Disable sensitive when there's only one function.

* Update Sweetener to have the property sensitive in Items.
* Add the conditionals when:
  - Adding a function
  - Removing a function
  - Using the command entrie
* Also removed very old code.

Signed-off-by: Daniel Francis <francis@sugarlabs.org>

4 files changed, 35 insertions, 51 deletions

diff --git a/canvas.py b/canvas.py
index 62c660b..818445a 100644
--- a/canvas.py
+++ b/canvas.py
@@ -204,6 +204,11 @@ class Canvas(gtk.HPaned):
         self.functions_list.append_function(color, text)
         self.update_graph(None, self.functions_list.get_list())
         widget.set_text('')
+        number = len(self.functions_list.get_list())
+        if number == 1:
+            self.toolbar_box.remove_function.sensitive = False
+        else:
+            self.toolbar_box.remove_function.sensitive = True
 
     def _update_scale(self, widget=None):
         xscale, yscale = self.toolbar_box.view.get_scale()
@@ -340,6 +345,7 @@ class Canvas(gtk.HPaned):
     def _remove_function(self, widget):
         self.functions_list.remove_function()
         self.update_graph(None, self.functions_list.get_list())
+        return len(self.functions_list.get_list())
 
     def _append_function(self, widget):
         if len(self.functions_list.get_list()) % 2 == 0:
@@ -348,6 +354,7 @@ class Canvas(gtk.HPaned):
             color = profile.get_stroke_color(self)
         self.functions_list.append_function(color)
         self.update_graph(None, self.functions_list.get_list())
+        return len(self.functions_list.get_list())
 
     def update_graph(self, widget, info):
 #        self._evaluate_cb(None, self.toolbar_box.evaluate_entry.get_text())
diff --git a/desktop/sweetener b/desktop/sweetener
-Subproject 9c7c915efa9d1815ea2e47f29ff549781d50c08
+Subproject d0a2a5ed99725f7ae9eb429467952e09b92b091
diff --git a/options.py b/options.py
index 81510c7..0ea4176 100644
--- a/options.py
+++ b/options.py
@@ -18,6 +18,9 @@
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 # MA 02110-1301, USA.
 
+import logging
+logger = logging.getLogger('options')
+
 from gettext import gettext as _
 import gobject
 import gtk
@@ -244,11 +247,11 @@ class ViewOptions(ItemGroup):
 
 
 class Options(ItemBox):
-    __gsignals__ = {'append-function': (gobject.SIGNAL_RUN_FIRST,
-                                        gobject.TYPE_NONE,
+    __gsignals__ = {'append-function': (gobject.SIGNAL_RUN_LAST,
+                                        gobject.TYPE_INT,
                                         tuple()),
-                    'remove-function': (gobject.SIGNAL_RUN_FIRST,
-                                        gobject.TYPE_NONE,
+                    'remove-function': (gobject.SIGNAL_RUN_LAST,
+                                        gobject.TYPE_INT,
                                         tuple()),
                     'color-updated': (gobject.SIGNAL_RUN_FIRST,
                                       gobject.TYPE_NONE,
@@ -274,13 +277,14 @@ class Options(ItemBox):
         add_function = Item(gtk.STOCK_ADD, True)
         add_function.tooltip = _('Append a new function')
         add_function.connect('activate',
-                             lambda w: self.emit('append-function'))
+                             self._append_function_cb)
         self.ghost.append_item(add_function)
-        remove_function = Item(gtk.STOCK_REMOVE, True)
-        remove_function.tooltip = _('Remove the selected function')
-        remove_function.connect('activate',
-                                lambda w: self.emit('remove-function'))
-        self.ghost.append_item(remove_function)
+        self.remove_function = Item(gtk.STOCK_REMOVE, True)
+        self.remove_function.tooltip = _('Remove the selected function')
+        self.remove_function.connect('activate',
+                                     self._remove_function_cb)
+        self.ghost.append_item(self.remove_function)
+        self.remove_function.sensitive = False
         self.color_item = ColorItem(activity, True)
         self.color_item.tooltip = _('Plot color')
         self.color_item.connect('updated',
@@ -316,45 +320,18 @@ class Options(ItemBox):
         self.ghost.append_item(evaluate_entry_item)
         self.help = Help(self)
 
-"""
-    def export_as_png(self, path):
-        jobject = datastore.create()
-        jobject.metadata['title'] = self.activity.metadata["title"]
-        jobject.metadata['mime_type'] = "image/png"
-        self.emit('save-png', '/tmp/graph-plotter.png')
-        jobject.set_file_path('/tmp/graph-plotter.png')
-        datastore.write(jobject)
+    def _append_function_cb(self, widget):
+        number = self.emit('append-function')
+        logger.debug(number)
+        if number == 1:
+            self.remove_function.sensitive = False
+        else:
+            self.remove_function.sensitive = True
 
-    def setup_help_button(self):
-        helpbutton = HelpButton()
-        helpbutton.add_section(_('Plotting functions'))
-        helpbutton.add_paragraph(_('Append a new function.'), 'gtk-add')
-        helpbutton.add_paragraph(_('Remove a function.'), 'gtk-remove')
-        helpbutton.add_paragraph(
-                            _('Choose the color for the selected function.'),
-                                'color-preview')
-        helpbutton.add_section(_('Watching the graph'))
-        helpbutton.add_paragraph(_('Zoom into the graph.'), 'zoom-in')
-        helpbutton.add_paragraph(_('Zoom out from the graph.'), 'zoom-out')
-        helpbutton.add_paragraph(_('Reset zoom level.'), 'zoom-original')
-        helpbutton.add_paragraph(_('Customize the scale range. \n\
-Remember to press enter after editing the entries.'), 'cell-size')
-        helpbutton.add_paragraph(
-   _('You can zoom in directly into the graph by selecting an area to expand'))
-        helpbutton.add_paragraph(
-             _('Hold the Shift key and move the mouse to traverse the graph.'))
-        helpbutton.add_paragraph(
-            _('Do click for switch between the mouse pointing modes.'))
-        helpbutton.add_section(_('Some settings'))
-        helpbutton.add_paragraph(_('Connect the plotted points.'),
-                                 'connect-points')
-        helpbutton.add_paragraph(_('Show the grid.'), 'insert-table')
-        helpbutton.add_section(
-                        _('From algebraic expressions to linear expressions'))
-        helpbutton.add_paragraph(_('Multiplication: ') + '*')
-        helpbutton.add_paragraph(_('Division: ') + '/')
-        helpbutton.add_paragraph(_('Integer division: ') + '//')
-        helpbutton.add_paragraph(_('Power: ') + '^')
-        helpbutton.show_all()
-        self.toolbar.insert(helpbutton, -1)
-"""
+    def _remove_function_cb(self, widget):
+        number = self.emit('remove-function')
+        logger.debug(number)
+        if number == 1:
+            self.remove_function.sensitive = False
+        else:
+            self.remove_function.sensitive = True
diff --git a/sugar/sweetener b/sugar/sweetener
-Subproject 2b200cda7787769b6cc718a8ffd6addb4e67503
+Subproject e3affd5174a3171926bebad53dada2432b55875