closes #6928

public/src/modules/categorySearch.js

@@ -0,0 +1,44 @@
+'use strict';
+
+define('categorySearch', function () {
+	var categorySearch = {};
+
+	categorySearch.init = function (el) {
+		if (utils.isTouchDevice()) {
+			return;
+		}
+		var searchEl = el.find('[component="category-selector-search"]');
+		var categoryEls = el.find('[component="category/list"] [data-cid]');
+		el.on('show.bs.dropdown', function () {
+			function updateList() {
+				var val = searchEl.find('input').val().toLowerCase();
+				var noMatch = true;
+				categoryEls.each(function () {
+					var liEl = $(this);
+					var isMatch = liEl.attr('data-name').toLowerCase().indexOf(val) !== -1;
+					if (noMatch && isMatch) {
+						noMatch = false;
+					}
+					liEl.toggleClass('hidden', !isMatch);
+				});
+
+				el.find('[component="category/list"] [component="category/no-matches"]').toggleClass('hidden', !noMatch);
+			}
+			el.find('.dropdown-toggle').addClass('hidden');
+			searchEl.removeClass('hidden').on('click', function (ev) {
+				ev.preventDefault();
+				ev.stopPropagation();
+			});
+			searchEl.find('input').val('').focus().on('keyup', updateList);
+			updateList();
+		});
+
+		el.on('hide.bs.dropdown', function () {
+			el.find('.dropdown-toggle').removeClass('hidden');
+			searchEl.addClass('hidden').off('click');
+			searchEl.find('input').off('keyup');
+		});
+	};
+
+	return categorySearch;
+});

public/src/modules/categorySelector.js

@@ -1,6 +1,6 @@
 'use strict';
 
-define('categorySelector', ['benchpress', 'translator'], function (Benchpress, translator) {
+define('categorySelector', ['benchpress', 'translator', 'categorySearch'], function (Benchpress, translator, categorySearch) {
 	var categorySelector = {};
 	var selectedCategory;
 	var el;
@@ -14,29 +14,7 @@ define('categorySelector', ['benchpress', 'translator'], function (Benchpress, t
 			callback(selectedCategory);
 		});
 
-		var searchEl = el.find('[component="category-selector-search"]');
-		var categoryEls = el.find('.category-dropdown-menu .category');
-		el.on('show.bs.dropdown', function () {
-			function updateList() {
-				var val = searchEl.find('input').val().toLowerCase();
-				categoryEls.each(function () {
-					var liEl = $(this);
-					liEl.toggleClass('hidden', liEl.attr('data-name').toLowerCase().indexOf(val) === -1);
-				});
-			}
-
-			searchEl.removeClass('hidden').on('click', function (ev) {
-				ev.preventDefault();
-				ev.stopPropagation();
-			});
-			searchEl.find('input').val('').on('keyup', updateList);
-			updateList();
-		});
-
-		el.on('hide.bs.dropdown', function () {
-			searchEl.addClass('hidden').off('click');
-			searchEl.find('input').off('keyup');
-		});
+		categorySearch.init(el);
 	};
 
 	categorySelector.getSelectedCategory = function () {

public/src/modules/topicList.js

@@ -1,6 +1,11 @@
 'use strict';
 
-define('topicList', ['forum/infinitescroll', 'handleBack', 'topicSelect'], function (infinitescroll, handleBack, topicSelect) {
+define('topicList', [
+	'forum/infinitescroll',
+	'handleBack',
+	'topicSelect',
+	'categorySearch',
+], function (infinitescroll, handleBack, topicSelect, categorySearch) {
 	var TopicList = {};
 	var templateName = '';
 
@@ -156,6 +161,8 @@ define('topicList', ['forum/infinitescroll', 'handleBack', 'topicSelect'], funct
 			return cids;
 		}
 
+		categorySearch.init($('[component="category/dropdown"]'));
+
 		$('[component="category/dropdown"]').on('hidden.bs.dropdown', function () {
 			var cids = getSelectedCids();
 			var changed = ajaxify.data.selectedCids.length !== cids.length;

src/meta/js.js

@@ -66,6 +66,7 @@ JS.scripts = {
 		'public/src/modules/topicSelect.js',
 		'public/src/modules/topicList.js',
 		'public/src/modules/categorySelector.js',
+		'public/src/modules/categorySearch.js',
 		'public/src/modules/share.js',
 		'public/src/modules/alerts.js',
 		'public/src/modules/taskbar.js',