horizontalStep function

int horizontalStep(
  1. LogicalKeyboardKey key,
  2. TextDirection dir
)

Resolves a horizontal arrow key to a logical index step for the given text dir. Returns +1 (next index) or -1 (previous index) for the right/left arrows, mirrored under RTL, and 0 for any other key.

Implementation

int horizontalStep(LogicalKeyboardKey key, TextDirection dir) {
  final rtl = dir == TextDirection.rtl;
  if (key == LogicalKeyboardKey.arrowRight) return rtl ? -1 : 1;
  if (key == LogicalKeyboardKey.arrowLeft) return rtl ? 1 : -1;
  return 0;
}