Add filter-by-category functionality (#171)

- Added API for configuring categories
- Added display for categories above page
- Reduced height of page by 1 row to make room for categories
- Added L/R scroll through when there are more categories than columns
- Added pre-filter methods for categories and uncategorised items
- Added categories for (most) items in the default game


Co-authored-by: Oversword <bionc:oversword.co.uk>

.luacheckrc

@@ -14,6 +14,7 @@ read_globals = {
 	"ItemStack", "datastorage",
 
 	"hb",
+	"doors",
 }
 
 files["callbacks.lua"].ignore = { "player", "draw_lite_mode" }

callbacks.lua

@@ -19,6 +19,8 @@ minetest.register_on_joinplayer(function(player)
 	unified_inventory.active_search_direction[player_name] = "nochange"
 	unified_inventory.apply_filter(player, "", "nochange")
 	unified_inventory.current_searchbox[player_name] = ""
+	unified_inventory.current_category[player_name] = "all"
+	unified_inventory.current_category_scroll[player_name] = 0
 	unified_inventory.alternate[player_name] = 1
 	unified_inventory.current_item[player_name] = nil
 	unified_inventory.current_craft_direction[player_name] = "recipe"
@@ -69,6 +71,41 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 		unified_inventory.current_searchbox[player_name] = fields.searchbox
 	end
 
+
+	local clicked_category
+	for name, value in pairs(fields) do
+		local category_name = string.match(name, "^category_(.+)$")
+		if category_name then
+			clicked_category = category_name
+			break
+		end
+	end
+
+	if clicked_category
+	and clicked_category ~= unified_inventory.current_category[player_name] then
+		unified_inventory.current_category[player_name] = clicked_category
+		unified_inventory.apply_filter(player, unified_inventory.current_searchbox[player_name], "nochange")
+		unified_inventory.set_inventory_formspec(player,
+				unified_inventory.current_page[player_name])
+	end
+
+	if fields.next_category then
+		local scroll = math.min(#unified_inventory.category_list-ui_peruser.pagecols, unified_inventory.current_category_scroll[player_name] + 1)
+		if scroll ~= unified_inventory.current_category_scroll[player_name] then
+			unified_inventory.current_category_scroll[player_name] = scroll
+			unified_inventory.set_inventory_formspec(player,
+					unified_inventory.current_page[player_name])
+		end
+	end
+	if fields.prev_category then
+		local scroll = math.max(0, unified_inventory.current_category_scroll[player_name] - 1)
+		if scroll ~= unified_inventory.current_category_scroll[player_name] then
+			unified_inventory.current_category_scroll[player_name] = scroll
+			unified_inventory.set_inventory_formspec(player,
+					unified_inventory.current_page[player_name])
+		end
+	end
+
 	for i, def in pairs(unified_inventory.buttons) do
 		if fields[def.name] then
 			def.action(player)
@@ -126,6 +163,7 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 			clicked_item = unified_inventory.demangle_for_formspec(mangled_item)
 			if string.sub(clicked_item, 1, 6) == "group:" then
 				-- Change search filter to this group
+				unified_inventory.current_category[player_name] = "all"
 				apply_new_filter(player, clicked_item, new_dir)
 				return
 			end

category.lua

@@ -0,0 +1,149 @@
+local S = minetest.get_translator("unified_inventory")
+
+unified_inventory.registered_categories = {}
+unified_inventory.registered_category_items = {}
+unified_inventory.category_list = {}
+
+local function char_to_sort_index(char_code)
+	if char_code <= 32 then
+		-- Command codes, no thanks
+		return 0
+	end
+	if char_code <= 64 then
+		-- Sorts numbers, and some punctuation, after letters
+		return char_code
+	end
+	if char_code >= 158 then
+		-- Out of sortable range
+		return 0
+	end
+	if char_code > 122 then
+		-- Avoids overlap with {, |, } and ~
+		return char_code - 58
+	end
+	if char_code > 96 then
+		-- Normalises lowercase with uppercase
+		return char_code - 96
+	end
+	return char_code - 64
+end
+
+local function string_to_sort_index(str)
+	local max_chars = 5
+	local power = 100
+	local index = 0
+	for i=1,math.min(#str, max_chars) do
+		index = index + (char_to_sort_index(string.byte(str, i))/(power^i))
+	end
+	return index
+end
+
+function update_category_list()
+	local category_list = {}
+	table.insert(category_list, {
+		name = "all",
+		label = S("All Items"),
+		symbol = "ui_category_all.png",
+		index = -2,
+	})
+	table.insert(category_list, {
+		name = "uncategorized",
+		label = S("Misc. Items"),
+		symbol = "ui_category_none.png",
+		index = -1,
+	})
+	for category, def in pairs(unified_inventory.registered_categories) do
+		table.insert(category_list, {
+			name = category,
+			label = def.label or category,
+			symbol = def.symbol,
+			index = def.index or                    -- sortby defined order
+					string_to_sort_index(category)  -- or do a rudimentary alphabetical sort
+		})
+	end
+	table.sort(category_list, function (a,b)
+		return a.index < b.index
+	end)
+	unified_inventory.category_list = category_list
+end
+
+local function ensure_category_exists(category_name)
+	if not unified_inventory.registered_categories[category_name] then
+		unified_inventory.registered_categories[category_name] = {
+			symbol = "default:stick",
+			label = category_name
+		}
+	end
+	if not unified_inventory.registered_category_items[category_name] then
+		unified_inventory.registered_category_items[category_name] = {}
+	end
+end
+
+function unified_inventory.register_category(category_name, config)
+	ensure_category_exists(category_name)
+	if config and config.symbol then
+		unified_inventory.set_category_symbol(category_name, config.symbol)
+	end
+	if config and config.label then
+		unified_inventory.set_category_label(category_name, config.label)
+	end
+	if config and config.index then
+		unified_inventory.set_category_index(category_name, config.index)
+	end
+	if config and config.items then
+		unified_inventory.add_category_items(category_name, config.items)
+	end
+	update_category_list()
+end
+function unified_inventory.set_category_symbol(category_name, symbol)
+	ensure_category_exists(category_name)
+	unified_inventory.registered_categories[category_name].symbol = symbol
+	update_category_list()
+end
+function unified_inventory.set_category_label(category_name, label)
+	ensure_category_exists(category_name)
+	unified_inventory.registered_categories[category_name].label = label
+	update_category_list()
+end
+function unified_inventory.set_category_index(category_name, index)
+	ensure_category_exists(category_name)
+	unified_inventory.registered_categories[category_name].index = index
+	update_category_list()
+end
+function unified_inventory.add_category_item(category_name, item)
+	ensure_category_exists(category_name)
+	unified_inventory.registered_category_items[category_name][item] = true
+end
+function unified_inventory.add_category_items(category_name, items)
+	for _,item in ipairs(items) do
+		unified_inventory.add_category_item(category_name, item)
+	end
+end
+
+function unified_inventory.remove_category_item(category_name, item)
+	unified_inventory.registered_category_items[category_name][item] = nil
+end
+function unified_inventory.remove_category(category_name)
+	unified_inventory.registered_categories[category_name] = nil
+	unified_inventory.registered_category_items[category_name] = nil
+	update_category_list()
+end
+
+function unified_inventory.find_category(item)
+	-- Returns the first category the item exists in
+	-- Best for checking if an item has any category at all
+	for category, items in pairs(unified_inventory.registered_category_items) do
+		if items[item] then return category end
+	end
+end
+function unified_inventory.find_categories(item)
+	-- Returns all the categories the item exists in
+	-- Best for listing all categories
+	local categories = {}
+	for category, items in pairs(unified_inventory.registered_category_items) do
+		if items[item] then
+			table.insert(categories, category)
+		end
+	end
+	return categories
+end

