refactor: Implement Compose without global state

Thanks to the previous commit, a modifier key can now be more complex
than just a KeyValue.Modifier. This allows a more elegant implementation
of the compose key, that could be taken as a base for other features
(eg. unicode hex entry, hangul)

The COMPOSE_PENDING modifier is removed as keys of kind Compose_pending
can act as a modifier. This has the advantage of highlighting the key
that was last pressed in the sequence.

Rules are added to Pointers: Non-special but latchable keys must clear
latches and cannot be locked with a long press. These rules were not
needed before but were intended.

1 files changed, 6 insertions, 11 deletions

diff --git a/srcs/juloo.keyboard2/ComposeKey.java b/srcs/juloo.keyboard2/ComposeKey.java
index dd805a5..ef5a7f2 100644
--- a/srcs/juloo.keyboard2/ComposeKey.java
+++ b/srcs/juloo.keyboard2/ComposeKey.java
@@ -4,31 +4,26 @@ import java.util.Arrays;
 
 public final class ComposeKey
 {
-  /** Apply the pending compose sequence to [kv]. Returns [null] if [kv] is not
-      part of the pending sequence. */
+  /** Apply the pending compose sequence to [kv]. */
   public static KeyValue apply(int state, KeyValue kv)
   {
     switch (kv.getKind())
     {
       case Char:
         KeyValue res = apply(state, kv.getChar());
-        // Dim characters not part of any sequence instead of removing them.
+        // Grey-out characters not part of any sequence.
         if (res == null)
           return kv.withFlags(kv.getFlags() | KeyValue.FLAG_GREYED);
         return res;
-      /* These keys must not be removed. */
+      /* These keys are not greyed. */
       case Event:
       case Modifier:
+      case Compose_pending:
         return kv;
-      /* These keys cannot be part of sequences. */
-      case String:
-      case Keyevent:
-      case Editing:
-      case Placeholder:
+      /* Other keys cannot be part of sequences. */
+      default:
         return kv.withFlags(kv.getFlags() | KeyValue.FLAG_GREYED);
-      case Compose_pending: return null;
     }
-    return null;
   }
 
   /** Apply the pending compose sequence to char [c]. */