wip: ui system

* added UIsModule entrypoint
* removed UiClickEvent.kt in favor of kotlin functions
* added BukkitExtensions.kt

simplecoreapi/src/main/kotlin/xyz/theprogramsrc/simplecoreapi/spigot/extensions/BukkitExtensions.kt

@@ -0,0 +1,24 @@
+package xyz.theprogramsrc.simplecoreapi.spigot.extensions
+
+import org.bukkit.Bukkit
+import org.bukkit.event.Event
+import org.bukkit.event.Listener
+import org.bukkit.plugin.Plugin
+import org.bukkit.plugin.PluginManager
+
+/**
+ * Registers an event listener
+ * @param listener the listener to register
+ * @param plugin the plugin to register the listener for
+ * @see PluginManager.registerEvents
+ */
+fun registerEvent(listener: Listener, plugin: Plugin) =
+    Bukkit.getPluginManager().registerEvents(listener, plugin)
+
+/**
+ * Calls an event
+ * @param event the event to call
+ * @see PluginManager.callEvent
+ */
+fun callEvent(event: Event) =
+    Bukkit.getPluginManager().callEvent(event)

simplecoreapi/src/main/kotlin/xyz/theprogramsrc/simplecoreapi/spigot/modules/uismodule/UIsModule.kt

@@ -0,0 +1,17 @@
+package xyz.theprogramsrc.simplecoreapi.spigot.modules.uismodule
+
+import xyz.theprogramsrc.simplecoreapi.global.module.Module
+import xyz.theprogramsrc.simplecoreapi.global.module.ModuleDescription
+
+class UIsModule : Module {
+
+    override val description: ModuleDescription = ModuleDescription(
+        name = "UIsModule",
+        version = "1.0.0",
+        authors = listOf("Im-Fran")
+    )
+
+    override fun onEnable() {}
+
+    override fun onDisable() {}
+}

simplecoreapi/src/main/kotlin/xyz/theprogramsrc/simplecoreapi/spigot/modules/uismodule/models/UiEntry.kt

@@ -0,0 +1,26 @@
+package xyz.theprogramsrc.simplecoreapi.spigot.modules.uismodule.models
+
+import org.bukkit.entity.Player
+import org.bukkit.inventory.ItemStack
+import xyz.theprogramsrc.simplecoreapi.spigot.modules.uismodule.ui.Ui
+
+/**
+ * Representation of an Ui Entry, which is an item in an Ui.
+ * @param slot the slot of where the item should be placed
+ * @param item the item that should be displayed in the slot (as a function, so it can be dynamic)
+ * @param action the action that should be executed when a player clicks on the item. The action should return true if the UI should be closed after the action is executed, false otherwise.
+ * @param dynamic if true, this item will be updated at least every tick (20 times per second)
+ */
+data class UiEntry(
+    val slot: Int,
+    val item: () -> ItemStack,
+    val action: (Ui, Player) -> Unit = { _, _ -> },
+    val dynamic: Boolean = false
+) {
+
+    /**
+     * The cached item, which is the item that will be displayed in the UI.
+     * This is used to avoid calling the [item] function every time the UI is updated (unless it's dynamic).
+     */
+    val cachedItem = item.invoke()
+}

simplecoreapi/src/main/kotlin/xyz/theprogramsrc/simplecoreapi/spigot/modules/uismodule/ui/Ui.kt

@@ -2,9 +2,15 @@ package xyz.theprogramsrc.simplecoreapi.spigot.modules.uismodule.ui
 
 import org.bukkit.Bukkit
 import org.bukkit.entity.Player
+import org.bukkit.event.EventHandler
+import org.bukkit.event.HandlerList
+import org.bukkit.event.Listener
+import org.bukkit.event.inventory.InventoryClickEvent
 import org.bukkit.inventory.Inventory
-import org.bukkit.inventory.ItemStack
-import xyz.theprogramsrc.simplecoreapi.spigot.modules.uismodule.ui.events.UiClickEvent
+import xyz.theprogramsrc.simplecoreapi.spigot.SpigotLoader
+import xyz.theprogramsrc.simplecoreapi.spigot.extensions.bukkitColor
+import xyz.theprogramsrc.simplecoreapi.spigot.extensions.registerEvent
+import xyz.theprogramsrc.simplecoreapi.spigot.modules.uismodule.models.UiEntry
 
 /**
  * Representation of a "raw" UI, meaning there are no
@@ -13,14 +19,75 @@ import xyz.theprogramsrc.simplecoreapi.spigot.modules.uismodule.ui.events.UiClic
  * @param player the player that should see the UI
  * @param title the title of the UI
  * @param rows the amount of rows the UI should have
- * @param items the items that should be displayed in the UI
- * @param actions the actions that should be executed when a player clicks on an item
+ * @param entries a list of [UiEntry] that will contain the items of the UI
+ * @param shouldCloseInventory whether the UI should be able to be closed by the player or not (usually when pressing the ESC or inventory key)
  */
 class Ui(
     val player: Player,
     val title: String,
     val rows: Int = 1,
-    val items: Map<Int, ItemStack> = emptyMap(),
-    val actions: Map<Int, (UiClickEvent) -> Boolean> = emptyMap(),
-) {
+    val entries: List<UiEntry>,
+    val shouldCloseInventory: Boolean = true
+): Listener {
+
+    private val mappedEntries = entries.associateBy { it.slot }
+    val inventory: Inventory
+
+    init {
+        check(rows in 1..6) { "Invalid amount of rows: $rows. Must be between 1 and 6" }
+        check(title.bukkitColor().isNotBlank()) { "Invalid title: $title" }
+        check(entries.isNotEmpty()) { "Entries cannot be empty" }
+        inventory = Bukkit.createInventory(null, rows * 9, title.bukkitColor())
+    }
+
+    /**
+     * Opens the UI to the player
+     */
+    fun open() {
+        if(!inventory.isEmpty) {
+            HandlerList.unregisterAll(this)
+        }
+        inventory.clear()
+        mappedEntries.forEach { (slot, entry) ->
+            check(slot in 0 until inventory.size) { "Invalid slot: $slot. Must be between 0 and ${inventory.size}" }
+            inventory.setItem(slot, entry.cachedItem)
+        }
+        registerEvent(this, SpigotLoader.instance)
+        player.openInventory(inventory)
+    }
+
+    /**
+     * Closes the UI to the player
+     */
+    fun close() {
+        HandlerList.unregisterAll(this)
+        player.closeInventory()
+    }
+
+    @EventHandler
+    fun onClick(e: InventoryClickEvent) {
+        if(e.whoClicked.uniqueId != player.uniqueId && e.clickedInventory != inventory) {
+            return
+        }
+
+        val slot = e.slot
+
+        if(mappedEntries[slot]?.cachedItem?.isSimilar(e.currentItem) != true) {
+            return
+        }
+
+        e.isCancelled = true
+        mappedEntries[slot]?.action?.invoke(this, player)
+    }
+
+    @EventHandler
+    fun onClose(e: InventoryClickEvent) {
+        if (e.whoClicked.uniqueId != player.uniqueId && e.clickedInventory != inventory) {
+            return
+        }
+
+        if (!shouldCloseInventory) {
+            open()
+        }
+    }
 }