EkaiLastAction Undo/Redo for charts

CATEGORY: Add-On · For NinjaTrader 8 · Undo and redo the last action

HOW IT WORKS: NinjaTrader 8 lacks a native undo/redo function for chart operations—actions such as accidentally deleting a line, moving a drawing to the wrong spot, changing its color, or removing an indicator by mistake cannot be reversed. EkaiLastAction adds this functionality: Ctrl+Alt+Z undoes the most recent chart action—whether it is a drawing, an edit (moving, resizing, color, formatting), adding or removing an indicator, or a structural change—and Ctrl+Alt+Y reapplies it if you change your mind.

Explicit scope, not a hidden limitation: EkaiLastAction undoes and redoes a single step—the most recent one. It does not maintain a full session history; as soon as a new action occurs, the previous undoable/redoable action is completely replaced. It does exactly what its name implies.

How changes are detected and reversed: EkaiLastAction compares the NinjaTrader workspace XML—the same source the platform uses to save and restore charts—before and after each detected change. Undoing or redoing is always achieved by restoring the corresponding XML.

IMPORTANT LIMITATION (NO EXCEPTIONS): Every undo or redo operation—even for something as simple as a single line stroke—rebuilds the chart entirely. This takes between 600 and 900 milliseconds and causes a brief screen flicker for each operation.

Other known limitations:

Certain drawing elements (such as price axis region highlighting) are not saved in the workspace XML due to NinjaTrader's own platform design; therefore, undoing them is impossible by any means.
The state exists in memory only while the chart is open; it is lost upon closing the chart and is not a permanent history. Drawings automatically created by indicators or strategies do not count as user actions, even though the XML includes them.

FOR WHOM: Any trader who regularly uses NinjaTrader 8 charts involving manual drawings, indicators, or structural changes and wants the ability to correct the last error without having to redo the work by hand—with full confidence that what is undone is exactly what was done—in exchange for a brief, consistent delay on each operation.

TECHNICAL REQUIREMENTS: NinjaTrader 8. Installs as an AddOn (NinjaScript Editor → AddOns folder).