uiitem and template refactoring; new smelter ui wip

assets/mods/basegame/crafting/fixtures.json

@@ -55,5 +55,11 @@
     "ingredients": [
       [1, 6, "basegame:51"]
     ]
+  },
+  "item@basegame:6": { /* storage chest */
+    "workbench": "basiccrafting",
+    "ingredients": [
+      [1, 20, "$WOOD"] /* 1 chest = 20 wood */
+    ]
   }
 }

src/net/torvald/terrarum/modulebasegame/gameactors/FixtureSmelterBasic.kt

@@ -14,6 +14,7 @@ import net.torvald.terrarum.modulebasegame.TerrarumIngame
 import net.torvald.terrarum.modulebasegame.gameitems.FixtureItemBase
 import net.torvald.terrarum.modulebasegame.ui.UICrafting
 import net.torvald.terrarum.modulebasegame.ui.UIInventoryFull
+import net.torvald.terrarum.modulebasegame.ui.UISmelterBasic
 import net.torvald.terrarumsansbitmap.gdx.TextureRegionPack
 
 /**
@@ -28,7 +29,7 @@ class FixtureSmelterBasic : FixtureBase, CraftingStation {
     constructor() : super(
         BlockBox(BlockBox.NO_COLLISION, 3, 4), // temporary value, will be overwritten by spawn()
         nameFun = { Lang["ITEM_SMELTER_SMALL"] },
-        mainUI = UICrafting(null)
+        mainUI = UISmelterBasic()
     ) {
         CommonResourcePool.addToLoadingList("particles-tiki_smoke.tga") {
             TextureRegionPack(ModMgr.getGdxFile("basegame", "particles/bigger_smoke.tga"), 16, 16)

src/net/torvald/terrarum/modulebasegame/ui/UICrafting.kt

@@ -15,6 +15,7 @@ import net.torvald.terrarum.modulebasegame.gameactors.CraftingStation
 import net.torvald.terrarum.modulebasegame.gameactors.FixtureInventory
 import net.torvald.terrarum.modulebasegame.gameactors.InventoryPair
 import net.torvald.terrarum.modulebasegame.ui.UIItemInventoryItemGrid.Companion.listGap
+import net.torvald.terrarum.modulebasegame.ui.UITemplateHalfInventory.Companion.INVENTORY_NAME_TEXT_GAP
 import net.torvald.terrarum.ui.*
 import net.torvald.terrarum.ui.UIItemCatBar.Companion.FILTER_CAT_ALL
 import net.torvald.unicode.getKeycapPC
@@ -30,7 +31,7 @@ class UICrafting(val full: UIInventoryFull?) : UICanvas(
     toggleButtonLiteral = if (full == null) "control_gamepad_start" else null
 ), HasInventory {
 
-    override var width = App.scr.width
+    override var width = Toolkit.drawWidth
     override var height = App.scr.height
 
     private val playerThings = UITemplateHalfInventory(this, false).also {
@@ -82,7 +83,6 @@ class UICrafting(val full: UIInventoryFull?) : UICanvas(
 
     override fun getNegotiator() = negotiator
     override fun getFixtureInventory(): FixtureInventory = craftables
-
     override fun getPlayerInventory(): FixtureInventory = INGAME.actorNowPlaying!!.inventory
 
     private val halfSlotOffset = (UIItemInventoryElemSimple.height + listGap) / 2
@@ -93,7 +93,6 @@ class UICrafting(val full: UIInventoryFull?) : UICanvas(
     private val thisOffsetY =  UIInventoryFull.INVENTORY_CELLS_OFFSET_Y()
     private val cellsWidth = (listGap + UIItemInventoryElemWide.height) * 6 - listGap
 
-    private val TEXT_GAP = 26
     private val LAST_LINE_IN_GRID = ((UIItemInventoryElemWide.height + listGap) * (UIInventoryFull.CELLS_VRT - 2)) + 22//359 // TEMPORARY VALUE!
 
     private var recipeClicked: CraftingCodex.CraftingRecipe? = null
@@ -443,11 +442,9 @@ class UICrafting(val full: UIInventoryFull?) : UICanvas(
         // text label for two inventory grids
         val craftingLabel = Lang["GAME_CRAFTING"]
         val ingredientsLabel = Lang["GAME_INVENTORY_INGREDIENTS"]
-        val playerName = INGAME.actorNowPlaying!!.actorValue.getAsString(AVKey.NAME).orEmpty().let { it.ifBlank { Lang["GAME_INVENTORY"] } }
 
