// Unity C# reference source

// Copyright (c) Unity Technologies. For terms of use, see

// https://unity3d.com/legal/licenses/Unity_Reference_Only_License

using System;

using System.Runtime.CompilerServices;

using UnityEngine;

using UnityEngine.Bindings;

namespace UnityEngine.InputForUI

{

[VisibleToOtherModules("UnityEngine.UIElementsModule")]

internal struct EventModifiers

{

// Types of modifier key that can be active during a keystroke event.

[Flags]

public enum Modifiers : uint

{

LeftShift = 1u << 0,

RightShift = 1u << 1,

Shift = LeftShift | RightShift,

LeftCtrl = 1u << 2,

RightCtrl = 1u << 3,

Ctrl = LeftCtrl | RightCtrl,

LeftAlt = 1u << 4,

// Generally try to avoid using RightAlt for anything hardcoded due to it being the same as AltGr key.

RightAlt = 1u << 5,

Alt = LeftAlt | RightAlt,

// If Windows or Command key is pressed.

LeftMeta = 1u << 6,

RightMeta = 1u << 7,

Meta = LeftMeta | RightMeta,

CapsLock = 1u << 8,

Numlock = 1u << 9,

// TODO For some reason IMGUI also has a flag if any F1-F15 keys are pressed + extra keys.

// TODO Not sure what it is about or how it is used exactly.

// TODO https://github.cds.internal.unity3d.com/unity/unity/blob/trunk/Modules/IMGUI/Event.cs#L228-L256

FunctionKey = 1u << 10,

Numeric = 1u << 11

}

private uint _state;

[MethodImpl(MethodImplOptions.AggressiveInlining)]

public bool IsPressed(Modifiers mod) => (_state & (uint)mod) != 0;

public bool isShiftPressed => IsPressed(Modifiers.Shift);

public bool isCtrlPressed => IsPressed(Modifiers.Ctrl);

public bool isAltPressed => IsPressed(Modifiers.Alt);

public bool isMetaPressed => IsPressed(Modifiers.Meta);

public bool isCapsLockEnabled => IsPressed(Modifiers.CapsLock);

public bool isNumLockEnabled => IsPressed(Modifiers.Numlock);

public bool isFunctionKeyPressed => IsPressed(Modifiers.FunctionKey);

public bool isNumericPressed => IsPressed(Modifiers.Numeric);

[MethodImpl(MethodImplOptions.AggressiveInlining)]

public void SetPressed(Modifiers modifier, bool pressed)

{

if (pressed)

_state |= (uint)modifier;

else

_state &= ~(uint)modifier;

}

public void Reset()

{

_state = 0;

}

private static void Append(ref string str, string value)

{

str = string.IsNullOrEmpty(str) ? value : $"{str},{value}";

}

public override string ToString()

{

var str = string.Empty;

if (IsPressed(Modifiers.LeftShift))

Append(ref str, "LeftShift");

if (IsPressed(Modifiers.RightShift))

Append(ref str, "RightShift");

if (IsPressed(Modifiers.LeftCtrl))

Append(ref str, "LeftCtrl");

if (IsPressed(Modifiers.RightCtrl))

Append(ref str, "RightCtrl");

if (IsPressed(Modifiers.LeftAlt))

Append(ref str, "LeftAlt");

if (IsPressed(Modifiers.RightAlt))

Append(ref str, "RightAlt");

if (IsPressed(Modifiers.LeftMeta))

Append(ref str, "LeftMeta");

if (IsPressed(Modifiers.RightMeta))

Append(ref str, "RightMeta");

if (IsPressed(Modifiers.CapsLock))

Append(ref str, "CapsLock");

if (IsPressed(Modifiers.Numlock))

Append(ref str, "Numlock");

if (IsPressed(Modifiers.FunctionKey))

Append(ref str, "FunctionKey");

if (IsPressed(Modifiers.Numeric))

Append(ref str, "Numeric");

return str;

}

}

}