wxPython/samples/embedded/embedded.cpp

   1 //----------------------------------------------------------------------
   2 // Name:        embedded.cpp
   3 // Purpose:     To serve as an example of how to use wxPython from
   4 //              within a C++ wxWindows program.
   5 //
   6 // Author:      Robin Dunn
   7 //
   8 // Created:     1-May-2002
   9 // RCS-ID:      $Id$
  10 // Copyright:   (c) 2002 by Total Control Software
  11 // Licence:     wxWindows license
  12 //----------------------------------------------------------------------
  13
  14 // For compilers that support precompilation, includes "wx/wx.h".
  15 #include <wx/wxprec.h>
  16
  17 #ifdef __BORLANDC__
  18     #pragma hdrstop
  19 #endif
  20
  21 #ifndef WX_PRECOMP
  22     #include <wx/wx.h>
  23 #endif
  24
  25 #include <wx/splitter.h>
  26
  27 #if defined(__WXGTK__) || defined(__WXMOTIF__) || defined(__WXMAC__) || defined(__WXMGL__)
  28     #include "mondrian.xpm"
  29 #endif
  30
  31 // Import Python and wxPython headers
  32 #include <Python.h>
  33 #include <wxPython.h>
  34
  35 //----------------------------------------------------------------------
  36 // Class definitions
  37
  38 class MyApp : public wxApp
  39 {
  40 public:
  41     virtual bool OnInit();
  42     virtual ~MyApp();
  43     void Init_wxPython();
  44 private:
  45     PyThreadState* main_tstate;
  46 };
  47
  48
  49 class MyFrame : public wxFrame
  50 {
  51 public:
  52     MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size);
  53     void RedirectStdio();
  54     wxWindow* DoPythonStuff(wxWindow* parent);
  55     void OnExit(wxCommandEvent& event);
  56     void OnPyFrame(wxCommandEvent& event);
  57
  58 private:
  59     DECLARE_EVENT_TABLE()
  60 };
  61
  62 //----------------------------------------------------------------------
  63 // MyApp methods
  64
  65
  66 bool MyApp::OnInit()
  67 {
  68     Init_wxPython();
  69     MyFrame *frame = new MyFrame(_T("Embedded wxPython Test"),
  70                                  wxPoint(50, 50), wxSize(700, 600));
  71     frame->Show(TRUE);
  72     return TRUE;
  73 }
  74
  75
  76 void MyApp::Init_wxPython()
  77 {
  78     // Initialize Python
  79     Py_Initialize();
  80     PyEval_InitThreads();
  81
  82     // Load the wxPython core API.  Imports the wxPython.wxc
  83     // module and sets a pointer to a function table located there.
  84     wxPyCoreAPI_IMPORT();
  85
  86     // Save the current Python thread state and release the
  87     // Global Interpreter Lock.
  88     main_tstate = wxPyBeginAllowThreads();
  89 }
  90
  91
  92 MyApp::~MyApp()
  93 {
  94     // Restore the thread state and tell Python to cleanup after itself.
  95     wxPyEndAllowThreads(main_tstate);
  96     Py_Finalize();
  97 }
  98
  99 IMPLEMENT_APP(MyApp)
 100
 101 //----------------------------------------------------------------------
 102
 103 enum
 104 {
 105     ID_EXIT=1001,
 106     ID_PYFRAME
 107 };
 108
 109
 110 BEGIN_EVENT_TABLE(MyFrame, wxFrame)
 111     EVT_MENU(ID_EXIT,      MyFrame::OnExit)
 112     EVT_MENU(ID_PYFRAME,   MyFrame::OnPyFrame)
 113 END_EVENT_TABLE()
 114
 115
 116
 117 MyFrame::MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size)
 118     : wxFrame(NULL, -1, title, pos, size,
 119               wxDEFAULT_FRAME_STYLE|wxNO_FULL_REPAINT_ON_RESIZE)
 120 {
 121     SetIcon(wxICON(mondrian));
 122
 123     wxMenuBar* mbar = new wxMenuBar;
 124     wxMenu*    menu = new wxMenu;
 125     menu->Append(ID_PYFRAME, "Make wx&Python frame");
 126     menu->AppendSeparator();
 127     menu->Append(ID_EXIT, "&Close Frame\tAlt-X");
 128     mbar->Append(menu, "&File");
 129     SetMenuBar(mbar);
 130
 131     CreateStatusBar();
 132     RedirectStdio();
 133
 134     // Make some child windows from C++
 135     wxSplitterWindow* sp = new wxSplitterWindow(this, -1);
 136     wxPanel* p1 = new wxPanel(sp, -1);
 137     p1->SetFont(wxFont(12, wxSWISS, wxNORMAL, wxBOLD));
 138     new wxStaticText(p1, -1,
 139                  wxT("The frame, menu, splitter, this panel and this text were created in C++..."),
 140                  wxPoint(10,10));
 141
 142     // And get a panel from Python
 143     wxWindow* p2 = DoPythonStuff(sp);
 144
 145     sp->SplitHorizontally(p1, p2, GetClientSize().y/4);
 146 }
 147
 148 void MyFrame::OnExit(wxCommandEvent& event)
 149 {
 150     Close();
 151 }
 152
 153
 154 //----------------------------------------------------------------------
 155 // This is were the fun begins...
