Fix iterative load to not clear and re-draw items.

main.py

@@ -58,7 +58,10 @@ class MainWindow(Gtk.Window):
         self.set_child(self.scrollview)
 
         self.loading += 1
-        self.task_manager.get_task_list(self.on_task_list_ready)
+        self.task_manager.get_task_list(
+            self.on_task_list_update,
+            self.on_task_list_ready,
+        )
 
     ## Rendering
     def build_agenda_task_row(self, task):
@@ -94,21 +97,14 @@ class MainWindow(Gtk.Window):
                 self.progress_spinner.stop()
 
     ## Callbacks
-    def on_task_list_ready(self, agenda):
-        # TODO: Avoid reconstructing the whole list every time
-        i = 0
-        child = self.task_list.get_first_child()
-        while child is not None:
-            was = child
-            child = child.get_next_sibling()
-            i += 1
-            self.task_list.remove(was)
-
-        for item in agenda.with_hour:
+    def on_task_list_update(self, new_rows):
+        for item in new_rows.with_hour:
             self.task_list.append(self.build_agenda_task_row(item))
 
-        for item in agenda.no_hour:
+        for item in new_rows.no_hour:
             self.task_list.append(self.build_agenda_task_row(item))
+
+    def on_task_list_ready(self, success):
         self.on_ready()
 
     ## Reactions

task_manager.py

@@ -91,22 +91,19 @@ class TaskManager:
 
         self.docs = docs
 
-    def get_task_list(self, callback):
+    def get_task_list(self, progress_callback, complete_callback):
         def aux():
             if self.docs is None:
                 last_result = None
+                # No docs read yet, load them iteratively
                 for doc in self.load():
-                    result = self.get_agenda()
-                    if ((last_result is None)
-                    or (len(result.with_hour) != len(last_result.with_hour)) 
-                    or  (len(result.no_hour) != len(last_result.no_hour))):
-                        print("Loaded:", doc._path)
-                        GObject.idle_add(callback, result)
-                print("Load completed")
+                    result = self.get_agenda_from_doc(doc)
+                    GObject.idle_add(progress_callback, result)
             else:
                 result = self.get_agenda()
                 print("Result", result)
-                GObject.idle_add(callback, result)
+                GObject.idle_add(progress_callback, result)
+            GObject.idle_add(complete_callback, True)
 
         thread = threading.Thread(target=aux)
         thread.start()
@@ -153,3 +150,39 @@ class TaskManager:
             with_hour=sorted(items_with_hour, key=lambda x: x.scheduled.time),
             no_hour=other_items,
         )
+
+    def get_agenda_from_doc(self, doc: OrgDoc) -> Agenda:
+        headline_count = 0
+        items_in_agenda = []
+        now = datetime.now()
+
+        for hl in doc.getAllHeadlines():
+            headline_count += 1
+
+            if (
+                hl.scheduled
+                and isinstance(hl.scheduled, OrgTime)
+                and hl.scheduled.time.active
+            ):
+                if is_today(hl.scheduled):
+                    items_in_agenda.append(hl)
+                elif (hl.scheduled.time.to_datetime() < now) and hl.is_todo:
+                    items_in_agenda.append(hl)
+
+        items_with_hour = [
+            item
+            for item in items_in_agenda
+            if item.scheduled and is_today(item.scheduled) and item.scheduled.time.hour
+        ]
+        other_items = [
+            item
+            for item in items_in_agenda
+            if not (
+                item.scheduled and is_today(item.scheduled) and item.scheduled.time.hour
+            )
+        ]
+
+        return Agenda(
+            with_hour=sorted(items_with_hour, key=lambda x: x.scheduled.time),
+            no_hour=other_items,
+        )