How to add feature to change label colors with keyboard

[kgupta359]

Hi @wkentaro, thanks for the wonderful repository! I want to add a feature that will make my life simpler - I want to be able to change the labels using keyboard shortcuts, so that when I click on a polygon and press a certain key, that polygon's label changes to another label. This will be very helpful for me personally as I'll be editing labels of hundreds of images (I'll be looking at each image and changing the labels). I do not want to edit the shape of the annotation this way, only the label.

Any pointers on how to implement something like this are welcome. If you could let me know which scripts I should look into and modify to accomplish this, it'll be really helpful. Thanks!