'Disable' table buttons when an action is invalid

skin_api.lua

@@ -41,6 +41,7 @@ cartographer.skin = {
             },
             button = {
                 font_color = "#694a3a",
+                disabled_font_color = "#606060",
                 texture = "cartographer_simple_table_button",
                 selected_texture = "cartographer_simple_table_button_pressed",
                 hovered_texture = "cartographer_simple_table_button_hovered",
@@ -84,6 +85,7 @@ cartographer.skin = {
             },
             button = {
                 font_color = "#694a3a",
+                disabled_font_color = "#606060",
                 texture = "cartographer_simple_table_button",
                 selected_texture = "cartographer_simple_table_button_pressed",
                 hovered_texture = "cartographer_simple_table_button_hovered",
@@ -127,6 +129,7 @@ cartographer.skin = {
             },
             button = {
                 font_color = "#1f2533",
+                disabled_font_color = "#606060",
                 texture = "cartographer_advanced_table_button",
                 selected_texture = "cartographer_advanced_table_button_pressed",
                 hovered_texture = "cartographer_advanced_table_button_hovered",

table.lua

@@ -48,21 +48,34 @@ end
 -- Get the material cost of the craft settings from the given table metadata
 -- meta: The metadata to read
 --
--- Returns a table with the material costs
+-- Returns a table with the material costs, and a boolean indicating if the
+-- costs were positive or negative before clamping.
 local function get_craft_material_cost(meta)
     local cost = get_material_cost(meta:get_int("size") or SIZE_SMALL, meta:get_int("detail") or 0);
-
     local stack = meta:get_inventory():get_stack("output", 1);
+    local is_positive = true;
+
     if stack:get_name() == "cartographer:map" then
-
         local smeta = stack:get_meta();
-
         local sub_cost = get_material_cost(smeta:get_int("cartographer:size") or SIZE_SMALL, (smeta:get_int("cartographer:detail") or 1) - 1);
+        is_positive = cost.paper >= sub_cost.paper and cost.pigment >= sub_cost.pigment;
         cost.paper = math.max(cost.paper - sub_cost.paper, 0);
         cost.pigment = math.max(cost.pigment - sub_cost.pigment, 0);
     end
 
-    return cost;
+    return cost, is_positive;
+end
+
+-- Check if the given table metadata has enough materials to cover the given
+-- cost table.
+-- cost: A table of material costs
+-- meta: The metadata
+--
+-- Returns true if the table's materials can cover the cost
+local function can_afford(cost, meta)
+    return cost.paper + cost.pigment > 0
+       and cost.paper <= meta:get_int("paper")
+       and cost.pigment <= meta:get_int("pigment");
 end
 
 -- Get the material cost of the copy settings from the given table metadata
@@ -123,6 +136,24 @@ end
 
 local fs = {};
 
+-- Draw a button, with support for enabled/disabled states
+-- x: The x position of the button
+-- y: The y position of the button
+-- w: The width of the button
+-- h: The height of the button
+-- id: The element id
+-- text: The text to display in the button
+-- enabled: Whether or not the button is enabled
+--
+-- Returns a formspec string
+function fs.button(x, y, w, h, id, text, enabled)
+    if enabled then
+        return string.format("button[%f,%f;%f,%f;%s;%s]", x, y, w, h, id, text);
+    end
+
+    return string.format("button[%f,%f;%f,%f;disabled_button;%s]", x, y, w, h, text);
+end
+
 -- Draw a 1px thick horizontal separator formspec element
 -- y: The y position of the separator
 -- skin: A 9-slice background skin table
@@ -154,7 +185,8 @@ function fs.header(w, h, rank, tab, skin)
         data = data .. string.format("button[3.25,-0.425;1.5,0.55;tab3;Copy Map]", tab);
     end
 
