Added animation

app/src/main/java/eu/kanade/tachiyomi/widget/RevealAnimationView.kt

@@ -0,0 +1,79 @@
+package eu.kanade.tachiyomi.widget
+
+import android.animation.Animator
+import android.animation.AnimatorListenerAdapter
+import android.annotation.TargetApi
+import android.content.Context
+import android.os.Build
+import android.util.AttributeSet
+import android.view.View
+import android.view.ViewAnimationUtils
+
+@TargetApi(Build.VERSION_CODES.LOLLIPOP)
+class RevealAnimationView @JvmOverloads constructor(context: Context, attrs: AttributeSet? = null) :
+        View(context, attrs) {
+
+    /**
+     * Hides the animation view with a animation
+     *
+     * @param centerX x starting point
+     * @param centerY y starting point
+     * @param initialRadius size of radius of animation
+     */
+    fun hideRevealEffect(centerX: Int, centerY: Int, initialRadius: Int) {
+        if (Build.VERSION.SDK_INT >= 21) {
+
+            // Make the view visible.
+            this.visibility = View.VISIBLE
+
+            // Create the animation (the final radius is zero).
+            val anim = ViewAnimationUtils.createCircularReveal(
+                    this, centerX, centerY, initialRadius.toFloat(), 0f)
+
+            // Set duration of animation.
+            anim.duration = 500
+
+            // make the view invisible when the animation is done
+            anim.addListener(object : AnimatorListenerAdapter() {
+                override fun onAnimationEnd(animation: Animator) {
+                    super.onAnimationEnd(animation)
+                    this@RevealAnimationView.visibility = View.INVISIBLE
+                }
+            })
+
+            anim.start()
+        }
+    }
+
+    /**
+     * Fills the animation view with a animation
+     *
+     * @param centerX x starting point
+     * @param centerY y starting point
+     * @param listener animation listener
+     *
+     * @return sdk version lower then 21
+     */
+    fun showRevealEffect(centerX: Int, centerY: Int, listener: Animator.AnimatorListener): Boolean {
+        if (Build.VERSION.SDK_INT >= 21) {
+
+            this.visibility = View.VISIBLE
+
+            val height = this.height
+
+            // Create animation
+            val anim = ViewAnimationUtils.createCircularReveal(
+                    this, centerX, centerY, 0f, height.toFloat())
+
+            // Set duration of animation
+            anim.duration = 350
+
+            anim.addListener(listener)
+            anim.start()
+            return true
+        }
+        return false
+    }
+
+
+}