17 files changed, 241 insertions, 169 deletions
diff --git a/grc/core/CMakeLists.txt b/grc/core/CMakeLists.txt
index 623d912d47..8aee8116b2 100644
--- a/grc/core/CMakeLists.txt
+++ b/grc/core/CMakeLists.txt
@@ -20,6 +20,7 @@
 ########################################################################
 GR_PYTHON_INSTALL(FILES
     Block.py
+    Config.py
     Connection.py
     Constants.py
     Element.py
diff --git a/grc/core/Config.py b/grc/core/Config.py
new file mode 100644
index 0000000000..ac38d9978c
--- /dev/null
+++ b/grc/core/Config.py
@@ -0,0 +1,55 @@
+"""
+Copyright 2016 Free Software Foundation, Inc.
+This file is part of GNU Radio
+
+GNU Radio Companion is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; either version 2
+of the License, or (at your option) any later version.
+
+GNU Radio Companion is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+"""
+
+import os
+from os.path import expanduser, normpath, expandvars, exists
+
+
+class Config(object):
+
+    key = 'grc'
+    name = 'GNU Radio Companion (no gui)'
+    license = __doc__.strip()
+    website = 'http://gnuradio.org'
+
+    hier_block_lib_dir = os.environ.get('GRC_HIER_PATH', expanduser('~/.grc_gnuradio'))
+
+    def __init__(self, prefs_file, version, version_parts=None):
+        self.prefs = prefs_file
+        self.version = version
+        self.version_parts = version_parts or version[1:].split('-', 1)[0].split('.')[:3]
+
+    @property
+    def block_paths(self):
+        path_list_sep = {'/': ':', '\\': ';'}[os.path.sep]
+
+        paths_sources = (
+            self.hier_block_lib_dir,
+            os.environ.get('GRC_BLOCKS_PATH', ''),
+            self.prefs.get_string('grc', 'local_blocks_path', ''),
+            self.prefs.get_string('grc', 'global_blocks_path', ''),
+        )
+
+        collected_paths = sum((paths.split(path_list_sep)
+                               for paths in paths_sources), [])
+
+        valid_paths = [normpath(expanduser(expandvars(path)))
+                       for path in collected_paths if exists(path)]
+
+        return valid_paths
diff --git a/grc/core/FlowGraph.py b/grc/core/FlowGraph.py
index 3d744f74c4..af6d35f7fb 100644
--- a/grc/core/FlowGraph.py
+++ b/grc/core/FlowGraph.py
@@ -370,7 +370,7 @@ class FlowGraph(Element):
         n['block'] = [b.export_data() for b in blocks]
         n['connection'] = [c.export_data() for c in connections]
         instructions = odict({
-            'created': '.'.join(self.get_parent().config.version2),
+            'created': '.'.join(self.get_parent().config.version_parts),
             'format': FLOW_GRAPH_FILE_FORMAT_VERSION,
         })
         return odict({'flow_graph': n, '_instructions': instructions})
diff --git a/grc/core/Param.py b/grc/core/Param.py
index 0be30975e0..99106defe4 100644
--- a/grc/core/Param.py
+++ b/grc/core/Param.py
@@ -20,7 +20,6 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 import ast
 
 import re
-from gnuradio import eng_notation, gr
 
 from . import Constants
 from .Constants import VECTOR_TYPES, COMPLEX_TYPES, REAL_TYPES, INT_TYPES
@@ -31,8 +30,12 @@ from .utils import odict
 import __builtin__
 
 
-ID_BLACKLIST = ['self', 'options', 'gr', 'blks2', 'wxgui', 'wx', 'math', 'forms', 'firdes'] + \
-    filter(lambda x: not x.startswith('_'), dir(gr.top_block())) + dir(__builtin__)
+ID_BLACKLIST = ['self', 'options', 'gr', 'blks2', 'wxgui', 'wx', 'math', 'forms', 'firdes'] + dir(__builtin__)
+try:
+    from gnuradio import gr
+    ID_BLACKLIST.extend(attr for attr in dir(gr.top_block()) if not attr.startswith('_'))
+except ImportError:
+    pass
 
