Improve Material ink effects

sky/framework/fn.dart

Index: sky/framework/fn.dart
diff --git a/sky/framework/fn.dart b/sky/framework/fn.dart
index 000e9d3fe91495dc785dfd65ae83d43c254c82a4..a0ec7abf62d0de59e01dcc721cbfac587b1224bf 100644
--- a/sky/framework/fn.dart
+++ b/sky/framework/fn.dart
@@ -175,6 +175,7 @@ class EventTarget extends Node  {
     GestureEventListener onGestureScrollStart,
     GestureEventListener onGestureScrollUpdate,
     GestureEventListener onGestureTap,
+    GestureEventListener onGestureTapDown,
     PointerEventListener onPointerCancel,
     PointerEventListener onPointerDown,
     PointerEventListener onPointerMove,
@@ -197,6 +198,8 @@ class EventTarget extends Node  {
       listeners['gesturescrollupdate'] = onGestureScrollUpdate;
     if (onGestureTap != null)
       listeners['gesturetap'] = onGestureTap;
+    if (onGestureTapDown != null)
+      listeners['gesturetapdown'] = onGestureTapDown;
     if (onPointerCancel != null)
       listeners['pointercancel'] = onPointerCancel;
     if (onPointerDown != null)
@@ -216,6 +219,7 @@ class EventTarget extends Node  {
     GestureEventListener onGestureScrollStart,
     GestureEventListener onGestureScrollUpdate,
     GestureEventListener onGestureTap,
+    GestureEventListener onGestureTapDown,
     PointerEventListener onPointerCancel,
     PointerEventListener onPointerDown,
     PointerEventListener onPointerMove,
@@ -229,6 +233,7 @@ class EventTarget extends Node  {
          onGestureScrollUpdate: onGestureScrollUpdate,
          onGestureScrollStart: onGestureScrollStart,
          onGestureTap: onGestureTap,
+         onGestureTapDown: onGestureTapDown,
          onPointerCancel: onPointerCancel,
          onPointerDown: onPointerDown,
          onPointerMove: onPointerMove,