-    return data .. string.format("style_type[button;border=false;bgimg=%s.png;bgimg_hovered=%s.png;bgimg_pressed=%s.png;bgimg_middle=%s;textcolor=%s]", skin.button.texture, skin.button.hovered_texture, skin.button.pressed_texture, tostring(skin.button.radius), skin.button.font_color);
+    return data .. string.format("style_type[button;border=false;bgimg=%s.png;bgimg_hovered=%s.png;bgimg_pressed=%s.png;bgimg_middle=%s;textcolor=%s]", skin.button.texture, skin.button.hovered_texture, skin.button.pressed_texture, tostring(skin.button.radius), skin.button.font_color)
+                .. string.format("style[disabled_button;bgimg=;bgimg_hovered=;bgimg_pressed=;textcolor=%s]", skin.button.disabled_font_color);
 end
 
 -- Draw material counters from a table's metadata
@@ -205,13 +237,14 @@ end
 -- Returns a formspec string
 function fs.convert(x, y, pos, skin)
     local meta = minetest.get_meta(pos);
+    local value = cartographer.get_material_value(meta:get_inventory():get_stack("input", 1));
 
     return string.format("container[%f,%f]", x, y)
         .. "formspec_version[3]"
         .. inventory_bg(0, 0, 1, 1, skin.slot)
         .. string.format("list[nodemeta:%d,%d,%d;input;0,0;1,1;]", pos.x, pos.y, pos.z)
-        .. "button[1.25,0.5;2,0.5;convert;Convert Materials]"
+        .. fs.button(1.25, 0.5, 2, 0.5, "convert", "Convert Materials", value.paper + value.pigment > 0)
-        .. fs.cost(1.25, 0.125, cartographer.get_material_value(meta:get_inventory():get_stack("input", 1)), skin)
+        .. fs.cost(1.25, 0.125, value, skin)
         .. "container_end[]";
 end
 
@@ -225,12 +258,13 @@ end
 --
 -- Returns a formspec string
 function fs.craft(x, y, pos, rank, meta, skin)
+    local cost, is_positive = get_craft_material_cost(meta);
     local data = string.format("container[%f,%f]", x, y)
               .. "formspec_version[3]"
               .. inventory_bg(0, 0.75, 1, 1, skin.slot)
               .. string.format("list[nodemeta:%d,%d,%d;output;0,0.75;1,1;]", pos.x, pos.y, pos.z)
-              .. "button[1.25,1.25;2,0.5;craft;Craft Map]"
+              .. fs.button(1.25, 1.25, 2, 0.5, "craft", "Craft Map", is_positive and can_afford(cost, meta))
-              .. fs.cost(1.25, 0.875, get_craft_material_cost(meta), skin);
+              .. fs.cost(1.25, 0.875, cost, skin);
 
     if rank > 1 then
         local size = "s";
@@ -276,13 +310,14 @@ end
 -- Returns a formspec string
 function fs.copy(x, y, pos, skin)
     local meta = minetest.get_meta(pos);
+    local costs = get_copy_material_cost(meta);
 
     return string.format("container[%f,%f]", x, y)
         .. "formspec_version[3]"
         .. inventory_bg(0, 0, 1, 1, skin.slot)
         .. string.format("list[nodemeta:%d,%d,%d;copy_input;0,0;1,1;]", pos.x, pos.y, pos.z)
-        .. "button[1.25,0.5;2,0.5;copy;Copy Map]"
+        .. fs.button(1.25, 0.5, 2, 0.5, "copy", "Copy Map", can_afford(costs, meta))
-        .. fs.cost(1.25, 0.125, get_copy_material_cost(meta), skin)
+        .. fs.cost(1.25, 0.125, costs, skin)
         .. inventory_bg(8.75, 0, 1, 1, skin.slot)
         .. string.format("list[nodemeta:%d,%d,%d;copy_output;8.75,0;1,1;]", pos.x, pos.y, pos.z)
         .. "container_end[]";
@@ -367,7 +402,6 @@ end
 -- fields: A table containing the input
 minetest.register_on_player_receive_fields(function(player, name, fields)
     if name == "simple_table" then
-        minetest.chat_send_all(name..": ");
         local meta = minetest.get_meta(player_tables[player:get_player_name()].pos);
 
         if fields["convert"] then
@@ -385,35 +419,19 @@ minetest.register_on_player_receive_fields(function(player, name, fields)
             local size = meta:get_int("size");
             local detail = meta:get_int("detail");
             local scale = meta:get_int("scale");
-            local paper = meta:get_int("paper");
+            local cost, is_positive = get_craft_material_cost(meta);
-            local pigment = meta:get_int("pigment");
 
