Does embedded Viewer can do something such "Fence view". The part that is displayed is dynamic, depending on the position of the mouse
typo - "Fence view"
Fence View is not built into Embed API but you can use the gotoLocation call to scroll the file based on mouse position and then create your own fence in an element that overlaps the embedded view.
there is a free tool you can try - maipdf
their fence view looks like this