default-categories.lua

@@ -0,0 +1,704 @@
+local S = minetest.get_translator("unified_inventory")
+
+unified_inventory.register_category('plants', {
+	symbol = "flowers:tulip",
+	label = S("Plant Life")
+})
+unified_inventory.register_category('building', {
+	symbol = "default:brick",
+	label = S("Building Materials")
+})
+unified_inventory.register_category('tools', {
+	symbol = "default:pick_diamond",
+	label = S("Tools")
+})
+unified_inventory.register_category('minerals', {
+	symbol = "default:iron_lump",
+	label = S("Minerals and Metals")
+})
+unified_inventory.register_category('environment', {
+	symbol = "default:dirt_with_grass",
+	label = S("Environment and Worldgen")
+})
+unified_inventory.register_category('lighting', {
+	symbol = "default:torch",
+	label = S("Lighting")
+})
+
+
+if unified_inventory.automatic_categorization then
+	minetest.register_on_mods_loaded(function()
+
+		-- Add biome nodes to environment category
+		for _,def in pairs(minetest.registered_biomes) do
+			local env_nodes = {
+				def.node_riverbed, def.node_top, def.node_filler, def.node_dust,
+			}
+			for i,node in pairs(env_nodes) do
+				if node then
+					unified_inventory.add_category_item('environment', node)
+				end
+			end
+		end
+
+		-- Add minable ores to minerals and everything else (pockets of stone & sand variations) to environment
+		for _,item in  pairs(minetest.registered_ores) do
+			if item.ore_type == "scatter" then
+				local drop = minetest.registered_nodes[item.ore].drop
+				if drop and drop ~= "" then
+					unified_inventory.add_category_item('minerals', item.ore)
+					unified_inventory.add_category_item('minerals', drop)
+				else
+					unified_inventory.add_category_item('environment', item.ore)
+				end
+			else
+				unified_inventory.add_category_item('environment', item.ore)
+			end
+		end
+
+		-- Add items by item definition
+		for name, def in pairs(minetest.registered_items) do
+			local group = def.groups or {}
+			if not group.not_in_creative_inventory then
+				if group.stair or
+				   group.slab or
+				   group.wall or
+				   group.fence then
+					unified_inventory.add_category_item('building', name)
+				elseif group.flora or
+					   group.flower or
+					   group.seed or
+					   group.leaves or
+					   group.sapling or
+					   group.tree then
+					unified_inventory.add_category_item('plants', name)
+				elseif def.type == 'tool' then
+					unified_inventory.add_category_item('tools', name)
+				elseif def.liquidtype == 'source' then
+					unified_inventory.add_category_item('environment', name)
+				elseif def.light_source and def.light_source > 0 then
+					unified_inventory.add_category_item('lighting', name)
+				elseif group.door or
+					   minetest.global_exists("doors") and (
+					     doors.registered_doors and doors.registered_doors[name..'_a'] or
+					     doors.registered_trapdoors and doors.registered_trapdoors[name]
+					   ) then
+					unified_inventory.add_category_item('building', name)
+				end
+			end
+		end
+	end)
+end
+
+-- [[
+unified_inventory.add_category_items('plants', {
+	"default:dry_grass_5",
+	"default:acacia_sapling",
+	"default:blueberry_bush_sapling",
+	"default:grass_2",
+	"default:pine_bush_stem",
+	"default:leaves",
+	"default:pine_needles",
+	"default:cactus",
+	"default:junglegrass",
+	"default:pine_sapling",
+	"default:sapling",
+	"default:bush_stem",
+	"default:dry_grass_2",
+	"default:fern_1",
+	"default:grass_3",
+	"default:marram_grass_1",
+	"default:pine_tree",
+	"default:dry_grass_3",
+	"default:dry_shrub",
+	"default:grass_4",
+	"default:marram_grass_2",
+	"default:jungleleaves",
+	"default:apple",
+	"default:tree",
+	"default:aspen_tree",
+	"default:bush_sapling",
+	"default:grass_5",
+	"default:blueberry_bush_leaves_with_berries",