 _check_id_matcher = re.compile('^[a-z|A-Z]\w*$')
 _show_id_matcher = re.compile('^(variable\w*|parameter|options|notebook)$')
@@ -51,22 +54,23 @@ def _get_elem(lst, key):
 
 def num_to_str(num):
     """ Display logic for numbers """
+    def eng_notation(value, fmt='g'):
+        """Convert a number to a string in engineering notation.  E.g., 5e-9 -> 5n"""
+        template = '{:' + fmt + '}{}'
+        magnitude = abs(value)
+        for exp, symbol in zip(range(9, -15-1, -3), 'GMk munpf'):
+            factor = 10 ** exp
+            if magnitude >= factor:
+                return template.format(value / factor, symbol.strip())
+        return template.format(value, '')
+
     if isinstance(num, COMPLEX_TYPES):
         num = complex(num)  # Cast to python complex
         if num == 0:
             return '0'
-        elif num.imag == 0:
-            # Value is real
-            return '{}'.format(eng_notation.num_to_str(num.real))
-        elif num.real == 0:
-            # Value is imaginary
-            return '{}j'.format(eng_notation.num_to_str(num.imag))
-        elif num.imag < 0:
-            return '{}-{}j'.format(eng_notation.num_to_str(num.real),
-                                   eng_notation.num_to_str(abs(num.imag)))
-        else:
-            return '{}+{}j'.format(eng_notation.num_to_str(num.real),
-                                   eng_notation.num_to_str(num.imag))
+        output = eng_notation(num.real) if num.real else ''
+        output += eng_notation(num.imag, '+g' if output else 'g') + 'j' if num.imag else ''
+        return output
     else:
         return str(num)
 
diff --git a/grc/core/Platform.py b/grc/core/Platform.py
index 97e2b38309..4c1e6f471a 100644
--- a/grc/core/Platform.py
+++ b/grc/core/Platform.py
@@ -19,10 +19,10 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 
 import os
 import sys
-from gnuradio import gr
 
 from . import ParseXML, Messages, Constants
 
+from .Config import Config
 from .Element import Element
 from .generator import Generator
 from .FlowGraph import FlowGraph
@@ -34,59 +34,9 @@ from .Param import Param
 from .utils import odict, extract_docs
 
 
-from os.path import expanduser, normpath, expandvars, dirname, exists
-
-
-class Config(object):
-
-    key = 'grc'
-    name = 'GNU Radio Companion'
-    license = __doc__.strip()
-    website = 'http://gnuradio.org'
-    version = gr.version()
-    version2 = (gr.major_version(), gr.api_version(), gr.minor_version())
-
-    hier_block_lib_dir = os.environ.get('GRC_HIER_PATH', expanduser('~/.grc_gnuradio'))
-
-    def __init__(self):
-        self.prefs = self._get_prefs()
-
-        if not exists(self.hier_block_lib_dir):
-            os.mkdir(self.hier_block_lib_dir)
-
-    @staticmethod
-    def _get_prefs():
-        try:
-            from gnuradio import gr
-            prefs = gr.prefs()
-        except ImportError:
-            import ConfigParser
-            prefs = ConfigParser.ConfigParser()
-
-        return prefs
-
-    @property
-    def block_paths(self):
-        path_list_sep = {'/': ':', '\\': ';'}[os.path.sep]
-
-        paths_sources = (
-            self.hier_block_lib_dir,
-            os.environ.get('GRC_BLOCKS_PATH', ''),
-            self.prefs.get_string('grc', 'local_blocks_path', ''),
-            self.prefs.get_string('grc', 'global_blocks_path', ''),
-        )
-
-        collected_paths = sum((paths.split(path_list_sep)
-                               for paths in paths_sources), [])
-
-        valid_paths = [normpath(expanduser(expandvars(path)))
-                       for path in collected_paths if exists(path)]
-
-        return valid_paths
-
-
 class Platform(Element):
 
