) hInstance, \
 313                            (WXHINSTANCE) hPrevInstance,\
 314                            m_lpCmdLine, nCmdShow);\
 315         }
 316
 317 #else
 318     #define IMPLEMENT_WXWIN_MAIN
 319 #endif
 320
 321 // use this macro exactly once, the argument is the name of the wxApp-derived
 322 // class which is the class of your application
 323 #define IMPLEMENT_APP(appname)                          \
 324     wxApp *wxCreateApp() { return new appname; }      \
 325     wxAppInitializer wxTheAppInitializer((wxAppInitializerFunction) wxCreateApp); \
 326     appname& wxGetApp() { return *(appname *)wxTheApp; } \
 327     IMPLEMENT_WXWIN_MAIN
 328
 329 #define DECLARE_APP(appname) extern appname& wxGetApp();
 330
 331 #endif
 332     // _WX_APP_H_BASE_