+	"default:acacia_bush_sapling",
+	"default:grass_1",
+	"default:aspen_leaves",
+	"default:marram_grass_3",
+	"default:large_cactus_seedling",
+	"default:junglesapling",
+	"default:dry_grass_4",
+	"default:acacia_bush_stem",
+	"default:papyrus",
+	"default:pine_bush_needles",
+	"default:bush_leaves",
+	"default:fern_3",
+	"default:aspen_sapling",
+	"default:acacia_tree",
+	"default:apple_mark",
+	"default:acacia_leaves",
+	"default:jungletree",
+	"default:dry_grass_1",
+	"default:acacia_bush_leaves",
+	"default:emergent_jungle_sapling",
+	"default:fern_2",
+	"default:blueberries",
+	"default:sand_with_kelp",
+	"default:blueberry_bush_leaves",
+	"default:pine_bush_sapling",
+
+	"farming:cotton",
+	"farming:cotton_1",
+	"farming:cotton_2",
+	"farming:cotton_3",
+	"farming:cotton_4",
+	"farming:cotton_5",
+	"farming:cotton_6",
+	"farming:cotton_7",
+	"farming:cotton_8",
+	"farming:cotton_wild",
+	"farming:seed_cotton",
+	"farming:seed_wheat",
+	"farming:straw",
+	"farming:wheat",
+	"farming:wheat_1",
+	"farming:wheat_2",
+	"farming:wheat_3",
+	"farming:wheat_4",
+	"farming:wheat_5",
+	"farming:wheat_6",
+	"farming:wheat_7",
+	"farming:wheat_8",
+
+	"flowers:chrysanthemum_green",
+	"flowers:dandelion_white",
+	"flowers:dandelion_yellow",
+	"flowers:geranium",
+	"flowers:mushroom_brown",
+	"flowers:mushroom_red",
+	"flowers:rose",
+	"flowers:tulip",
+	"flowers:tulip_black",
+	"flowers:viola",
+	"flowers:waterlily",
+	"flowers:waterlily_waving",
+})
+
+unified_inventory.add_category_items('tools', {
+	"default:sword_diamond",
+	"default:axe_diamond",
+	"default:shovel_diamond",
+	"default:axe_steel",
+	"default:shovel_mese",
+	"default:sword_wood",
+	"default:pick_bronze",
+	"default:axe_stone",
+	"default:sword_stone",
+	"default:pick_stone",
+	"default:shovel_stone",
+	"default:sword_mese",
+	"default:shovel_bronze",
+	"default:sword_bronze",
+	"default:axe_bronze",
+	"default:shovel_steel",
+	"default:sword_steel",
+	"default:axe_mese",
+	"default:shovel_wood",
+	"default:pick_mese",
+	"default:axe_wood",
+	"default:pick_diamond",
+	"default:pick_wood",
+	"default:pick_steel",
+
+	"farming:hoe_bronze",
+	"farming:hoe_diamond",
+	"farming:hoe_mese",
+	"farming:hoe_steel",
+	"farming:hoe_stone",
+	"farming:hoe_wood",
+
+	"fire:flint_and_steel",
+	"map:mapping_kit",
+	"screwdriver:screwdriver",
+
+	"fireflies:bug_net",
+	"bucket:bucket_empty",
+
+	"binoculars:binoculars",
+	"default:skeleton_key",
+})
+
+unified_inventory.add_category_items('minerals', {
+	"default:stone_with_copper",
+	"default:stone_with_gold",
+	"default:stone_with_iron",
+	"default:copper_ingot",
+	"default:copper_lump",
+	"default:gold_lump",
+	"default:diamondblock",
+	"default:stone_with_diamond",
+	"default:stone_with_mese",
+	"default:steel_ingot",
+	"default:gold_ingot",
+	"default:iron_lump",
+	"default:tinblock",
+	"default:tin_lump",
+	"default:stone_with_tin",
+	"default:mese_crystal",
+	"default:diamond",
+	"default:bronze_ingot",
+	"default:mese",
+	"default:mese_crystal_fragment",
+	"default:copperblock",
+	"default:stone_with_coal",
+	"default:steelblock",
+	"default:tin_ingot",
+	"default:coalblock",
+	"default:coal_lump",
+	"default:bronzeblock",
+	"default:goldblock",
+
+	"stairs:slab_bronzeblock",
+	"stairs:slab_copperblock",
+	"stairs:slab_steelblock",
+	"stairs:slab_tinblock",
+	"stairs:stair_bronzeblock",
+	"stairs:stair_copperblock",
+	"stairs:stair_inner_bronzeblock",
+	"stairs:stair_inner_copperblock",
+	"stairs:stair_inner_steelblock",
+	"stairs:stair_inner_tinblock",
+	"stairs:stair_outer_bronzeblock",
+	"stairs:stair_outer_copperblock",
+	"stairs:stair_outer_steelblock",
+	"stairs:stair_outer_tinblock",
+	"stairs:stair_steelblock",
+	"stairs:stair_tinblock",
+})
+
+unified_inventory.add_category_items('building', {
