Fix panning not working on additionnal window

[qsavoye]

Description

This PR fixes an issue where panning functionality was not working in additional windows due to an incorrect instanceof check.

Changes Made

• Updated the instanceof check to properly handle additional windows/instances.

Before the Fix

Panning gestures (e.g., drag-to-move) were ignored or broken in additional windows or instances.

After the Fix

Panning now works as expected in all windows, including secondary or embedded instances.

How to Test

1. Open the application in multiple windows or iframes.
2. Attempt to pan (drag-to-move) in each window.
3. Verify that panning works smoothly in all instances.