+    Config = Config
     Generator = Generator
     FlowGraph = FlowGraph
     Connection = Connection
@@ -96,11 +46,11 @@ class Platform(Element):
 
     is_platform = True
 
-    def __init__(self):
+    def __init__(self, *args, **kwargs):
         """ Make a platform for GNU Radio """
         Element.__init__(self)
 
-        self.config = Config()
+        self.config = self.Config(*args, **kwargs)
 
         self.block_docstrings = {}
         self.block_docstrings_loaded_callback = lambda: None  # dummy to be replaced by BlockTreeWindow
diff --git a/grc/core/generator/Generator.py b/grc/core/generator/Generator.py
index 5c2fa6e0d5..91671072d6 100644
--- a/grc/core/generator/Generator.py
+++ b/grc/core/generator/Generator.py
@@ -259,9 +259,12 @@ class HierBlockGenerator(TopBlockGenerator):
         TopBlockGenerator.__init__(self, flow_graph, file_path)
         platform = flow_graph.get_parent()
 
+        hier_block_lib_dir = platform.config.hier_block_lib_dir
+        if not os.path.exists(hier_block_lib_dir):
+            os.mkdir(hier_block_lib_dir)
+
         self._mode = HIER_BLOCK_FILE_MODE
-        self.file_path = os.path.join(platform.config.hier_block_lib_dir,
-                                      self._flow_graph.get_option('id') + '.py')
+        self.file_path = os.path.join(hier_block_lib_dir, self._flow_graph.get_option('id') + '.py')
         self._file_path_xml = self.file_path + '.xml'
 
     def get_file_path_xml(self):
@@ -388,4 +391,4 @@ class QtHierBlockGenerator(HierBlockGenerator):
             "\n#set $win = 'self.%s' % $id"
             "\n${gui_hint()($win)}"
         )
-        return n
-\ No newline at end of file
+        return n
diff --git a/grc/core/utils/epy_block_io.py b/grc/core/utils/epy_block_io.py
index c070e1c3f3..df3a4bbc3e 100644
--- a/grc/core/utils/epy_block_io.py
+++ b/grc/core/utils/epy_block_io.py
@@ -2,9 +2,6 @@
 import inspect
 import collections
 
-from gnuradio import gr
-import pmt
-
 
 TYPE_MAP = {
     'complex64': 'complex', 'complex': 'complex',
@@ -31,21 +28,27 @@ def _ports(sigs, msgs):
     return ports
 
 
-def _blk_class(source_code):
+def _find_block_class(source_code, cls):
     ns = {}
     try:
         exec source_code in ns
     except Exception as e:
         raise ValueError("Can't interpret source code: " + str(e))
     for var in ns.itervalues():
-        if inspect.isclass(var) and issubclass(var, gr.gateway.gateway_block):
+        if inspect.isclass(var) and issubclass(var, cls):
             return var
     raise ValueError('No python block class found in code')
 
 
 def extract(cls):
+    try:
+        from gnuradio import gr
+        import pmt
+    except ImportError:
+        raise EnvironmentError("Can't import GNU Radio")
+
     if not inspect.isclass(cls):
-        cls = _blk_class(cls)
+        cls = _find_block_class(cls, gr.gateway.gateway_block)
 
     spec = inspect.getargspec(cls.__init__)
     defaults = map(repr, spec.defaults or ())
diff --git a/grc/gui/ActionHandler.py b/grc/gui/ActionHandler.py
index 139bbedffd..24add2780f 100644
--- a/grc/gui/ActionHandler.py
+++ b/grc/gui/ActionHandler.py
@@ -23,8 +23,7 @@ import gtk
 import os
 import subprocess
 