-        App.fontGame.draw(batch, craftingLabel, thisOffsetX + (cellsWidth - App.fontGame.getWidth(craftingLabel)) / 2, thisOffsetY - TEXT_GAP)
-        App.fontGame.draw(batch, ingredientsLabel, thisOffsetX + (cellsWidth - App.fontGame.getWidth(ingredientsLabel)) / 2, thisOffsetY + LAST_LINE_IN_GRID - TEXT_GAP)
-        App.fontGame.draw(batch, playerName, thisOffsetX2 + (cellsWidth - App.fontGame.getWidth(playerName)) / 2, thisOffsetY - TEXT_GAP)
+        App.fontGame.draw(batch, craftingLabel, thisOffsetX + (cellsWidth - App.fontGame.getWidth(craftingLabel)) / 2, thisOffsetY - INVENTORY_NAME_TEXT_GAP)
+        App.fontGame.draw(batch, ingredientsLabel, thisOffsetX + (cellsWidth - App.fontGame.getWidth(ingredientsLabel)) / 2, thisOffsetY + LAST_LINE_IN_GRID - INVENTORY_NAME_TEXT_GAP)
 
 
         // control hints
@@ -456,11 +453,11 @@ class UICrafting(val full: UIInventoryFull?) : UICanvas(
         App.fontGame.draw(batch, controlHelp, controlHintXPos, UIInventoryFull.yEnd - 20)
 
         
-        if (full != null) {
+        if (INGAME.actorNowPlaying != null) {
             //draw player encumb
             val encumbBarXPos = thisXend - UIInventoryCells.weightBarWidth + 36
             val encumbBarYPos = UIInventoryFull.yEnd - 20 + 3f
-            UIInventoryCells.drawEncumbranceBar(batch, encumbBarXPos, encumbBarYPos, encumbrancePerc, full.actor.inventory)
+            UIInventoryCells.drawEncumbranceBar(batch, encumbBarXPos, encumbBarYPos, encumbrancePerc, INGAME.actorNowPlaying!!.inventory)
         }
 
 

src/net/torvald/terrarum/modulebasegame/ui/UIItemInventoryEquippedView.kt

@@ -44,19 +44,19 @@ class UIItemInventoryEquippedView(
 
     private val equipPosIcon = CommonResourcePool.getAsTextureRegionPack("inventory_category")
     private val cellToIcon = intArrayOf(0,1,2,3,4,5,6,7,6,7,6,7)
-    private val equipPosIconCol = Color(0xdddddd7f.toInt())
 
     private val itemGrid = Array<UIItemInventoryCellBase>(2 * 6) {
         UIItemInventoryElemSimple(
-                parentUI = parentUI,
-                initialX = this.posX + (UIItemInventoryElemSimple.height + listGap) * ((it + 4) % 2),
-                initialY = this.posY + (UIItemInventoryElemSimple.height + listGap) * ((it + 4) / 2),
-                item = null,
-                amount = UIItemInventoryElemWide.UNIQUE_ITEM_HAS_NO_AMOUNT,
-                itemImage = null,
-                drawBackOnNull = true,
-                keyDownFun = createInvCellGenericKeyDownFun(),
-                touchDownFun = createInvCellGenericTouchDownFun(inventoryListRebuildFun) // to "unselect" the equipped item and main item grid would "untick" accordingly
+            parentUI = parentUI,
+            initialX = this.posX + (UIItemInventoryElemSimple.height + listGap) * ((it + 4) % 2),
+            initialY = this.posY + (UIItemInventoryElemSimple.height + listGap) * ((it + 4) / 2),
+            item = null,
+            amount = UIItemInventoryElemWide.UNIQUE_ITEM_HAS_NO_AMOUNT,
+            itemImage = null,
+            drawBackOnNull = true,
+            keyDownFun = createInvCellGenericKeyDownFun(),
+            touchDownFun = createInvCellGenericTouchDownFun(inventoryListRebuildFun), // to "unselect" the equipped item and main item grid would "untick" accordingly
+            emptyCellIcon = equipPosIcon.get(cellToIcon[it], 1)
         )
     }
 
@@ -107,10 +107,6 @@ class UIItemInventoryEquippedView(
         // slot image on each cells
         itemGrid.forEachIndexed { index, cell ->
             cell.render(frameDelta, batch, camera)
-            if (cell.item == null) {
-                batch.color = equipPosIconCol
-                batch.draw(equipPosIcon.get(cellToIcon[index], 1), 15f + cell.posX, 15f + cell.posY)
-            }
         }
 
