Improved announce stream UI performance

sbapp/main.py

@@ -149,6 +149,10 @@ class SidebandApp(MDApp):
         else:
             self.sideband.start()
 
+        # Pre-load announce stream widgets
+        self.init_announces_view()
+        self.announces_view.update()
+
 
     #################################################
     # General helpers                               #
@@ -245,6 +249,8 @@ class SidebandApp(MDApp):
         else:
             self.icon = self.sideband.asset_dir+"/icon.png"
 
+        self.announces_view = None
+
         screen = Builder.load_string(root_layout)
 
         return screen
@@ -304,6 +310,8 @@ class SidebandApp(MDApp):
 
         self.root.ids.screen_manager.app = self
         self.root.ids.app_version_info.text = "Sideband v"+__version__+" "+__variant__
+        self.root.ids.screen_manager.transition.duration = 0.25
+        self.root.ids.screen_manager.transition.bind(on_complete=self.screen_transition_complete)
 
         Clock.schedule_once(self.start_core, 3.5)
     
@@ -958,21 +966,24 @@ class SidebandApp(MDApp):
 
     ### Announce Stream screen
     ######################################
-    def announces_action(self, sender=None):
-        self.root.ids.screen_manager.transition.direction = "left"
-        self.root.ids.nav_drawer.set_state("closed")
+    def init_announces_view(self, sender=None):
+        if not self.announces_view:
             self.announces_view = Announces(self)
-
-
-        # info = "The [b]Announce Stream[/b] feature is not yet implemented in Sideband.\n\nWant it faster? Go to [u][ref=link]https://unsigned.io/sideband[/ref][/u] to support the project."
-        # self.root.ids.announces_info.text = info
-        # self.root.ids.announces_info.bind(on_ref_press=link_exec)
+            self.sideband.setstate("app.flags.new_announces", True)
 
             for child in self.root.ids.announces_scrollview.children:
                 self.root.ids.announces_scrollview.remove_widget(child)
 
             self.root.ids.announces_scrollview.add_widget(self.announces_view.get_widget())
 
+    def announces_action(self, sender=None):
+        self.root.ids.screen_manager.transition.direction = "left"
+        self.root.ids.nav_drawer.set_state("closed")
+        
+        if self.sideband.getstate("app.flags.new_announces"):
+            self.init_announces_view()
+            self.announces_view.update()
+
         self.root.ids.screen_manager.current = "announces_screen"
         self.sideband.setstate("app.displaying", self.root.ids.screen_manager.current)
 
@@ -982,6 +993,9 @@ class SidebandApp(MDApp):
     def announce_filter_action(self, sender=None):
         pass
 
+    def screen_transition_complete(self, sender):
+        if self.root.ids.screen_manager.current == "announces_screen":
+            pass
 
     ### Keys screen
     ######################################

sbapp/sideband/core.py

@@ -622,18 +622,22 @@ class SidebandCore():
             return None
         else:
             announces = []
+            added_dests = []
             for entry in result:
                 try:
+                    if not entry[2] in added_dests:
                         announce = {
                             "dest": entry[2],
                             "data": entry[3].decode("utf-8"),
                             "time": entry[1],
                             "type": entry[4]
                         }
+                        added_dests.append(entry[2])
                         announces.append(announce)
                 except Exception as e:
                     RNS.log("Exception while fetching announce from DB: "+str(e), RNS.LOG_ERROR)
 
+            announces.reverse()
             return announces
 
     def _db_conversation(self, context_dest):
@@ -855,6 +859,9 @@ class SidebandCore():
         db = sqlite3.connect(self.db_path)
         dbc = db.cursor()
 
+        query = "delete from announce where (source=:source);"
+        dbc.execute(query, {"source": destination_hash})
+
         query = "INSERT INTO announce (received, source, data, dest_type) values (?, ?, ?, ?)"
         data = (
             time.time(),

sbapp/ui/announces.py

@@ -23,7 +23,12 @@ class Announces():
         self.context_dests = []
         self.added_item_dests = []
         self.list = None
-        self.update()
+        self.fetch_announces()
+        self.list = MDList()
+        # self.update()
+
+    def fetch_announces(self):
+        self.announces = self.app.sideband.list_announces()
 
     def reload(self):
         self.clear_list()
@@ -37,8 +42,7 @@ class Announces():
         self.added_item_dests = []
 
     def update(self):
-        self.clear_list()
-        self.announces = self.app.sideband.list_announces()
+        self.fetch_announces()
         self.update_widget()
         self.app.sideband.setstate("app.flags.new_announces", False)
 
@@ -46,6 +50,23 @@ class Announces():
         if self.list == None:
             self.list = MDList()
 
+        remove_widgets = []
+        for item in self.list.children:
+            if not item.sb_uid in (a["dest"] for a in self.announces):
+                remove_widgets.append(item)
+            
+            else:
+                for announce in self.announces:
+                    if announce["dest"] == item.sb_uid:
+                        if announce["time"] > item.ts:
+                            remove_widgets.append(item)
+                            break
+
+        for item in remove_widgets:
+            if item.sb_uid in self.added_item_dests:
+                self.added_item_dests.remove(item.sb_uid)
+            self.list.remove_widget(item)
+
         for announce in self.announces:
             context_dest = announce["dest"]
             ts = announce["time"]
@@ -100,6 +121,7 @@ class Announces():
                 item = OneLineAvatarIconListItem(text=time_string+": "+disp_name, on_release=gen_info(time_string, context_dest, a_data, dest_type))
                 item.add_widget(iconl)
                 item.sb_uid = context_dest
+                item.ts = ts
 
                 def gen_del(dest, item):
                     def x():
@@ -191,7 +213,7 @@ class Announces():
                 item.add_widget(item.iconr)
                 
                 self.added_item_dests.append(context_dest)
-                self.list.add_widget(item)
+                self.list.add_widget(item, index=len(self.list.children))
 
     def get_widget(self):
         return self.list