+            if is_positive and can_afford(cost, meta) then
+                meta:set_int("paper",  meta:get_int("paper") - cost.paper);
+                meta:set_int("pigment", meta:get_int("paper") - cost.pigment);
 
                 local inv = meta:get_inventory();
                 local stack = inv:get_stack("output", 1);
 
-            local cost = get_craft_material_cost(meta);
-
                 if stack:is_empty() then
-                if paper >= cost.paper and pigment >= cost.pigment then
-                    paper = paper - cost.paper;
-                    pigment = pigment - cost.pigment;
-                    meta:set_int("paper", paper);
-                    meta:set_int("pigment", pigment);
-
-                    cartographer.map_sound("cartographer_write", player);
                     inv:set_stack("output", 1, cartographer.create_map_item(size, 1 + detail, scale));
-                end
                 else
                     local smeta = stack:get_meta();
-                local old_size = smeta:get_int("cartographer:size");
-                local old_detail = smeta:get_int("cartographer:detail") - 1;
-                if old_detail <= detail and old_size <= size and not (old_detail == detail and old_size == size) and paper >= cost.paper and pigment >= cost.pigment then
-                    paper = paper - cost.paper;
-                    pigment = pigment - cost.pigment;
-                    meta:set_int("paper", paper);
-                    meta:set_int("pigment", pigment);
-
                     smeta:set_int("cartographer:detail", 1 + detail);
                     cartographer.resize_map_item(smeta, size);
 
@@ -421,34 +439,21 @@ minetest.register_on_player_receive_fields(function(player, name, fields)
                     if map then
                         map.detail = 1 + detail;
                     end
-                    cartographer.map_sound("cartographer_write", player);
                     inv:set_stack("output", 1, stack);
                 end
-            end
-        elseif fields["copy"] then
-            local paper = meta:get_int("paper");
-            local pigment = meta:get_int("pigment");
-
-            local inv = meta:get_inventory();
-            local in_stack = inv:get_stack("copy_input", 1);
-            local out_stack = inv:get_stack("copy_output", 1);
-
-
-            if out_stack:is_empty() and in_stack:get_name() == "cartographer:map" then
-                local smeta = in_stack:get_meta();
-                local size = smeta:get_int("cartographer:size") or SIZE_SMALL;
-                local detail = smeta:get_int("cartographer:detail") or 1;
-                local cost = get_material_cost(size, detail - 1);
-
-                if paper >= cost.paper and pigment >= cost.pigment then
-                    paper = paper - cost.paper;
-                    pigment = pigment - cost.pigment;
-                    meta:set_int("paper", paper);
-                    meta:set_int("pigment", pigment);
 
                 cartographer.map_sound("cartographer_write", player);
-                    inv:set_stack("copy_output", 1, cartographer.copy_map_item(in_stack));
             end
+        elseif fields["copy"] then
+            local cost = get_copy_material_cost(meta);
+            if can_afford(cost, meta) then
+                meta:set_int("paper",  meta:get_int("paper") - cost.paper);
+                meta:set_int("pigment", meta:get_int("paper") - cost.pigment);
+
+                cartographer.map_sound("cartographer_write", player);
+
+                local inv = meta:get_inventory();
+                inv:set_stack("copy_output", 1, cartographer.copy_map_item(inv:get_stack("copy_input", 1)));
             end
         elseif fields["s"] then
             meta:set_int("size", SIZE_SMALL);