 

src/net/torvald/terrarum/modulebasegame/ui/UIJukeboxInventory.kt

@@ -4,13 +4,13 @@ import com.badlogic.gdx.graphics.Color
 import com.badlogic.gdx.graphics.OrthographicCamera
 import com.badlogic.gdx.graphics.g2d.SpriteBatch
 import net.torvald.terrarum.*
-import net.torvald.terrarum.gameactors.AVKey
 import net.torvald.terrarum.langpack.Lang
 import net.torvald.terrarum.modulebasegame.gameactors.ActorInventory
 import net.torvald.terrarum.modulebasegame.gameactors.InventoryPair
 import net.torvald.terrarum.modulebasegame.gameitems.ItemFileRef
 import net.torvald.terrarum.modulebasegame.ui.UIItemInventoryCellCommonRes.defaultInventoryCellTheme
 import net.torvald.terrarum.modulebasegame.ui.UIJukebox.Companion.SLOT_SIZE
+import net.torvald.terrarum.modulebasegame.ui.UITemplateHalfInventory.Companion.INVENTORY_NAME_TEXT_GAP
 import net.torvald.terrarum.ui.*
 import net.torvald.terrarum.ui.UIItemInventoryElemWide
 import net.torvald.unicode.EMDASH
@@ -117,13 +117,8 @@ class UIJukeboxInventory(val parent: UIJukebox) : UICanvas() {
         uiItems.forEach { it.render(frameDelta, batch, camera) }
 
         // chest name text
-        val chestName = Lang["ITEM_JUKEBOX"]
-        val playerName = INGAME.actorNowPlaying!!.actorValue.getAsString(AVKey.NAME).orEmpty().let { it.ifBlank { Lang["GAME_INVENTORY"] } }
-
         batch.color = Color.WHITE
-        App.fontGame.draw(batch, chestName, thisOffsetX + (cellsWidth - App.fontGame.getWidth(chestName)) / 2, thisOffsetY - 30)
-        App.fontGame.draw(batch, playerName, thisOffsetX2 + (cellsWidth - App.fontGame.getWidth(playerName)) / 2, thisOffsetY - 30)
-
+        Toolkit.drawTextCentered(batch, App.fontGame, Lang["ITEM_JUKEBOX"], cellsWidth, thisOffsetX, thisOffsetY - INVENTORY_NAME_TEXT_GAP)
     }
 
