1
0
mirror of https://github.com/ppy/osu.git synced 2024-12-17 01:32:55 +08:00
osu-lazer/osu.Game/Screens/Edit/Compose/Components/Timeline/ZoomableScrollContainer.cs
2020-01-09 13:43:44 +09:00

188 lines
6.4 KiB
C#

// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
// See the LICENCE file in the repository root for full licence text.
using System;
using osu.Framework.Graphics;
using osu.Framework.Graphics.Containers;
using osu.Framework.Graphics.Transforms;
using osu.Framework.Input.Events;
using osu.Framework.Utils;
using osu.Game.Graphics.Containers;
using osuTK;
namespace osu.Game.Screens.Edit.Compose.Components.Timeline
{
public class ZoomableScrollContainer : OsuScrollContainer
{
/// <summary>
/// The time to zoom into/out of a point.
/// All user scroll input will be overwritten during the zoom transform.
/// </summary>
public double ZoomDuration;
/// <summary>
/// The easing with which to transform the zoom.
/// </summary>
public Easing ZoomEasing;
private readonly Container zoomedContent;
protected override Container<Drawable> Content => zoomedContent;
private float currentZoom = 1;
public ZoomableScrollContainer()
: base(Direction.Horizontal)
{
base.Content.Add(zoomedContent = new Container { RelativeSizeAxes = Axes.Y });
}
private int minZoom = 1;
/// <summary>
/// The minimum zoom level allowed.
/// </summary>
public int MinZoom
{
get => minZoom;
set
{
if (value < 1)
throw new ArgumentException($"{nameof(MinZoom)} must be >= 1.", nameof(value));
minZoom = value;
if (Zoom < value)
Zoom = value;
}
}
private int maxZoom = 60;
/// <summary>
/// The maximum zoom level allowed.
/// </summary>
public int MaxZoom
{
get => maxZoom;
set
{
if (value < 1)
throw new ArgumentException($"{nameof(MaxZoom)} must be >= 1.", nameof(value));
maxZoom = value;
if (Zoom > value)
Zoom = value;
}
}
/// <summary>
/// Gets or sets the content zoom level of this <see cref="ZoomableScrollContainer"/>.
/// </summary>
public float Zoom
{
get => zoomTarget;
set
{
value = Math.Clamp(value, MinZoom, MaxZoom);
if (IsLoaded)
setZoomTarget(value, ToSpaceOfOtherDrawable(new Vector2(DrawWidth / 2, 0), zoomedContent).X);
else
currentZoom = zoomTarget = value;
}
}
protected override void LoadComplete()
{
base.LoadComplete();
// This width only gets updated on the application of a transform, so this needs to be initialized here.
updateZoomedContentWidth();
}
protected override bool OnScroll(ScrollEvent e)
{
if (e.IsPrecise)
// for now, we don't support zoom when using a precision scroll device. this needs gesture support.
return base.OnScroll(e);
setZoomTarget(zoomTarget + e.ScrollDelta.Y, zoomedContent.ToLocalSpace(e.ScreenSpaceMousePosition).X);
return true;
}
private void updateZoomedContentWidth() => zoomedContent.Width = DrawWidth * currentZoom;
private float zoomTarget = 1;
private void setZoomTarget(float newZoom, float focusPoint)
{
zoomTarget = Math.Clamp(newZoom, MinZoom, MaxZoom);
transformZoomTo(zoomTarget, focusPoint, ZoomDuration, ZoomEasing);
}
private void transformZoomTo(float newZoom, float focusPoint, double duration = 0, Easing easing = Easing.None)
=> this.TransformTo(this.PopulateTransform(new TransformZoom(focusPoint, zoomedContent.DrawWidth, Current), newZoom, duration, easing));
private class TransformZoom : Transform<float, ZoomableScrollContainer>
{
/// <summary>
/// The focus point in absolute coordinates local to the content.
/// </summary>
private readonly float focusPoint;
/// <summary>
/// The size of the content.
/// </summary>
private readonly float contentSize;
/// <summary>
/// The scroll offset at the start of the transform.
/// </summary>
private readonly float scrollOffset;
/// <summary>
/// Transforms <see cref="ZoomableScrollContainer.currentZoom"/> to a new value.
/// </summary>
/// <param name="focusPoint">The focus point in absolute coordinates local to the content.</param>
/// <param name="contentSize">The size of the content.</param>
/// <param name="scrollOffset">The scroll offset at the start of the transform.</param>
public TransformZoom(float focusPoint, float contentSize, float scrollOffset)
{
this.focusPoint = focusPoint;
this.contentSize = contentSize;
this.scrollOffset = scrollOffset;
}
public override string TargetMember => nameof(currentZoom);
private float valueAt(double time)
{
if (time < StartTime) return StartValue;
if (time >= EndTime) return EndValue;
return Interpolation.ValueAt(time, StartValue, EndValue, StartTime, EndTime, Easing);
}
protected override void Apply(ZoomableScrollContainer d, double time)
{
float newZoom = valueAt(time);
float focusOffset = focusPoint - scrollOffset;
float expectedWidth = d.DrawWidth * newZoom;
float targetOffset = expectedWidth * (focusPoint / contentSize) - focusOffset;
d.currentZoom = newZoom;
d.updateZoomedContentWidth();
// Temporarily here to make sure ScrollTo gets the correct DrawSize for scrollable area.
// TODO: Make sure draw size gets invalidated properly on the framework side, and remove this once it is.
d.Invalidate(Invalidation.DrawSize);
d.ScrollTo(targetOffset, false);
}
protected override void ReadIntoStartValue(ZoomableScrollContainer d) => StartValue = d.currentZoom;
}
}
}