Changed generic observer pattern and project dependency in plots to be a two-way selection-listener model.

The project listens to selections done in plot and broadcasts it back to all plots (including source) which allows them to redraw properly.

system/plots.py

@@ -60,7 +60,7 @@ class Plot (gtk.Frame):
         self.sel_obj = None
         self.active = False
         self.title = title
-        self.project = None
+        self.selection_listener = None
 
     def get_title(self):
         return self.title
@@ -76,11 +76,17 @@ class Plot (gtk.Frame):
             self.set_shadow_type(gtk.SHADOW_OUT)
         self.active = active
 
-    def update(self, key):
+    def selection_changed(self, selection):
         pass
 
-    def set_project(self, project):
-        self.project = project
+    def set_selection_listener(self, listener):
+        """Allow project to listen to selections.
+
+        The selection will propagate back to all plots through the
+        selection_changed() method. The listener will be called as
+        listener(dimension_name, ids).
+        """
+        self.selection_listener = listener
 
     def get_toolbar(self):
         return None
@@ -365,8 +371,9 @@ class LinePlot(Plot):
         silent_eval("k <- sapply(1:length(res), function(id) rev(res[[id]]$y))")
         self._bg_matrix = bg_matrix = rpy.r("k")
         rpy.r.rm(["k", "res", "m"])
-        
-        self.update(None)
+
+        # Hack - we draw plot in selection_changed()
+        self.selection_changed(None)
 
         self.add(self.canvas)
         self.canvas.show()
@@ -379,15 +386,14 @@ class LinePlot(Plot):
         self.canvas.draw()
         return self._toolbar
 
-    def update(self, key):
+    def selection_changed(self, selection):
         self.ax.clear()
         
         rows, cols = self._bg_matrix.shape
         self.ax.imshow(self._bg_matrix, cmap=cm.Greys, extent=(0.5, cols+0.5, self._ymin, self._ymax))
 
-        if self.project:
-            curr_sel = self.project.get_selection() # get selection object
-            ids = curr_sel['ids'] # current identifiers
+        if selection:
+            ids = selection['ids'] # current identifiers
             index = [ind for id,ind in self._dataset['ids'].items() if id in ids] #conversion to index
             for i in index:
                 line = self._dataset.get_matrix()[i]
@@ -457,11 +463,10 @@ class ScatterPlot(Plot):
         for ind in index:
             ids.append(reverse[ind])
             
-        self.project.set_selection(self.current_dim,ids)
+        self.selection_listener(self.current_dim,ids)
 
-    def update(self, key):
-        curr_sel = self.project.get_selection() # get selection object
-        ids = curr_sel[self.current_dim] # current identifiers
+    def selection_changed(self, selection):
+        ids = selection[self.current_dim] # current identifiers
         
         index = [ind for id,ind in self.dataset[self.current_dim].items() if id in ids] #conversion to index
         xdata_new = scipy.take(self.xaxis_data,index) #take data

system/project.py

@@ -12,35 +12,20 @@ class Project:
 
         self.name = name
         self.dim_names = []
-        self._observers = {}
+        self._selection_observers = []
         self.current_data = None
         self.datasets = []
         self.sel_obj = dataset.Selection()
         
-    def attach(self,observer,key):
-        """Attach observer for selection updates"""
-        if not self._observers.has_key(key):
-            self._observers[key]=[]        
-        if not observer in self._observers[key]:
-            self._observers[key].append(observer)
-
-    def detach(self,observer,key):
-        """Detach observer for selection updates"""
-        try:
-            self._observers[key].remove(observer)
-        except ValueError:
-            pass
-
-    def notify(self,key,modifier=None):
+    def notify_selection_listeners(self):
         """Notifies observers"""
-        for observer in self._observers[key]:
-            if modifier != observer:
-                observer.update(key)
+        for observer in self._selection_observers:
+            observer.selection_changed(self.get_selection())
 
     def set_selection(self,dim_name,selection):
         """Sets a current selection and notify observers"""
         self.sel_obj.current_selection[dim_name] = set(selection)
-        self.notify('selection_update')
+        self.notify_selection_listeners()
 
     def get_selection(self):
         """Returns the current selection object"""
@@ -71,10 +56,9 @@ class Project:
                 self.add_dataset(d)
                 self.data_tree_insert(it, d.get_name(), d)
             elif isinstance(d, plots.Plot):
-#                self.add_view(d)
                 self.data_tree_insert(it, d.get_title(), d)
-                d.set_project(self)
-                self.attach(d, 'selection_update')
+                d.set_selection_listener(self.set_selection)
+                self._selection_observers.append(d)
 
     def data_tree_insert(self, parent, text, data):
         tree = self.data_tree