     override fun dispose() {

src/net/torvald/terrarum/modulebasegame/ui/UISmelterBasic.kt

@@ -0,0 +1,174 @@
+package net.torvald.terrarum.modulebasegame.ui
+
+import com.badlogic.gdx.graphics.Color
+import com.badlogic.gdx.graphics.OrthographicCamera
+import com.badlogic.gdx.graphics.g2d.SpriteBatch
+import net.torvald.terrarum.*
+import net.torvald.terrarum.gameitems.GameItem
+import net.torvald.terrarum.langpack.Lang
+import net.torvald.terrarum.modulebasegame.gameactors.FixtureInventory
+import net.torvald.terrarum.modulebasegame.gameitems.FixtureItemBase
+import net.torvald.terrarum.ui.*
+import net.torvald.terrarumsansbitmap.gdx.TextureRegionPack
+import net.torvald.unicode.getKeycapPC
+
+/**
+ * Created by minjaesong on 2024-01-29.
+ */
+class UISmelterBasic() : UICanvas(
+    toggleKeyLiteral = "control_key_inventory",
+    toggleButtonLiteral = "control_gamepad_start"
+), HasInventory {
+
+    override var width = Toolkit.drawWidth
+    override var height = App.scr.height
+
+    private val playerThings = UITemplateHalfInventory(this, false).also {
+        it.itemListTouchDownFun = { gameItem, _, _, _, _ ->
+
+
+        }
+    }
+
+    private val negotiator = object : InventoryTransactionNegotiator() {
+        override fun accept(player: FixtureInventory, fixture: FixtureInventory, item: GameItem, amount: Long) {
+//            TODO()
+        }
+
+        override fun refund(fixture: FixtureInventory, player: FixtureInventory, item: GameItem, amount: Long) {
+//            TODO()
+        }
+    }
+
+    override fun getNegotiator() = negotiator
+    override fun getFixtureInventory(): FixtureInventory = TODO()
+    override fun getPlayerInventory(): FixtureInventory = INGAME.actorNowPlaying!!.inventory
+
+    init {
+        CommonResourcePool.addToLoadingList("basegame_gui_smelter_icons") {
+            TextureRegionPack(ModMgr.getGdxFile("basegame", "gui/smelter_icons.tga"), 20, 20)
+        }
+        CommonResourcePool.loadAll()
+    }
+
+    private val smelterCellIcons = CommonResourcePool.getAsTextureRegionPack("basegame_gui_smelter_icons")
+
+    private var smelterBackdrop =
+        FixtureItemBase.getItemImageFromSingleImage("basegame", "sprites/fixtures/smelter_tall.tga")
+
+    private var fuelCaloriesNow = 0f
+    private var fuelCaloriesMax: Float? = null
+
+    private var temperature = 0f // 0f..1f
+    private var progress = 0f
+
+
+    private val leftPanelWidth = playerThings.width
+    private val leftPanelHeight = playerThings.height
+    private val leftPanelX = playerThings.posX - leftPanelWidth - UIItemInventoryItemGrid.listGap - UIItemInventoryElemWide.height
+    private val leftPanelY = playerThings.posY
+
+    private val backdropColour = Color(0x7f7f7fff)
+    private val backdropZoom = 6
+    private val backdropX = (leftPanelX + (leftPanelWidth - smelterBackdrop.regionWidth * backdropZoom) / 2).toFloat()
+    private val backdropY = (leftPanelY + (leftPanelHeight - smelterBackdrop.regionHeight * backdropZoom) / 2).toFloat()
+
+    private val oreX = backdropX + 12 * backdropZoom + 3
+    private val oreY = backdropY + 23 * backdropZoom + 3
+
+    private val fireboxX = backdropX + 12 * backdropZoom + 3
+    private val fireboxY = backdropY + 39 * backdropZoom + 3
+
+    private val productX = backdropX + 37 * backdropZoom + 3
+    private val productY = backdropY + 39 * backdropZoom + 3
+
+    private val oreItemSlot = UIItemInventoryElemSimple(
+        this, oreX.toInt(), oreY.toInt(),
+        emptyCellIcon = smelterCellIcons.get(1, 1),
+        keyDownFun = { _, _, _, _, _ -> },
+        touchDownFun = { item, amount, _, _, _ -> }
+    )
+    private val fireboxItemSlot = UIItemInventoryElemSimple(
+        this, fireboxX.toInt(), fireboxY.toInt(),
+        emptyCellIcon = smelterCellIcons.get(0, 0),
+        keyDownFun = { _, _, _, _, _ -> },
+        touchDownFun = { item, amount, _, _, _ -> }
+    )
+    private val productItemslot = UIItemInventoryElemSimple(
+        this, productX.toInt(), productY.toInt(),
+        emptyCellIcon = smelterCellIcons.get(1, 0),
+        keyDownFun = { _, _, _, _, _ -> },
+        touchDownFun = { item, amount, _, _, _ -> }
+    )
+
+    private var encumbrancePerc = 0f
+
+    private fun itemListUpdate() {
+        // let itemlists be sorted
+//        itemListCraftable.rebuild(UIItemCatBar.FILTER_CAT_ALL)
+        playerThings.rebuild(UIItemCatBar.FILTER_CAT_ALL)
+        encumbrancePerc = getPlayerInventory().let {
+            it.capacity.toFloat() / it.maxCapacity
+        }
+    }
+
+    init {
+        addUIitem(playerThings)
+        addUIitem(fireboxItemSlot)
+        addUIitem(oreItemSlot)
+        addUIitem(productItemslot)
+    }
+
+    override fun show() {
+        super.show()
+        playerThings.setGetInventoryFun { INGAME.actorNowPlaying!!.inventory }
+        itemListUpdate()
+
+        UIItemInventoryItemGrid.tooltipShowing.clear()
+        INGAME.setTooltipMessage(null)
+    }
+
+    override fun updateUI(delta: Float) {
+        uiItems.forEach { it.update(delta) }
+    }
+
+    private val controlHelp: String
+        get() = if (App.environment == RunningEnvironment.PC)
+            "${getKeycapPC(ControlPresets.getKey("control_key_inventory"))} ${Lang["GAME_ACTION_CLOSE"]}"
+        else
+            "${App.gamepadLabelStart} ${Lang["GAME_ACTION_CLOSE"]}"
+
+    override fun renderUI(frameDelta: Float, batch: SpriteBatch, camera: OrthographicCamera) {
+        batch.color = backdropColour
+        batch.draw(smelterBackdrop, backdropX, backdropY, smelterBackdrop.regionWidth * 6f, smelterBackdrop.regionHeight * 6f)
+
+        uiItems.forEach { it.render(frameDelta, batch, camera) }
+
+
+
+
+        // control hints
+        batch.color = Color.WHITE
+        val controlHintXPos = leftPanelX + 2f
+        blendNormalStraightAlpha(batch)
+        App.fontGame.draw(batch, controlHelp, controlHintXPos, UIInventoryFull.yEnd - 20)
+
+
+        if (INGAME.actorNowPlaying != null) {
+            //draw player encumb
+            val encumbBarXPos = playerThings.posX + playerThings.width - UIInventoryCells.weightBarWidth + 36
+            val encumbBarYPos = UIInventoryFull.yEnd - 20 + 3f
+            UIInventoryCells.drawEncumbranceBar(batch, encumbBarXPos, encumbBarYPos, encumbrancePerc, INGAME.actorNowPlaying!!.inventory)
+        }
+
+
+        blendNormalStraightAlpha(batch)
+    }
+
+    override fun dispose() {
+    }
+
+
+
+
+}

