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 #include <Python.h>
  15
  16
  17 // For compilers that support precompilation, includes "wx/wx.h".
  18 #include <wx/wxprec.h>
  19
  20 #ifdef __BORLANDC__
  21     #pragma hdrstop
  22 #endif
  23
  24 #ifndef WX_PRECOMP
  25     #include <wx/wx.h>
  26 #endif
  27
  28 #include <wx/splitter.h>
  29
  30 #if defined(__WXGTK__) || defined(__WXMOTIF__) || defined(__WXMAC__) || defined(__WXMGL__)
  31     #include "mondrian.xpm"
  32 #endif
  33
  34 // Import Python and wxPython headers
  35 #include <wx/wxPython/wxPython.h>
  36
  37
  38 //----------------------------------------------------------------------
  39 // Class definitions
  40
  41 class MyApp : public wxApp
  42 {
  43 public:
  44     virtual bool OnInit();
  45     virtual int  OnExit();
  46     bool Init_wxPython();
  47 private:
  48     PyThreadState* m_mainTState;
  49 };
  50
  51
  52 class MyFrame : public wxFrame
  53 {
  54 public:
  55     MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size);
  56     void RedirectStdio();
  57     wxWindow* DoPythonStuff(wxWindow* parent);
  58     void OnExit(wxCommandEvent& event);
  59     void OnPyFrame(wxCommandEvent& event);
  60
  61 private:
  62     DECLARE_EVENT_TABLE()
  63 };
  64
  65 //----------------------------------------------------------------------
  66 // MyApp methods
  67
  68
  69 bool MyApp::OnInit()
  70 {
  71     if ( !Init_wxPython() )
  72         // don't start the app if we can't initialize wxPython.
  73         return false;
  74
  75     MyFrame *frame = new MyFrame(_T("Embedded wxPython Test"),
  76                                  wxDefaultPosition, wxSize(700, 600));
  77     frame->Show(true);
  78     return true;
  79 }
  80
  81
  82
  83 bool MyApp::Init_wxPython()
  84 {
  85     // Initialize Python
  86     Py_Initialize();
  87     PyEval_InitThreads();
  88
  89     // Load the wxPython core API.  Imports the wx._core_ module and sets a
  90     // local pointer to a function table located there.  The pointer is used
  91     // internally by the rest of the API functions.
  92     if ( ! wxPyCoreAPI_IMPORT() ) {
  93         wxLogError(wxT("***** Error importing the wxPython API! *****"));
  94         PyErr_Print();
  95         Py_Finalize();
  96         return false;
  97     }
  98
  99     // Save the current Python thread state and release the
 100     // Global Interpreter Lock.
 101     m_mainTState = wxPyBeginAllowThreads();
 102
 103     return true;
 104 }
 105
 106
 107 int MyApp::OnExit()
 108 {
 109     // Restore the thread state and tell Python to cleanup after itself.
 110     // wxPython will do its own cleanup as part of that process.  This is done
 111     // in OnExit instead of ~MyApp because OnExit is only called if OnInit is
 112     // successful.
 113     wxPyEndAllowThreads(m_mainTState);
 114     Py_Finalize();
 115     return 0;
 116 }
 117
 118
 119 IMPLEMENT_APP(MyApp)
 120
 121 //----------------------------------------------------------------------
 122
 123 enum
 124 {
 125     ID_EXIT=1001,
 126     ID_PYFRAME
 127 };
 128
 129
 130 BEGIN_EVENT_TABLE(MyFrame, wxFrame)
 131     EVT_MENU(ID_EXIT,      MyFrame::OnExit)
 132     EVT_MENU(ID_PYFRAME,   MyFrame::OnPyFrame)
 133 END_EVENT_TABLE()
 134
 135
 136
 137 MyFrame::MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size)
 138     : wxFrame(NULL, -1, title, pos, size,
 139               wxDEFAULT_FRAME_STYLE|wxNO_FULL_REPAINT_ON_RESIZE)
 140 {
 141     SetIcon(wxICON(mondrian));
 142
 143     wxMenuBar* mbar = new wxMenuBar;
 144     wxMenu*    menu = new wxMenu;
 145     menu->Append(ID_PYFRAME, _T("Make wx&Python frame"));
 146     menu->AppendSeparator();
 147     menu->Append(ID_EXIT, _T("&Close Frame\tAlt-X"));
 148     mbar->Append(menu, _T("&File"));
 149     SetMenuBar(mbar);
 150
 151     CreateStatusBar();
 152     RedirectStdio();
 153
 154     // Make some child windows from C++
 155     wxSplitterWindow* sp = new wxSplitterWindow(this, -1);
 156     wxPanel* p1 = new wxPanel(sp, -1, wxDefaultPosition, wxDefaultSize, wxSUNKEN_BORDER);
 157
 158     new wxStaticText(p1, -1,
 159                  _T("The frame, menu, splitter, this panel and this text were created in C++..."),
 160                  wxPoint(10,10));
 161
 162     // And get a panel from Python
 163     wxWindow* p2 = DoPythonStuff(sp);
 164
 165     sp->SplitHorizontally(p1, p2, GetClientSize().y/4);
 166 }
 167
 168 void MyFrame::OnExit(wxCommandEvent& event)
 169 {
 170     Close();
 171 }
 172
 173
 174 //----------------------------------------------------------------------
 175 // This is where the fun begins...
