Add stable-alike BackButton

osu.Game/Graphics/UserInterface/BackButton.cs

@@ -0,0 +1,84 @@
+// Copyright (c) 2007-2016 ppy Pty Ltd <contact@ppy.sh>.
+// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu-framework/master/LICENCE
+
+using OpenTK;
+using OpenTK.Graphics;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.UserInterface;
+using osu.Framework.Graphics.Transformations;
+using osu.Framework.Input;
+
+namespace osu.Game.Graphics.UserInterface
+{
+    // Basic back button as it was on stable (kinda). No skinning possible for now
+    class BackButton : ExtendableButton
+    {
+        private TextAwesome icon;
+        private Vector2 iconPos = new Vector2(20, 0);
+
+        public BackButton()
+        {
+            InitialExtendLenght = new Vector2(40, 0);
+            ExtendLenght = new Vector2(60, 0);
+
+            RelativeSizeAxes = Axes.Y;
+            Width = 80;
+            //Height = 40; // should be set or should be relative?
+
+            Text = @"Back";
+
+            BGColour = new Color4(195, 40, 140, 255);
+            Colour = new Color4(238, 51, 153, 255);
+
+            Children = new Drawable[]
+            {
+                icon = new TextAwesome
+                {
+                    Anchor = Anchor.CentreLeft,
+                    TextSize = 25,
+                    Position = iconPos,
+                    Icon = FontAwesome.fa_osu_left_o
+                }
+            };
+
+            // HACK: because it never uses InitialExtendLenght that we give to it on creation
+            textContainer.Position = Position + InitialExtendLenght; 
+        }
+        protected override bool OnHover(InputState state)
+        {
+            bool result = base.OnHover(state);
+
+            icon.ClearTransformations();
+
+            icon.MoveToX(iconPos.X + 10, 150, EasingTypes.OutElastic);
+
+            int duration = 0; //(int)(Game.Audio.BeatLength / 2);
+            if (duration == 0) duration = 250;
+
+            double offset = 0; //(1 - Game.Audio.SyncBeatProgress) * duration;
+            double startTime = Time.Current + offset;
+
+            // basic pulse
+            icon.Transforms.Add(new TransformScale
+            {
+                StartValue = new Vector2(1.1f, 1.1f),
+                EndValue = Vector2.One,
+                StartTime = startTime,
+                EndTime = startTime + duration,
+                Easing = EasingTypes.Out,
+                LoopCount = -1,
+                LoopDelay = duration
+            });
+
+            return result;
+        }
+
+        protected override void OnHoverLost(InputState state)
+        {
+            icon.ClearTransformations();
+            icon.MoveToX(iconPos.X, 150, EasingTypes.OutElastic);
+
+            base.OnHoverLost(state);
+        }
+    }
+}