+	"default:fence_rail_aspen_wood",
+	"default:fence_rail_acacia_wood",
+	"default:fence_junglewood",
+	"default:fence_rail_junglewood",
+	"default:fence_aspen_wood",
+	"default:fence_pine_wood",
+	"default:fence_rail_wood",
+	"default:fence_rail_pine_wood",
+	"default:fence_acacia_wood",
+	"default:junglewood",
+	"default:acacia_wood",
+	"default:aspen_wood",
+	"default:fence_wood",
+	"default:pine_wood",
+	"default:silver_sandstone",
+	"default:desert_sandstone",
+	"default:sandstone_block",
+	"default:desert_sandstone_brick",
+	"default:stone_block",
+	"default:stonebrick",
+	"default:obsidian_glass",
+	"default:desert_sandstone_block",
+	"default:silver_sandstone_brick",
+	"default:brick",
+	"default:obsidianbrick",
+	"default:sandstonebrick",
+	"default:sandstone",
+	"default:desert_stone_block",
+	"default:silver_sandstone_block",
+	"default:wood",
+	"default:obsidian_block",
+	"default:glass",
+	"default:clay_brick",
+	"default:desert_stonebrick",
+	"default:desert_cobble",
+	"default:cobble",
+	"default:mossycobble",
+
+	"doors:door_glass",
+	"doors:door_glass_a",
+	"doors:door_glass_b",
+	"doors:door_glass_c",
+	"doors:door_glass_d",
+	"doors:door_obsidian_glass",
+	"doors:door_obsidian_glass_a",
+	"doors:door_obsidian_glass_b",
+	"doors:door_obsidian_glass_c",
+	"doors:door_obsidian_glass_d",
+	"doors:door_steel",
+	"doors:door_steel_a",
+	"doors:door_steel_b",
+	"doors:door_steel_c",
+	"doors:door_steel_d",
+	"doors:door_wood",
+	"doors:door_wood_a",
+	"doors:door_wood_b",
+	"doors:door_wood_c",
+	"doors:door_wood_d",
+	"doors:gate_acacia_wood_closed",
+	"doors:gate_acacia_wood_open",
+	"doors:gate_aspen_wood_closed",
+	"doors:gate_aspen_wood_open",
+	"doors:gate_junglewood_closed",
+	"doors:gate_junglewood_open",
+	"doors:gate_pine_wood_closed",
+	"doors:gate_pine_wood_open",
+	"doors:gate_wood_closed",
+	"doors:gate_wood_open",
+	"doors:hidden",
+	"doors:trapdoor",
+	"doors:trapdoor_open",
+	"doors:trapdoor_steel",
+	"doors:trapdoor_steel_open",
+
+	"stairs:slab_bronzeblock",
+	"stairs:slab_copperblock",
+	"stairs:slab_steelblock",
+	"stairs:slab_tinblock",
+	"stairs:stair_bronzeblock",
+	"stairs:stair_copperblock",
+	"stairs:stair_inner_bronzeblock",
+	"stairs:stair_inner_copperblock",
+	"stairs:stair_inner_steelblock",
+	"stairs:stair_inner_tinblock",
+	"stairs:stair_outer_bronzeblock",
+	"stairs:stair_outer_copperblock",
+	"stairs:stair_outer_steelblock",
+	"stairs:stair_outer_tinblock",
+	"stairs:stair_steelblock",
+	"stairs:stair_tinblock",
+
+	"stairs:slab_acacia_wood",
+	"stairs:slab_aspen_wood",
+	"stairs:slab_brick",
+	"stairs:slab_cobble",
+	"stairs:slab_desert_cobble",
+	"stairs:slab_desert_sandstone",
+	"stairs:slab_desert_sandstone_block",
+	"stairs:slab_desert_sandstone_brick",
+	"stairs:slab_desert_stone",
+	"stairs:slab_desert_stone_block",
+	"stairs:slab_desert_stonebrick",
+	"stairs:slab_glass",
+	"stairs:slab_goldblock",
+	"stairs:slab_ice",
+	"stairs:slab_junglewood",
+	"stairs:slab_mossycobble",
+	"stairs:slab_obsidian",
+	"stairs:slab_obsidian_block",
+	"stairs:slab_obsidian_glass",
+	"stairs:slab_obsidianbrick",
+	"stairs:slab_pine_wood",
+	"stairs:slab_sandstone",
+	"stairs:slab_sandstone_block",
+	"stairs:slab_sandstonebrick",
+	"stairs:slab_silver_sandstone",
+	"stairs:slab_silver_sandstone_block",
+	"stairs:slab_silver_sandstone_brick",
+	"stairs:slab_snowblock",
+	"stairs:slab_stone",
+	"stairs:slab_stone_block",
+	"stairs:slab_stonebrick",
+	"stairs:slab_straw",
+	"stairs:slab_wood",
+	"stairs:stair_acacia_wood",
+	"stairs:stair_aspen_wood",
+	"stairs:stair_brick",
+	"stairs:stair_cobble",
+	"stairs:stair_desert_cobble",
+	"stairs:stair_desert_sandstone",
+	"stairs:stair_desert_sandstone_block",
+	"stairs:stair_desert_sandstone_brick",
+	"stairs:stair_desert_stone",
