Merged grc developer branch r10679:10938

Misc fixes and internal changes.
Added help menu for usage tips.
Added drag and drop for blocks.
Removed callback controls, adopted forms.
Any type can have enumerated options.



git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@10941 221aa14e-8319-0410-a670-987f0aec2ac5

8 files changed, 203 insertions, 155 deletions

diff --git a/grc/src/gui/ActionHandler.py b/grc/src/gui/ActionHandler.py
index 91dd0fb45..da0909a64 100644
--- a/grc/src/gui/ActionHandler.py
+++ b/grc/src/gui/ActionHandler.py
@@ -1,5 +1,5 @@
 """
-Copyright 2007 Free Software Foundation, Inc.
+Copyright 2007, 2008, 2009 Free Software Foundation, Inc.
 This file is part of GNU Radio
 
 GNU Radio Companion is free software; you can redistribute it and/or
@@ -19,7 +19,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 
 import os
 import signal 
-from Constants import DIR_LEFT, DIR_RIGHT, IMAGE_FILE_EXTENSION
+from Constants import IMAGE_FILE_EXTENSION
 import Actions
 import pygtk
 pygtk.require('2.0')
@@ -32,7 +32,8 @@ from .. utils import ParseXML
 import random
 from .. platforms.gui.Platform import Platform
 from MainWindow import MainWindow
-from Dialogs import AboutDialog
+from ParamsDialog import ParamsDialog
+import Dialogs
 from FileDialogs import OpenFlowGraphFileDialog, SaveFlowGraphFileDialog, SaveImageFileDialog
 
 gobject.threads_init()
@@ -57,7 +58,7 @@ class ActionHandler:
 		#setup the main window
 		self.main_window = MainWindow(self.handle_states, platform)
 		self.main_window.connect('delete_event', self._quit)
-		self.main_window.connect('key_press_event', self._handle_key_press)
+		self.main_window.connect('key-press-event', self._handle_key_press)
 		self.get_page = self.main_window.get_page
 		self.get_flow_graph = self.main_window.get_flow_graph
 		self.get_focus_flag = self.main_window.drawing_area.get_focus_flag
@@ -72,32 +73,25 @@ class ActionHandler:
 
 	def _handle_key_press(self, widget, event):
 		"""
-		Handle key presses from the keyboard and translate key combos into actions.
-		This key press handler is called before the gtk accelerators kick in.
-		This handler ensures that key presses without a mod mask,
-		only pass to the accelerators if the flow graph is in focus.
-		This function also handles keys that accelerators refuse to handle: left/right,
-		and keys that are not registered with an accelerator: +/-.
-		@return false to let the accelerators handle the key action
+		Handle key presses from the keyboard and translate key combinations into actions.
+		This key press handler is called prior to the gtk key press handler.
+		This handler bypasses built in accelerator key handling when in focus because
+		* some keys are ignored by the accelerators like the direction keys,
+		* some keys are not registered to any accelerators but are still used.
+		When not in focus, gtk and the accelerators handle the the key press.
+		@return false to let gtk handle the key action
 		"""
-		if self.get_focus_flag():
-			try:
-				self.handle_states({
-					'Left': Actions.BLOCK_ROTATE_LEFT,
-					'Right': Actions.BLOCK_ROTATE_RIGHT,
-					'Up': Actions.BLOCK_DEC_TYPE,
-					'Down': Actions.BLOCK_INC_TYPE,
-					'equal': Actions.PORT_CONTROLLER_INC,
-					'plus': Actions.PORT_CONTROLLER_INC,
-					'KP_Add': Actions.PORT_CONTROLLER_INC,
-					'minus': Actions.PORT_CONTROLLER_DEC,
-					'KP_Subtract': Actions.PORT_CONTROLLER_DEC,
-				}[gtk.gdk.keyval_name(event.keyval)])
-				return True
-			#focus: always return false for accelerator to handle
-			except: return False
-		#no focus: only allow accelerator to handle when a mod is used
-		return not event.state
+		#dont allow key presses to queue up
+		if gtk.events_pending(): return True
+		#extract action name from this key press
+		key_name = gtk.gdk.keyval_name(event.keyval)
+		mod_mask = event.state
+		action_name = Actions.get_action_name_from_key_name(key_name, mod_mask)
+		#handle the action if flow graph is in focus
+		if action_name and self.get_focus_flag():
+			self.handle_states(action_name)
+			return True #handled by this method
+		return False #let gtk handle the key press
 
