adding back button evaluation so you can do 1/60, 90*0.1 etc as well as dimension conversion 1km-10cm+4ft

Note...
- Python3.1 you don't need to add the .0 for divisions anymore (was esp annoying for button eval)
- Simple dimension input, imperial mi/yd/ft/in, metric km/m/cm/mm,  Later could display these values and have a pref for scene scale, atm it assumes 1BU == 1m.

release/ui/bpy_ops.py

@@ -111,3 +111,48 @@ class bpy_ops_submodule_op(object):
 
 import bpy
 bpy.ops = bpy_ops()
+
+
+
+
+# A bit out of place but add button conversion code here
+module_type = type(__builtins__)
+import types
+mod = types.ModuleType('button_convert')
+
+import sys
+sys.modules['button_convert'] = mod
+
+def convert(expr):
+	
+	def replace(string, unit, scaler):
+		# in need of regex
+		change = True
+		while change:
+			change = False
+			i = string.find(unit)
+			if i != -1:
+				if i>0 and not string[i-1].isalpha():
+					i_end = i+len(unit)
+					if i_end+1 >= len(string) or (not string[i_end+1].isalpha()):
+						string = string.replace(unit, scaler)
+						change = True
+		# print(string)
+		return string
+	
+	#imperial
+	expr = replace(expr, 'mi', '*1609.344')
+	expr = replace(expr, 'yd', '*0.9144')
+	expr = replace(expr, 'ft', '*0.3048')
+	expr = replace(expr, 'in', '*0.0254')
+	
+	# metric
+	expr = replace(expr, 'km', '*1000')
+	expr = replace(expr, 'm', '')
+	expr = replace(expr, 'cm', '*0.01')
+	expr = replace(expr, 'mm', '*0.001')
+	
+	return expr
+
+mod.convert = convert
+

source/blender/editors/interface/SConscript

@@ -9,6 +9,7 @@ for source in env.Glob('*_api.c'):
 incs = '../include ../../blenlib ../../blenfont ../../blenkernel ../../makesdna ../../imbuf'
 incs += ' ../../makesrna ../../windowmanager #/intern/guardedalloc'
 incs += ' #/extern/glew/include'
+incs += ' ../../python/' # python button eval
 
 defs = []
 

source/blender/editors/interface/interface.c

@@ -66,6 +66,8 @@
 #include "RNA_access.h"
 #include "RNA_types.h"
 
+#include "BPY_extern.h"
+
 #include "interface_intern.h"
 
 #define MENU_WIDTH 			120
@@ -1434,10 +1436,9 @@ int ui_set_but_string(bContext *C, uiBut *but, const char *str)
 		double value;
 
 		/* XXX 2.50 missing python api */
-#if 0
-		if(BPY_button_eval(str, &value)) {
-			BKE_report(CTX_reports(C), RPT_WARNING, "Invalid Python expression, check console");
-			value = 0.0f; /* Zero out value on error */
+#ifndef DISABLE_PYTHON
+		if(BPY_button_eval(C, str, &value)) {
+			value = ui_get_but_val(but); /* use its original value */
 			
 			if(str[0])
 				return 0;

source/blender/python/BPY_extern.h

@@ -122,7 +122,7 @@ extern "C" {
 	void BPY_pydriver_update(void);
 	float BPY_pydriver_eval(struct ChannelDriver *driver);
 
-	int BPY_button_eval(char *expr, double *value);
+	int BPY_button_eval(struct bContext *C, char *expr, double *value);
 
 /* format importer hook */
 	int BPY_call_importloader( char *name );

source/blender/python/intern/bpy_interface.c

@@ -804,3 +804,65 @@ float BPY_pydriver_eval (ChannelDriver *driver)
 
 	return result;
 }
+
+int BPY_button_eval(bContext *C, char *expr, double *value)
+{
+	PyGILState_STATE gilstate;
+	PyObject *dict, *retval, *expr_conv;
+	int error_ret = 0;
+	
+	if (!value || !expr || expr[0]=='\0') return -1;
+	
+	bpy_context_set(C, &gilstate);
+	
+	// experemental, fun. "button_convert.convert" is currently defined in bpy_ops.py
+	{
+		PyObject *mod= PyDict_GetItemString(PySys_GetObject("modules"), "button_convert");
+		if(mod && PyModule_Check(mod))	{
+			PyObject *mod_dict= PyModule_GetDict(mod);
+			PyObject *func= PyDict_GetItemString(mod_dict, "convert");
+			if(func) {
+				PyObject *expr_conv = PyObject_CallFunction(func, "s", expr);
+				if(expr_conv==NULL) {
+					PyErr_Print();
+					PyErr_Clear();
+				}
+				else {
+					expr= _PyUnicode_AsString(expr_conv); /* TODO, check */
+				}
+			}
+		}
+	}
+	
+	dict= CreateGlobalDictionary(C);
+	retval = PyRun_String(expr, Py_eval_input, dict, dict);
+	
+	if(expr_conv) {
+		Py_DECREF(expr_conv); /* invalidates expr */
+	}
+	
+	if (retval == NULL) {
+		error_ret= -1;
+	}
+	else {
+		double val = PyFloat_AsDouble(retval);
+		Py_DECREF(retval);
+		
+		if(val==-1 && PyErr_Occurred()) {
+			error_ret= -1;
+		}
+		else {
+			*value= val;
+		}
+	}
+	
+	if(error_ret) {
+		BPy_errors_to_report(CTX_wm_reports(C));
+	}
+	
+	Py_DECREF(dict);
+	bpy_context_clear(C, &gilstate);
+	
+	return error_ret;
+}
+