src/net/torvald/terrarum/modulebasegame/ui/UIStorageChest.kt

@@ -95,7 +95,7 @@ internal class UIStorageChest : UICanvas(
         catBar.selectionChangeListener = { old, new -> itemListUpdate() }
 
 
-        itemListChest = UITemplateHalfInventory(this, true) { getFixtureInventory() }.also {
+        itemListChest = UITemplateHalfInventory(this, true, { getFixtureInventory() }, { chestNameFun() }).also {
             it.itemListKeyDownFun = { _, _, _, _, _ -> Unit }
             it.itemListTouchDownFun = { gameItem, amount, button, _, _ ->
                 if (button == App.getConfigInt("config_mouseprimary")) {
@@ -210,19 +210,12 @@ internal class UIStorageChest : UICanvas(
         blendNormalStraightAlpha(batch)
 
         // encumbrance meter
-        val chestName = chestNameFun()
-        val playerName = INGAME.actorNowPlaying!!.actorValue.getAsString(AVKey.NAME).orEmpty().let { it.ifBlank { Lang["GAME_INVENTORY"] } }
         val encumbBarXPos = itemListPlayer.posX + itemListPlayer.width - UIInventoryCells.weightBarWidth + 36
         val yEnd = -UIInventoryFull.YPOS_CORRECTION + (App.scr.height + UIInventoryFull.internalHeight).div(2).toFloat() // directly copied from UIInventoryFull.yEnd
         val encumbBarYPos = yEnd - 20 + 3 // dunno why but extra 3 px is needed
 
         UIInventoryCells.drawEncumbranceBar(batch, encumbBarXPos, encumbBarYPos, encumbrancePerc, getPlayerInventory())
 
-        // chest name text
-        batch.color = Color.WHITE
-        App.fontGame.draw(batch, chestName, thisOffsetX + (cellsWidth - App.fontGame.getWidth(chestName)) / 2, thisOffsetY - 30)
-        App.fontGame.draw(batch, playerName, thisOffsetX2 + (cellsWidth - App.fontGame.getWidth(playerName)) / 2, thisOffsetY - 30)
-
         // control hint
         App.fontGame.draw(batch, controlHelp, thisOffsetX - 34f, encumbBarYPos - 3)
 

src/net/torvald/terrarum/modulebasegame/ui/UITemplateHalfInventory.kt

@@ -1,10 +1,13 @@
 package net.torvald.terrarum.modulebasegame.ui
 
+import com.badlogic.gdx.graphics.Color
 import com.badlogic.gdx.graphics.OrthographicCamera
 import com.badlogic.gdx.graphics.g2d.SpriteBatch
 import net.torvald.terrarum.*
+import net.torvald.terrarum.gameactors.AVKey
 import net.torvald.terrarum.gameitems.GameItem
 import net.torvald.terrarum.gameitems.ItemID
+import net.torvald.terrarum.langpack.Lang
 import net.torvald.terrarum.modulebasegame.gameactors.ActorInventory
 import net.torvald.terrarum.modulebasegame.gameactors.FixtureInventory
 import net.torvald.terrarum.modulebasegame.gameactors.InventoryPair
@@ -22,9 +25,14 @@ import net.torvald.terrarum.ui.*
 class UITemplateHalfInventory(
     parent: UICanvas,
     drawOnLeft: Boolean,
-    getInventoryFun: () -> FixtureInventory = { INGAME.actorNowPlaying!!.inventory }
+    getInventoryFun: () -> FixtureInventory = { INGAME.actorNowPlaying!!.inventory },
+    val inventoryNameFun: () -> String = { INGAME.actorNowPlaying!!.actorValue.getAsString(AVKey.NAME).orEmpty().let { it.ifBlank { Lang["GAME_INVENTORY"] } } }
 ) : UITemplate(parent) {
 