 	def _quit(self, window, event):
 		"""
@@ -138,7 +132,7 @@ class ActionHandler:
 				Actions.APPLICATION_QUIT, Actions.FLOW_GRAPH_NEW,
 				Actions.FLOW_GRAPH_OPEN, Actions.FLOW_GRAPH_SAVE_AS,
 				Actions.FLOW_GRAPH_CLOSE, Actions.ABOUT_WINDOW_DISPLAY,
-				Actions.FLOW_GRAPH_SCREEN_CAPTURE,
+				Actions.FLOW_GRAPH_SCREEN_CAPTURE, Actions.HELP_WINDOW_DISPLAY,
 			): Actions.get_action_from_name(action).set_sensitive(True)
 			if not self.init_file_paths:
 				self.init_file_paths = Preferences.files_open()
@@ -193,13 +187,13 @@ class ActionHandler:
 		elif state == Actions.BLOCK_MOVE:
 			self.get_page().get_state_cache().save_new_state(self.get_flow_graph().export_data())
 			self.get_page().set_saved(False)
-		elif state == Actions.BLOCK_ROTATE_LEFT:
-			if self.get_flow_graph().rotate_selected(DIR_LEFT):
+		elif state == Actions.BLOCK_ROTATE_CCW:
+			if self.get_flow_graph().rotate_selected(90):
 				self.get_flow_graph().update()
 				self.get_page().get_state_cache().save_new_state(self.get_flow_graph().export_data())
 				self.get_page().set_saved(False)
-		elif state == Actions.BLOCK_ROTATE_RIGHT:
-			if self.get_flow_graph().rotate_selected(DIR_RIGHT):
+		elif state == Actions.BLOCK_ROTATE_CW:
+			if self.get_flow_graph().rotate_selected(-90):
 				self.get_flow_graph().update()
 				self.get_page().get_state_cache().save_new_state(self.get_flow_graph().export_data())
 				self.get_page().set_saved(False)
@@ -238,12 +232,15 @@ class ActionHandler:
 		# Window stuff
 		##################################################
 		elif state == Actions.ABOUT_WINDOW_DISPLAY:
-			AboutDialog()
+			Dialogs.AboutDialog()
+		elif state == Actions.HELP_WINDOW_DISPLAY:
+			Dialogs.HelpDialog()
 		##################################################
 		# Param Modifications
 		##################################################
 		elif state == Actions.BLOCK_PARAM_MODIFY:
-			if self.get_flow_graph().param_modify_selected():
+			selected_block = self.get_flow_graph().get_selected_block()
+			if selected_block and ParamsDialog(selected_block).run():
 				self.get_flow_graph().update()
 				self.get_page().get_state_cache().save_new_state(self.get_flow_graph().export_data())
 				self.get_page().set_saved(False)
@@ -296,7 +293,7 @@ class ActionHandler:
 		elif state == Actions.FLOW_GRAPH_SCREEN_CAPTURE:
 			file_path = SaveImageFileDialog(self.get_page().get_file_path()).run()
 			if file_path is not None:
-				pixmap = self.get_flow_graph().get_drawing_area().pixmap
+				pixmap = self.get_flow_graph().get_pixmap()
 				width, height = pixmap.get_size()
 				pixbuf = gtk.gdk.Pixbuf(gtk.gdk.COLORSPACE_RGB, 0, 8, width, height)
 				pixbuf.get_from_drawable(pixmap, pixmap.get_colormap(), 0, 0, 0, 0, width, height)
@@ -333,8 +330,8 @@ class ActionHandler:
 		#update general buttons
 		Actions.get_action_from_name(Actions.ELEMENT_DELETE).set_sensitive(bool(self.get_flow_graph().get_selected_elements()))
 		Actions.get_action_from_name(Actions.BLOCK_PARAM_MODIFY).set_sensitive(bool(self.get_flow_graph().get_selected_block()))
-		Actions.get_action_from_name(Actions.BLOCK_ROTATE_RIGHT).set_sensitive(bool(self.get_flow_graph().get_selected_blocks()))
-		Actions.get_action_from_name(Actions.BLOCK_ROTATE_LEFT).set_sensitive(bool(self.get_flow_graph().get_selected_blocks()))
+		Actions.get_action_from_name(Actions.BLOCK_ROTATE_CCW).set_sensitive(bool(self.get_flow_graph().get_selected_blocks()))
+		Actions.get_action_from_name(Actions.BLOCK_ROTATE_CW).set_sensitive(bool(self.get_flow_graph().get_selected_blocks()))
 		#update cut/copy/paste
 		Actions.get_action_from_name(Actions.BLOCK_CUT).set_sensitive(bool(self.get_flow_graph().get_selected_blocks()))
 		Actions.get_action_from_name(Actions.BLOCK_COPY).set_sensitive(bool(self.get_flow_graph().get_selected_blocks()))
@@ -348,7 +345,7 @@ class ActionHandler:
 		Actions.get_action_from_name(Actions.FLOW_GRAPH_SAVE).set_sensitive(not self.get_page().get_saved())
 		self.main_window.update()
 		#draw the flow graph
-		self.get_flow_graph().draw()
+		self.get_flow_graph().queue_draw()
 
 	def update_exec_stop(self):
 		"""
diff --git a/grc/src/gui/Actions.py b/grc/src/gui/Actions.py
index 16f12dd4c..9b687df7e 100644
--- a/grc/src/gui/Actions.py
+++ b/grc/src/gui/Actions.py
@@ -1,5 +1,5 @@
 """
-Copyright 2007 Free Software Foundation, Inc.
+Copyright 2007, 2008, 2009 Free Software Foundation, Inc.
 This file is part of GNU Radio
 
