fix(ripple): Relax deduplication conditions for touch devices (#1990)

packages/mdc-ripple/constants.js

@@ -40,6 +40,7 @@ const numbers = {
   INITIAL_ORIGIN_SCALE: 0.6,
   DEACTIVATION_TIMEOUT_MS: 225, // Corresponds to $mdc-ripple-translate-duration (i.e. activation animation duration)
   FG_DEACTIVATION_MS: 150, // Corresponds to $mdc-ripple-fade-out-duration (i.e. deactivation animation duration)
+  TAP_DELAY_MS: 300, // Delay between touch and simulated mouse events on touch devices
 };
 
 export {cssClasses, strings, numbers};

packages/mdc-ripple/foundation.js

@@ -295,8 +295,7 @@ class MDCRippleFoundation extends MDCFoundation {
 
     // Avoid reacting to follow-on events fired by touch device after an already-processed user interaction
     const previousActivationEvent = this.previousActivationEvent_;
-    const isSameInteraction = previousActivationEvent && e && previousActivationEvent.type !== e.type &&
-      previousActivationEvent.clientX === e.clientX && previousActivationEvent.clientY === e.clientY;
+    const isSameInteraction = previousActivationEvent && e && previousActivationEvent.type !== e.type;
     if (isSameInteraction) {
       return;
     }
@@ -428,7 +427,7 @@ class MDCRippleFoundation extends MDCFoundation {
     this.activationState_ = this.defaultActivationState_();
     // Touch devices may fire additional events for the same interaction within a short time.
     // Store the previous event until it's safe to assume that subsequent events are for new interactions.
-    setTimeout(() => this.previousActivationEvent_ = null, 100);
+    setTimeout(() => this.previousActivationEvent_ = null, MDCRippleFoundation.numbers.TAP_DELAY_MS);
   }
 
   /**

test/unit/mdc-ripple/foundation-deactivation.test.js

@@ -333,7 +333,7 @@ testFoundation('only re-activates when there are no additional pointer events to
 
     documentHandlers.mouseup();
     mockRaf.flush();
-    clock.tick(DEACTIVATION_TIMEOUT_MS);
+    clock.tick(numbers.TAP_DELAY_MS);
 
     // Finally, verify that since mouseup happened, we can re-activate the ripple.
     handlers.mousedown({pageX: 0, pageY: 0});