-from . import Dialogs, Preferences, Actions, Executor
-from .Constants import DEFAULT_CANVAS_SIZE, IMAGE_FILE_EXTENSION, GR_PREFIX, XTERM_EXECUTABLE
+from . import Dialogs, Preferences, Actions, Executor, Constants
 from .FileDialogs import (OpenFlowGraphFileDialog, SaveFlowGraphFileDialog,
                           SaveReportsFileDialog, SaveScreenShotDialog,
                           OpenQSSFileDialog)
@@ -32,8 +31,7 @@ from .MainWindow import MainWindow
 from .ParserErrorsDialog import ParserErrorsDialog
 from .PropsDialog import PropsDialog
 
-from ..core import Constants, ParseXML
-from ..core import Messages
+from ..core import ParseXML, Messages
 
 gobject.threads_init()
 
@@ -487,12 +485,13 @@ class ActionHandler:
                     self.main_window.menu_bar.refresh_submenus()
 
         elif action == Actions.FLOW_GRAPH_OPEN_QSS_THEME:
-            file_paths = OpenQSSFileDialog(GR_PREFIX + '/share/gnuradio/themes/').run()
+            file_paths = OpenQSSFileDialog(self.platform.config.install_prefix +
+                                           '/share/gnuradio/themes/').run()
             if file_paths:
                 try:
-                    from gnuradio import gr
-                    gr.prefs().set_string("qtgui", "qss", file_paths[0])
-                    gr.prefs().save()
+                    prefs = self.platform.config.prefs
+                    prefs.set_string("qtgui", "qss", file_paths[0])
+                    prefs.save()
                 except Exception as e:
                     Messages.send("Failed to save QSS preference: " + str(e))
         elif action == Actions.FLOW_GRAPH_CLOSE:
@@ -522,7 +521,7 @@ class ActionHandler:
             file_path, background_transparent = SaveScreenShotDialog(self.get_page().get_file_path()).run()
             if file_path is not None:
                 pixbuf = self.get_flow_graph().get_drawing_area().get_screenshot(background_transparent)
-                pixbuf.save(file_path, IMAGE_FILE_EXTENSION[1:])
+                pixbuf.save(file_path, Constants.IMAGE_FILE_EXTENSION[1:])
         ##################################################
         # Gen/Exec/Stop
         ##################################################
@@ -540,10 +539,11 @@ class ActionHandler:
         elif action == Actions.FLOW_GRAPH_EXEC:
             if not self.get_page().get_proc():
                 Actions.FLOW_GRAPH_GEN()
-                if Preferences.xterm_missing() != XTERM_EXECUTABLE:
-                    if not os.path.exists(XTERM_EXECUTABLE):
-                        Dialogs.MissingXTermDialog(XTERM_EXECUTABLE)
-                    Preferences.xterm_missing(XTERM_EXECUTABLE)
+                xterm = self.platform.config.xterm_executable
+                if Preferences.xterm_missing() != xterm:
+                    if not os.path.exists(xterm):
+                        Dialogs.MissingXTermDialog(xterm)
+                    Preferences.xterm_missing(xterm)
                 if self.get_page().get_saved() and self.get_page().get_file_path():
                     Executor.ExecFlowGraphThread(self)
         elif action == Actions.FLOW_GRAPH_KILL:
@@ -634,7 +634,7 @@ class ActionHandler:
         self.main_window.update()
         try: #set the size of the flow graph area (if changed)
