Autocomplete on space bar and undo on delete (#1179)

* Refactor: Implement the space key as an editing action

The space key is no longer a CHAR key but now an EDITING key. This
allows changing the behavior of the space bar while allowing custom
layout users to define a key outputing a space as before.

KeyModifier and ComposeKey are updated to treat the space key as before.

* Enter the best suggestion when the space bar is pressed

* Refactor: Implement backspace as an editing action

* Undo suggestion when delete is pressed

The delete key (backspace internally) undoes the suggestion if the last
action done was entering the suggestion with either the space bar or the
candidates view.

* Add an option to enable space bar autocomplete

This option is off by default. Undoing a completion with backspace works
in any case.

* Refactor: Track selection emptyness in CurrentlyTypedWord

This removes an expensive RPC call.

1 files changed, 10 insertions, 3 deletions

diff --git a/srcs/juloo.keyboard2/KeyValue.java b/srcs/juloo.keyboard2/KeyValue.java
index 1fb84f4..769bd29 100644
--- a/srcs/juloo.keyboard2/KeyValue.java
+++ b/srcs/juloo.keyboard2/KeyValue.java
@@ -81,6 +81,8 @@ public final class KeyValue implements Comparable<KeyValue>
     DELETE_WORD,
     FORWARD_DELETE_WORD,
     SELECTION_CANCEL,
+    SPACE_BAR,
+    BACKSPACE,
   }
 
   public static enum Placeholder
@@ -401,7 +403,12 @@ public final class KeyValue implements Comparable<KeyValue>
 
   private static KeyValue editingKey(int symbol, Editing action)
   {
-    return editingKey(String.valueOf((char)symbol), action, FLAG_KEY_FONT);
+    return editingKey(symbol, action, 0);
+  }
+
+  private static KeyValue editingKey(int symbol, Editing action, int flags)
+  {
+    return editingKey(String.valueOf((char)symbol), action, flags | FLAG_KEY_FONT);
   }
 
   /** A key that slides the property specified by [s] by the amount specified
@@ -658,7 +665,6 @@ public final class KeyValue implements Comparable<KeyValue>
       case "page_down": return keyeventKey(0xE003, KeyEvent.KEYCODE_PAGE_DOWN, 0);
       case "home": return keyeventKey(0xE00B, KeyEvent.KEYCODE_MOVE_HOME, FLAG_SMALLER_FONT);
       case "end": return keyeventKey(0xE00C, KeyEvent.KEYCODE_MOVE_END, FLAG_SMALLER_FONT);
-      case "backspace": return keyeventKey(0xE011, KeyEvent.KEYCODE_DEL, 0);
       case "delete": return keyeventKey(0xE010, KeyEvent.KEYCODE_FORWARD_DEL, 0);
       case "insert": return keyeventKey("Ins", KeyEvent.KEYCODE_INSERT, FLAG_SMALLER_FONT);
       case "f1": return keyeventKey("F1", KeyEvent.KEYCODE_F1, 0);
@@ -680,7 +686,7 @@ public final class KeyValue implements Comparable<KeyValue>
       /* Spaces */
       case "\\t": return charKey("\\t", '\t', 0); // Send the tab character
       case "\\n": return charKey("\\n", '\n', 0); // Send the newline character
-      case "space": return charKey(0xE00D, ' ', FLAG_SMALLER_FONT | FLAG_GREYED);
+      case "space": return editingKey(0xE00D, Editing.SPACE_BAR, FLAG_SMALLER_FONT | FLAG_GREYED);
       case "nbsp": return charKey("\u237d", '\u00a0', FLAG_SMALLER_FONT);
       case "nnbsp": return charKey("\u2423", '\u202F', FLAG_SMALLER_FONT);
 
@@ -729,6 +735,7 @@ public final class KeyValue implements Comparable<KeyValue>
       case "halfspace": return charKey(0xE018, '\u200C', 0); // zero-width non joiner
 
       /* Editing keys */
+      case "backspace": return editingKey(0xE011, Editing.BACKSPACE, 0);
       case "copy": return editingKey(0xE030, Editing.COPY);
       case "paste": return editingKey(0xE032, Editing.PASTE);
       case "cut": return editingKey(0xE031, Editing.CUT);