implement update action for reload button

src/browser/main/tab/page/navigation/mod.rs

@@ -66,7 +66,7 @@ impl Navigation {
     pub fn update(&self) {
         self.base.update();
         self.history.update();
-        self.reload.update();
+        self.reload.update(!self.request.is_empty());
         self.request.update();
         self.bookmark.update();
     }

src/browser/main/tab/page/navigation/reload/mod.rs

@@ -1,4 +1,4 @@
-use gtk::Button;
+use gtk::{prelude::WidgetExt, Button};
 
 pub struct Reload {
     widget: Button,
@@ -18,8 +18,8 @@ impl Reload {
     }
 
     // Actions
-    pub fn update(&self) {
-        // @TODO
+    pub fn update(&self, is_enabled: bool) {
+        self.widget.set_sensitive(is_enabled);
     }
 
     // Getters

src/browser/main/tab/page/navigation/request/mod.rs

@@ -1,4 +1,4 @@
-use gtk::Entry;
+use gtk::{prelude::EntryExt, Entry};
 
 pub struct Request {
     widget: Entry,
@@ -25,4 +25,8 @@ impl Request {
     pub fn widget(&self) -> &Entry {
         &self.widget
     }
+
+    pub fn is_empty(&self) -> bool {
+        0 == self.widget.text_length()
+    }
 }