narrow: Move the top of narrow notices to message_scroll.js.

We refactor these 2 notices to match with the loading indicators,
thus they have been moved to `message_scroll.js`.

After a successful message fetch, we have logic to decide whether
we want to display the notices and also whether we want to hide
the loading indicators (which are already displayed).

We also conservatively hide the notices similar to the indicators
every time we narrow.
The only exception is that we show the history limit notice on
deactivating the narrow (visiting `home_msg_list`).

frontend_tests/node_tests/message_fetch.js

@@ -30,13 +30,11 @@ set_global('message_scroll', {
     hide_loading_older: noop,
     show_loading_newer: noop,
     hide_loading_newer: noop,
+    update_top_of_narrow_notices: () => {},
 });
 set_global('message_util', {});
 set_global('message_store', {});
 set_global('narrow_state', {});
-set_global('notifications', {
-    update_top_of_narrow_notices: () => {},
-});
 set_global('pm_list', {});
 set_global('server_events', {});
 set_global('stream_list', {

frontend_tests/node_tests/narrow_activate.js

@@ -75,6 +75,7 @@ function test_helper() {
     stub('hashchange', 'save_narrow');
     stub('message_scroll', 'hide_indicators');
     stub('message_scroll', 'show_loading_older');
+    stub('message_scroll', 'hide_top_of_narrow_notices');
     stub('notifications', 'clear_compose_notifications');
     stub('notifications', 'redraw_title');
     stub('search', 'update_button_visibility');
@@ -86,8 +87,6 @@ function test_helper() {
     stub('unread_ops', 'process_visible');
     stub('compose', 'update_closed_compose_buttons_for_stream');
     stub('compose', 'update_closed_compose_buttons_for_private');
-    stub('notifications', 'hide_history_limit_notice');
-    stub('notifications', 'hide_end_of_results_notice');
 
     return {
         clear: () => {
@@ -201,8 +200,7 @@ run_test('basics', () => {
     helper.assert_events([
         'notifications.clear_compose_notifications',
         'notifications.redraw_title',
-        'notifications.hide_history_limit_notice',
-        'notifications.hide_end_of_results_notice',
+        'message_scroll.hide_top_of_narrow_notices',
         'message_scroll.hide_indicators',
         'ui_util.change_tab_to',
         'unread_ops.process_visible',

static/js/message_fetch.js

@@ -79,7 +79,7 @@ function get_messages_success(data, opts) {
                 history_limited: data.history_limited,
             });
         }
-        notifications.update_top_of_narrow_notices(opts.msg_list);
+        message_scroll.update_top_of_narrow_notices(opts.msg_list);
     }
 
     if (opts.num_after > 0) {

static/js/message_scroll.js

@@ -41,6 +41,65 @@ exports.hide_indicators = function () {
     exports.hide_loading_newer();
 };
 
+exports.show_history_limit_notice = function () {
+    $(".top-messages-logo").hide();
+    $(".history-limited-box").show();
+    exports.hide_empty_narrow_message();
+};
+
+exports.hide_history_limit_notice = function () {
+    $(".top-messages-logo").show();
+    $(".history-limited-box").hide();
+};
+
+exports.hide_end_of_results_notice = function () {
+    $(".all-messages-search-caution").hide();
+};
+
+exports.show_end_of_results_notice = function () {
+    $(".all-messages-search-caution").show();
+    // Set the link to point to this search with streams:public added.
+    // It's a bit hacky to use the href, but
+    // !filter.includes_full_stream_history() implies streams:public
+    // wasn't already present.
+    $(".all-messages-search-caution a.search-shared-history").attr(
+        "href", window.location.hash.replace("#narrow/", "#narrow/streams/public/")
+    );
+};
+
+exports.update_top_of_narrow_notices = function (msg_list) {
+    // Assumes that the current state is all notices hidden (i.e. this
+    // will not hide a notice that should not be there)
+    if (msg_list !== current_msg_list) {
+        return;
+    }
+
+    if (msg_list.data.fetch_status.has_found_oldest() &&
+        current_msg_list !== home_msg_list) {
+        const filter = narrow_state.filter();
+        // Potentially display the notice that lets users know
+        // that not all messages were searched.  One could
+        // imagine including `filter.is_search()` in these
+        // conditions, but there's a very legitimate use case
+        // for moderation of searching for all messages sent
+        // by a potential spammer user.
+        if (!filter.contains_only_private_messages() &&
+            !filter.includes_full_stream_history() &&
+            !filter.is_personal_filter()) {
+            exports.show_end_of_results_notice();
+        }
+    }
+
+    if (msg_list.data.fetch_status.history_limited()) {
+        exports.show_history_limit_notice();
+    }
+};
+
+exports.hide_top_of_narrow_notices = function () {
+    exports.hide_end_of_results_notice();
+    exports.hide_history_limit_notice();
+};
+
 exports.actively_scrolling = function () {
     return actively_scrolling;
 };

