refactor(defaultTheme): remove legacy compat API guard

Author: marjune163

src/tpl/defaultTheme/frontend/index.js

@@ -39,14 +39,6 @@
 	var lastFocused;
 
 	function enableFilter() {
-		if (!document.querySelector) {
-			var filter = document.getElementById && document.getElementById('panel-filter');
-			if (filter) {
-				filter.className += ' none';
-			}
-			return;
-		}
-
 		// pre check
 		var filter = document.body.querySelector('.filter');
 		if (!filter) {
@@ -187,8 +179,6 @@
 	}
 
 	function keepFocusOnBackwardForward() {
-		if (window.onpageshow === undefined || !document.querySelector) return;
-
 		function onFocus(e) {
 			var link = e.target;
 			while (link && !(link instanceof HTMLAnchorElement)) {
@@ -210,8 +200,6 @@
 	}
 
 	function focusChildOnNavUp() {
-		if (!document.querySelector) return;
-
 		function extractCleanUrl(url) {
 			var sepIndex = url.indexOf('?');
 			if (sepIndex < 0) sepIndex = url.indexOf('#');
@@ -261,14 +249,6 @@
 	}
 
 	function enableKeyboardNavigate() {
-		if (
-			!document.querySelector ||
-			!document.addEventListener ||
-			!document.body.parentElement
-		) {
-			return;
-		}
-
 		var pathList = document.body.querySelector('.path-list');
 		var itemList = document.body.querySelector('.item-list');
 		if (!pathList && !itemList) {
@@ -536,10 +516,6 @@
 	}
 
 	function enhanceUpload() {
-		if (!document.querySelector || !document.addEventListener) {
-			return;
-		}
-
 		var upload = document.body.querySelector('.upload');
 		if (!upload) {
 			return;
@@ -1197,14 +1173,8 @@
 	}
 
 	function enableNonRefreshDelete() {
-		if (!document.querySelector) {
-			return;
-		}
-
 		var itemList = document.body.querySelector('.item-list');
-		if (!itemList || !itemList.addEventListener) {
-			return;
-		}
+		if (!itemList) return;
 		if (!itemList.classList.contains('has-deletable')) return;
 
 		itemList.addEventListener('submit', function (e) {