+    companion object {
+        const val INVENTORY_NAME_TEXT_GAP = 28
+    }
+
     val itemList: UIItemInventoryItemGrid
 
     private val halfSlotOffset = (UIItemInventoryElemSimple.height + UIItemInventoryItemGrid.listGap) / 2
@@ -78,8 +86,13 @@ class UITemplateHalfInventory(
         itemList.getInventory = getter
     }
 
-    inline fun update(delta: Float) = itemList.update(delta)
-    inline fun render(frameDelta: Float, batch: SpriteBatch, camera: OrthographicCamera) = itemList.render(frameDelta, batch, camera)
+    override fun update(delta: Float) = itemList.update(delta)
+    override fun render(frameDelta: Float, batch: SpriteBatch, camera: OrthographicCamera) {
+        itemList.render(frameDelta, batch, camera)
+
+        batch.color = Color.WHITE
+        Toolkit.drawTextCentered(batch, App.fontGame, inventoryNameFun(), width, posX, thisOffsetY - INVENTORY_NAME_TEXT_GAP)
+    }
 
     var posX: Int
         get() = itemList.posX
@@ -95,4 +108,7 @@ class UITemplateHalfInventory(
     override fun getUIitems(): List<UIItem> {
         return listOf(itemList)
     }
+
+    override fun dispose() {
+    }
 }

src/net/torvald/terrarum/ui/UICanvas.kt

@@ -97,7 +97,7 @@ abstract class UICanvas(
     open var openCloseTime: Second = OPENCLOSE_GENERIC
 
 
-    protected val uiItems = ArrayList<UIItem>()
+    protected val uiItems = ArrayList<UIItemisable>()
 
 
     val relativeMouseX: Int
@@ -189,12 +189,9 @@ abstract class UICanvas(
 
     abstract override fun dispose()
 
-    fun addUIitem(uiItem: UIItem) {
+    fun addUIitem(uiItem: UIItemisable) {
         if (!uiItems.contains(uiItem)) uiItems.add(uiItem)
     }
-    fun addUIitem(template: UITemplate) {
-        template.getUIitems().forEach { addUIitem(it) }
-    }
 
     fun mouseInScreen(x: Int, y: Int) = x in 0 until App.scr.windowW && y in 0 until App.scr.windowH
 

src/net/torvald/terrarum/ui/UIItem.kt

@@ -52,7 +52,7 @@ import net.torvald.terrarum.gamecontroller.TerrarumKeyboardEvent
  *
  * Created by minjaesong on 2015-12-31.
  */
-abstract class UIItem(var parentUI: UICanvas, val initialX: Int, val initialY: Int): Disposable { // do not replace parentUI to UIHandler!
+abstract class UIItem(var parentUI: UICanvas, val initialX: Int, val initialY: Int): UIItemisable() { // do not replace parentUI to UIHandler!
 
     // X/Y Position relative to the containing canvas
     var posX: Int = initialX
@@ -145,11 +145,7 @@ abstract class UIItem(var parentUI: UICanvas, val initialX: Int, val initialY: I
     open var isActive = true
 
 
-    open fun show() {}
-    open fun hide() {}
-
-
-    open fun update(delta: Float) {
+    override fun update(delta: Float) {
         if (parentUI.isVisible) {
             if (isActive) {
                 updateListener.invoke(delta)
@@ -177,7 +173,7 @@ abstract class UIItem(var parentUI: UICanvas, val initialX: Int, val initialY: I
     /**
      * In this time, you do write like: ```draw(posX + 4, posY + 32)```, unlike UICanvas, because posX/posY comes from the parent UI.
      */
-    open fun render(frameDelta: Float, batch: SpriteBatch, camera: OrthographicCamera) {
+    override fun render(frameDelta: Float, batch: SpriteBatch, camera: OrthographicCamera) {
         if (parentUI.isVisible) {
 //            if (isActive) {
                 mouseOverCall?.render(frameDelta, batch, camera)
@@ -190,7 +186,7 @@ abstract class UIItem(var parentUI: UICanvas, val initialX: Int, val initialY: I
     }
 