             new_size = (self.get_flow_graph().get_option('window_size') or
-                        DEFAULT_CANVAS_SIZE)
+                        self.platform.config.default_canvas_size)
             if self.get_flow_graph().get_size() != tuple(new_size):
                 self.get_flow_graph().set_size(*new_size)
         except: pass
diff --git a/grc/gui/CMakeLists.txt b/grc/gui/CMakeLists.txt
index 7e4355357b..e9c4f71e69 100644
--- a/grc/gui/CMakeLists.txt
+++ b/grc/gui/CMakeLists.txt
@@ -22,6 +22,7 @@ GR_PYTHON_INSTALL(FILES
     external_editor.py
     Block.py
     Colors.py
+    Config.py
     Constants.py
     Connection.py
     Element.py
diff --git a/grc/gui/Config.py b/grc/gui/Config.py
new file mode 100644
index 0000000000..9b0c5d4afe
--- /dev/null
+++ b/grc/gui/Config.py
@@ -0,0 +1,74 @@
+"""
+Copyright 2016 Free Software Foundation, Inc.
+This file is part of GNU Radio
+
+GNU Radio Companion is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; either version 2
+of the License, or (at your option) any later version.
+
+GNU Radio Companion is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+"""
+
+import sys
+import os
+from ..core.Config import Config as _Config
+from . import Constants
+
+
+class Config(_Config):
+
+    name = 'GNU Radio Companion'
+
+    gui_prefs_file = os.environ.get(
+        'GRC_PREFS_PATH', os.path.expanduser('~/.gnuradio/grc.conf'))
+
+    def __init__(self, install_prefix, *args, **kwargs):
+        _Config.__init__(self, *args, **kwargs)
+        self.install_prefix = install_prefix
+        Constants.update_font_size(self.font_size)
+
+    @property
+    def editor(self):
+        return self.prefs.get_string('grc', 'editor', '')
+
+    @editor.setter
+    def editor(self, value):
+        self.prefs.get_string('grc', 'editor', value)
+        self.prefs.save()
+
+    @property
+    def xterm_executable(self):
+        return self.prefs.get_string('grc', 'xterm_executable', 'xterm')
+
+    @property
+    def default_canvas_size(self):
+        try:  # ugly, but matches current code style
+            raw = self.prefs.get_string('grc', 'canvas_default_size', '1280, 1024')
+            value = tuple(int(x.strip('() ')) for x in raw.split(','))
+            if len(value) != 2 or not all(300 < x < 4096 for x in value):
+                raise Exception()
+            return value
+        except:
+            print >> sys.stderr, "Error: invalid 'canvas_default_size' setting."
+            return Constants.DEFAULT_CANVAS_SIZE_DEFAULT
+
+    @property
+    def font_size(self):
+        try:  # ugly, but matches current code style
+            font_size = self.prefs.get_long('grc', 'canvas_font_size',
+                                            Constants.DEFAULT_FONT_SIZE)
+            if font_size <= 0:
+                raise Exception()
+        except:
+            font_size = Constants.DEFAULT_FONT_SIZE
+            print >> sys.stderr, "Error: invalid 'canvas_font_size' setting."
+
+        return font_size
diff --git a/grc/gui/Constants.py b/grc/gui/Constants.py
index b891c5b313..e267c6ca02 100644
--- a/grc/gui/Constants.py
+++ b/grc/gui/Constants.py
@@ -17,28 +17,10 @@ along with this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 """
 
