Add slot binding

src/main/kotlin/util/mc/ScreenUtil.kt

@@ -0,0 +1,26 @@
+package moe.nea.firmament.util.mc
+
+import net.minecraft.client.gui.screen.Screen
+import net.minecraft.client.gui.screen.ingame.HandledScreen
+import net.minecraft.entity.player.PlayerInventory
+import net.minecraft.screen.slot.Slot
+
+object ScreenUtil {
+	private var lastScreen: Screen? = null
+	private var slotsByIndex: Map<SlotIndex, Slot> = mapOf()
+
+	data class SlotIndex(val index: Int, val isPlayerInventory: Boolean)
+
+	fun Screen.getSlotsByIndex(): Map<SlotIndex, Slot> {
+		if (this !is HandledScreen<*>) return mapOf()
+		if (lastScreen === this) return slotsByIndex
+		lastScreen = this
+		slotsByIndex = this.screenHandler.slots.associate {
+			SlotIndex(it.index, it.inventory is PlayerInventory) to it
+		}
+		return slotsByIndex
+	}
+
+	fun Screen.getSlotByIndex( index: Int, isPlayerInventory: Boolean): Slot? =
+		getSlotsByIndex()[SlotIndex(index, isPlayerInventory)]
+}

src/main/kotlin/util/mc/SlotUtils.kt

@@ -0,0 +1,35 @@
+package moe.nea.firmament.util.mc
+
+import net.minecraft.screen.ScreenHandler
+import net.minecraft.screen.slot.Slot
+import net.minecraft.screen.slot.SlotActionType
+import moe.nea.firmament.util.MC
+
+object SlotUtils {
+	fun Slot.clickMiddleMouseButton(handler: ScreenHandler) {
+		MC.interactionManager?.clickSlot(
+			handler.syncId,
+			this.id,
+			2,
+			SlotActionType.CLONE,
+			MC.player
+		)
+	}
+
+	fun Slot.swapWithHotBar(handler: ScreenHandler, hotbarIndex: Int) {
+		MC.interactionManager?.clickSlot(
+			handler.syncId, this.id,
+			hotbarIndex, SlotActionType.SWAP,
+			MC.player)
+	}
+
+	fun Slot.clickRightMouseButton(handler: ScreenHandler) {
+		MC.interactionManager?.clickSlot(
+			handler.syncId,
+			this.id,
+			1,
+			SlotActionType.PICKUP,
+			MC.player
+		)
+	}
+}