paper-ripple provides a visual effect that other paper elements can use to simulate a rippling effect emanating from the point of contact. The effect can be visualized as a concentric circle with motion.

Example:

<paper-ripple></paper-ripple>

paper-ripple listens to "mousedown" and "mouseup" events so it would display ripple effect when touches on it. You can also defeat the default behavior and manually route the down and up actions to the ripple element. Note that it is important if you call downAction() you will have to make sure to call upAction() so that paper-ripple would end the animation loop.

Example:

<paper-ripple id="ripple" style="pointer-events: none;"></paper-ripple>
...
<script>
  downAction: function(e) {
    this.$.ripple.downAction({x: e.x, y: e.y});
  },
  upAction: function(e) {
    this.$.ripple.upAction();
  }
</script>

Styling ripple effect:

Use CSS color property to style the ripple:

paper-ripple {
  color: #4285f4;
}

Note that CSS color property is inherited so it is not required to set it on the paper-ripple element directly.

By default, the ripple is centered on the point of contact. Apply the recenters attribute to have the ripple grow toward the center of its container.

<paper-ripple recenters></paper-ripple>

Apply center to center the ripple inside its container from the start.

<paper-ripple center></paper-ripple>

Apply circle class to make the rippling effect within a circle.

<paper-ripple class="circle"></paper-ripple>