wayland: keyboard: release keys while the keymap is changing

Keeping the keys pressed can confuse some compositors, and the key codes
may change. Release any keys that are pressed while the keymap is
changing, and press them again afterwards.

src/core/button.rs

@@ -206,6 +206,10 @@ impl<D: Display, K: Keyboard> Button<D, K> {
                 self.kbd.release(Layout::modifier_keysym(modifier));
             }
 
+            if old == ModState::Released {
+                self.kbd.press(Layout::modifier_keysym(modifier));
+            }
+
             if old == ModState::Released || new == ModState::Released {
                 self.layout.update_modifiers(&self.modifiers);
                 if Layout::is_keysym_modifier(modifier) {
@@ -213,10 +217,6 @@ impl<D: Display, K: Keyboard> Button<D, K> {
                 }
             }
 
-            if old == ModState::Released {
-                self.kbd.press(Layout::modifier_keysym(modifier));
-            }
-
             true
         } else {
             false

src/core/layout.rs

@@ -165,10 +165,8 @@ impl Part {
     fn modify_no_fn(orig_sym: Keysym) -> Keysym
     {
         match orig_sym {
-            /*
             Keysym::F11 => Keysym::NoSymbol,
             Keysym::F12 => Keysym::NoSymbol,
-            */
             _ => orig_sym,
         }
     }

src/wayland/keyboard.rs

@@ -27,6 +27,7 @@ pub struct VirtualKeyboard {
     keymap_id: u8,
 
     keycodes: HashMap<Keysym, u8>,
+    pressed: [Keysym; 248],
     mod_state: u32,
 }
 
@@ -47,7 +48,8 @@ impl VirtualKeyboard {
             keymap,
             keymap_id: 1,
 
-            keycodes: HashMap::new(),
+            keycodes: HashMap::with_capacity(248),
+            pressed: [Keysym::NoSymbol; 248],
             mod_state: 0,
         }
     }
@@ -101,6 +103,7 @@ impl Keyboard for VirtualKeyboard {
         }
 
         let keycode = *self.keycodes.get(&sym).unwrap();
+        self.pressed[keycode as usize] = sym;
         self.vk.key(0, keycode as u32, 1);
     }
 
@@ -127,6 +130,7 @@ impl Keyboard for VirtualKeyboard {
         }
 
         let keycode = *self.keycodes.get(&sym).unwrap();
+        self.pressed[keycode as usize] = Keysym::NoSymbol;
         self.vk.key(0, keycode as u32, 0);
     }
 
@@ -143,12 +147,9 @@ impl Keyboard for VirtualKeyboard {
         let path = format!("/tmp/ufkbd-keymap-pid{}-{}",
                            process::id(), self.keymap_id);
         self.keymap = OpenOptions::new()
-                       .read(true)
+                       .read(true).write(true)
-                       .write(true)
+                       .create(true).truncate(true)
-                       .create(true)
+                       .open(path).unwrap();
-                       .truncate(true)
-                       .open(path)
-                       .unwrap();
 
         self.keymap.write(b"xkb_keymap {\n").unwrap();
         self.keymap.write(b"  xkb_symbols \"ufkbd\" {\n").unwrap();
@@ -193,7 +194,28 @@ impl Keyboard for VirtualKeyboard {
         self.keymap.write(b"  };\n").unwrap();
         self.keymap.write(b"};\n").unwrap();
 
+        if self.mod_state != 0 {
+            self.vk.modifiers(0, 0, 0, 0);
+        }
+
+        for (code, sym) in self.pressed.iter().enumerate() {
+            if *sym != Keysym::NoSymbol {
+                self.vk.key(0, code as u32, 0);
+            }
+        }
+
         let len = self.keymap.stream_position().unwrap() as u32;
         self.vk.keymap(KeymapFormat::XkbV1 as u32, self.keymap.as_fd(), len);
+
+        if self.mod_state != 0 {
+            self.vk.modifiers(self.mod_state, 0, 0, 0);
+        }
+
+        for sym in &self.pressed {
+            if *sym != Keysym::NoSymbol {
+                let code = *self.keycodes.get(&sym).unwrap();
+                self.vk.key(0, code as u32, 1);
+            }
+        }
     }
 }