Merge branch 'master' into Private_Messages

osu.Game/Graphics/Containers/ShakeContainer.cs

@@ -0,0 +1,39 @@
+// Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
+// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+
+namespace osu.Game.Graphics.Containers
+{
+    /// <summary>
+    /// A container that adds the ability to shake its contents.
+    /// </summary>
+    public class ShakeContainer : Container
+    {
+        /// <summary>
+        /// Shake the contents of this container.
+        /// </summary>
+        /// <param name="maximumLength">The maximum length the shake should last.</param>
+        public void Shake(double maximumLength)
+        {
+            const float shake_amount = 8;
+            const float shake_duration = 30;
+
+            // if we don't have enough time, don't bother shaking.
+            if (maximumLength < shake_duration * 2)
+                return;
+
+            var sequence = this.MoveToX(shake_amount, shake_duration / 2, Easing.OutSine).Then()
+                               .MoveToX(-shake_amount, shake_duration, Easing.InOutSine).Then();
+
+            // if we don't have enough time for the second shake, skip it.
+            if (maximumLength > shake_duration * 4)
+                sequence = sequence
+                           .MoveToX(shake_amount, shake_duration, Easing.InOutSine).Then()
+                           .MoveToX(-shake_amount, shake_duration, Easing.InOutSine).Then();
+
+            sequence.MoveToX(0, shake_duration / 2, Easing.InSine);
+        }
+    }
+}