ui: keyboard input fixes (#432, #476) (#477)

* Fix Cmd-V typing v, suppress key_type on ctrl/logo, closes #432
Only send key_type() when modifiers are not pressed.

* Fix backspace repeat and inserting ⌂, closes #476
Handle backspace in key_type instead of key_press, so we get
auto-repeat for free, and can suppress typing the character.

src/main.rs

@@ -638,7 +638,7 @@ fn handle_window_event<T>(
                 }
 
                 WindowEvent::ReceivedCharacter(codepoint) => {
-                    if !game.focused {
+                    if !game.focused && !game.is_ctrl_pressed && !game.is_logo_pressed {
                         ui_container.key_type(game, codepoint);
                     }
                 }

src/ui/mod.rs

@@ -1537,9 +1537,6 @@ impl UIElement for TextBox {
         ctrl_pressed: bool,
     ) {
         match (key, down) {
-            (VirtualKeyCode::Back, _) => {
-                self.input.pop();
-            }
             (VirtualKeyCode::Return, false) => {
                 use std::mem;
                 let len = self.submit_funcs.len();
@@ -1564,6 +1561,12 @@ impl UIElement for TextBox {
     }
 
     fn key_type(&mut self, _game: &mut crate::Game, c: char) {
+        if c == '\x7f' || c == '\x08' {
+            // Backspace
+            self.input.pop();
+            return;
+        }
+
         self.input.push(c);
     }