From ddd2ffe26a5c89c91708d648b6c5f19635a76c07 Mon Sep 17 00:00:00 2001
From: Diogo Peralta Cordeiro <mail@diogo.site>
Date: Tue, 7 Sep 2021 15:20:28 +0100
Subject: [PATCH] [TWIG] Add extension to check if Firefox is being used

---
 src/Twig/Extension.php   | 1 +
 src/Twig/Runtime.php     | 6 ++++++
 templates/base.html.twig | 8 +++++---
 3 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/src/Twig/Extension.php b/src/Twig/Extension.php
index 5501665190..d60329fbf7 100644
--- a/src/Twig/Extension.php
+++ b/src/Twig/Extension.php
@@ -58,6 +58,7 @@ class Extension extends AbstractExtension
             new TwigFunction('handle_event', [Runtime::class, 'handleEvent']),
             new TwigFunction('config', [Runtime::class, 'getConfig']),
             new TwigFunction('icon', [Runtime::class, 'embedSvgIcon'], ['needs_environment' => true]),
+            new TwigFunction('is_firefox', [Runtime::class, 'isFirefox']),
         ];
     }
 }
diff --git a/src/Twig/Runtime.php b/src/Twig/Runtime.php
index 42e3676aef..bdba0717c9 100644
--- a/src/Twig/Runtime.php
+++ b/src/Twig/Runtime.php
@@ -116,6 +116,12 @@ class Runtime implements RuntimeExtensionInterface, EventSubscriberInterface
         return $twig->render('@public_path/assets/icons/' . $icon_name . '.svg.twig', ['iconClass' => $icon_css_class]);
     }
 
+    public function isFirefox(): bool
+    {
+        $re = '/.*(?i)\bfirefox\b.*/m';
+        return preg_match(pattern: $re, subject: $this->request->headers->get('User-Agent')) === 1;
+    }
+
     // ----------------------------------------------------------
 
     /**
diff --git a/templates/base.html.twig b/templates/base.html.twig
index f1047d795d..895fd7f6e1 100644
--- a/templates/base.html.twig
+++ b/templates/base.html.twig
@@ -37,9 +37,11 @@
     <br>
 
     <p>
-        <em><b>Firefox based browser: </b> <kbd>Alt</kbd> + <kbd>Shift</kbd> + "access key"</em>
-        <br>
-        <em><b>Others: </b> <kbd>Alt</kbd> + "access key"</em>
+        {% if is_firefox() == true %}
+            <em><kbd>Alt</kbd> + <kbd>Shift</kbd> + "access key"</em>
+        {% else %}
+            <em><kbd>Alt</kbd> + "access key"</em>
+        {% endif %}
     </p>
 
     <ul>