keymap: Make acceptable by Xwayland

Xwayland is more strict about accepting key maps than Wayland, and it also fails silently. Instead of fixing the other parts of the stack to reshape accepted Wayland key maps into acceptable Xorg key maps, this patch makes Squeekboard serve the maximum compatibility version in the first place.

Compatibility not actually guaranteed, that's purely observational.

Layouts with many characters (above 240) may lose some characters. This is again due to Xwayland accepting stricter layouts than Wayland.

src/keyboard.rs

@@ -138,25 +138,43 @@ pub fn generate_keymap(
 
     xkb_keycodes \"squeekboard\" {{
         minimum = 8;
-        maximum = 255;"
+        maximum = 999;"
     )?;
     
-    for (name, state) in keystates.iter() {
-        match &state.action {
+    // Not all layouts fit in 255 characters... so bump the limit to 999.
+    // Xorg can only consume up to 255, so this may not work in Xwayland.
+    // Two possible solutions:
+    // - use levels to cram multiple characters into one key
+    // - swap layouts on key presses
+    for keycode in 9..999 {
+        write!(
+            buf,
+            "
+        <I{}> = {0};",
+            keycode,
+        )?;
+    }
+
+    writeln!(
+        buf,
+        "
+        indicator 1 = \"Caps Lock\"; // Xwayland won't accept without it.
+    }};
+    
+    xkb_symbols \"squeekboard\" {{
+"
+    )?;
+    
+    for (_name, state) in keystates.iter() {
+        match &state.action{
             Action::Submit { text: _, keys } => {
-                if let 0 = keys.len() {
-                    log_print!(
-                        logging::Level::Warning,
-                        "Key {} has no keysyms", name,
-                    );
-                };
                 for (named_keysym, keycode) in keys.iter().zip(&state.keycodes) {
                     write!(
                         buf,
                         "
-        <{}> = {};",
-                        named_keysym.0,
+        key <I{}> {{ [ {} ] }};",
                         keycode,
+                        named_keysym.0,
                     )?;
                 }
             },
@@ -165,7 +183,7 @@ pub fn generate_keymap(
                 write!(
                     buf,
                     "
-        <BackSpace> = {};",
+        key <I{}> {{ [ BackSpace ] }};",
                     keycodes.next().expect("Erase key has no keycode"),
                 )?;
                 if let Some(_) = keycodes.next() {
@@ -175,51 +193,46 @@ pub fn generate_keymap(
                     );
                 }
             },
-            _ => {},
+            Action::SetView(_) => {},
+            Action::LockView{ .. } => {},
+            Action::ApplyModifier(_) => {},
+            Action::ShowPreferences => {},
         }
     }
-    
-    writeln!(
-        buf,
-        "
-    }};
-    
-    xkb_symbols \"squeekboard\" {{
 
-        name[Group1] = \"Letters\";
-        name[Group2] = \"Numbers/Symbols\";
-        
-        key <BackSpace> {{ [ BackSpace ] }};"
-    )?;
-    
-    for (_name, state) in keystates.iter() {
-        if let Action::Submit { text: _, keys } = &state.action {
-            for keysym in keys.iter() {
-                write!(
-                    buf,
-                    "
-        key <{}> {{ [ {0} ] }};",
-                    keysym.0,
-                )?;
-            }
-        }
-    }
     writeln!(
         buf,
         "
     }};
 
     xkb_types \"squeekboard\" {{
+        virtual_modifiers Squeekboard; // No modifiers! Needed for Xorg for some reason.
+    
+        // Those names are needed for Xwayland.
+        type \"ONE_LEVEL\" {{
+            modifiers= none;
+            level_name[Level1]= \"Any\";
+        }};
+        type \"TWO_LEVEL\" {{
+            level_name[Level1]= \"Base\";
+        }};
+        type \"ALPHABETIC\" {{
+            level_name[Level1]= \"Base\";
+        }};
+        type \"KEYPAD\" {{
+            level_name[Level1]= \"Base\";
+        }};
+        type \"SHIFT+ALT\" {{
+            level_name[Level1]= \"Base\";
+        }};
 
-	type \"TWO_LEVEL\" {{
-            modifiers = Shift;
-            map[Shift] = Level2;
-            level_name[Level1] = \"Base\";
-            level_name[Level2] = \"Shift\";
-	}};
     }};
 
     xkb_compatibility \"squeekboard\" {{
+        // Needed for Xwayland again.
+        interpret Any+AnyOf(all) {{
+            action= SetMods(modifiers=modMapMods,clearLocks);
+        }};
     }};
 }};"
     )?;

src/tests.rs

@@ -68,7 +68,7 @@ fn check_layout(layout: Layout) {
                     match state.key_get_one_sym(*keycode) {
                         xkb::KEY_NoSymbol => {
                             eprintln!("{}", keymap_str);
-                            panic!("Keysym {} on key {:?} can't be resolved", keycode, button.name);
+                            panic!("Keysym for code {} on key {} ({:?}) can't be resolved", keycode, button.name.to_string_lossy(), button.name);
                         },
                         _ => {},
                     }