pm_list: Handle narrow functions separately for pm_section.

This commit is a preparatory commit which introduces
`handle_narrow_deactivated` and `handle_narrow_activated`
functions in pm_list.js, separately from top_left_corner.js,
to reduce the complexity of handling private messages section
separately.

frontend_tests/node_tests/top_left_corner.js

@@ -30,7 +30,7 @@ run_test("narrowing", ({override}) => {
 
     assert.ok(!pm_expanded);
     let filter = new Filter([{operator: "is", operand: "private"}]);
-    top_left_corner.handle_narrow_activated(filter);
+    pm_list.handle_narrow_activated(filter);
     assert.ok(pm_expanded);
 
     const alice = {
@@ -49,23 +49,23 @@ run_test("narrowing", ({override}) => {
 
     pm_expanded = false;
     filter = new Filter([{operator: "pm-with", operand: "alice@example.com"}]);
-    top_left_corner.handle_narrow_activated(filter);
+    pm_list.handle_narrow_activated(filter);
     assert.ok(pm_expanded);
 
     pm_expanded = false;
     filter = new Filter([{operator: "pm-with", operand: "bob@example.com,alice@example.com"}]);
-    top_left_corner.handle_narrow_activated(filter);
+    pm_list.handle_narrow_activated(filter);
     assert.ok(pm_expanded);
 
     pm_expanded = false;
     filter = new Filter([{operator: "pm-with", operand: "not@valid.com"}]);
-    top_left_corner.handle_narrow_activated(filter);
+    pm_list.handle_narrow_activated(filter);
     assert.ok(!pm_expanded);
 
     pm_expanded = false;
     people.deactivate(alice);
     filter = new Filter([{operator: "pm-with", operand: "alice@example.com"}]);
-    top_left_corner.handle_narrow_activated(filter);
+    pm_list.handle_narrow_activated(filter);
     assert.ok(pm_expanded);
 
     filter = new Filter([{operator: "is", operand: "mentioned"}]);
@@ -84,6 +84,7 @@ run_test("narrowing", ({override}) => {
 
     pm_closed = false;
     top_left_corner.handle_narrow_deactivated();
+    pm_list.handle_narrow_deactivated();
 
     assert.ok($(".top_left_all_messages").hasClass("active-filter"));
     assert.ok(!$(".top_left_mentions").hasClass("active-filter"));

static/js/narrow.js

@@ -25,6 +25,7 @@ import * as narrow_state from "./narrow_state";
 import * as notifications from "./notifications";
 import {page_params} from "./page_params";
 import * as people from "./people";
+import * as pm_list from "./pm_list";
 import * as recent_topics_ui from "./recent_topics_ui";
 import * as recent_topics_util from "./recent_topics_util";
 import * as resize from "./resize";
@@ -570,6 +571,7 @@ export function activate(raw_operators, opts) {
     const current_filter = narrow_state.filter();
 
     top_left_corner.handle_narrow_activated(current_filter);
+    pm_list.handle_narrow_activated(current_filter);
     stream_list.handle_narrow_activated(current_filter);
     typing_events.render_notifications_for_narrow();
     message_view_header.initialize();
@@ -980,6 +982,7 @@ function handle_post_narrow_deactivate_processes() {
     }
 
     top_left_corner.handle_narrow_deactivated();
+    pm_list.handle_narrow_deactivated();
     stream_list.handle_narrow_deactivated();
     compose_closed_ui.update_buttons_for_stream();
     message_edit.handle_narrow_deactivated();

static/js/pm_list.js

@@ -1,6 +1,7 @@
 import $ from "jquery";
 
 import * as narrow_state from "./narrow_state";
+import * as people from "./people";
 import * as pm_list_data from "./pm_list_data";
 import * as pm_list_dom from "./pm_list_dom";
 import * as stream_popover from "./stream_popover";
@@ -74,3 +75,36 @@ export function update_dom_with_unread_counts(counts) {
     update_private_messages();
     set_count(counts.private_message_count);
 }
+
+function should_expand_pm_list(filter) {
+    const op_is = filter.operands("is");
+
+    if (op_is.length >= 1 && op_is.includes("private")) {
+        return true;
+    }
+
+    const op_pm = filter.operands("pm-with");
+
+    if (op_pm.length !== 1) {
+        return false;
+    }
+
+    const emails_strings = op_pm[0];
+    const emails = emails_strings.split(",");
+
+    const has_valid_emails = people.is_valid_bulk_emails_for_compose(emails);
+
+    return has_valid_emails;
+}
+
+export function handle_narrow_activated(filter) {
+    if (should_expand_pm_list(filter)) {
+        expand();
+    } else {
+        close();
+    }
+}
+
+export function handle_narrow_deactivated() {
+    close();
+}

static/js/top_left_corner.js

@@ -1,6 +1,5 @@
 import $ from "jquery";
 
-import * as people from "./people";
 import * as pm_list from "./pm_list";
 import * as resize from "./resize";
 import * as ui_util from "./ui_util";
@@ -36,27 +35,6 @@ function deselect_top_left_corner_items() {
     remove($(".top_left_recent_topics"));
 }
 
-function should_expand_pm_list(filter) {
-    const op_is = filter.operands("is");
-
-    if (op_is.length >= 1 && op_is.includes("private")) {
-        return true;
-    }
-
-    const op_pm = filter.operands("pm-with");
-
-    if (op_pm.length !== 1) {
-        return false;
-    }
-
-    const emails_strings = op_pm[0];
-    const emails = emails_strings.split(",");
-
-    const has_valid_emails = people.is_valid_bulk_emails_for_compose(emails);
-
-    return has_valid_emails;
-}
-
 export function handle_narrow_activated(filter) {
     deselect_top_left_corner_items();
 
@@ -84,17 +62,10 @@ export function handle_narrow_activated(filter) {
             $filter_li.addClass("active-filter");
         }
     }
-
-    if (should_expand_pm_list(filter)) {
-        pm_list.expand();
-    } else {
-        pm_list.close();
-    }
 }
 
 export function handle_narrow_deactivated() {
     deselect_top_left_corner_items();
-    pm_list.close();
 
     const $filter_li = $(".top_left_all_messages");
     $filter_li.addClass("active-filter");