core: layout: store keysym availability

src/core/button.rs

@@ -204,6 +204,12 @@ impl<D: Display, K: Keyboard> Button<D, K> {
         &self.modifiers
     }
 
+    #[inline(always)]
+    pub fn update_keys_supported(&mut self)
+    {
+        self.layout.update_keys_supported(&self.kbd)
+    }
+
     pub fn next_time(&self) -> Option<Instant>
     {
         let id = *self.timers.front()?;
@@ -229,7 +235,7 @@ impl<D: Display, K: Keyboard> Button<D, K> {
             }
 
             if old == ModState::Released || new == ModState::Released {
-                self.layout.update_modifiers(&self.modifiers);
+                self.layout.update_modifiers(&self.kbd, &self.modifiers);
                 if Layout::is_keysym_modifier(modifier) {
                     self.kbd.change_layout(&self.layout);
                 }

src/core/layout.rs

@@ -3,6 +3,7 @@
  * Copyright (c) 2024, Richard Acayan. All rights reserved.
  */
 
+use crate::core::Keyboard;
 use crate::core::button::ModState;
 use crate::core::expat;
 use std::cmp::Ordering;
@@ -68,9 +69,10 @@ impl KeyValue {
 
 pub struct Part {
     orig: KeyValue,
-
     val: KeyValue,
 
+    key_avail: bool,
+
     presses: u32,
 }
 
@@ -304,6 +306,8 @@ impl Part {
             orig,
             val,
 
+            key_avail: false,
+
             presses: 0,
         }
     }
@@ -332,6 +336,18 @@ impl Part {
         self.presses
     }
 
+    #[inline(always)]
+    pub fn key_available(&self) -> bool
+    {
+        self.key_avail
+    }
+
+    fn update_keys_supported<K: Keyboard>(&mut self, kbd: &K)
+    {
+        let key_supp = kbd.key_supported(self.val.0);
+        self.key_avail = self.val.0 != Keysym::NoSymbol && key_supp;
+    }
+
     pub fn modifier_id(&self) -> usize
     {
         match self.val.0 {
@@ -343,7 +359,9 @@ impl Part {
         }
     }
 
-    pub fn update_modifiers(&mut self, mod_state: &[ModState])
+    pub fn update_modifiers<K: Keyboard>(&mut self,
+                                         kbd: &K,
+                                         mod_state: &[ModState])
     {
         let mut val = self.orig.clone();
 
@@ -357,6 +375,8 @@ impl Part {
             val = Self::modify_shift_label(&val);
         }
 
+        let key_supp = kbd.key_supported(self.val.0);
+        self.key_avail = self.val.0 != Keysym::NoSymbol && key_supp;
         self.val = val;
     }
 
@@ -653,12 +673,23 @@ impl Layout {
         }
     }
 
-    pub fn update_modifiers(&mut self, mod_state: &[ModState])
+    pub fn update_modifiers<K: Keyboard>(&mut self, kbd: &K, mod_state: &[ModState])
     {
         for row in self.rows.iter_mut() {
             for key in row.iter_mut() {
                 for part in key.parts.iter_mut() {
-                    part.update_modifiers(mod_state);
+                    part.update_modifiers(kbd, mod_state);
+                }
+            }
+        }
+    }
+
+    pub fn update_keys_supported<K: Keyboard>(&mut self, kbd: &K)
+    {
+        for row in self.rows.iter_mut() {
+            for key in row.iter_mut() {
+                for part in key.parts.iter_mut() {
+                    part.update_keys_supported(kbd);
                 }
             }
         }