BlockTreeWindow.py

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"""
Copyright 2007 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
"""
##@package grc.gui.BlockTreeWindow
#The block selection panel gives the user a tree selection to choose a block.
#@author Josh Blum

from grc.Constants import *
import pygtk
pygtk.require('2.0')
import gtk
import gobject

NAME_INDEX = 0
KEY_INDEX = 1

class BlockTreeWindow(gtk.VBox):
        """The block selection panel."""

        def __init__(self, platform, get_flow_graph):
                """!
                BlockTreeWindow constructor.
                Create a tree view of the possible blocks in the platform.
                The tree view nodes will be category names, the leaves will be block names.
                A mouse double click or button press action will trigger the add block event.
                @param platform the particular platform will all block prototypes
                @param get_flow_graph get the selected flow graph
                """
                gtk.VBox.__init__(self)
                self.platform = platform
                self.get_flow_graph = get_flow_graph
                #make the tree model for holding blocks
                self.treestore = gtk.TreeStore(gobject.TYPE_STRING, gobject.TYPE_STRING)
                self.treeview = gtk.TreeView(self.treestore)
                self.treeview.set_enable_search(False) #disable pop up search box
                self.treeview.add_events(gtk.gdk.BUTTON_PRESS_MASK)
                self.treeview.connect('button_press_event', self._handle_mouse_button_press)
                selection = self.treeview.get_selection()
                selection.set_mode('single')
                selection.connect('changed', self._handle_selection_change)
                renderer = gtk.CellRendererText()
                column = gtk.TreeViewColumn('Blocks', renderer, text=NAME_INDEX)
                self.treeview.append_column(column)
                #make the scrolled window to hold the tree view
                scrolled_window = gtk.ScrolledWindow()
                scrolled_window.set_policy(gtk.POLICY_AUTOMATIC, gtk.POLICY_AUTOMATIC)
                scrolled_window.add_with_viewport(self.treeview)
                scrolled_window.set_size_request(BLOCK_SELECTION_WINDOW_WIDTH, -1)
                self.pack_start(scrolled_window)
                #add button
                self.add_button = gtk.Button(None, 'gtk-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
                #add blocks and categories
                self.platform.load_block_tree(self)
                #initialize
                self._update_add_button()

        ############################################################
        ## Block Tree Methods
        ############################################################
        def add_block(self, category, block=None):
                """!
                Add a block with category to this selection window.
                Add only the category when block is None.
                @param category the category string
                @param block the block object or None
                """
                #rectify category
                category = filter(lambda x: x, category.split('/'))
                #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])
                                self.treestore.set_value(iter, KEY_INDEX, '')
                                self.categories[sub_category] = iter
                #add block
                if block is None: return
                iter = self.treestore.insert_before(self.categories[tuple(category)], None)
                self.treestore.set_value(iter, NAME_INDEX, block.get_name())
                self.treestore.set_value(iter, KEY_INDEX, block.get_key())

        ############################################################
        ## Helper Methods
        ############################################################
        def _get_selected_block_key(self):
                """!
                Get the currently selected block key.
                @return the key of the selected block or a empty string
                """
                selection = self.treeview.get_selection()
                treestore, iter = selection.get_selected()
                return iter and treestore.get_value(iter, KEY_INDEX) or ''

        def _update_add_button(self):
                """!
                Update the add button's sensitivity.
                The button should be active only if a block is selected.
                """
                key = self._get_selected_block_key()
                self.add_button.set_sensitive(bool(key))

        def _add_selected_block(self):
                """!
                Add the selected block with the given key to the flow graph.
                """
                key = self._get_selected_block_key()
                if key: self.get_flow_graph().add_new_block(key)

        ############################################################
        ## Event Handlers
        ############################################################
        def _handle_mouse_button_press(self, widget, event):
                """!
                Handle the mouse button press.
                If a left double click is detected, call add selected block.
                """
                if event.button == 1 and event.type == gtk.gdk._2BUTTON_PRESS:
                        self._add_selected_block()

        def _handle_selection_change(self, selection):
                """!
                Handle a selection change in the tree view.
                If a selection changes, set the add button sensitive.
                """
                self._update_add_button()

        def _handle_add_button(self, widget):
                """!
                Handle the add button clicked signal.
                Call add selected block.
                """
                self._add_selected_block()

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