suppress finalize for manually disposed panels

MLEM.Ui/Elements/Panel.cs

@@ -15,7 +15,7 @@ namespace MLEM.Ui.Elements {
     /// Additionally, a panel can be set to <see cref="scrollOverflow"/> on construction, which causes all elements that don't fit into the panel to be hidden until scrolled to using a <see cref="ScrollBar"/>.
     /// As this behavior is accomplished using a <see cref="RenderTarget2D"/>, scrolling panels need to have their <see cref="DrawEarly"/> methods called using <see cref="UiSystem.DrawEarly"/>.
     /// </summary>
-    public class Panel : Element {
+    public class Panel : Element, IDisposable {
 
         /// <summary>
         /// The texture that this panel should have, or null if it should be invisible.
@@ -76,6 +76,10 @@ namespace MLEM.Ui.Elements {
             }
         }
 
+        ~Panel() {
+            this.Dispose();
+        }
+
         /// <inheritdoc />
         public override void ForceUpdateArea() {
             if (this.scrollOverflow) {
@@ -178,13 +182,10 @@ namespace MLEM.Ui.Elements {
                     batch.Begin(SpriteSortMode.Deferred, blendState, samplerState, null, null, null, trans);
                     base.Draw(time, batch, alpha, blendState, samplerState, trans);
                     batch.End();
-                    // also draw any children early within the render target with the translation applied
-                    base.DrawEarly(time, batch, alpha, blendState, samplerState, trans);
                 }
-            } else {
+            }
             base.DrawEarly(time, batch, alpha, blendState, samplerState, matrix);
         }
-        }
 
         /// <inheritdoc />
         public override Element GetElementUnderPos(Vector2 position) {
@@ -234,5 +235,14 @@ namespace MLEM.Ui.Elements {
             }
         }
 
+        /// <inheritdoc />
+        public void Dispose() {
+            if (this.renderTarget != null) {
+                this.renderTarget.Dispose();
+                this.renderTarget = null;
+            }
+            GC.SuppressFinalize(this);
+        }
+
     }
 }