 GNU Radio Companion is free software; you can redistribute it and/or
@@ -28,8 +28,8 @@ APPLICATION_INITIALIZE = 'app init'
 APPLICATION_QUIT = 'app quit'
 PARAM_MODIFY = 'param modify'
 BLOCK_MOVE = 'block move'
-BLOCK_ROTATE_LEFT = 'block rotate left'
-BLOCK_ROTATE_RIGHT = 'block rotate right'
+BLOCK_ROTATE_CCW = 'block rotate ccw'
+BLOCK_ROTATE_CW = 'block rotate cw'
 BLOCK_PARAM_MODIFY = 'block param modify'
 BLOCK_INC_TYPE = 'block increment type'
 BLOCK_DEC_TYPE = 'block decrement type'
@@ -56,60 +56,85 @@ FLOW_GRAPH_EXEC = 'flow graph exec'
 FLOW_GRAPH_KILL = 'flow graph kill'
 FLOW_GRAPH_SCREEN_CAPTURE = 'flow graph screen capture'
 ABOUT_WINDOW_DISPLAY = 'about window display'
+HELP_WINDOW_DISPLAY = 'help window display'
 
 ######################################################################################################
 # Action Key Map
 ######################################################################################################
-_actions_key_map = {
-	#action name: (key name, mask)
-	FLOW_GRAPH_NEW: ('n', gtk.gdk.CONTROL_MASK),
-	FLOW_GRAPH_OPEN: ('o', gtk.gdk.CONTROL_MASK),
-	FLOW_GRAPH_SAVE: ('s', gtk.gdk.CONTROL_MASK),
-	FLOW_GRAPH_CLOSE: ('w', gtk.gdk.CONTROL_MASK),
-	APPLICATION_QUIT: ('q', gtk.gdk.CONTROL_MASK),
-	FLOW_GRAPH_UNDO: ('z', gtk.gdk.CONTROL_MASK),
-	FLOW_GRAPH_REDO: ('y', gtk.gdk.CONTROL_MASK),
-	ELEMENT_DELETE: ('Delete', 0),
-	BLOCK_ROTATE_LEFT: ('Left', 0),
-	BLOCK_ROTATE_RIGHT: ('Right', 0),
-	BLOCK_PARAM_MODIFY: ('Return', 0),
-	BLOCK_ENABLE: ('e', 0),
-	BLOCK_DISABLE: ('d', 0),
-	BLOCK_CUT: ('x', gtk.gdk.CONTROL_MASK),
-	BLOCK_COPY: ('c', gtk.gdk.CONTROL_MASK),
-	BLOCK_PASTE: ('v', gtk.gdk.CONTROL_MASK),
-	FLOW_GRAPH_GEN: ('F5', 0),
-	FLOW_GRAPH_EXEC: ('F6', 0),
-	FLOW_GRAPH_KILL: ('F7', 0),
-	FLOW_GRAPH_SCREEN_CAPTURE: ('Print', 0),
-}
+_actions_key_list = (
+	#action name, key name, mod mask
+	(FLOW_GRAPH_NEW, 'n', gtk.gdk.CONTROL_MASK),
+	(FLOW_GRAPH_OPEN, 'o', gtk.gdk.CONTROL_MASK),
+	(FLOW_GRAPH_SAVE, 's', gtk.gdk.CONTROL_MASK),
+	(FLOW_GRAPH_SAVE_AS, 's', gtk.gdk.CONTROL_MASK | gtk.gdk.SHIFT_MASK),
+	(FLOW_GRAPH_CLOSE, 'w', gtk.gdk.CONTROL_MASK),
+	(APPLICATION_QUIT, 'q', gtk.gdk.CONTROL_MASK),
+	(FLOW_GRAPH_UNDO, 'z', gtk.gdk.CONTROL_MASK),
+	(FLOW_GRAPH_REDO, 'y', gtk.gdk.CONTROL_MASK),
+	(ELEMENT_DELETE, 'Delete', 0),
+	(BLOCK_ROTATE_CCW, 'Left', 0),
+	(BLOCK_ROTATE_CW, 'Right', 0),
+	(BLOCK_DEC_TYPE, 'Up', 0),
+	(BLOCK_INC_TYPE, 'Down', 0),
+	(BLOCK_PARAM_MODIFY, 'Return', 0),
+	(BLOCK_ENABLE, 'e', 0),
+	(BLOCK_DISABLE, 'd', 0),
+	(BLOCK_CUT, 'x', gtk.gdk.CONTROL_MASK),
+	(BLOCK_COPY, 'c', gtk.gdk.CONTROL_MASK),
+	(BLOCK_PASTE, 'v', gtk.gdk.CONTROL_MASK),
+	(FLOW_GRAPH_GEN, 'F5', 0),
+	(FLOW_GRAPH_EXEC, 'F6', 0),
+	(FLOW_GRAPH_KILL, 'F7', 0),
+	(FLOW_GRAPH_SCREEN_CAPTURE, 'Print', 0),
+	(HELP_WINDOW_DISPLAY, 'F1', 0),
+	#the following have no associated gtk.Action
+	(PORT_CONTROLLER_INC, 'equal', 0),
+	(PORT_CONTROLLER_INC, 'plus', 0),
+	(PORT_CONTROLLER_INC, 'KP_Add', 0),
+	(PORT_CONTROLLER_DEC, 'minus', 0),
+	(PORT_CONTROLLER_DEC, 'KP_Subtract', 0),
+)
+
+_actions_key_dict = dict(((key_name, mod_mask), action_name) for action_name, key_name, mod_mask in _actions_key_list)
+def get_action_name_from_key_name(key_name, mod_mask=0):
+	"""
+	Get the action name associated with the key name and mask.
+	Both keyname and mask have to match.
+	@param key_name the name of the key
+	@param mod_mask the key press mask (shift, ctrl) 0 for none
+	@return the action name or blank string
+	"""
+	key_name_mod_mask = (key_name, mod_mask)
+	if key_name_mod_mask in _actions_key_dict: return _actions_key_dict[key_name_mod_mask]
+	return ''
 