+	"stairs:stair_desert_stone_block",
+	"stairs:stair_desert_stonebrick",
+	"stairs:stair_glass",
+	"stairs:stair_goldblock",
+	"stairs:stair_ice",
+	"stairs:stair_inner_acacia_wood",
+	"stairs:stair_inner_aspen_wood",
+	"stairs:stair_inner_brick",
+	"stairs:stair_inner_cobble",
+	"stairs:stair_inner_desert_cobble",
+	"stairs:stair_inner_desert_sandstone",
+	"stairs:stair_inner_desert_sandstone_block",
+	"stairs:stair_inner_desert_sandstone_brick",
+	"stairs:stair_inner_desert_stone",
+	"stairs:stair_inner_desert_stone_block",
+	"stairs:stair_inner_desert_stonebrick",
+	"stairs:stair_inner_glass",
+	"stairs:stair_inner_goldblock",
+	"stairs:stair_inner_ice",
+	"stairs:stair_inner_junglewood",
+	"stairs:stair_inner_mossycobble",
+	"stairs:stair_inner_obsidian",
+	"stairs:stair_inner_obsidian_block",
+	"stairs:stair_inner_obsidian_glass",
+	"stairs:stair_inner_obsidianbrick",
+	"stairs:stair_inner_pine_wood",
+	"stairs:stair_inner_sandstone",
+	"stairs:stair_inner_sandstone_block",
+	"stairs:stair_inner_sandstonebrick",
+	"stairs:stair_inner_silver_sandstone",
+	"stairs:stair_inner_silver_sandstone_block",
+	"stairs:stair_inner_silver_sandstone_brick",
+	"stairs:stair_inner_snowblock",
+	"stairs:stair_inner_stone",
+	"stairs:stair_inner_stone_block",
+	"stairs:stair_inner_stonebrick",
+	"stairs:stair_inner_straw",
+	"stairs:stair_inner_wood",
+	"stairs:stair_junglewood",
+	"stairs:stair_mossycobble",
+	"stairs:stair_obsidian",
+	"stairs:stair_obsidian_block",
+	"stairs:stair_obsidian_glass",
+	"stairs:stair_obsidianbrick",
+	"stairs:stair_outer_acacia_wood",
+	"stairs:stair_outer_aspen_wood",
+	"stairs:stair_outer_brick",
+	"stairs:stair_outer_cobble",
+	"stairs:stair_outer_desert_cobble",
+	"stairs:stair_outer_desert_sandstone",
+	"stairs:stair_outer_desert_sandstone_block",
+	"stairs:stair_outer_desert_sandstone_brick",
+	"stairs:stair_outer_desert_stone",
+	"stairs:stair_outer_desert_stone_block",
+	"stairs:stair_outer_desert_stonebrick",
+	"stairs:stair_outer_glass",
+	"stairs:stair_outer_goldblock",
+	"stairs:stair_outer_ice",
+	"stairs:stair_outer_junglewood",
+	"stairs:stair_outer_mossycobble",
+	"stairs:stair_outer_obsidian",
+	"stairs:stair_outer_obsidian_block",
+	"stairs:stair_outer_obsidian_glass",
+	"stairs:stair_outer_obsidianbrick",
+	"stairs:stair_outer_pine_wood",
+	"stairs:stair_outer_sandstone",
+	"stairs:stair_outer_sandstone_block",
+	"stairs:stair_outer_sandstonebrick",
+	"stairs:stair_outer_silver_sandstone",
+	"stairs:stair_outer_silver_sandstone_block",
+	"stairs:stair_outer_silver_sandstone_brick",
+	"stairs:stair_outer_snowblock",
+	"stairs:stair_outer_stone",
+	"stairs:stair_outer_stone_block",
+	"stairs:stair_outer_stonebrick",
+	"stairs:stair_outer_straw",
+	"stairs:stair_outer_wood",
+	"stairs:stair_pine_wood",
+	"stairs:stair_sandstone",
+	"stairs:stair_sandstone_block",
+	"stairs:stair_sandstonebrick",
+	"stairs:stair_silver_sandstone",
+	"stairs:stair_silver_sandstone_block",
+	"stairs:stair_silver_sandstone_brick",
+	"stairs:stair_snowblock",
+	"stairs:stair_stone",
+	"stairs:stair_stone_block",
+	"stairs:stair_stonebrick",
+	"stairs:stair_straw",
+	"stairs:stair_wood",
+
+	"xpanes:bar",
+	"xpanes:bar_flat",
+	"xpanes:door_steel_bar",
+	"xpanes:door_steel_bar_a",
+	"xpanes:door_steel_bar_b",
+	"xpanes:door_steel_bar_c",
+	"xpanes:door_steel_bar_d",
+	"xpanes:obsidian_pane",
+	"xpanes:obsidian_pane_flat",
+	"xpanes:pane",
+	"xpanes:pane_flat",
+	"xpanes:trapdoor_steel_bar",
+	"xpanes:trapdoor_steel_bar_open",
+
+	"walls:cobble",
+	"walls:desertcobble",
+	"walls:mossycobble",
+})
+
+unified_inventory.add_category_items('environment', {
+	"air",
+	"default:cave_ice",
+	"default:dirt_with_rainforest_litter",
+	"default:gravel",
+	"default:dry_dirt_with_dry_grass",
+	"default:permafrost",
