         var minDelta:Number = -scrollR.top;
                 
         // ToDo: what if blockDirection!=TB and direction!=LTR?                   
-        switch (scrollUnit)
-        {
-            case ScrollUnit.UP:
+        switch (navigationUnit)
+        {
+            case NavigationUnit.UP:
                 return _textContainerManager.getScrollDelta(-1);
                 
-            case ScrollUnit.DOWN:
+            case NavigationUnit.DOWN:
                 return _textContainerManager.getScrollDelta(1);
                 
-            case ScrollUnit.PAGE_UP:
+            case NavigationUnit.PAGE_UP:
                 return Math.max(minDelta, -scrollR.height);
                 
-            case ScrollUnit.PAGE_DOWN:
+            case NavigationUnit.PAGE_DOWN:
                 return Math.min(maxDelta, scrollR.height);
                 
-            case ScrollUnit.HOME:
+            case NavigationUnit.HOME:
                 return minDelta;
                 
-            case ScrollUnit.END:
+            case NavigationUnit.END:
                 return maxDelta;
                 
             default:

     *  @playerversion AIR 1.5
     *  @productversion Flex 4
     */
    public function getHorizontalScrollPositionDelta(scrollUnit:uint):Number
    {
        var scrollR:Rectangle = scrollRect;
        if (!scrollR)

import spark.components.TextSelectionVisibility;
import spark.core.CSSTextLayoutFormat;
import spark.core.IViewport;
import spark.core.NavigationUnit;
import spark.events.TextOperationEvent;
import spark.primitives.supportClasses.RichEditableTextContainerManager;
import spark.utils.TextUtil;
