Add complex keys (#774)

This allows to add new kinds of keys that need more data without making
KeyValue's footprint bigger for common keys.

This changes the [_symbol] field into [_payload], which holds the same
as the previous field for more common keys but can hold bigger objects
for keys of the new "Complex" kind.

This also adds a complex key: String keys with a symbol different than
the outputted string.

Unit tests are added as the Java language is not helpful in making
robust code.

srcs/juloo.keyboard2/KeyValue.java

@@ -91,7 +91,8 @@ public final class KeyValue implements Comparable<KeyValue>
   {
     Char, String, Keyevent, Event, Compose_pending, Hangul_initial,
     Hangul_medial, Modifier, Editing, Placeholder,
-    Cursor_move // Value is encoded as a 16-bit integer
+    Cursor_move, // Value is encoded as a 16-bit integer.
+    Complex, // [_payload] is a [KeyValue.Complex], value is [Complex.Kind].
   }
 
   private static final int FLAGS_OFFSET = 19;
@@ -129,7 +130,13 @@ public final class KeyValue implements Comparable<KeyValue>
     check((((Kind.values().length - 1) << KIND_OFFSET) & ~KIND_BITS) == 0);
   }
 
-  private final String _symbol;
+  /**
+   * The symbol that is rendered on the keyboard as a [String].
+   * Except for keys of kind:
+   * - [String], this is also the string to output.
+   * - [Complex], this is an instance of [KeyValue.Complex].
+   */
+  private final Object _payload;
 
   /** This field encodes three things: Kind, flags and value. */
   private final int _code;
@@ -153,7 +160,9 @@ public final class KeyValue implements Comparable<KeyValue>
       When [getKind() == Kind.String], also the string to send. */
   public String getString()
   {
-    return _symbol;
+    if (getKind() == Kind.Complex)
+      return ((Complex)_payload).getSymbol();
+    return (String)_payload;
   }
 
   /** Defined only when [getKind() == Kind.Char]. */
@@ -211,25 +220,32 @@ public final class KeyValue implements Comparable<KeyValue>
     return (short)(_code & VALUE_BITS);
   }
 
+  /** Defined only when [getKind() == Kind.Complex]. */
+  public Complex getComplex()
+  {
+    return (Complex)_payload;
+  }
+
+  /** Defined only when [getKind() == Kind.Complex]. */
+  public Complex.Kind getComplexKind()
+  {
+    return Complex.Kind.values()[(_code & VALUE_BITS)];
+  }
+
   /* Update the char and the symbol. */
   public KeyValue withChar(char c)
   {
     return new KeyValue(String.valueOf(c), Kind.Char, c, getFlags());
   }
 
-  public KeyValue withSymbol(String s)
-  {
-    return new KeyValue(s, (_code & KIND_BITS), (_code & VALUE_BITS), getFlags());
-  }
-
   public KeyValue withKeyevent(int code)
   {
-    return new KeyValue(_symbol, Kind.Keyevent, code, getFlags());
+    return new KeyValue(getString(), Kind.Keyevent, code, getFlags());
   }
 
   public KeyValue withFlags(int f)
   {
-    return new KeyValue(_symbol, (_code & KIND_BITS), (_code & VALUE_BITS), f);
+    return new KeyValue(getString(), (_code & KIND_BITS), (_code & VALUE_BITS), f);
   }
 
   @Override
@@ -247,7 +263,9 @@ public final class KeyValue implements Comparable<KeyValue>
     d = _code - snd._code;
     if (d != 0)
       return d;
-    return _symbol.compareTo(snd._symbol);
+    if (getKind() == Kind.Complex)
+      return ((Complex)_payload).compareTo((Complex)snd._payload);
+    return ((String)_payload).compareTo((String)snd._payload);
   }
 
   /** Type-safe alternative to [equals]. */
@@ -255,24 +273,36 @@ public final class KeyValue implements Comparable<KeyValue>
   {
     if (snd == null)
       return false;
-    return _symbol.equals(snd._symbol) && _code == snd._code;
+    return _code == snd._code && _payload.equals(snd._payload);
   }
 
   @Override
   public int hashCode()
   {
-    return _symbol.hashCode() + _code;
+    return _payload.hashCode() + _code;
   }
 