 ######################################################################################################
 # Actions
 ######################################################################################################
 _actions_list = (
-	gtk.Action(FLOW_GRAPH_NEW, '_New', 'Create a new flow graph', 'gtk-new'),
-	gtk.Action(FLOW_GRAPH_OPEN, '_Open', 'Open an existing flow graph', 'gtk-open'),
-	gtk.Action(FLOW_GRAPH_SAVE, '_Save', 'Save the current flow graph', 'gtk-save'),
-	gtk.Action(FLOW_GRAPH_SAVE_AS, 'Save _As', 'Save the current flow graph as...', 'gtk-save-as'),
-	gtk.Action(FLOW_GRAPH_CLOSE, '_Close', 'Close the current flow graph', 'gtk-close'),
-	gtk.Action(APPLICATION_QUIT, '_Quit', 'Quit program', 'gtk-quit'),
-	gtk.Action(FLOW_GRAPH_UNDO, '_Undo', 'Undo a change to the flow graph', 'gtk-undo'),
-	gtk.Action(FLOW_GRAPH_REDO, '_Redo', 'Redo a change to the flow graph', 'gtk-redo'),
-	gtk.Action(ELEMENT_DELETE, '_Delete', 'Delete the selected blocks', 'gtk-delete'),
-	gtk.Action(BLOCK_ROTATE_LEFT, 'Rotate _Left', 'Rotate the selected blocks 90 degrees', 'gtk-go-back'),
-	gtk.Action(BLOCK_ROTATE_RIGHT, 'Rotate _Right', 'Rotate the selected blocks -90 degrees', 'gtk-go-forward'),
-	gtk.Action(BLOCK_PARAM_MODIFY, '_Properties', 'Modify params for the selected block', 'gtk-properties'),
-	gtk.Action(BLOCK_ENABLE, 'E_nable', 'Enable the selected blocks', 'gtk-connect'),
-	gtk.Action(BLOCK_DISABLE, 'D_isable', 'Disable the selected blocks', 'gtk-disconnect'),
-	gtk.Action(BLOCK_CUT, 'Cu_t', 'Cut', 'gtk-cut'),
-	gtk.Action(BLOCK_COPY, '_Copy', 'Copy', 'gtk-copy'),
-	gtk.Action(BLOCK_PASTE, '_Paste', 'Paste', 'gtk-paste'),
-	gtk.Action(ABOUT_WINDOW_DISPLAY, '_About', 'About this program', 'gtk-about'),
-	gtk.Action(FLOW_GRAPH_GEN, '_Generate', 'Generate the flow graph', 'gtk-convert'),
-	gtk.Action(FLOW_GRAPH_EXEC, '_Execute', 'Execute the flow graph', 'gtk-execute'),
-	gtk.Action(FLOW_GRAPH_KILL, '_Kill', 'Kill the flow graph', 'gtk-stop'),
-	gtk.Action(FLOW_GRAPH_SCREEN_CAPTURE, 'S_creen Capture', 'Create a screen capture of the flow graph', 'gtk-print'),
+	gtk.Action(FLOW_GRAPH_NEW, '_New', 'Create a new flow graph', gtk.STOCK_NEW),
+	gtk.Action(FLOW_GRAPH_OPEN, '_Open', 'Open an existing flow graph', gtk.STOCK_OPEN),
+	gtk.Action(FLOW_GRAPH_SAVE, '_Save', 'Save the current flow graph', gtk.STOCK_SAVE),
+	gtk.Action(FLOW_GRAPH_SAVE_AS, 'Save _As', 'Save the current flow graph as...', gtk.STOCK_SAVE_AS),
+	gtk.Action(FLOW_GRAPH_CLOSE, '_Close', 'Close the current flow graph', gtk.STOCK_CLOSE),
+	gtk.Action(APPLICATION_QUIT, '_Quit', 'Quit program', gtk.STOCK_QUIT),
+	gtk.Action(FLOW_GRAPH_UNDO, '_Undo', 'Undo a change to the flow graph', gtk.STOCK_UNDO),
+	gtk.Action(FLOW_GRAPH_REDO, '_Redo', 'Redo a change to the flow graph', gtk.STOCK_REDO),
+	gtk.Action(ELEMENT_DELETE, '_Delete', 'Delete the selected blocks', gtk.STOCK_DELETE),
+	gtk.Action(BLOCK_ROTATE_CCW, 'Rotate Counterclockwise', 'Rotate the selected blocks 90 degrees to the left', gtk.STOCK_GO_BACK),
+	gtk.Action(BLOCK_ROTATE_CW, 'Rotate Clockwise', 'Rotate the selected blocks 90 degrees to the right', gtk.STOCK_GO_FORWARD),
+	gtk.Action(BLOCK_PARAM_MODIFY, '_Properties', 'Modify params for the selected block', gtk.STOCK_PROPERTIES),
+	gtk.Action(BLOCK_ENABLE, 'E_nable', 'Enable the selected blocks', gtk.STOCK_CONNECT),
+	gtk.Action(BLOCK_DISABLE, 'D_isable', 'Disable the selected blocks', gtk.STOCK_DISCONNECT),
+	gtk.Action(BLOCK_CUT, 'Cu_t', 'Cut', gtk.STOCK_CUT),
+	gtk.Action(BLOCK_COPY, '_Copy', 'Copy', gtk.STOCK_COPY),
+	gtk.Action(BLOCK_PASTE, '_Paste', 'Paste', gtk.STOCK_PASTE),
+	gtk.Action(ABOUT_WINDOW_DISPLAY, '_About', 'About this program', gtk.STOCK_ABOUT),
+	gtk.Action(HELP_WINDOW_DISPLAY, '_Help', 'Usage Tips', gtk.STOCK_HELP),
+	gtk.Action(FLOW_GRAPH_GEN, '_Generate', 'Generate the flow graph', gtk.STOCK_CONVERT),
+	gtk.Action(FLOW_GRAPH_EXEC, '_Execute', 'Execute the flow graph', gtk.STOCK_EXECUTE),
+	gtk.Action(FLOW_GRAPH_KILL, '_Kill', 'Kill the flow graph', gtk.STOCK_STOP),
+	gtk.Action(FLOW_GRAPH_SCREEN_CAPTURE, 'S_creen Capture', 'Create a screen capture of the flow graph', gtk.STOCK_PRINT),
 )
 def get_all_actions(): return _actions_list
 
