store update callback; also remove update callback when removing plot

actor.py

@@ -55,6 +55,7 @@ class Actor:
 
     def __init__(self, pvname, cache_size=100):
         self.src, self.plt, self.cache, self._update = decide_src_plt_cache(pvname)
+        self.cb = None
 
     def update(self):
         self._update(self.plt, self.cache)

director.py

@@ -43,24 +43,35 @@ class Director:
             print("caught:", type(e), e)
             return
 
-        def add_header_widgets(fig):
-            btn = Button(label="🗙", button_type="light", width=35)
-            lbl_width = fig.width - btn.width
-            lbl = Div(text=fig.name, align="center", style={"font-size": "150%"}, width=lbl_width)
-            res = column(row(btn, lbl), fig, Spacer(height=35))
-            btn.on_click(lambda: self.remove_plot(res))
-            return res
+        self.frame(a)
+        self.add_plot(a)
 
+
+    def frame(self, a):
+        fig = a.plt.fig
+        btn = Button(label="🗙", button_type="light", width=35)
+        lbl_width = fig.width - btn.width
+        lbl = Div(text=fig.name, align="center", style={"font-size": "150%"}, width=lbl_width)
+        framed_fig = column(row(btn, lbl), fig, Spacer(height=35))
+        btn.on_click(lambda: self.remove_plot(a))
+        a.plt.fig = framed_fig
+
+
+    def add_plot(self, a):
+        print("Add plot:", a)
         fig = a.plt.fig
-        fig = add_header_widgets(fig)
 #        self.layout.children.append(fig)
         self.layout.children.insert(1, fig) # 1 to skip TextInput
-        self.doc.add_periodic_callback(a.update, 1000)
+        assert a.cb is None #TODO
+        a.cb = self.doc.add_periodic_callback(a.update, 1000)
 
 
-    def remove_plot(self, which):
-        print("Remove plot:", which)
-        self.layout.children.remove(which)
+    def remove_plot(self, a):
+        print("Remove plot:", a)
+        fig = a.plt.fig
+        self.layout.children.remove(fig)
+        assert a.cb is not None #TODO
+        self.doc.remove_periodic_callback(a.cb)