-import os
-import sys
-
-import pygtk
-pygtk.require('2.0')
 import gtk
 
-from gnuradio import gr
-
-prefs = gr.prefs()
-GR_PREFIX = gr.prefix()
-EDITOR = prefs.get_string('grc', 'editor', '')
-XTERM_EXECUTABLE = prefs.get_string('grc', 'xterm_executable', 'xterm')
+from ..core.Constants import *
 
-PREFS_FILE = os.environ.get(
-        'GRC_PREFS_PATH',
-        os.path.expanduser('~/.gnuradio/grc.conf')
-)
-PREFS_FILE_OLD = os.environ.get(
-        'GRC_PREFS_PATH',
-        os.path.expanduser('~/.grc')
-)
 
 # default path for the open/save dialogs
 DEFAULT_FILE_PATH = os.getcwd()
@@ -60,28 +42,12 @@ MIN_DIALOG_HEIGHT = 500
 DEFAULT_BLOCKS_WINDOW_WIDTH = 100
 DEFAULT_REPORTS_WINDOW_WIDTH = 100
 
-try:  # ugly, but matches current code style
-    raw = prefs.get_string('grc', 'canvas_default_size', '1280, 1024')
-    DEFAULT_CANVAS_SIZE = tuple(int(x.strip('() ')) for x in raw.split(','))
-    if len(DEFAULT_CANVAS_SIZE) != 2 or not all(300 < x < 4096 for x in DEFAULT_CANVAS_SIZE):
-        raise Exception()
-except:
-    DEFAULT_CANVAS_SIZE = 1280, 1024
-    print >> sys.stderr, "Error: invalid 'canvas_default_size' setting."
-
-#  flow-graph canvas fonts
-try:  # ugly, but matches current code style
-    FONT_SIZE = prefs.get_long('grc', 'canvas_font_size', 8)
-    if FONT_SIZE <= 0:
-        raise Exception()
-except:
-    FONT_SIZE = 8
-    print >> sys.stderr, "Error: invalid 'canvas_font_size' setting."
-FONT_FAMILY = "Sans"
-BLOCK_FONT = "%s %f" % (FONT_FAMILY, FONT_SIZE)
-PORT_FONT = BLOCK_FONT
-PARAM_FONT = "%s %f" % (FONT_FAMILY, FONT_SIZE - 0.5)
+DEFAULT_CANVAS_SIZE_DEFAULT = 1280, 1024
 
+FONT_SIZE = DEFAULT_FONT_SIZE = 8
+FONT_FAMILY = "Sans"
+BLOCK_FONT = PORT_FONT = "Sans 8"
+PARAM_FONT = "Sans 7.5"
 
 # size of the state saving cache in the flow graph (undo/redo functionality)
 STATE_CACHE_SIZE = 42
@@ -100,8 +66,7 @@ CANVAS_GRID_SIZE = 8
 # port constraint dimensions
 PORT_BORDER_SEPARATION = 8
 PORT_SPACING = 2 * PORT_BORDER_SEPARATION
-PORT_SEPARATION = PORT_SPACING + 2 * PORT_LABEL_PADDING + int(1.5 * FONT_SIZE)
-PORT_SEPARATION += -PORT_SEPARATION % (2 * CANVAS_GRID_SIZE)  # even multiple
+PORT_SEPARATION = 32
 
 PORT_MIN_WIDTH = 20
 PORT_LABEL_HIDDEN_WIDTH = 10
@@ -130,3 +95,17 @@ SCROLL_DISTANCE = 15
 
 # How close the mouse click can be to a line and register a connection select.
 LINE_SELECT_SENSITIVITY = 5
+
+
+def update_font_size(font_size):
+    global PORT_SEPARATION, BLOCK_FONT, PORT_FONT, PARAM_FONT, FONT_SIZE
+
+    FONT_SIZE = font_size
+    BLOCK_FONT = "%s %f" % (FONT_FAMILY, font_size)
+    PORT_FONT = BLOCK_FONT
+    PARAM_FONT = "%s %f" % (FONT_FAMILY, font_size - 0.5)
+
+    PORT_SEPARATION = PORT_SPACING + 2 * PORT_LABEL_PADDING + int(1.5 * font_size)
+    PORT_SEPARATION += -PORT_SEPARATION % (2 * CANVAS_GRID_SIZE)  # even multiple
+
+update_font_size(DEFAULT_FONT_SIZE)
diff --git a/grc/gui/Dialogs.py b/grc/gui/Dialogs.py
index c5b4d8b2a7..6cfdd50a34 100644
--- a/grc/gui/Dialogs.py
+++ b/grc/gui/Dialogs.py
@@ -22,7 +22,7 @@ import gtk
 import sys
 from distutils.spawn import find_executable
 
-from . import Utils, Actions, Constants
+from . import Utils, Actions
 from ..core import Messages
 
 
@@ -238,7 +238,7 @@ def MissingXTermDialog(xterm):
     )
 