+	"default:desert_stone",
+	"default:ice",
+	"default:dry_dirt",
+	"default:obsidian",
+	"default:sand",
+	"default:river_water_source",
+	"default:dirt_with_snow",
+	"default:dirt_with_grass",
+	"default:water_flowing",
+	"default:dirt",
+	"default:desert_sand",
+	"default:permafrost_with_moss",
+	"default:dirt_with_coniferous_litter",
+	"default:water_source",
+	"default:dirt_with_dry_grass",
+	"default:river_water_flowing",
+	"default:stone",
+	"default:snow",
+	"default:lava_flowing",
+	"default:lava_source",
+	"default:permafrost_with_stones",
+	"default:dirt_with_grass_footsteps",
+	"default:silver_sand",
+	"default:snowblock",
+	"default:clay",
+
+	"farming:desert_sand_soil",
+	"farming:desert_sand_soil_wet",
+	"farming:dry_soil",
+	"farming:dry_soil_wet",
+	"farming:soil",
+	"farming:soil_wet",
+})
+
+unified_inventory.add_category_items('lighting', {
+	"default:mese_post_light_junglewood",
+	"default:torch_ceiling",
+	"default:meselamp",
+	"default:torch",
+	"default:mese_post_light_acacia_wood",
+	"default:mese_post_light",
+	"default:torch_wall",
+	"default:mese_post_light_pine_wood",
+	"default:mese_post_light_aspen_wood"
+})
+--]]
+
+
+--[[ UNCATEGORISED
+
+	"farming:string",
+
+	"beds:bed_bottom",
+	"beds:bed_top",
+	"beds:fancy_bed_bottom",
+	"beds:fancy_bed_top",
+	"boats:boat",
+	"bones:bones",
+
+	"bucket:bucket_lava",
+	"bucket:bucket_river_water",
+	"bucket:bucket_water",
+
+	"butterflies:butterfly_red",
+	"butterflies:butterfly_violet",
+	"butterflies:butterfly_white",
+	"butterflies:hidden_butterfly_red",
+	"butterflies:hidden_butterfly_violet",
+	"butterflies:hidden_butterfly_white",
+
+	"carts:brakerail",
+	"carts:cart",
+	"carts:powerrail",
+	"carts:rail",
+
+	"default:book",
+	"default:book_written",
+	"default:bookshelf",
+	"default:chest",
+	"default:chest_locked",
+	"default:chest_locked_open",
+	"default:chest_open",
+	"default:clay_lump",
+	"default:cloud",
+	"default:coral_brown",
+	"default:coral_cyan",
+	"default:coral_green",
+	"default:coral_orange",
+	"default:coral_pink",
+	"default:coral_skeleton",
+	"default:flint",
+	"default:furnace",
+	"default:furnace_active",
+	"default:key",
+	"default:ladder_steel",
+	"default:ladder_wood",
+	"default:obsidian_shard",
+	"default:paper",
+	"default:sign_wall_steel",
+	"default:sign_wall_wood",
+	"default:stick",
+
+	"fire:basic_flame",
+	"fire:permanent_flame",
+	"fireflies:firefly",
+	"fireflies:firefly_bottle",
+	"fireflies:hidden_firefly",
+
+	"ignore",
+	"unknown",
+
+	"tnt:boom",
+	"tnt:gunpowder",
+	"tnt:gunpowder_burning",
+	"tnt:tnt",
+	"tnt:tnt_burning",
+	"tnt:tnt_stick",
+
+	"vessels:drinking_glass",
+	"vessels:glass_bottle",
+	"vessels:glass_fragments",
+	"vessels:shelf",
+	"vessels:steel_bottle",
+
+	"dye:black",
+	"dye:blue",
+	"dye:brown",
+	"dye:cyan",
+	"dye:dark_green",
+	"dye:dark_grey",
+	"dye:green",
+	"dye:grey",
+	"dye:magenta",
+	"dye:orange",
+	"dye:pink",
+	"dye:red",
+	"dye:violet",
+	"dye:white",
+	"dye:yellow",
+
+	"wool:black",
+	"wool:blue",
+	"wool:brown",
+	"wool:cyan",
+	"wool:dark_green",
+	"wool:dark_grey",
+	"wool:green",
+	"wool:grey",
+	"wool:magenta",
+	"wool:orange",
+	"wool:pink",
+	"wool:red",
+	"wool:violet",
+	"wool:white",
+	"wool:yellow",
+
+	"unified_inventory:bag_large",
+	"unified_inventory:bag_medium",
+	"unified_inventory:bag_small",
+--]]
+
+--[[ LIST UNCATEGORIZED AFTER LOAD
+minetest.register_on_mods_loaded(function()
+	minetest.after(1, function ( )
+		local l = {}
+		for name,_ in pairs(minetest.registered_items) do
+			if not unified_inventory.find_category(name) then
+				-- minetest.log("error", minetest.serialize(minetest.registered_items[name]))
+				table.insert(l, name)
+			end
+		end
+		table.sort(l)
+		minetest.log(table.concat(l, '",'.."\n"..'"'))
+	end)
+end)
+--]]

