Demo mode and BPython:

- small additions and fixes to enable the demo mode;

- Added sleep() to Blender.sys and 17 new functions to Blender.Window module:
    things to help demo script writing and as a bonus read / write access to Blender's input event queue;

- updates in docs, those interested please check Window.py in python/api2_2x/doc/ to read about the new Blender.Window functions.

----

Demo mode should be working well now for (I) playing rt animation -- aka ALT+A -- and (II) rendering pics and anims and playing anims.  I'll still add access to radiosity data and functions.

PS: Joseph Gilbert made (II) possible with the Scene.Render module he added for 2.32.  He's been coding great things for bpython, so I'd like to take the chance to point that and thank him here.

source/blender/python/BPY_interface.c

@@ -49,6 +49,7 @@
 #include <BKE_global.h>
 #include <BKE_library.h>
 #include <BKE_main.h>
+#include <BKE_object.h> /* during_scriptlink() */
 #include <BKE_text.h>
 #include <BKE_utildefines.h>
 #include <BPI_script.h>
@@ -902,7 +903,8 @@ static PyObject *ID_asPyObject(ID *id)
 	case ID_SCE:
 		return Scene_CreatePyObject((Scene*) id);
 	default:
-		return NULL;
+		Py_INCREF (Py_None);
+		return Py_None;
 	}
 }
 
@@ -913,9 +915,18 @@ void BPY_do_pyscript(ID *id, short event)
 	if (scriptlink && scriptlink->totscript) {
 		PyObject *dict;
 		PyObject *ret;
-		int index;
+		int index, during_slink = during_scriptlink();
 
-			// set globals in Blender module to identify scriptlink
+		/* invalid scriptlinks (new .blend was just loaded), return */
+		if (during_slink < 0) return;
+
+		/* tell we're running a scriptlink.  The sum also tells if this script
+		 * is running nested inside another.  Blender.Load needs this info to
+		 * avoid trouble with invalid slink pointers. */
+		during_slink++;
+		disable_where_scriptlink(during_slink);
+
+		/* set globals in Blender module to identify scriptlink */
 		Py_INCREF(Py_True);
 		PyDict_SetItemString(g_blenderdict, "bylink", Py_True);
 		PyDict_SetItemString(g_blenderdict, "link", ID_asPyObject(id));
@@ -928,22 +939,33 @@ void BPY_do_pyscript(ID *id, short event)
 				dict = CreateGlobalDictionary();
 				ret = RunPython ((Text*) scriptlink->scripts[index], dict);
 				ReleaseGlobalDictionary (dict);
+
 				if (!ret) {
 					/* Failed execution of the script */
 					BPY_Err_Handle (scriptlink->scripts[index]->name+2);
-					BPY_end_python ();
-					BPY_start_python ();
+					//BPY_end_python ();
+					//BPY_start_python ();
 				} else {
 					Py_DECREF (ret);
 				}
+				/* If a scriptlink has just loaded a new .blend file, the
+				 * scriptlink pointer became invalid (see api2_2x/Blender.c),
+				 * so we stop here. */
+				if (during_scriptlink() == -1) {
+					during_slink = 1;
+					break;
+				}
 			}
 		}
 
-			// cleanup bylink flag and clear link so PyObject can be released
+		disable_where_scriptlink(during_slink - 1);
+
+		/* cleanup bylink flag and clear link so PyObject can be released */
 		Py_INCREF(Py_False);
 		PyDict_SetItemString(g_blenderdict, "bylink", Py_False);
 		Py_INCREF(Py_None);
 		PyDict_SetItemString(g_blenderdict, "link", Py_None);
+		PyDict_SetItemString(g_blenderdict, "event", PyString_FromString(""));
 	}
 }