 156
 157
 158 char* python_code1 = "\
 159 from wxPython.wx import wxFrame\n\
 160 f = wxFrame(None, -1, 'Hello from wxPython!', size=(250, 150))\n\
 161 f.Show()\n\
 162 ";
 163
 164 void MyFrame::OnPyFrame(wxCommandEvent& event)
 165 {
 166     // For simple Python code that doesn't have to interact with the
 167     // C++ code in any way, you can execute it with PyRun_SimpleString.
 168
 169
 170     // First, whenever you do anyting with Python objects or code, you
 171     // *MUST* aquire the Global Interpreter Lock and block other
 172     // Python threads from running.
 173     wxPyBeginBlockThreads();
 174
 175     // Execute the code in the __main__ module
 176     PyRun_SimpleString(python_code1);
 177
 178     // Finally, release the GIL and let other Python threads run.
 179     wxPyEndBlockThreads();
 180 }
 181
 182
 183 void MyFrame::RedirectStdio()
 184 {
 185     // This is a helpful little tidbit to help debugging and such.  It
 186     // redirects Python's stdout and stderr to a window that will popup
 187     // only on demand when something is printed, like a traceback.
 188     char* python_redirect = "\
 189 import sys\n\
 190 from wxPython.wx import wxPyOnDemandOutputWindow\n\
 191 output = wxPyOnDemandOutputWindow()\n\
 192 sys.stdin = sys.stderr = output\n\
 193 ";
 194     wxPyBeginBlockThreads();
 195     PyRun_SimpleString(python_redirect);
 196     wxPyEndBlockThreads();
 197 }
 198
 199
 200
 201
 202 char* python_code2 = "\
 203 import embedded_sample\n\
 204 \n\
 205 def makeWindow(parent):\n\
 206     win = embedded_sample.MyPanel(parent)\n\
 207     return win\n\
 208 ";
 209
 210 wxWindow* MyFrame::DoPythonStuff(wxWindow* parent)
 211 {
 212     // More complex embedded situations will require passing C++ objects to
 213     // Python and/or returning objects from Python to be used in C++.  This
 214     // sample shows one way to do it.  NOTE: The above code could just have
 215     // easily come from a file, or the whole thing coupld be in the Python
 216     // module that is imported and manipulated directly in this C++ code.  See
 217     // the Python API for more details.
 218
 219     wxWindow* window = NULL;
 220     PyObject* result;
 221
 222     // As always, first grab the GIL
 223     wxPyBeginBlockThreads();
 224
 225     // Now make a dictionary to serve as the global namespace when the code is
 226     // executed.  Put a reference to the builtins module in it.  (Yes, the
 227     // names are supposed to be different, I don't know why...)
 228     PyObject* globals = PyDict_New();
 229     PyObject* builtins = PyImport_ImportModule("__builtin__");
 230     PyDict_SetItemString(globals, "__builtins__", builtins);
 231     Py_DECREF(builtins);
 232
 233     // Execute the code to make the makeWindow function
 234     result = PyRun_String(python_code2, Py_file_input, globals, globals);
 235     // Was there an exception?
 236     if (! result) {
 237         PyErr_Print();
 238         wxPyEndBlockThreads();
 239         return NULL;
 240     }
 241     Py_DECREF(result);
 242
 243     // Now there should be an object named 'makeWindow' in the dictionary that
 244     // we can grab a pointer to:
 245     PyObject* func = PyDict_GetItemString(globals, "makeWindow");
 246     wxASSERT(PyCallable_Check(func));
 247
 248     // Now build an argument tuple and call the Python function.  Notice the
 249     // use of another wxPython API to take a wxWindows object and build a
 250     // wxPython object that wraps it.
 251     PyObject* arg = wxPyMake_wxObject(parent);
 252     wxASSERT(arg != NULL);
 253
 254     PyObject* tuple = PyTuple_New(1);
 255     PyTuple_SET_ITEM(tuple, 0, arg);
 256     result = PyEval_CallObject(func, tuple);
 257
 258     // Was there an exception?
 259     if (! result)
 260         PyErr_Print();
 261     else {
 262         // Otherwise, get the returned window out of Python-land and
 263         // into C++-ville...
 264         bool error = SWIG_GetPtrObj(result, (void**)&window, "_wxWindow_p");
 265         wxASSERT_MSG(!error, wxT("Returned object was not a wxWindow!"));
 266         Py_DECREF(result);
 267     }
 268
 269     // Release the python objects we still have
 270     Py_DECREF(globals);
 271     Py_DECREF(tuple);
 272
 273     // Finally, after all Python stuff is done, release the GIL
 274     wxPyEndBlockThreads();
 275
 276     return window;
 277 }
 278
 279
 280 //----------------------------------------------------------------------
 281
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