Add inventort scroll

main.lua

@@ -1,8 +1,25 @@
 -- Imports
 local util = require("util")
 local window = require("window")
+local entity = require("entity")
 local button = require("button")
 
+function min(a, b)
+    if a < b then
+        return a
+    else
+        return b
+    end
+end
+
+function max(a, b)
+    if a > b then
+        return a
+    else
+        return b
+    end
+end
+
 -- entities that has update method
 active_entities = {}
 
@@ -38,7 +55,6 @@ screen = {
 }
 
 screen.mousepressed = window.mousepressed(function (self, x, y, button)
-    log:log(string.format("%d, %d", x, y))
     current_room:mousepressed(x, y, button)
 end)
 
@@ -53,11 +69,85 @@ inventory = {
     height = 60,
     selected_item = nil,
     items = {},
+    item_idx = 1,
 }
 
+local cells = math.floor((inventory.width - 60) / 60)
+
+function inventory:setpos(idx, item)
+    local x = 30 + (idx - 1) * 60 + (60 - item.width) / 2
+    local y = (60 - item.height) / 2
+
+    item:setpos(x, y)
+end
+
+function inventory:move(d)
+    self.item_idx = self.item_idx + d
+
+    if self.item_idx < 1 then
+        self.item_idx = 1
+    elseif self.item_idx + cells - 1 > #self.items then
+        self.item_idx = max(1, #self.items - cells + 1)
+    end
+
+    for i = 1, min(#self.items, cells) do
+        local idx = self.item_idx + i - 1
+        self:setpos(i, self.items[idx])
+    end
+end
+
+function inventory:pickup(item)
+    util.add_entity(self.items, item)
+    self:move(#self.items)
+end
+
+function inventory:drop(item)
+    util.del_entity(self.items, item)
+    self:move(0)
+end
+
+function inventory:use()
+    self:drop(self.selected_item)
+    self.selected_item = nil
+end
+
+local move_left = entity:from{
+    x = 0, y = 0,
+    width = 20,
+    height = 60,
+}
+
+move_left.draw = window.draw(function (self)
+    love.graphics.polygon('line', 15, 5, 5, 30, 15, 55)
+end)
+
+move_left.mousepressed = window.mousepressed(function (self, x, y, button)
+    inventory:move(-1)
+end)
+
+local move_right = entity:from{
+    x = inventory.width - 20,
+    y = 0,
+    width = 20,
+    height = 60,
+}
+
+move_right.draw = window.draw(function (self)
+    love.graphics.polygon('line', 5, 5, 15, 30, 5, 55)
+end)
+
+move_right.mousepressed = window.mousepressed(function (self, x, y, button)
+    inventory:move(1)
+end)
+
 inventory.mousepressed = window.mousepressed(function (self, x, y, button)
-    for i, v in ipairs(self.items) do
-        if v:mousepressed(x, y, button) then
+    move_left:mousepressed(x, y, button)
+    move_right:mousepressed(x, y, button)
+
+    for i = 1, min(cells, #self.items) do
+        local item = self.items[self.item_idx + i - 1]
+
+        if item:mousepressed(x, y, button) then
             return true
         end
     end
@@ -66,9 +156,15 @@ inventory.mousepressed = window.mousepressed(function (self, x, y, button)
 end)
 
 inventory.draw = window.draw(function (self)
-    for i, item in pairs(self.items) do
+    move_left:draw()
+    move_right:draw()
+
+    for i = 1, min(#self.items, cells) do
+        local idx = i + self.item_idx - 1
+        local item = self.items[idx]
+
         if self.selected_item and self.selected_item == item then
-            love.graphics.circle('line', 60*i - 30, 30, 25)
+            love.graphics.circle('line', 60*i, 30, 25)
         end
 
         item:draw()
@@ -77,31 +173,6 @@ inventory.draw = window.draw(function (self)
     window.draw_border(self.width, self.height)
 end)
 
-function inventory:set_pos(idx, item)
-    local x = (idx - 1) * 60 + (60 - item.width) / 2
-    local y = (60 - item.height) / 2
-
-    item:setpos(x, y)
-end
-
-function inventory:pickup(item)
-    util.add_entity(self.items, item)
-    self:set_pos(item.idx[self.items], item)
-end
-
-function inventory:drop(item)
-    util.del_entity(self.items, item)
-
-    for i, v in ipairs(self.items) do
-        self:set_pos(i, v)
-    end
-end
-
-function inventory:use()
-    self:drop(self.selected_item)
-    self.selected_item = nil
-end
-
 log = {
     x = inventory.width , y = 0,
     width = WIDTH - screen.width,