scottplot-syncing-modifier-keys-for-mousewheel

ScottPlot tracks modifier keys through KeyDown/KeyUp events, which only fire when the control has keyboard focus. MouseWheel events fire based on mouse position, so the wheel handler runs but sees an empty internal keyboard state until you click the control.

Read the global modifier state with System.Windows.Input.Keyboard.Modifiers and send a matching KeyDown or KeyUp action to ScottPlot's UserInputProcessor before processing each MouseWheel event. This updates the internal keyboard state without requiring focus.

Calling Keyboard.Focus on MouseEnter works but steals focus from TextBoxes and disrupts Tab navigation. Syncing Keyboard.Modifiers into the input processor solves the problem without any focus side effects, so it is the preferred approach.

No. The user can press or release Ctrl between wheel events, so a cached sync becomes stale. You must sync the modifier state immediately before processing each MouseWheel action.

Yes. Keyboard.Modifiers queries the OS-level key state globally, independent of which element has keyboard focus. This makes it reliable for syncing modifier state into controls that track keys via focus-dependent KeyDown/KeyUp events.