Merge branch 'control-reference' of https://github.com/Tryibion/FlaxEngine into Tryibion-control-reference

Source/Engine/UI/ControlReference.cs

@@ -0,0 +1,111 @@
+using System;
+using System.Collections.Generic;
+using FlaxEngine;
+using FlaxEngine.GUI;
+
+namespace FlaxEngine;
+
+/// <summary>
+/// The control reference interface.
+/// </summary>
+public interface IControlReference
+{
+    /// <summary>
+    /// The UIControl.
+    /// </summary>
+    public UIControl UIControl { get; }
+    
+    /// <summary>
+    /// The Control type
+    /// </summary>
+    /// <returns>The Control Type</returns>
+    public Type GetControlType();
+    
+    /// <summary>
+    /// A safe set of the UI Control. Will warn if Control is of the wrong type.
+    /// </summary>
+    /// <param name="uiControl">The UIControl to set.</param>
+    public void Set(UIControl uiControl);
+}
+
+/// <summary>
+/// ControlReference class.
+/// </summary>
+[Serializable]
+public struct ControlReference<T> : IControlReference where T : Control
+{
+    [Serialize, ShowInEditor]
+    private UIControl _uiControl;
+
+    /// <summary>
+    /// Default constructor for ControlReference;
+    /// </summary>
+    public ControlReference()
+    {
+        _uiControl = null;
+    }
+
+    /// <inheritdoc />
+    public Type GetControlType()
+    {
+        return typeof(T);
+    }
+
+    /// <summary>
+    /// The Control attached to the UI Control.
+    /// </summary>
+    [HideInEditor]
+    public T Control
+    {
+        get
+        {
+            if (_uiControl != null && _uiControl.Control is T t)
+                return t;
+            else
+            {
+                Debug.Write(LogType.Warning, "Trying to get Control from ControlReference but UIControl is null, or UIControl.Control is null, or UIControl.Control is not the correct type.");
+                return null;
+            }
+        }
+    }
+
+    /// <inheritdoc />
+    public UIControl UIControl => _uiControl;
+
+    /// <inheritdoc />
+    public void Set(UIControl uiControl)
+    {
+        if (uiControl == null)
+        {
+            Clear();
+            return;
+        }
+        
+        if (uiControl.Control is T castedControl)
+            _uiControl = uiControl;
+        else
+            Debug.Write(LogType.Warning, "Trying to set ControlReference but UIControl.Control is null or UIControl.Control is not the correct type.");
+    }
+
+    /// <summary>
+    /// Clears the UIControl reference.
+    /// </summary>
+    public void Clear()
+    {
+        _uiControl = null;
+    }
+
+    /// <summary>
+    /// The implicit operator for the Control.
+    /// </summary>
+    /// <param name="reference">The ControlReference</param>
+    /// <returns>The Control.</returns>
+    public static implicit operator T(ControlReference<T> reference) => reference.Control;
+
+    /// <summary>
+    /// The implicit operator for the UIControl
+    /// </summary>
+    /// <param name="reference">The ControlReference</param>
+    /// <returns>The UIControl.</returns>
+    public static implicit operator UIControl(ControlReference<T> reference) => reference.UIControl;
+}