Disable double-tap mobile gesture if swipe gesture is disabled

Fixes #441.

locale/translations/en_US.json

@@ -308,7 +308,7 @@
     "form.prefs.select.alphabetical": "Alphabetical",
     "form.prefs.select.unread_count": "Unread count",
     "form.prefs.label.keyboard_shortcuts": "Enable keyboard shortcuts",
-    "form.prefs.label.entry_swipe": "Enable swipe gesture on entries on mobile",
+    "form.prefs.label.entry_swipe": "Enable swipe and double-tap gestures on entries on mobile",
     "form.prefs.label.show_reading_time": "Show estimated reading time for entries",
     "form.prefs.label.custom_css": "Custom CSS",
     "form.prefs.label.entry_order": "Entry sorting column",

template/templates/views/entry.html

@@ -143,7 +143,7 @@
     </div>
     {{ end }}
     {{ end }}
-    <article role="article" class="entry-content" dir="auto">
+    <article role="article" class="entry-content {{ if $.user.EntrySwipe }}double-tap{{ end }}" dir="auto">
         {{ if .user }}
             {{ noescape (proxyFilter .entry.Content) }}
         {{ else }}

ui/static/js/touch_handler.js

@@ -104,7 +104,7 @@ class TouchHandler {
         });
 
         let entryContentElement = document.querySelector(".entry-content");
-        if (entryContentElement) {
+        if (entryContentElement && entryContentElement.classList.contains('double-tap')) {
             let doubleTapTimers = {
                 previous: null,
                 next: null