Add method to return character from char event. (#744)

* Add method to return character from char event.

* return the char for AltChar and CtrlChar events also

---------

Co-authored-by: tidub <57918941+tidub@users.noreply.github.com>

cursive-core/src/event.rs

@@ -533,6 +533,16 @@ pub enum Event {
 }
 
 impl Event {
+    /// Returns the character, if `self` is a char event.
+    pub fn char(&self) -> Option<char> {
+        match *self {
+            Event::Char(c) => Some(c),
+            Event::AltChar(c) => Some(c),
+            Event::CtrlChar(c) => Some(c),
+            _ => None,
+        }
+    }
+
     /// Returns the position of the mouse, if `self` is a mouse event.
     pub fn mouse_position(&self) -> Option<Vec2> {
         if let Event::Mouse { position, .. } = *self {
@@ -542,7 +552,7 @@ impl Event {
         }
     }
 
-    /// Returns a mutable reference to the position of the mouse/
+    /// Returns a mutable reference to the position of the mouse.
     ///
     /// Returns `None` if `self` is not a mouse event.
     pub fn mouse_position_mut(&mut self) -> Option<&mut Vec2> {