doc/mod_api.txt

@@ -101,3 +101,72 @@ Register a non-standard craft recipe:
 		-- ^ Same as `minetest.register_recipe`
 	})
 
+
+Categories
+----------
+
+Register a new category:
+	The config table (second argument) is optional, and all its members are optional
+	See the unified_inventory.set_category_* functions for more details on the members of the config table
+
+	unified_inventory.register_category("category_name", {
+		symbol = "mod_name:item_name" or "texture.png",
+		label = "Human Readable Label",
+		index = 5,
+		items = {
+			"mod_name:item_name",
+			"another_mod:different_item"
+		}
+	})
+
+Add / override the symbol for a category:
+	The category does not need to exist first
+	The symbol can be an item name or a texture image
+	If unset this will default to "default:stick"
+
+	unified_inventory.set_category_symbol("category_name", "mod_name:item_name" or "texture.png")
+
+Add / override the human readable label for a category:
+	If unset this will default to the category name
+
+	unified_inventory.set_category_label("category_name", "Human Readable Label")
+
+Add / override the sorting index of the category:
+	Must be a number, can also be negative (-5) or fractional (2.345)
+	This determines the position the category appears in the list of categories
+	The "all" meta-category has index -2, the "misc"/"uncategorized" meta-category has index -1, use a negative number smaller than these to make a category appear before these in the list
+	By default categories are sorted alphabetically with an index between 0.0101(AA) and 0.2626(ZZ)
+
+	unified_inventory.set_category_index("category_name", 5)
+
+Add a single item to a category:
+
+	unified_inventory.add_category_item("category_name", "mod_name:item_name")
+
+Add multiple items to a category:
+
+	unified_inventory.add_category_items("category_name", {
+		"mod_name:item_name",
+		"another_mod:different_item"
+	})
+
+Remove an item from a category:
+
+	unified_inventory.remove_category_item("category_name", "mod_name:item_name")
+
+Remove a category entirely:
+
+	unified_inventory.remove_category("category_name")
+
+Finding existing items in categories:
+	This will find the first category an item exists in
+	It should be used for checking if an item is catgorised
+	Returns "category_name" or nil
+
+	unified_inventory.find_category("mod_name:item_name")
+
+
+	This will find all the categories an item exists in
+	Returns a number indexed table (list) of category names
+
+	unified_inventory.find_categories("mod_name:item_name")

init.lua

@@ -10,6 +10,8 @@ unified_inventory = {
 	alternate = {},
 	current_page = {},
 	current_searchbox = {},
+	current_category = {},
+	current_category_scroll = {},
 	current_index = {},
 	current_item = {},
 	current_craft_direction = {},
@@ -33,6 +35,9 @@ unified_inventory = {
 	-- "Lite" mode
 	lite_mode = minetest.settings:get_bool("unified_inventory_lite"),
 
+	-- Items automatically added to categories based on item definitions
+	automatic_categorization = (minetest.settings:get_bool("unified_inventory_automatic_categorization") ~= false),
+
 	-- Trash enabled
 	trash_enabled = (minetest.settings:get_bool("unified_inventory_trash") ~= false),
 	imgscale = 1.25,
@@ -52,9 +57,9 @@ ui.style_full = {
 	formw = 17.75,
 	formh = 12.25,
 	pagecols = 8,
-	pagerows = 10,
+	pagerows = 9,
 	page_x = 10.75,
-	page_y = 1.45,
+	page_y = 2.30,
 	craft_x = 2.8,
 	craft_y = 1.15,
 	craftresult_x = 7.8,
@@ -85,9 +90,9 @@ ui.style_lite = {
 	formw = 14,
 	formh = 9.75,
 	pagecols = 4,
-	pagerows = 6,
+	pagerows = 5,
 	page_x = 10.5,
-	page_y = 1.25,
+	page_y = 2.15,
 	craft_x = 2.6,
 	craft_y = 0.75,
 	craftresult_x = 5.75,
@@ -100,9 +105,9 @@ ui.style_lite = {
 	craft_guide_resultstr_y = 0.35,
 	give_btn_x = 0.15,
 	main_button_x = 10.5,
-	main_button_y = 7.9,
+	main_button_y = 8.15,
 	page_buttons_x = 10.5,
-	page_buttons_y = 6.3,
+	page_buttons_y = 6.15,
 	searchwidth = 1.6,
 	form_header_x =  0.2,
 	form_header_y =  0.2,
@@ -149,6 +154,8 @@ if sfinv then
 end
 
 dofile(modpath.."/group.lua")
+dofile(modpath.."/category.lua")
+dofile(modpath.."/default-categories.lua")
 dofile(modpath.."/internal.lua")
 dofile(modpath.."/callbacks.lua")
 dofile(modpath.."/match_craft.lua")

internal.lua

@@ -25,6 +25,20 @@ function ui.get_per_player_formspec(player_name)
 	return table.copy(draw_lite_mode and ui.style_lite or ui.style_full), draw_lite_mode
 end
 
+local function formspec_button(ui_peruser, name, image, offset, pos, scale, label)
+	local element = 'image_button'
+	if minetest.registered_items[image] then
+		element = 'item_image_button'
+	end
+	local spc = (1-scale)*ui_peruser.btn_size/2
+	local size = ui_peruser.btn_size*scale
+	return string.format("%s[%f,%f;%f,%f;%s;%s;]", element,
+		(offset.x or offset[1]) + ( ui_peruser.btn_spc * (pos.x or pos[1]) ) + spc,
+		(offset.y or offset[2]) + ( ui_peruser.btn_spc * (pos.y or pos[2]) ) + spc,
+		size, size, image, name) ..
+		string.format("tooltip[%s;%s]", name, F(label or name))
+end
+
 function ui.get_formspec(player, page)
 
 	if not player then
@@ -107,6 +121,48 @@ function ui.get_formspec(player, page)
 		return table.concat(formspec, "")
 	end
 
