Allow searching for groups.

Also make "group buttons" apply the filter to that group.

callbacks.lua

@@ -118,6 +118,11 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 		if string.sub(name, 1, 12) == "item_button_" then
 			clicked_item = string.sub(name, 13)
 			break
+		elseif string.sub(name, 1, 11) == "item_group_" then
+			minetest.sound_play("click",
+					{to_player=player_name, gain = 0.1})
+			unified_inventory.apply_filter(player, "group:"..string.sub(name, 12))
+			return
 		end
 	end
 	if clicked_item then

internal.lua

@@ -97,6 +97,24 @@ function unified_inventory.apply_filter(player, filter)
 		lfilter = ""
 	end
 	unified_inventory.filtered_items_list[player_name]={}
+	if lfilter:sub(1, 6) == "group:" then
+		local groups = lfilter:sub(7):split(",")
+		for name, def in pairs(minetest.registered_items) do
+			if def.groups then
+				local all = true
+				for _, group in ipairs(groups) do
+					if not (def.groups[group] and (def.groups[group] > 0)) then
+						all = false
+						break
+					end
+				end
+				if all then
+					table.insert(unified_inventory.filtered_items_list[player_name], name)
+					size = size + 1
+				end
+			end
+		end
+	else
 		for name, def in pairs(minetest.registered_items) do
 			if (not def.groups.not_in_creative_inventory or
 			   def.groups.not_in_creative_inventory == 0)
@@ -108,7 +126,7 @@ function unified_inventory.apply_filter(player, filter)
 					size = size + 1
 				end
 			end
-	
+		end
 	end
 	table.sort(unified_inventory.filtered_items_list[player_name])
 	unified_inventory.filtered_items_list_size[player_name] = size

register.lua

@@ -213,7 +213,8 @@ unified_inventory.register_page("craftguide", {
 					local group = string.sub(item, 7)
 					formspec = formspec.."image_button["
 						..(1.0 + x)..","..(0.0 + y)..";1.1,1.1;"
-						.."ui_group.png;;"
+						.."ui_group.png;"
+						.."item_group_"..minetest.formspec_escape(group)..";"
 						..minetest.formspec_escape(group).."]"
 				else
 					formspec = formspec.."item_image_button["