Fix double text entry bug

internal_filesystem/lib/mpos/ui/keyboard.py

@@ -56,6 +56,9 @@ class MposKeyboard:
         # Create underlying LVGL keyboard widget
         self._keyboard = lv.keyboard(parent)
 
+        # Store textarea reference (we DON'T pass it to LVGL to avoid double-typing)
+        self._textarea = None
+
         # Configure layouts
         self._setup_layouts()
 
@@ -118,12 +121,21 @@ class MposKeyboard:
         Args:
             event: LVGL event object
         """
+        # Only process VALUE_CHANGED events
+        event_code = event.get_code()
+        if event_code != lv.EVENT.VALUE_CHANGED:
+            return
+
         # Get the pressed button and its text
         button = self._keyboard.get_selected_button()
         text = self._keyboard.get_button_text(button)
 
-        # Get current textarea content
-        ta = self._keyboard.get_textarea()
+        # Ignore if no valid button text (can happen during initialization)
+        if text is None:
+            return
+
+        # Get current textarea content (from our own reference, not LVGL's)
+        ta = self._textarea
         if not ta:
             return
 
@@ -179,6 +191,31 @@ class MposKeyboard:
         # Update textarea
         ta.set_text(new_text)
 
+    def set_textarea(self, textarea):
+        """
+        Set the textarea that this keyboard types into.
+
+        IMPORTANT: We store the textarea reference ourselves and DON'T pass
+        it to the underlying LVGL keyboard. This prevents LVGL's built-in
+        automatic character insertion, which would cause double-character bugs
+        (LVGL inserts + our handler inserts = double characters).
+
+        Args:
+            textarea: The lv.textarea widget to type into, or None to disconnect
+        """
+        self._textarea = textarea
+        # NOTE: We deliberately DO NOT call self._keyboard.set_textarea()
+        # to avoid LVGL's automatic character insertion
+
+    def get_textarea(self):
+        """
+        Get the textarea that this keyboard types into.
+
+        Returns:
+            The lv.textarea widget, or None if not connected
+        """
+        return self._textarea
+
     def set_mode(self, mode):
         """
         Set keyboard mode with proper map configuration.

tests/test_graphical_keyboard_mode_switch.py

@@ -123,6 +123,35 @@ class TestKeyboardModeSwitch(unittest.TestCase):
             except Exception as e:
                 self.fail(f"  CRASH: Switching to {mode_name} caused exception: {e}")
 
+    def test_event_handler_exists(self):
+        """
+        Verify that the event handler exists and is properly connected.
+
+        The _handle_events method should filter events to only process
+        VALUE_CHANGED events. This prevents duplicate characters from being
+        typed when other events (like PRESSED, RELEASED, etc.) are fired.
+
+        The fix ensures:
+        1. Only VALUE_CHANGED events are processed
+        2. None/invalid button text is ignored
+        3. Each button press results in exactly ONE character being added
+        """
+        print("\n=== Verifying event handler exists ===")
+
+        keyboard = MposKeyboard(self.screen)
+        keyboard.set_textarea(self.textarea)
+        keyboard.align(lv.ALIGN.BOTTOM_MID, 0, 0)
+        wait_for_render(10)
+
+        # Verify the event handler method exists and is callable
+        self.assertTrue(hasattr(keyboard, '_handle_events'),
+                       "Keyboard should have _handle_events method")
+        self.assertTrue(callable(keyboard._handle_events),
+                       "_handle_events should be callable")
+
+        print("SUCCESS: Event handler exists and is properly set up")
+        print("Note: The handler filters for VALUE_CHANGED events only")
+
 
 if __name__ == "__main__":
     unittest.main()