 
-def ChooseEditorDialog():
+def ChooseEditorDialog(config):
     # Give the option to either choose an editor or use the default
     # Always return true/false so the caller knows it was successful
     buttons = (
@@ -264,10 +264,7 @@ def ChooseEditorDialog():
         file_dialog.set_current_folder('/usr/bin')
         try:
             if file_dialog.run() == gtk.RESPONSE_OK:
-                file_path = file_dialog.get_filename()
-                Constants.prefs.set_string('grc', 'editor', file_path)
-                Constants.prefs.save()
-                Constants.EDITOR = file_path
+                config.editor = file_path = file_dialog.get_filename()
                 file_dialog.destroy()
                 return file_path
         finally:
@@ -285,16 +282,12 @@ def ChooseEditorDialog():
             if process is None:
                 raise ValueError("Can't find default editor executable")
             # Save
-            Constants.prefs.set_string('grc', 'editor', process)
-            Constants.prefs.save()
-            Constants.EDITOR = process
+            config.editor = process
             return process
         except Exception:
             Messages.send('>>> Unable to load the default editor. Please choose an editor.\n')
             # Just reset of the constant and force the user to select an editor the next time
-            Constants.prefs.set_string('grc', 'editor', '')
-            Constants.prefs.save()
-            Constants.EDITOR = ""
+            config.editor = ''
             return
 
     Messages.send('>>> No editor selected.\n')
diff --git a/grc/gui/Executor.py b/grc/gui/Executor.py
index 96b95f4c7a..f75f514cdb 100644
--- a/grc/gui/Executor.py
+++ b/grc/gui/Executor.py
@@ -25,7 +25,6 @@ import re
 from distutils.spawn import find_executable
 
 from ..core import Messages
-from .Constants import XTERM_EXECUTABLE
 
 
 class ExecFlowGraphThread(threading.Thread):
@@ -41,6 +40,7 @@ class ExecFlowGraphThread(threading.Thread):
         threading.Thread.__init__(self)
         self.update_exec_stop = action_handler.update_exec_stop
         self.flow_graph = action_handler.get_flow_graph()
+        self.xterm_executable = action_handler.platform.config.xterm_executable
         #store page and dont use main window calls in run
         self.page = action_handler.get_page()
         #get the popen
@@ -70,7 +70,7 @@ class ExecFlowGraphThread(threading.Thread):
             raise ValueError("Can't parse run command {!r}: {}".format(run_command, e))
 
         # When in no gui mode on linux, use a graphical terminal (looks nice)
-        xterm_executable = find_executable(XTERM_EXECUTABLE)
+        xterm_executable = find_executable(self.xterm_executable)
         if generator.generate_options == 'no_gui' and xterm_executable:
             run_command_args = [xterm_executable, '-e', run_command]
 
diff --git a/grc/gui/FlowGraph.py b/grc/gui/FlowGraph.py
index 25fb157b1e..2f8ca0070e 100644
--- a/grc/gui/FlowGraph.py
+++ b/grc/gui/FlowGraph.py
@@ -88,8 +88,9 @@ class FlowGraph(Element, _Flowgraph):
         if target in self._external_updaters:
             editor = self._external_updaters[target]
         else:
-            editor = (find_executable(Constants.EDITOR) or
-                      Dialogs.ChooseEditorDialog())
+            config = self.get_parent().config
+            editor = (find_executable(config.editor) or
+                      Dialogs.ChooseEditorDialog(config))
             if not editor:
                 return
             updater = functools.partial(
@@ -106,9 +107,7 @@ class FlowGraph(Element, _Flowgraph):
             # Problem launching the editor. Need to select a new editor.
             Messages.send('>>> Error opening an external editor. Please select a different editor.\n')
             # Reset the editor to force the user to select a new one.
-            Constants.prefs.set_string('grc', 'editor', '')
-            Constants.prefs.save()
-            Constants.EDITOR = ""
+            self.get_parent().config.editor = ''
 
     def handle_external_editor_change(self, new_value, target):
         try:
diff --git a/grc/gui/Param.py b/grc/gui/Param.py
index 647e81746a..bf0a59b96b 100644
--- a/grc/gui/Param.py
+++ b/grc/gui/Param.py
@@ -23,7 +23,7 @@ import pygtk
 pygtk.require('2.0')
 import gtk
 