     // keyboard controlled
-    open fun keyDown(keycode: Int): Boolean {
+    override fun keyDown(keycode: Int): Boolean {
         if (parentUI.isVisible && isEnabled) {
             keyDownListener.invoke(keycode)
             return true
@@ -198,7 +194,7 @@ abstract class UIItem(var parentUI: UICanvas, val initialX: Int, val initialY: I
 
         return false
     }
-    open fun keyUp(keycode: Int): Boolean {
+    override fun keyUp(keycode: Int): Boolean {
         if (parentUI.isVisible && isEnabled) {
             keyUpListener.invoke(keycode)
             return true
@@ -206,7 +202,7 @@ abstract class UIItem(var parentUI: UICanvas, val initialX: Int, val initialY: I
 
         return false
     }
-    open fun keyTyped(character: Char): Boolean  {
+    override fun keyTyped(character: Char): Boolean  {
         if (parentUI.isVisible && isEnabled) {
             keyTypedListener.invoke(character)
             return true
@@ -216,7 +212,7 @@ abstract class UIItem(var parentUI: UICanvas, val initialX: Int, val initialY: I
     }
 
     // mouse controlled
-    open fun touchDragged(screenX: Int, screenY: Int, pointer: Int): Boolean {
+    override fun touchDragged(screenX: Int, screenY: Int, pointer: Int): Boolean {
         if (parentUI.isVisible && isEnabled) {
             touchDraggedListener.invoke(itemRelativeMouseX, itemRelativeMouseY, pointer)
             return true
@@ -224,7 +220,7 @@ abstract class UIItem(var parentUI: UICanvas, val initialX: Int, val initialY: I
 
         return false
     }
-    open fun touchDown(screenX: Int, screenY: Int, pointer: Int, button: Int): Boolean {
+    override fun touchDown(screenX: Int, screenY: Int, pointer: Int, button: Int): Boolean {
         var actionDone = false
 
         if (parentUI.isVisible && isEnabled) {
@@ -241,7 +237,7 @@ abstract class UIItem(var parentUI: UICanvas, val initialX: Int, val initialY: I
 
         return actionDone
     }
-    open fun touchUp(screenX: Int, screenY: Int, pointer: Int, button: Int): Boolean {
+    override fun touchUp(screenX: Int, screenY: Int, pointer: Int, button: Int): Boolean {
         clickOnceListenerFired = false
 
         if (parentUI.isVisible && mouseUp) {
@@ -251,7 +247,7 @@ abstract class UIItem(var parentUI: UICanvas, val initialX: Int, val initialY: I
 
         return false
     }
-    open fun scrolled(amountX: Float, amountY: Float): Boolean {
+    override fun scrolled(amountX: Float, amountY: Float): Boolean {
         if (parentUI.isVisible && mouseUp && isEnabled) {
             scrolledListener.invoke(amountX, amountY)
             return true
@@ -259,9 +255,7 @@ abstract class UIItem(var parentUI: UICanvas, val initialX: Int, val initialY: I
 
         return false
     }
-    open fun inputStrobed(e: TerrarumKeyboardEvent) {
 
-    }
 
     abstract override fun dispose()
 

src/net/torvald/terrarum/ui/UIItemInventoryElemSimple.kt

@@ -35,6 +35,8 @@ class UIItemInventoryElemSimple(
     highlightEquippedItem: Boolean = true, // for some UIs that only cares about getting equipped slot number but not highlighting
     colourTheme: InventoryCellColourTheme = defaultInventoryCellTheme,
     var showItemCount: Boolean = true,
+    var emptyCellIcon: TextureRegion? = null, // icon to draw when the cell is empty
+    var emptyCellIconColour: Color = Color(0xdddddd7f.toInt()),
 ) : UIItemInventoryCellBase(parentUI, initialX, initialY, item, amount, itemImage, quickslot, equippedSlot, keyDownFun, touchDownFun, extraInfo, highlightEquippedItem, colourTheme) {
     
     companion object {
@@ -52,6 +54,9 @@ class UIItemInventoryElemSimple(
     private val imgOffsetX: Float
         get() = (this.height - itemImageOrDefault.regionWidth).div(2).toFloat() // to snap to the pixel grid
 
+    private val emptyCellIconOffsetX = (this.height - (emptyCellIcon?.regionWidth ?: 0)).div(2).toFloat()
+    private val emptyCellIconOffsetY = (this.height - (emptyCellIcon?.regionHeight ?: 0)).div(2).toFloat()
+
     override fun update(delta: Float) {
 