 176
 177
 178 char* python_code1 = "\
 179 import wx\n\
 180 f = wx.Frame(None, -1, 'Hello from wxPython!', size=(250, 150))\n\
 181 f.Show()\n\
 182 ";
 183
 184 void MyFrame::OnPyFrame(wxCommandEvent& event)
 185 {
 186     // For simple Python code that doesn't have to interact with the
 187     // C++ code in any way, you can execute it with PyRun_SimpleString.
 188
 189
 190     // First, whenever you do anything with Python objects or code, you
 191     // *MUST* aquire the Global Interpreter Lock and block other
 192     // Python threads from running.
 193     bool blocked = wxPyBeginBlockThreads();
 194
 195     // Execute the code in the __main__ module
 196     PyRun_SimpleString(python_code1);
 197
 198     // Finally, release the GIL and let other Python threads run.
 199     wxPyEndBlockThreads(blocked);
 200 }
 201
 202
 203 void MyFrame::RedirectStdio()
 204 {
 205     // This is a helpful little tidbit to help debugging and such.  It
 206     // redirects Python's stdout and stderr to a window that will popup
 207     // only on demand when something is printed, like a traceback.
 208     char* python_redirect = "\
 209 import sys\n\
 210 import wx\n\
 211 output = wx.PyOnDemandOutputWindow()\n\
 212 sys.stdin = sys.stderr = output\n\
 213 ";
 214     bool blocked = wxPyBeginBlockThreads();
 215     PyRun_SimpleString(python_redirect);
 216     wxPyEndBlockThreads(blocked);
 217 }
 218
 219
 220
 221
 222 char* python_code2 = "\
 223 import sys\n\
 224 sys.path.append('.')\n\
 225 import embedded_sample\n\
 226 \n\
 227 def makeWindow(parent):\n\
 228     win = embedded_sample.MyPanel(parent)\n\
 229     return win\n\
 230 ";
 231
 232 wxWindow* MyFrame::DoPythonStuff(wxWindow* parent)
 233 {
 234     // More complex embedded situations will require passing C++ objects to
 235     // Python and/or returning objects from Python to be used in C++.  This
 236     // sample shows one way to do it.  NOTE: The above code could just have
 237     // easily come from a file, or the whole thing could be in the Python
 238     // module that is imported and manipulated directly in this C++ code.  See
 239     // the Python API for more details.
 240
 241     wxWindow* window = NULL;
 242     PyObject* result;
 243
 244     // As always, first grab the GIL
 245     bool blocked = wxPyBeginBlockThreads();
 246
 247     // Now make a dictionary to serve as the global namespace when the code is
 248     // executed.  Put a reference to the builtins module in it.  (Yes, the
 249     // names are supposed to be different, I don't know why...)
 250     PyObject* globals = PyDict_New();
 251     PyObject* builtins = PyImport_ImportModule("__builtin__");
 252     PyDict_SetItemString(globals, "__builtins__", builtins);
 253     Py_DECREF(builtins);
 254
 255     // Execute the code to make the makeWindow function
 256     result = PyRun_String(python_code2, Py_file_input, globals, globals);
 257     // Was there an exception?
 258     if (! result) {
 259         PyErr_Print();
 260         wxPyEndBlockThreads(blocked);
 261         return NULL;
 262     }
 263     Py_DECREF(result);
 264
 265     // Now there should be an object named 'makeWindow' in the dictionary that
 266     // we can grab a pointer to:
 267     PyObject* func = PyDict_GetItemString(globals, "makeWindow");
 268     wxASSERT(PyCallable_Check(func));
 269
 270     // Now build an argument tuple and call the Python function.  Notice the
 271     // use of another wxPython API to take a wxWindows object and build a
 272     // wxPython object that wraps it.
 273     PyObject* arg = wxPyMake_wxObject(parent);
 274     wxASSERT(arg != NULL);
 275     PyObject* tuple = PyTuple_New(1);
 276     PyTuple_SET_ITEM(tuple, 0, arg);
 277     result = PyEval_CallObject(func, tuple);
 278
 279     // Was there an exception?
 280     if (! result)
 281         PyErr_Print();
 282     else {
 283         // Otherwise, get the returned window out of Python-land and
 284         // into C++-ville...
 285         bool success = wxPyConvertSwigPtr(result, (void**)&window, _T("wxWindow"));
 286         wxASSERT_MSG(success, _T("Returned object was not a wxWindow!"));
 287         Py_DECREF(result);
 288     }
 289
 290     // Release the python objects we still have
 291     Py_DECREF(globals);
 292     Py_DECREF(tuple);
 293
 294     // Finally, after all Python stuff is done, release the GIL
 295     wxPyEndBlockThreads(blocked);
 296
 297     return window;
 298 }
 299
 300
 301 //----------------------------------------------------------------------
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