From b4103798f51fe143134a7f71c33eee96b75ac9fd Mon Sep 17 00:00:00 2001
From: Keegan McAllister <keegan@humbughq.com>
Date: Tue, 11 Sep 2012 15:37:09 -0400
Subject: [PATCH] Speed up narrowing

(imported from commit e1f06866ebc7d3dae3a5813565002853a6f6d8ba)
---
 zephyr/static/js/zephyr.js | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/zephyr/static/js/zephyr.js b/zephyr/static/js/zephyr.js
index a5b8d0a461..bb9c5aec12 100644
--- a/zephyr/static/js/zephyr.js
+++ b/zephyr/static/js/zephyr.js
@@ -326,6 +326,10 @@ function apply_view(element) {
 }
 
 function do_narrow(description, filter_function) {
+    // Hide the messages temporarily, so the browser doesn't waste time
+    // incrementally recalculating the layout.
+    $("#main_div").hide();
+
     // We want the zephyr on which the narrow happened to stay in the same place if possible.
     var old_top = $("#main_div").offset().top - get_selected_zephyr_row().offset().top;
     current_view_predicate = filter_function;
@@ -333,6 +337,9 @@ function do_narrow(description, filter_function) {
         apply_view($(this));
     });
 
+    // Show the new set of messages.
+    $("#main_div").show();
+
     select_zephyr(selected_zephyr_id);
     scroll_to_selected();