@@ -122,16 +147,21 @@ def get_action_from_name(action_name):
 	@throw KeyError bad action name
 	@return a gtk action object
 	"""
-	if _actions_dict.has_key(action_name): return _actions_dict[action_name]
+	if action_name in _actions_dict: return _actions_dict[action_name]
 	raise KeyError('Action Name: "%s" does not exist'%action_name)
 
+######################################################################################################
+# Accelerators
+######################################################################################################
 _accel_group = gtk.AccelGroup()
 def get_accel_group(): return _accel_group
 
-#load the actions key map
 #set the accelerator group, and accelerator path
-#register the key and mod with the accelerator path
-for action_name, (key_name, mod) in _actions_key_map.iteritems():
-	get_action_from_name(action_name).set_accel_group(get_accel_group())
-	get_action_from_name(action_name).set_accel_path('<main>/'+action_name)
-	gtk.accel_map_add_entry('<main>/'+action_name, gtk.gdk.keyval_from_name(key_name),mod)
+#register the key name and mod mask with the accelerator path
+for action_name, key_name, mod_mask in _actions_key_list:
+	try:
+		accel_path = '<main>/'+action_name
+		get_action_from_name(action_name).set_accel_group(get_accel_group())
+		get_action_from_name(action_name).set_accel_path(accel_path)
+		gtk.accel_map_add_entry(accel_path, gtk.gdk.keyval_from_name(key_name), mod_mask)
+	except KeyError: pass #no action was created for this action name
diff --git a/grc/src/gui/Bars.py b/grc/src/gui/Bars.py
index c89aea580..52e7ba1f8 100644
--- a/grc/src/gui/Bars.py
+++ b/grc/src/gui/Bars.py
@@ -1,5 +1,5 @@
 """
-Copyright 2007 Free Software Foundation, Inc.
+Copyright 2007, 2008, 2009 Free Software Foundation, Inc.
 This file is part of GNU Radio
 
