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osu-lazer/osu.Game/Screens/Edit/Compose/Components/DragBox.cs

116 lines
3.4 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;
using osu.Framework.Allocation;
using osu.Framework.Graphics;
using osu.Framework.Graphics.Containers;
using osu.Framework.Graphics.Primitives;
using osu.Framework.Graphics.Shapes;
using osu.Framework.Input.Events;
using osuTK.Graphics;
namespace osu.Game.Screens.Edit.Compose.Components
{
/// <summary>
/// A box that displays the drag selection and provides selection events for users to handle.
/// </summary>
public class DragBox : CompositeDrawable, IStateful<Visibility>
{
protected readonly Action<RectangleF> PerformSelection;
protected Drawable Box;
/// <summary>
/// Creates a new <see cref="DragBox"/>.
/// </summary>
/// <param name="performSelection">A delegate that performs drag selection.</param>
public DragBox(Action<RectangleF> performSelection)
{
PerformSelection = performSelection;
RelativeSizeAxes = Axes.Both;
AlwaysPresent = true;
Alpha = 0;
}
[BackgroundDependencyLoader]
private void load()
{
InternalChild = Box = CreateBox();
}
protected virtual Drawable CreateBox() => new Container
{
Masking = true,
BorderColour = Color4.White,
BorderThickness = SelectionBox.BORDER_RADIUS,
Child = new Box
{
RelativeSizeAxes = Axes.Both,
Alpha = 0.1f
}
};
private RectangleF? dragRectangle;
/// <summary>
/// Handle a forwarded mouse event.
/// </summary>
/// <param name="e">The mouse event.</param>
/// <returns>Whether the event should be handled and blocking.</returns>
public virtual bool HandleDrag(MouseButtonEvent e)
{
var dragPosition = e.ScreenSpaceMousePosition;
var dragStartPosition = e.ScreenSpaceMouseDownPosition;
var dragQuad = new Quad(dragStartPosition.X, dragStartPosition.Y, dragPosition.X - dragStartPosition.X, dragPosition.Y - dragStartPosition.Y);
// We use AABBFloat instead of RectangleF since it handles negative sizes for us
var rec = dragQuad.AABBFloat;
dragRectangle = rec;
var topLeft = ToLocalSpace(rec.TopLeft);
var bottomRight = ToLocalSpace(rec.BottomRight);
Box.Position = topLeft;
Box.Size = bottomRight - topLeft;
return true;
}
private Visibility state;
public Visibility State
{
get => state;
set
{
if (value == state) return;
state = value;
this.FadeTo(state == Visibility.Hidden ? 0 : 1, 250, Easing.OutQuint);
StateChanged?.Invoke(state);
}
}
protected override void Update()
{
base.Update();
if (dragRectangle != null)
PerformSelection?.Invoke(dragRectangle.Value);
}
public override void Hide()
{
State = Visibility.Hidden;
dragRectangle = null;
}
public override void Show() => State = Visibility.Visible;
public event Action<Visibility> StateChanged;
}
}