-  public KeyValue(String s, int kind, int value, int flags)
+  public String toString()
   {
-    _symbol = s;
+    int value = _code & VALUE_BITS;
+    return "[KeyValue " + getKind().toString() + "+" + getFlags() + "+" + value + " \"" + getString() + "\"]";
+  }
+
+  private KeyValue(Object p, int kind, int value, int flags)
+  {
+    _payload = p;
     _code = (kind & KIND_BITS) | (flags & FLAGS_BITS) | (value & VALUE_BITS);
   }
 
-  public KeyValue(String s, Kind k, int v, int f)
+  public KeyValue(Complex p, Complex.Kind value, int flags)
   {
-    this(s, (k.ordinal() << KIND_OFFSET), v, f);
+    this((Object)p, (Kind.Complex.ordinal() << KIND_OFFSET), value.ordinal(),
+        flags);
+  }
+
+  public KeyValue(String p, Kind k, int v, int f)
+  {
+    this(p, (k.ordinal() << KIND_OFFSET), v, f);
   }
 
   private static KeyValue charKey(String symbol, char c, int flags)
@@ -397,6 +427,11 @@ public final class KeyValue implements Comparable<KeyValue>
     return KeyValue.makeCharKey((char)precomposed);
   }
 
+  public static KeyValue makeActionKey(String symbol)
+  {
+    return eventKey(symbol, Event.ACTION, FLAG_SMALLER_FONT);
+  }
+
   /** Make a key that types a string. A char key is returned for a string of
       length 1. */
   public static KeyValue makeStringKey(String str, int flags)
@@ -407,12 +442,36 @@ public final class KeyValue implements Comparable<KeyValue>
       return new KeyValue(str, Kind.String, 0, flags | FLAG_SMALLER_FONT);
   }
 
+  public static KeyValue makeStringKeyWithSymbol(String str, String symbol, int flags)
+  {
+    return new KeyValue(new Complex.StringWithSymbol(str, symbol),
+        Complex.Kind.StringWithSymbol, flags);
+  }
+
   /** Make a modifier key for passing to [KeyModifier]. */
   public static KeyValue makeInternalModifier(Modifier mod)
   {
     return new KeyValue("", Kind.Modifier, mod.ordinal(), 0);
   }
 
+  public static KeyValue parseKeyDefinition(String str)
+  {
+    if (str.length() < 2 || str.charAt(0) != ':')
+      return makeStringKey(str);
+    try
+    {
+      return KeyValueParser.parse(str);
+    }
+    catch (KeyValueParser.ParseError _e)
+    {
+      return makeStringKey(str);
+    }
+  }
+
+  /**
+   * Return a key by its name. If the given name doesn't correspond to a key
+   * defined in this function, it is passed to [parseStringKey] as a fallback.
+   */
   public static KeyValue getKeyByName(String name)
   {
     switch (name)
@@ -599,8 +658,8 @@ public final class KeyValue implements Comparable<KeyValue>
       case "ㅍ": return makeHangulInitial("ㅍ", 17);
       case "ㅎ": return makeHangulInitial("ㅎ", 18);
 
-      /* Fallback to a string key that types its name */
-      default: return makeStringKey(name);
+      /* The key is not one of the special ones. */
+      default: return parseKeyDefinition(name);
     }
   }
 
@@ -610,4 +669,49 @@ public final class KeyValue implements Comparable<KeyValue>
     if (!b)
       throw new RuntimeException("Assertion failure");
   }
+
+  public static abstract class Complex
+  {
+    public abstract String getSymbol();
+
+    /** [compareTo] can assume that [snd] is an instance of the same class. */
+    public abstract int compareTo(Complex snd);
+
+    public boolean equals(Object snd)
+    {
+      if (snd instanceof Complex)
+        return compareTo((Complex)snd) == 0;
+      return false;
+    }
+
+    /** [hashCode] will be called on this class. */
+
+    /** The kind is stored in the [value] field of the key. */
+    public static enum Kind
+    {
+      StringWithSymbol,
+    }
+
+    public static final class StringWithSymbol extends Complex
+    {
+      public final String str;
+      private final String _symbol;
+
+      public StringWithSymbol(String _str, String _sym)
+      {
+        str = _str;
+        _symbol = _sym;
+      }
+
+      public String getSymbol() { return _symbol; }
+
+      public int compareTo(Complex _snd)
+      {
+        StringWithSymbol snd = (StringWithSymbol)_snd;
+        int d = str.compareTo(snd.str);
+        if (d != 0) return d;
+        return _symbol.compareTo(snd._symbol);
+      }
+    }
+  };
 }