Implement abort on move outside keyboard

by adding a 1 px gutter at the top of the keyboard.
The fix in c40fbe2 already makes typing abort
when the user moves onto a pixel not occupied by a key.
But that only works for pixels inside the InputContainer.
This commit ensures that there is a 1 px row
which is key-free, at the top of our InputContainer.

Author: yawnoc

CHANGELOG.md

@@ -5,6 +5,7 @@
 
 - Fixed NullPointerException for `onSinglePointerTouchEvent` of null key
 - Fixed key press colour change dependent on activity background
+- Implemented abort on move outside keyboard (by adding 1 px gutter)
 - Reduced space bar height
 - Reduced digit row key height
 - Added fillColour attribute for the keyboard as a whole

app/src/main/java/io/github/yawnoc/strokeinput/InputContainer.java

@@ -32,7 +32,6 @@
     - Candidates bar
     - Keyboard
   TODO:
-    - Cancel key press if move outside keyboard
     - Switch to symbols keyboard
     - Candidates
 */

app/src/main/java/io/github/yawnoc/strokeinput/Keyboard.java

@@ -41,7 +41,9 @@ public class Keyboard {
   private static final int DEFAULT_KEY_TEXT_COLOUR = Color.WHITE;
   private static final int DEFAULT_KEY_TEXT_SIZE_SP = 32;
   private final int default_key_text_size_px;
+  
   private static final int DEFAULT_KEYBOARD_FILL_COLOUR = Color.BLACK;
+  private static final int KEYBOARD_GUTTER_HEIGHT_PX = 1;
 
   // Key properties
   private int keyWidth;
@@ -330,12 +332,12 @@ private void loadKeyboard(
       boolean inRow = false;
 
       int x = 0;
-      int y = 0;
+      int y = KEYBOARD_GUTTER_HEIGHT_PX;
       Key key = null;
       Row row = null;
 
-      int maximumX = 0;
-      int maximumY = 0;
+      int maximumX = x;
+      int maximumY = y;
 
       Resources resources = context.getResources();