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is there a way to DISABLE the ability to remove points with ALT-click (APPLE-click) from a locator pane? I'm writing a code that allows users to manually label objects in an image by connecting two consecutive points by a line. When the user is able to remove an arbitrary point from within the list, the connections between the points get messed up. Consider this snippet:

pts = {{0, 0}, {1, 1}};
LocatorPane[Dynamic[pts], 
Dynamic[Graphics[Line[{#[[1]], #[[2]]}] & /@ Partition[pts, 2]]], 
LocatorAutoCreate -> All]
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Points can be created by Mouse click alone, but deleted only with Click + Alt, so we can capture MouseClicks and pass them to LocatorPane only if Alt is not pressed.

EventHandler[#, {"MouseClicked" :> {}}, 
                PassEventsDown -> Dynamic[! CurrentValue["AltKey"]]
            ] &[

 LocatorPane[Dynamic[pts], 
  Dynamic[Graphics[Line[{#[[1]], #[[2]]}] & /@ Partition[pts, 2]]], 
  LocatorAutoCreate -> All]

]
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