diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index 35e166f..e855679 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -919,6 +919,9 @@
 
         // Custom content is completely hidden
         public void onHide();
+
+        // Custom content scroll progress changed. From 0 (not showing) to 1 (fully showing).
+        public void onScrollProgressChanged(float progress);
     }
 
     public interface QSBScroller {