Add inventory scheming (#18)

Author: Robotv2

src/main/java/fr/mrmicky/fastinv/InventoryScheme.java

@@ -0,0 +1,107 @@
+package fr.mrmicky.fastinv;
+
+import org.bukkit.event.inventory.InventoryClickEvent;
+import org.bukkit.inventory.ItemStack;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.function.Consumer;
+
+public class InventoryScheme {
+
+    private final List<String> masks = new ArrayList<>();
+    private final Map<Character, ItemStack> items = new HashMap<>();
+    private final Map<Character, Consumer<InventoryClickEvent>> handlers = new HashMap<>();
+
+    /**
+     * Add a mask to this scheme including all sort of characters.
+     * For example: "110101011"
+     *
+     * @param mask a 9 characters mask
+     * @return this scheme instance
+     */
+    public InventoryScheme mask(String mask) {
+        Objects.requireNonNull(mask);
+        this.masks.add(mask.length() > 9 ? mask.substring(0, 10) : mask);
+
+        return this;
+    }
+
+    /**
+     * Add multiples masks to this scheme including all sort of characters.
+     * For example: "111111111", "110101011", "111111111"
+     *
+     * @param masks multiple 9-characters masks
+     * @return this scheme instance
+     */
+    public InventoryScheme masks(String... masks) {
+        for (String mask : Objects.requireNonNull(masks)) {
+            mask(mask);
+        }
+        return this;
+    }
+
+    /**
+     * Bind character to the corresponding item in the inventory.
+     *
+     * @param character the associated character in the mask
+     * @param item      the item to use for this character
+     * @param handler   consumer for the item
+     * @return this scheme instance
+     */
+    public InventoryScheme bindItem(char character, ItemStack item, Consumer<InventoryClickEvent> handler) {
+        this.items.put(character, Objects.requireNonNull(item));
+
+        if (handler != null) {
+            this.handlers.put(character, handler);
+        }
+        return this;
+    }
+
+    /**
+     * Bind character to the corresponding item in the inventory.
+     *
+     * @param character the associated character in the mask
+     * @param item      the item to use for this character
+     * @return this scheme instance
+     */
+    public InventoryScheme bindItem(char character, ItemStack item) {
+        return this.bindItem(character, item, null);
+    }
+
+    /**
+     * Unbind any item from this character.
+     *
+     * @param character the character to unbind
+     * @return this scheme instance
+     */
+    public InventoryScheme unbindItem(char character) {
+        this.items.remove(character);
+        this.handlers.remove(character);
+        return this;
+    }
+
+    /**
+     * Apply the current inventory scheme to the FastInv instance.
+     *
+     * @param inv the FastInv instance to apply this scheme to
+     */
+    public void apply(FastInv inv) {
+        for (int line = 0; line < this.masks.size(); line++) {
+            String mask = this.masks.get(line);
+
+            for (int slot = 0; slot < mask.length(); slot++) {
+                char c = mask.charAt(slot);
+                ItemStack item = this.items.get(c);
+                Consumer<InventoryClickEvent> handler = this.handlers.get(c);
+
+                if (item != null) {
+                    inv.setItem(9 * line + slot, item, handler);
+                }
+            }
+        }
+    }
+}