 GNU Radio Companion is free software; you can redistribute it and/or
@@ -43,8 +43,8 @@ TOOLBAR_LIST = (
 	Actions.FLOW_GRAPH_EXEC,
 	Actions.FLOW_GRAPH_KILL,
 	None,
-	Actions.BLOCK_ROTATE_LEFT,
-	Actions.BLOCK_ROTATE_RIGHT,
+	Actions.BLOCK_ROTATE_CCW,
+	Actions.BLOCK_ROTATE_CW,
 	None,
 	Actions.BLOCK_ENABLE,
 	Actions.BLOCK_DISABLE,
@@ -73,8 +73,8 @@ MENU_BAR_LIST = (
 		Actions.BLOCK_PASTE,
 		Actions.ELEMENT_DELETE,
 		None,
-		Actions.BLOCK_ROTATE_LEFT,
-		Actions.BLOCK_ROTATE_RIGHT,
+		Actions.BLOCK_ROTATE_CCW,
+		Actions.BLOCK_ROTATE_CW,
 		None,
 		Actions.BLOCK_ENABLE,
 		Actions.BLOCK_DISABLE,
@@ -87,6 +87,8 @@ MENU_BAR_LIST = (
 		Actions.FLOW_GRAPH_KILL,
 	]),
 	(gtk.Action('Help', '_Help', None, None), [
+		Actions.HELP_WINDOW_DISPLAY,
+		None,
 		Actions.ABOUT_WINDOW_DISPLAY,
 	]),
 )
diff --git a/grc/src/gui/BlockTreeWindow.py b/grc/src/gui/BlockTreeWindow.py
index 94b9476c5..9e4bec3f9 100644
--- a/grc/src/gui/BlockTreeWindow.py
+++ b/grc/src/gui/BlockTreeWindow.py
@@ -1,5 +1,5 @@
 """
-Copyright 2007 Free Software Foundation, Inc.
+Copyright 2007, 2008, 2009 Free Software Foundation, Inc.
 This file is part of GNU Radio
 
 GNU Radio Companion is free software; you can redistribute it and/or
@@ -17,7 +17,7 @@ along with this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 """
 
-from Constants import DEFAULT_BLOCKS_WINDOW_WIDTH
+from Constants import DEFAULT_BLOCKS_WINDOW_WIDTH, DND_TARGETS
 import pygtk
 pygtk.require('2.0')
 import gtk
@@ -53,6 +53,9 @@ class BlockTreeWindow(gtk.VBox):
 		renderer = gtk.CellRendererText()
 		column = gtk.TreeViewColumn('Blocks', renderer, text=NAME_INDEX)
 		self.treeview.append_column(column)
+		#setup drag and drop
+		self.treeview.enable_model_drag_source(gtk.gdk.BUTTON1_MASK, DND_TARGETS, gtk.gdk.ACTION_COPY)
+		self.treeview.connect('drag-data-get', self._handle_drag_get_data)
 		#make the scrolled window to hold the tree view
 		scrolled_window = gtk.ScrolledWindow()
 		scrolled_window.set_policy(gtk.POLICY_AUTOMATIC, gtk.POLICY_AUTOMATIC)
@@ -60,12 +63,11 @@ class BlockTreeWindow(gtk.VBox):
 		scrolled_window.set_size_request(DEFAULT_BLOCKS_WINDOW_WIDTH, -1)
 		self.pack_start(scrolled_window)
 		#add button
-		self.add_button = gtk.Button(None, 'gtk-add')
+		self.add_button = gtk.Button(None, gtk.STOCK_ADD)
 		self.add_button.connect('clicked', self._handle_add_button)
 		self.pack_start(self.add_button, False)
-		#map categories to iters
-		self.categories = dict()
-		self.categories[tuple()] = None
+		#map categories to iters, automatic mapping for root
+		self._categories = {tuple(): None}
 		#add blocks and categories
 		self.platform.load_block_tree(self)
 		#initialize
@@ -78,22 +80,21 @@ class BlockTreeWindow(gtk.VBox):
 		"""
 		Add a block with category to this selection window.
 		Add only the category when block is None.
-		@param category the category string
+		@param category the category list
 		@param block the block object or None
 		"""
-		#rectify category
-		category = filter(lambda x: x, category.split('/'))
+		category = tuple(category)[1:] #tuple is hashable
 		#add category and all sub categories
-		for i in range(len(category)):
-			sub_category = tuple(category[:i+1])
-			if sub_category not in self.categories.keys():
-				iter = self.treestore.insert_before(self.categories[tuple(category[:i])], None)
-				self.treestore.set_value(iter, NAME_INDEX, '[ %s ]'%category[i])
+		for i, cat_name in enumerate(category):
+			sub_category = category[:i+1]
+			if sub_category not in self._categories:
+				iter = self.treestore.insert_before(self._categories[sub_category[:-1]], None)
+				self.treestore.set_value(iter, NAME_INDEX, '[ %s ]'%cat_name)
 				self.treestore.set_value(iter, KEY_INDEX, '')
-				self.categories[sub_category] = iter
+				self._categories[sub_category] = iter
 		#add block
 		if block is None: return
-		iter = self.treestore.insert_before(self.categories[tuple(category)], None)
+		iter = self.treestore.insert_before(self._categories[category], None)
 		self.treestore.set_value(iter, NAME_INDEX, block.get_name())
 		self.treestore.set_value(iter, KEY_INDEX, block.get_key())
 