static/js/narrow.js

@@ -148,8 +148,7 @@ exports.activate = function (raw_operators, opts) {
     const operators = filter.operators();
 
     update_narrow_title(filter);
-    notifications.hide_history_limit_notice();
-    notifications.hide_end_of_results_notice();
+    message_scroll.hide_top_of_narrow_notices();
     message_scroll.hide_indicators();
 
     blueslip.debug("Narrowed", {operators: operators.map(e => e.operator),
@@ -754,8 +753,8 @@ function handle_post_narrow_deactivate_processes() {
     tab_bar.initialize();
     exports.narrow_title = "home";
     notifications.redraw_title();
-    notifications.update_top_of_narrow_notices(home_msg_list);
-    notifications.hide_end_of_results_notice();
+    message_scroll.hide_top_of_narrow_notices();
+    message_scroll.update_top_of_narrow_notices(home_msg_list);
 }
 
 exports.deactivate = function () {

static/js/notifications.js

@@ -171,60 +171,6 @@ exports.redraw_title = function () {
     }
 };
 
-exports.show_history_limit_notice = function () {
-    $(".top-messages-logo").hide();
-    $(".history-limited-box").show();
-    narrow.hide_empty_narrow_message();
-};
-
-exports.hide_history_limit_notice = function () {
-    $(".top-messages-logo").show();
-    $(".history-limited-box").hide();
-};
-
-exports.hide_end_of_results_notice = function () {
-    $(".all-messages-search-caution").hide();
-};
-
-exports.show_end_of_results_notice = function () {
-    $(".all-messages-search-caution").show();
-    // Set the link to point to this search with streams:public added.
-    // It's a bit hacky to use the href, but
-    // !filter.includes_full_stream_history() implies streams:public
-    // wasn't already present.
-    $(".all-messages-search-caution a.search-shared-history").attr(
-        "href", window.location.hash.replace("#narrow/", "#narrow/streams/public/")
-    );
-};
-
-exports.update_top_of_narrow_notices = function (msg_list) {
-    if (msg_list !== current_msg_list) {
-        return;
-    }
-
-    if (msg_list.data.fetch_status.has_found_oldest() &&
-        current_msg_list !== home_msg_list) {
-        const filter = narrow_state.filter();
-        // Potentially display the notice that lets users know
-        // that not all messages were searched.  One could
-        // imagine including `filter.is_search()` in these
-        // conditions, but there's a very legitimate use case
-        // for moderation of searching for all messages sent
-        // by a potential spammer user.
-        if (!filter.contains_only_private_messages() &&
-            !filter.includes_full_stream_history() &&
-            !filter.is_personal_filter()) {
-            exports.show_end_of_results_notice();
-        }
-    }
-
-    if (msg_list.data.fetch_status.history_limited()) {
-        exports.show_history_limit_notice();
-    } else {
-        exports.hide_history_limit_notice();
-    }
-};
-
 function flash_pms() {
     // When you have unread PMs, toggle the favicon between the unread count and
     // a special icon indicating that you have unread PMs.