71 lines
2.7 KiB
C#
71 lines
2.7 KiB
C#
|
using System;
|
||
|
|
|
||
|
|
namespace UnityEngine.InputSystem.Utilities
|
||
|
|
{
|
||
|
|
/// <summary>
|
||
|
|
/// Provides type erasure and an abstraction of a saved state that
|
||
|
|
/// will (must) be restored at a later point.
|
||
|
|
/// </summary>
|
||
|
|
internal interface ISavedState
|
||
|
|
{
|
||
|
|
/// <summary>
|
||
|
|
/// Dispose current state, should be invoked before RestoreSavedState()
|
||
|
|
/// to dispose the current state before restoring a saved state.
|
||
|
|
/// </summary>
|
||
|
|
void StaticDisposeCurrentState();
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Restore previous state, should be invoked after StaticDisposeCurrentState().
|
||
|
|
/// </summary>
|
||
|
|
void RestoreSavedState();
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Provides functionality to store and support later restoration of a saved
|
||
|
|
/// state. The state is expected to be a value-type. If the state is not restored
|
||
|
|
/// it must be disposed to not leak resources.
|
||
|
|
/// </summary>
|
||
|
|
/// <typeparam name="T">The value-type representing the state to be stored.</typeparam>
|
||
|
|
internal sealed class SavedStructState<T> : ISavedState where T : struct
|
||
|
|
{
|
||
|
|
public delegate void TypedRestore(ref T state);
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Constructs a SavedStructState.
|
||
|
|
/// </summary>
|
||
|
|
/// <param name="state">The value-type state to be saved.</param>
|
||
|
|
/// <param name="restoreAction">The action to be carried out to restore state.</param>
|
||
|
|
/// <param name="staticDisposeCurrentState">The action to be carried out to dispose current state. May be null.</param>
|
||
|
|
internal SavedStructState(ref T state, TypedRestore restoreAction, Action staticDisposeCurrentState = null)
|
||
|
|
{
|
||
|
|
Debug.Assert(restoreAction != null, "Restore action is required");
|
||
|
|
|
||
|
|
m_State = state; // copy
|
||
|
|
m_RestoreAction = restoreAction;
|
||
|
|
m_StaticDisposeCurrentState = staticDisposeCurrentState;
|
||
|
|
}
|
||
|
|
|
||
|
|
public void StaticDisposeCurrentState()
|
||
|
|
{
|
||
|
|
if (m_StaticDisposeCurrentState != null)
|
||
|
|
{
|
||
|
|
m_StaticDisposeCurrentState();
|
||
|
|
m_StaticDisposeCurrentState = null;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
public void RestoreSavedState()
|
||
|
|
{
|
||
|
|
Debug.Assert(m_StaticDisposeCurrentState == null,
|
||
|
|
$"Should have been disposed via {nameof(StaticDisposeCurrentState)} before invoking {nameof(RestoreSavedState)}");
|
||
|
|
Debug.Assert(m_RestoreAction != null, $"Only invoke {nameof(RestoreSavedState)} once ");
|
||
|
|
m_RestoreAction(ref m_State);
|
||
|
|
m_RestoreAction = null;
|
||
|
|
}
|
||
|
|
|
||
|
|
private T m_State;
|
||
|
|
private TypedRestore m_RestoreAction;
|
||
|
|
private Action m_StaticDisposeCurrentState;
|
||
|
|
}
|
||
|
|
}
|