Proposals:

• Scaling of the items: The boxes have a fixed size. Find max(width, height) of the item and scale: height = height / max(width, height) * (heightOfItemBox - aFewPixelsPadding). Width works the same way.
• Sort the items by pack, then by name. This makes it way easier to find stuff even with big icons
• Show pack name in hover text (item description). Makes it easier to know where the item "post" came from
• if possible, show one pack per line. Don't know if cams GUI supports that

(Edit: translated to english)

Quick fix:

itemStackList.sort((a, b) => a.getDisplayName().compare(b.getDisplayName()));

Insert before this line:

This should sort the items by display name, thus making it easier to find stuff by name (as opposed to them being sorted by... key probably?).

If there is an easy way to get the name of the signal pack from the ItemStack that would be great (perhaps by looking for it with the item id?), but the line above is way better than the current behaviour.

Can create a pull request if you want, but I don't have the setup to test it at the moment.

Quick fix:

itemStackList.sort((a, b) => a.getDisplayName().compare(b.getDisplayName()));

Insert before this line:

LandOfSignals/src/main/java/net/landofrails/landofsignals/gui/GuiSelectSignal.java

Line 40 in 38b6a81

final ItemPickerGUI gui = new ItemPickerGUI(itemStackList, itemStack -> {

This should sort the items by display name, thus making it easier to find stuff by name (as opposed to them being sorted by... key probably?).

If there is an easy way to get the name of the signal pack from the ItemStack that would be great (perhaps by looking for it with the item id?), but the line above is way better than the current behaviour.

Can create a pull request if you want, but I don't have the setup to test it at the moment.

Thanks for you suggestion. Im currently working on a new major version.
As of the next major update, items will be displayed directly in the creative inventory tab, your sorting will be implemented (via UniqueID not Displayname, so it will be sorted and grouped by ContentPack)

done