@@ -127,6 +128,15 @@ class BlockTreeWindow(gtk.VBox):
 	############################################################
 	## Event Handlers
 	############################################################
+	def _handle_drag_get_data(self, widget, drag_context, selection_data, info, time):
+		"""
+		Handle a drag and drop by setting the key to the selection object.
+		This will call the destination handler for drag and drop.
+		Only call set when the key is valid to ignore DND from categories.
+		"""
+		key = self._get_selected_block_key()
+		if key: selection_data.set(selection_data.target, 8, key)
+
 	def _handle_mouse_button_press(self, widget, event):
 		"""
 		Handle the mouse button press.
diff --git a/grc/src/gui/Constants.py b/grc/src/gui/Constants.py
index 70e6b6b6e..f23ab8b13 100644
--- a/grc/src/gui/Constants.py
+++ b/grc/src/gui/Constants.py
@@ -1,5 +1,5 @@
 """
-Copyright 2008 Free Software Foundation, Inc.
+Copyright 2008, 2009 Free Software Foundation, Inc.
 This file is part of GNU Radio
 
 GNU Radio Companion is free software; you can redistribute it and/or
@@ -17,6 +17,9 @@ along with this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 """
 
+import pygtk
+pygtk.require('2.0')
+import gtk
 import os
 
 ##default path for the open/save dialogs
@@ -28,10 +31,6 @@ IMAGE_FILE_EXTENSION = '.png'
 ##name for new/unsaved flow graphs
 NEW_FLOGRAPH_TITLE = 'untitled'
 
-##rotation constants
-DIR_LEFT = 'left'
-DIR_RIGHT = 'right'
-
 ##main window constraints
 MIN_WINDOW_WIDTH = 600
 MIN_WINDOW_HEIGHT = 400
@@ -42,16 +41,8 @@ MIN_DIALOG_HEIGHT = 500
 DEFAULT_BLOCKS_WINDOW_WIDTH = 100
 DEFAULT_REPORTS_WINDOW_WIDTH = 100
 
-##How close can the mouse get to the window border before mouse events are ignored.
-BORDER_PROXIMITY_SENSITIVITY = 50
-##How close the mouse can get to the edge of the visible window before scrolling is invoked.
-SCROLL_PROXIMITY_SENSITIVITY = 30
-##When the window has to be scrolled, move it this distance in the required direction.
-SCROLL_DISTANCE = 15
-##The redrawing sensitivity, how many seconds must pass between motion events before a redraw?
-MOTION_DETECT_REDRAWING_SENSITIVITY = .02
-##How close the mouse click can be to a connection and register a connection select.
-CONNECTION_SELECT_SENSITIVITY = 5
-
 ##The size of the state saving cache in the flow graph (for undo/redo functionality)
 STATE_CACHE_SIZE = 42
+
+##Shared targets for drag and drop of blocks
+DND_TARGETS = [('STRING', gtk.TARGET_SAME_APP, 0)]
diff --git a/grc/src/gui/Dialogs.py b/grc/src/gui/Dialogs.py
index e15f8c574..d526b97b4 100644
--- a/grc/src/gui/Dialogs.py
+++ b/grc/src/gui/Dialogs.py
@@ -1,5 +1,5 @@
 """
-Copyright 2008 Free Software Foundation, Inc.
+Copyright 2008, 2009 Free Software Foundation, Inc.
 This file is part of GNU Radio
 
 GNU Radio Companion is free software; you can redistribute it and/or
@@ -20,7 +20,6 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 import pygtk
 pygtk.require('2.0')
 import gtk
-from Constants import MIN_DIALOG_WIDTH, MIN_DIALOG_HEIGHT
 from .. platforms.base.Constants import PACKAGE, VERSION
 import Preferences
 
@@ -82,3 +81,20 @@ Achilleas Anastasopoulos -> trellis support
 -----""")
 		self.run()
 		self.destroy()
+
+def HelpDialog():
+	MessageDialogHelper(
+		type=gtk.MESSAGE_INFO,
+		buttons=gtk.BUTTONS_CLOSE,
+		title='Help',
+		markup="""\
+<b>Usage Tips</b>
+
+<u>Add block</u>: drag and drop or double click a block in the block selection window.
+<u>Rotate block</u>: Select a block, press left/right on the keyboard.
+<u>Change type</u>: Select a block, press up/down on the keyboard.
+<u>Edit parameters</u>: double click on a block in the flow graph.
+<u>Make connection</u>: click on the source port of one block, then click on the sink port of another block.
+<u>Remove connection</u>: select the connection and press delete, or drag the connection.
+
+* See the menu for other keyboard shortcuts.""")
diff --git a/grc/src/gui/DrawingArea.py b/grc/src/gui/DrawingArea.py
index 3588e122d..5258979d8 100644
--- a/grc/src/gui/DrawingArea.py
+++ b/grc/src/gui/DrawingArea.py
@@ -1,5 +1,5 @@
 """
-Copyright 2007 Free Software Foundation, Inc.
+Copyright 2007, 2008, 2009 Free Software Foundation, Inc.
 This file is part of GNU Radio
 