-from . import Colors, Utils, Constants, Dialogs
+from . import Colors, Utils, Constants
 from .Element import Element
 
 from ..core.Param import Param as _Param
@@ -319,7 +319,9 @@ class FileParam(EntryParam):
         if self.param.get_key() == 'qt_qss_theme':
             dirname = os.path.dirname(dirname)  # trim filename
             if not os.path.exists(dirname):
-               dirname = os.path.join(Constants.GR_PREFIX, '/share/gnuradio/themes')
+               platform = self.param.get_parent().get_parent().get_parent()
+               dirname = os.path.join(platform.config.install_prefix,
+                                      '/share/gnuradio/themes')
         if not os.path.exists(dirname):
             dirname = os.getcwd()  # fix bad paths
 
diff --git a/grc/gui/Platform.py b/grc/gui/Platform.py
index cfd5ae3e3d..500df1cce4 100644
--- a/grc/gui/Platform.py
+++ b/grc/gui/Platform.py
@@ -22,9 +22,9 @@ import sys
 
 from ..core.Platform import Platform as _Platform
 
+from .Config import Config as _Config
 from .Block import Block as _Block
 from .Connection import Connection as _Connection
-from .Constants import PREFS_FILE, PREFS_FILE_OLD
 from .Element import Element
 from .FlowGraph import FlowGraph as _FlowGraph
 from .Param import Param as _Param
@@ -33,28 +33,30 @@ from .Port import Port as _Port
 
 class Platform(Element, _Platform):
 
-    def __init__(self):
+    def __init__(self, *args, **kwargs):
         Element.__init__(self)
-        _Platform.__init__(self)
+        _Platform.__init__(self, *args, **kwargs)
 
         # Ensure conf directories
-        if not os.path.exists(os.path.dirname(PREFS_FILE)):
-            os.mkdir(os.path.dirname(PREFS_FILE))
+        gui_prefs_file = self.config.gui_prefs_file
+        if not os.path.exists(os.path.dirname(gui_prefs_file)):
+            os.mkdir(os.path.dirname(gui_prefs_file))
 
         self._move_old_pref_file()
-        self._prefs_file = PREFS_FILE
 
     def get_prefs_file(self):
-        return self._prefs_file
+        return self.config.gui_prefs_file
 
-    @staticmethod
-    def _move_old_pref_file():
-        if PREFS_FILE == PREFS_FILE_OLD:
+    def _move_old_pref_file(self):
+        gui_prefs_file = self.config.gui_prefs_file
+        old_gui_prefs_file = os.environ.get(
+            'GRC_PREFS_PATH', os.path.expanduser('~/.grc'))
+        if gui_prefs_file == old_gui_prefs_file:
             return  # prefs file overridden with env var
-        if os.path.exists(PREFS_FILE_OLD) and not os.path.exists(PREFS_FILE):
+        if os.path.exists(old_gui_prefs_file) and not os.path.exists(gui_prefs_file):
             try:
                 import shutil
-                shutil.move(PREFS_FILE_OLD, PREFS_FILE)
+                shutil.move(old_gui_prefs_file, gui_prefs_file)
             except Exception as e:
                 print >> sys.stderr, e
 
@@ -66,3 +68,4 @@ class Platform(Element, _Platform):
     Block = _Block
     Port = _Port
     Param = _Param
+    Config = _Config
diff --git a/grc/scripts/gnuradio-companion b/grc/scripts/gnuradio-companion
index 3a3bf503c2..04529890da 100755
--- a/grc/scripts/gnuradio-companion
+++ b/grc/scripts/gnuradio-companion
@@ -123,7 +123,12 @@ def main():
     except:
         pass
 
-    ActionHandler(args, Platform())
+    ActionHandler(args, Platform(
+        prefs_file=gr.prefs(),
+        version=gr.version(),
+        version_parts=(gr.major_version(), gr.api_version(), gr.minor_version()),
+        install_prefix=gr.prefix()
+    ))
 
 
 if __name__ == '__main__':