     }
@@ -123,6 +128,15 @@ class UIItemInventoryElemSimple(
                 )
             }
 
+        }
+        else {
+
+            // empty cell image
+            emptyCellIcon?.let {
+                batch.color = emptyCellIconColour
+                batch.draw(it, posX + emptyCellIconOffsetX, posY + emptyCellIconOffsetY)
+            }
+
         }
 
         // see IFs above?

src/net/torvald/terrarum/ui/UITemplate.kt

@@ -1,10 +1,44 @@
 package net.torvald.terrarum.ui
 
+import com.badlogic.gdx.graphics.OrthographicCamera
+import com.badlogic.gdx.graphics.g2d.SpriteBatch
+import com.badlogic.gdx.utils.Disposable
+import net.torvald.terrarum.gamecontroller.TerrarumKeyboardEvent
+
 /**
  * Created by minjaesong on 2024-01-10.
  */
-abstract class UITemplate(val parent: UICanvas) {
+abstract class UITemplate(val parent: UICanvas) : UIItemisable() {
 
     abstract fun getUIitems(): List<UIItem>
 
+    override fun show() { getUIitems().forEach { it.show() } }
+    override fun hide() { getUIitems().forEach { it.hide() } }
+    override fun inputStrobed(e: TerrarumKeyboardEvent) { getUIitems().forEach { it.inputStrobed(e) } }
+    override fun touchDragged(screenX: Int, screenY: Int, pointer: Int): Boolean { getUIitems().forEach { it.touchDragged(screenX, screenY, pointer) }; return true }
+    override fun touchDown(screenX: Int, screenY: Int, pointer: Int, button: Int): Boolean { getUIitems().forEach { it.touchDown(screenX, screenY, pointer, button) }; return true }
+    override fun touchUp(screenX: Int, screenY: Int, pointer: Int, button: Int): Boolean { getUIitems().forEach { it.touchUp(screenX, screenY, pointer, button) }; return true }
+    override fun scrolled(amountX: Float, amountY: Float): Boolean { getUIitems().forEach { it.scrolled(amountX, amountY) }; return true }
+    override fun keyDown(keycode: Int): Boolean { getUIitems().forEach { it.keyDown(keycode) }; return true }
+    override fun keyUp(keycode: Int): Boolean { getUIitems().forEach { it.keyUp(keycode) }; return true }
+    override fun keyTyped(char: Char): Boolean { getUIitems().forEach { it.keyTyped(char) }; return true }
+
+}
+
+/**
+ * Created by minjaesong on 2024-01-29.
+ */
+abstract class UIItemisable : Disposable {
+    abstract fun update(delta: Float)
+    abstract fun render(frameDelta: Float, batch: SpriteBatch, camera: OrthographicCamera)
+    open fun show() {}
+    open fun hide() {}
+    open fun inputStrobed(e: TerrarumKeyboardEvent) {}
+    open fun touchDragged(screenX: Int, screenY: Int, pointer: Int): Boolean = false
+    open fun touchDown(screenX: Int, screenY: Int, pointer: Int, button: Int): Boolean = false
+    open fun touchUp(screenX: Int, screenY: Int, pointer: Int, button: Int): Boolean = false
+    open fun scrolled(amountX: Float, amountY: Float): Boolean = false
+    open fun keyDown(keycode: Int): Boolean = false
+    open fun keyUp(keycode: Int): Boolean = false
+    open fun keyTyped(char: Char): Boolean = false
 }

src/net/torvald/terrarum/ui/UITemplateCatBar.kt

@@ -1,5 +1,7 @@
 package net.torvald.terrarum.ui
 
+import com.badlogic.gdx.graphics.OrthographicCamera
+import com.badlogic.gdx.graphics.g2d.SpriteBatch
 import net.torvald.terrarum.App
 import net.torvald.terrarum.CommonResourcePool
 import net.torvald.terrarum.modulebasegame.ui.UIInventoryFull
@@ -34,4 +36,8 @@ class UITemplateCatBar(
     override fun getUIitems(): List<UIItem> {
         return listOf(catBar)
     }
+
+    override fun update(delta: Float) = catBar.update(delta)
+    override fun render(frameDelta: Float, batch: SpriteBatch, camera: OrthographicCamera) = catBar.render(frameDelta, batch, camera)
+    override fun dispose() = catBar.dispose()
 }