osu/osu.Game/Graphics/UserInterface/BackButton.cs

//Copyright (c) 2007-2016 ppy Pty Ltd <contact@ppy.sh>.
//Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE

using osu.Framework.Allocation;
using osu.Framework.Audio;
using osu.Framework.Audio.Sample;
using OpenTK;
using OpenTK.Graphics;
using osu.Framework.Graphics;
using osu.Framework.Graphics.Sprites;
using osu.Framework.Graphics.Containers;
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
    public class BackButton : ClickableContainer
    {
        private TextAwesome icon;

        private Box leftBox;
        private Box rightBox;

        private const double transform_time = 600;
        private const int pulse_length = 250;

        private const float shear = 0.15f;

        public static readonly Vector2 SIZE_EXTENDED = new Vector2(140, 50);
        public  static readonly Vector2 SIZE_RETRACTED = new Vector2(100, 50);
        private AudioSample sampleClick;

        public BackButton()
        {
            Size = SIZE_RETRACTED;
        }

        public override bool Contains(Vector2 screenSpacePos) => leftBox.Contains(screenSpacePos) || rightBox.Contains(screenSpacePos);

        protected override bool OnHover(InputState state)
        {
            icon.ClearTransformations();

            ResizeTo(SIZE_EXTENDED, transform_time, EasingTypes.OutElastic);

            int duration = 0; //(int)(Game.Audio.BeatLength / 2);
            if (duration == 0) duration = pulse_length;

            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),
                EndValue = Vector2.One,
                StartTime = startTime,
                EndTime = startTime + duration,
                Easing = EasingTypes.Out,
                LoopCount = -1,
                LoopDelay = duration
            });

            return true;
        }

        protected override void OnHoverLost(InputState state)
        {
            icon.ClearTransformations();

            ResizeTo(SIZE_RETRACTED, transform_time, EasingTypes.OutElastic);

            int duration = 0; //(int)(Game.Audio.BeatLength);
            if (duration == 0) duration = pulse_length * 2;

            double offset = 0; //(1 - Game.Audio.SyncBeatProgress) * duration;
            double startTime = Time.Current + offset;

            // slow pulse
            icon.Transforms.Add(new TransformScale
            {
                StartValue = new Vector2(1.1f),
                EndValue = Vector2.One,
                StartTime = startTime,
                EndTime = startTime + duration,
                Easing = EasingTypes.Out,
                LoopCount = -1,
                LoopDelay = duration
            });
        }

        [BackgroundDependencyLoader]
        private void load(AudioManager audio, OsuColour colours)
        {
            sampleClick = audio.Sample.Get(@"Menu/menuback");
            Children = new Drawable[]
            {
                new Container
                {
                    RelativeSizeAxes = Axes.Both,
                    Width = 0.4f,
                    Children = new Drawable[]
                    {
                        leftBox = new Box
                        {
                            RelativeSizeAxes = Axes.Both,
                            Colour = colours.PinkDark,
                            Shear = new Vector2(shear, 0),
                        },
                        icon = new TextAwesome
                        {
                            Anchor = Anchor.Centre,
                            TextSize = 25,
                            Icon = FontAwesome.fa_osu_left_o
                        },
                    }
                },
                new Container
                {
                    Origin = Anchor.TopRight,
                    Anchor = Anchor.TopRight,
                    RelativeSizeAxes = Axes.Both,
                    Width = 0.6f,
                    Children = new Drawable[]
                    {
                        rightBox = new Box
                        {
                            Colour = colours.Pink,
                            Origin = Anchor.TopLeft,
                            Anchor = Anchor.TopLeft,
                            RelativeSizeAxes = Axes.Both,
                            Shear = new Vector2(shear, 0),
                            EdgeSmoothness = new Vector2(1.5f, 0),
                        },
                        new SpriteText
                        {
                            Origin = Anchor.Centre,
                            Anchor = Anchor.Centre,
                            Text = @"Back",
                        }
                    }
                }
            };
        }

        protected override bool OnClick(InputState state)
        {
            var flash = new Box
            {
                RelativeSizeAxes = Axes.Both,
                Shear = new Vector2(shear, 0),
                Colour = Color4.White.Opacity(0.5f),
            };
            Add(flash);

            flash.FadeOutFromOne(200);
            flash.Expire();

            sampleClick.Play();

            return base.OnClick(state);
        }
    }
}