Update date separator at midnight

fixes #868

main/src/ui/conversation_content_view/date_separator_populator.vala

@@ -62,18 +62,46 @@ public class MetaDateItem : Plugins.MetaConversationItem {
     }
 
     public override Object? get_widget(Plugins.WidgetType widget_type) {
-        Box box = new Box(Orientation.HORIZONTAL, 10) { width_request=300, halign=Align.CENTER, visible=true };
+        return new DateSeparatorWidget(date);
-        box.add(new Separator(Orientation.HORIZONTAL) { valign=Align.CENTER, hexpand=true, visible=true });
-        string date_str = get_relative_time(date);
-        Label label = new Label(@"<span size='small'>$date_str</span>") { use_markup=true, halign=Align.CENTER, hexpand=false, visible=true };
-        label.get_style_context().add_class("dim-label");
-        box.add(label);
-        box.add(new Separator(Orientation.HORIZONTAL) { valign=Align.CENTER, hexpand=true, visible=true });
-        return box;
     }
 
     public override Gee.List<Plugins.MessageAction>? get_item_actions(Plugins.WidgetType type) { return null; }
 
+
+}
+
+public class DateSeparatorWidget : Box {
+
+    private DateTime date;
+    private Label label;
+    private uint time_update_timeout = 0;
+
+    public DateSeparatorWidget(DateTime date) {
+        Object(orientation:Orientation.HORIZONTAL, spacing:10);
+        width_request = 300;
+        halign = Align.CENTER;
+        visible = true;
+        this.date = date;
+
+        label = new Label("") { use_markup=true, halign=Align.CENTER, hexpand=false, visible=true };
+        label.get_style_context().add_class("dim-label");
+
+        this.add(new Separator(Orientation.HORIZONTAL) { valign=Align.CENTER, hexpand=true, visible=true });
+        this.add(label);
+        this.add(new Separator(Orientation.HORIZONTAL) { valign=Align.CENTER, hexpand=true, visible=true });
+
+        update_time();
+    }
+
+    private void update_time() {
+        label.label = @"<span size='small'>$(get_relative_time(date))</span>";
+        time_update_timeout = Timeout.add_seconds((int) get_next_time_change(), () => {
+            if (this.parent == null) return false;
+            update_time();
+            return false;
+        });
+    }
+
     private static string get_relative_time(DateTime time) {
         DateTime time_local = time.to_local();
         DateTime now_local = new DateTime.now_local();
@@ -98,6 +126,20 @@ public class MetaDateItem : Plugins.MetaConversationItem {
             return time_local.format(_("%b %d"));
         }
     }
+
+    private int get_next_time_change() {
+        DateTime now = new DateTime.now_local();
+        return (23 - now.get_hour()) * 3600 + (59 - now.get_minute()) * 60 + (59 - now.get_second()) + 1;
+    }
+
+    public override void dispose() {
+        base.dispose();
+
+        if (time_update_timeout != 0) {
+            Source.remove(time_update_timeout);
+            time_update_timeout = 0;
+        }
+    }
 }
 
 }