 GNU Radio Companion is free software; you can redistribute it and/or
@@ -20,7 +20,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 import pygtk
 pygtk.require('2.0')
 import gtk
-from Constants import MIN_WINDOW_WIDTH, MIN_WINDOW_HEIGHT
+from Constants import MIN_WINDOW_WIDTH, MIN_WINDOW_HEIGHT, DND_TARGETS
 
 class DrawingArea(gtk.DrawingArea):
 	"""
@@ -51,24 +51,26 @@ class DrawingArea(gtk.DrawingArea):
 			gtk.gdk.LEAVE_NOTIFY_MASK | \
 			gtk.gdk.ENTER_NOTIFY_MASK
 		)
+		#setup drag and drop
+		self.drag_dest_set(gtk.DEST_DEFAULT_ALL, DND_TARGETS, gtk.gdk.ACTION_COPY)
+		self.connect('drag-data-received', self._handle_drag_data_received)
 		#setup the focus flag
 		self._focus_flag = False
 		self.get_focus_flag = lambda: self._focus_flag
-		self.connect("leave-notify-event", self._handle_focus_event, False)
-		self.connect("enter-notify-event", self._handle_focus_event, True)
+		self.connect('leave-notify-event', self._handle_focus_event, False)
+		self.connect('enter-notify-event', self._handle_focus_event, True)
 		#pixmap for drawing
 		self.pixmap = None
-		self.gc = None
-
-	def draw(self):
-		"""
-		Draw the pixmap onto this drawing area.
-		"""
-		self.window.draw_drawable(self.gc, self.pixmap, 0, 0, 0, 0, -1, -1)
 
 	##########################################################################
 	## Handlers
 	##########################################################################
+	def _handle_drag_data_received(self, widget, drag_context, x, y, selection_data, info, time):
+		"""
+		Handle a drag and drop by adding a block at the given coordinate.
+		"""
+		self._main_window.get_flow_graph().add_new_block(selection_data.data, (x, y))
+
 	def _handle_focus_event(self, widget, event, focus_flag):
 		"""Record the focus state of the flow graph window."""
 		self._focus_flag = focus_flag
@@ -83,7 +85,6 @@ class DrawingArea(gtk.DrawingArea):
 			double_click=(event.type == gtk.gdk._2BUTTON_PRESS),
 			coordinate=(event.x, event.y),
 		)
-		return True
 
 	def _handle_mouse_button_release(self, widget, event):
 		"""
@@ -94,7 +95,6 @@ class DrawingArea(gtk.DrawingArea):
 			left_click=(event.button == 1),
 			coordinate=(event.x, event.y),
 		)
-		return True
 
 	def _handle_mouse_motion(self, widget, event):
 		"""
@@ -104,15 +104,15 @@ class DrawingArea(gtk.DrawingArea):
 		self._main_window.get_flow_graph().handle_mouse_motion(
 			coordinate=(event.x, event.y),
 		)
-		return True
 
 	def _handle_window_expose(self, widget, event):
 		"""
-		Called when the window initially appears or is resized: create a new pixmap, draw the flow graph.
+		Called when window is exposed, resized, or queue_draw is called.
 		"""
-		self.gc = self.window.new_gc()
+		gc = self.window.new_gc()
 		width, height = self.get_size_request()
 		if not self.pixmap or (width, height) != self.pixmap.get_size():
 			self.pixmap = gtk.gdk.Pixmap(self.window, width, height, -1)
-		self._main_window.get_flow_graph().draw()
-		return True
+		#double buffering: draw to pixmap, then draw pixmap
+		self._main_window.get_flow_graph().draw(gc, self.pixmap)
+		self.window.draw_drawable(gc, self.pixmap, 0, 0, 0, 0, -1, -1)
diff --git a/grc/src/gui/ParamsDialog.py b/grc/src/gui/ParamsDialog.py
index 5837ab7c4..6cc42e8fc 100644
--- a/grc/src/gui/ParamsDialog.py
+++ b/grc/src/gui/ParamsDialog.py
@@ -1,5 +1,5 @@
 """
-Copyright 2007 Free Software Foundation, Inc.
+Copyright 2007, 2008, 2009 Free Software Foundation, Inc.
 This file is part of GNU Radio
 
 GNU Radio Companion is free software; you can redistribute it and/or
@@ -45,9 +45,11 @@ class ParamsDialog(gtk.Dialog):
 		SignalBlockParamsDialog contructor.
 		@param block the signal block
 		"""
-		gtk.Dialog.__init__(self, buttons=('gtk-close', gtk.RESPONSE_CLOSE))
+		gtk.Dialog.__init__(self,
+			title='Properties: %s'%block.get_name(),
+			buttons=(gtk.STOCK_CLOSE, gtk.RESPONSE_CLOSE),
+		)
 		self.block = block
-		self.set_title('Properties: %s'%block.get_name())
 		self.set_size_request(MIN_DIALOG_WIDTH, MIN_DIALOG_HEIGHT)
 		vbox = gtk.VBox()
 		#Add the title label