Minecraft vanilla tab editing

My idea is that you can edit the vanilla order of creative mode tabs. You should be able to do it by putting it all into a java list, getting all of the items in the tab, or if there is already a file that Minecraft has that has all of the items. I at the very least want it possible to see the items and put custom ones between two if you can't reorder the whole tab. There should also be a reset button in case you mess up.