1 files changed, 29 insertions, 0 deletions
diff --git a/sdc-workflow-designer-ui/src/app/paletx/core/overlay/scroll/scroll-strategy.ts b/sdc-workflow-designer-ui/src/app/paletx/core/overlay/scroll/scroll-strategy.ts
new file mode 100644
index 00000000..d59651a7
--- /dev/null
+++ b/sdc-workflow-designer-ui/src/app/paletx/core/overlay/scroll/scroll-strategy.ts
@@ -0,0 +1,29 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+/* tslint:disable:array-type member-access variable-name typedef
+ only-arrow-functions directive-class-suffix component-class-suffix
+ component-selector*/
+import {OverlayRef} from '../overlay-ref';
+
+/**
+ * Describes a strategy that will be used by an overlay
+ * to handle scroll events while it is open.
+ */
+export abstract class ScrollStrategy {
+  enable: () => void;
+  disable: () => void;
+  attach: (overlayRef: OverlayRef) => void;
+}
+
+/**
+ * Returns an error to be thrown when attempting to attach an already-attached
+ * scroll strategy.
+ */
+export function getMdScrollStrategyAlreadyAttachedError(): Error {
+  return Error(`Scroll strategy has already been attached.`);
+}