+	-- Category filters
+
+	local categories_pos = { ui_peruser.page_x, ui_peruser.page_y-ui_peruser.btn_spc-0.5 }
+	local categories_scroll_pos = { ui_peruser.page_x, ui_peruser.form_header_y-(draw_lite_mode and 0 or 0.2) }
+
+	formspec[n] = string.format("background9[%f,%f;%f,%f;%s;false;3]",
+		ui_peruser.page_x-0.1, categories_scroll_pos[2],
+		(ui_peruser.btn_spc * ui_peruser.pagecols) + 0.13, 1.4+(draw_lite_mode and 0 or 0.2),
+		"ui_smallbg_9_sliced.png")
+	n = n + 1
+
+	formspec[n] = string.format("label[%f,%f;%s]", ui_peruser.page_x, ui_peruser.form_header_y+(draw_lite_mode and 0.3 or 0.2), "Category:")
+	n = n + 1
+
+	local scroll_offset = 0
+	local category_count = #unified_inventory.category_list
+	if category_count > ui_peruser.pagecols then
+		scroll_offset = unified_inventory.current_category_scroll[player_name]
+	end
+
+	for index, category in ipairs(unified_inventory.category_list) do
+		local column = index - scroll_offset
+		if column > 0 and column <= ui_peruser.pagecols then
+			local scale = 0.8
+			if unified_inventory.current_category[player_name] == category.name then
+				scale = 1
+			end
+			formspec[n] = formspec_button(ui_peruser, "category_"..category.name, category.symbol, categories_pos, {column-1, 0}, scale, category.label)
+			n = n + 1
+		end
+	end
+	if category_count > ui_peruser.pagecols and scroll_offset > 0 then
+		-- prev
+		formspec[n] = formspec_button(ui_peruser, "prev_category", "ui_left_icon.png", categories_scroll_pos, {ui_peruser.pagecols - 2, 0}, 0.8, S("Scroll categories left"))
+		n = n + 1
+	end
+	if category_count > ui_peruser.pagecols and category_count - scroll_offset > ui_peruser.pagecols then
+		-- next
+		formspec[n] = formspec_button(ui_peruser, "next_category", "ui_right_icon.png", categories_scroll_pos, {ui_peruser.pagecols - 1, 0}, 0.8, S("Scroll categories right"))
+		n = n + 1
+	end
+
 	-- Search box
 	formspec[n] = "field_close_on_enter[searchbox;false]"
 
@@ -205,16 +261,16 @@ function ui.get_formspec(player, page)
 			end
 		end
 		formspec[n] = string.format("label[%f,%f;%s: %s]",
-			ui_peruser.page_x, ui_peruser.form_header_y,
+			ui_peruser.page_buttons_x + ui_peruser.btn_spc * (draw_lite_mode and 1 or 2),
+			ui_peruser.page_buttons_y + 0.1 + ui_peruser.btn_spc * 2,
 			F(S("Page")), S("@1 of @2",page2,pagemax))
 	end
 	n= n+1
 
 	if ui.activefilter[player_name] ~= "" then
-		formspec[n] = string.format("label[%f,%f;%s:]",
+		formspec[n] = string.format("label[%f,%f;%s: %s]",
-			ui_peruser.page_x, ui_peruser.page_y - 0.65, F(S("Filter")))
+			ui_peruser.page_x, ui_peruser.page_y - 0.25,
-		formspec[n+1] = string.format("label[%f,%f;%s]",
+			F(S("Filter")), F(ui.activefilter[player_name]))
-			ui_peruser.page_x, ui_peruser.page_y - 0.25, F(ui.activefilter[player_name]))
 	end
 	return table.concat(formspec, "")
 end
@@ -225,6 +281,13 @@ function ui.set_inventory_formspec(player, page)
 	end
 end
 
+local function valid_def(def)
+	return (not def.groups.not_in_creative_inventory
+			or def.groups.not_in_creative_inventory == 0)
+		and def.description
+		and def.description ~= ""
+end
+
 --apply filter to the inventory list (create filtered copy of full one)
 function ui.apply_filter(player, filter, search_dir)
 	if not player then
@@ -256,15 +319,32 @@ function ui.apply_filter(player, filter, search_dir)
 		end
 	end
 	ui.filtered_items_list[player_name]={}
+	local category = ui.current_category[player_name] or 'all'
+	if category == 'all' then
 		for name, def in pairs(minetest.registered_items) do
-		if (not def.groups.not_in_creative_inventory
+			if valid_def(def)
-			or def.groups.not_in_creative_inventory == 0)
-		and def.description
-		and def.description ~= ""
 			and ffilter(name, def) then
 				table.insert(ui.filtered_items_list[player_name], name)
 			end
 		end
+	elseif category == 'uncategorized' then
+		for name, def in pairs(minetest.registered_items) do
+			if (not ui.find_category(name))
+			and valid_def(def)
+			and ffilter(name, def) then
+				table.insert(ui.filtered_items_list[player_name], name)
+			end
+		end
+	else
+		for name,exists in pairs(ui.registered_category_items[category]) do
+			local def = minetest.registered_items[name]
+			if exists and def
+			and valid_def(def)
+			and ffilter(name, def) then
+				table.insert(ui.filtered_items_list[player_name], name)
+			end
+		end
+	end
 	table.sort(ui.filtered_items_list[player_name])
 	ui.filtered_items_list_size[player_name] = #ui.filtered_items_list[player_name]
 	ui.current_index[player_name] = 1

settingtypes.txt

@@ -9,3 +9,6 @@ unified_inventory_bags (Enable bags) bool true
 #If enabled, the trash slot can be used by those without both creative
 #and the give privilege.
 unified_inventory_trash (Enable trash) bool true
+
+
+unified_inventory_automatic_categorization (Items automatically added to categories) bool true