- Switch ImRaii to new ref struct syntax

- Implement Disposable objects from ImSharp

Dalamud/Interface/Utility/Raii/Disposables/DisabledDisposable.cs

@@ -0,0 +1,58 @@
+// ReSharper disable once CheckNamespace
+
+using Dalamud.Bindings.ImGui;
+
+namespace Dalamud.Interface.Utility.Raii;
+
+public static partial class ImRaii
+{
+    /// <summary> A wrapper around disabled state. </summary>
+    public sealed class DisabledDisposable : IDisposable
+    {
+        /// <summary> The global count of disabled pushes to reenable. </summary>
+        public static int GlobalCount;
+
+        /// <summary> Gets the number of disabled states currently pushed using this disposable. </summary>
+        public int Count { get; private set; }
+
+        /// <summary> Push a disabled state onto the stack. </summary>
+        /// <param name="condition"> Whether to actually push a disabled state. </param>
+        /// <returns> A disposable object that can be used to push further disabled states for whatever reason and pop them on leaving scope. Use with using.</returns>
+        /// <remarks> If you need to keep a disabled state pushed longer than the current scope, use without using and use <seealso cref="PopUnsafe"/>. </remarks>
+        public DisabledDisposable Push(bool condition)
+            => condition ? this.Push() : this;
+
+        /// <inheritdoc cref="Push(bool)"/>
+        public DisabledDisposable Push()
+        {
+            ImGui.BeginDisabled(true);
+            ++this.Count;
+            ++GlobalCount;
+            return this;
+        }
+
+        /// <summary> Pop a number of disabled states. </summary>
+        /// <param name="num"> The number of disabled states to pop. This is clamped to the number of disabled states pushed by this object. </param>
+        public void Pop(int num = 1)
+        {
+            num = Math.Min(num, this.Count);
+            this.Count -= num;
+            GlobalCount -= num;
+            while (num-- > 0)
+                ImGui.EndDisabled();
+        }
+
+        /// <summary> Pop all disabled states. </summary>
+        public void Dispose()
+            => this.Pop(this.Count);
+
+        /// <summary> Pop a number of disabled states. </summary>
+        /// <param name="num"> The number of disabled states to pop. The number is not checked against the disabled stack. </param>
+        /// <remarks> Avoid using this function, and disabled states across scopes, as much as possible. </remarks>
+        public static void PopUnsafe(int num = 1)
+        {
+            while (num-- > 0)
+                ImGui.EndDisabled();
+        }
+    }
+}