Switch icon when toggling visibility of secure input

Switch between the eye icon and the icon with a slash through it.

src/widget/text_input/input.rs

@@ -111,7 +111,7 @@ where
                 .into(),
         )
 }
-/// Creates a new search [`TextInput`].
+/// Creates a new secure [`TextInput`].
 ///
 /// [`TextInput`]: widget::TextInput
 pub fn secure_input<'a, Message>(
@@ -139,7 +139,11 @@ where
     }
     if let Some(msg) = on_visible_toggle {
         input.trailing_icon(
-            crate::widget::icon::from_name("document-properties-symbolic")
+            crate::widget::icon::from_name(if hidden {
+                "document-properties-symbolic"
+            } else {
+                "image-red-eye-symbolic"
+            })
             .size(16)
             .apply(crate::widget::button)
             .style(crate::theme::Button::Icon)