diff --git a/src/main/java/de/studiocode/invui/gui/impl/BaseGUI.java b/src/main/java/de/studiocode/invui/gui/impl/BaseGUI.java
index e3703bb..869b458 100644
--- a/src/main/java/de/studiocode/invui/gui/impl/BaseGUI.java
+++ b/src/main/java/de/studiocode/invui/gui/impl/BaseGUI.java
@@ -97,7 +97,7 @@ public abstract class BaseGUI implements GUI {
case DROP_ONE_SLOT:
case PICKUP_ONE:
- cancel = virtualInventory.changeItemAmount(updateReason, slot, -1) != -1;
+ cancel = virtualInventory.setItemAmount(updateReason, slot, -1) != -1;
break;
case DROP_ALL_SLOT:
@@ -109,7 +109,7 @@ public abstract class BaseGUI implements GUI {
case PICKUP_HALF:
int amount = virtualInventory.getAmount(slot);
int halfAmount = amount / 2;
- int newAmount = virtualInventory.changeItemAmount(updateReason, slot, halfAmount);
+ int newAmount = virtualInventory.setItemAmount(updateReason, slot, halfAmount);
// amount did not change as predicted
if (newAmount != halfAmount) {
diff --git a/src/main/java/de/studiocode/invui/virtualinventory/VirtualInventory.java b/src/main/java/de/studiocode/invui/virtualinventory/VirtualInventory.java
index 4eb66ef..ef633b1 100644
--- a/src/main/java/de/studiocode/invui/virtualinventory/VirtualInventory.java
+++ b/src/main/java/de/studiocode/invui/virtualinventory/VirtualInventory.java
@@ -15,6 +15,7 @@ import org.jetbrains.annotations.Nullable;
import java.util.*;
import java.util.function.Consumer;
+import java.util.stream.Stream;
import static java.lang.Math.min;
@@ -204,6 +205,16 @@ public class VirtualInventory implements ConfigurationSerializable {
return items[slot];
}
+ /**
+ * Checks if there is an {@link ItemStack} on that slot.
+ *
+ * @param slot The Slot
+ * @return If there is an {@link ItemStack} on that slot.
+ */
+ public boolean hasItem(int slot) {
+ return items[slot] != null;
+ }
+
/**
* Gets the amount of items on a slot.
*
@@ -368,21 +379,22 @@ public class VirtualInventory implements ConfigurationSerializable {
}
/**
- * Changes the amount of an {@link ItemStack} on a slot to the given value.
+ * Sets the amount of an {@link ItemStack} on a slot to the given value
+ * while respecting the max allowed stack size on that slot.
*
* @param updateReason The reason used in the {@link ItemUpdateEvent}.
* @param slot The slot
* @param amount The amount to change to.
* @return The amount that it actually changed to.
- * @throws IllegalStateException If there is no ItemStack on that slot.
+ * @throws IllegalStateException If there is no {@link ItemStack} on that slot.
*/
- public int changeItemAmount(@Nullable UpdateReason updateReason, int slot, int amount) {
+ public int setItemAmount(@Nullable UpdateReason updateReason, int slot, int amount) {
ItemStack currentStack = items[slot];
- if (currentStack == null) throw new IllegalStateException("There is currently no ItemStack on that slot");
+ if (currentStack == null) throw new IllegalStateException("There is no ItemStack on that slot");
int maxStackSize = getMaxStackSize(slot, -1);
ItemStack newItemStack;
- if (amount != 0) {
+ if (amount > 0) {
newItemStack = currentStack.clone();
newItemStack.setAmount(min(amount, maxStackSize));
} else {
@@ -401,6 +413,24 @@ public class VirtualInventory implements ConfigurationSerializable {
return amount;
}
+ /**
+ * Adds a specific amount to an {@link ItemStack} on a slot while respecting
+ * the maximum allowed stack size on that slot. Returns 0 if there is no
+ * {@link ItemStack} on that slot.
+ *
+ * @param updateReason The reason used in the {@link ItemUpdateEvent}.
+ * @param slot The slot
+ * @param amount The amount to add
+ * @return The amount that was actually added.
+ */
+ public int addItemAmount(@Nullable UpdateReason updateReason, int slot, int amount) {
+ ItemStack currentStack = items[slot];
+ if (currentStack == null) return 0;
+
+ int currentAmount = currentStack.getAmount();
+ return setItemAmount(updateReason, slot, currentAmount + amount) - currentAmount;
+ }
+
/**
* Adds an {@link ItemStack} to the {@link VirtualInventory}.
* This method does not work the same way as Bukkit's addItem method
@@ -409,8 +439,7 @@ public class VirtualInventory implements ConfigurationSerializable {
* @param updateReason The reason used in the {@link ItemUpdateEvent}.
* @param itemStack The {@link ItemStack} to add
* @return The amount of items that didn't fit
- * @see #simulateAdd(ItemStack)
- * @see #simulateMultiAdd(List)
+ * @see #simulateAdd(ItemStack, ItemStack...)
*/
public int addItem(@Nullable UpdateReason updateReason, ItemStack itemStack) {
final int originalAmount = itemStack.getAmount();
@@ -440,6 +469,37 @@ public class VirtualInventory implements ConfigurationSerializable {
return amountLeft;
}
+ /**
+ * Simulates adding {@link ItemStack}s to this {@link VirtualInventory}
+ * and returns the amount of {@link ItemStack}s that did not fit.
+ *
+ * @return An array of integers representing the leftover amount for each {@link ItemStack} provided.
+ * The size of this array is always equal to the amount of {@link ItemStack}s provided as method parameters.
+ */
+ public int[] simulateAdd(@NotNull ItemStack itemStack, @NotNull ItemStack... itemStacks) {
+ if (itemStacks.length == 0) {
+ return new int[] {simulateSingleAdd(itemStack)};
+ } else {
+ ItemStack[] allStacks = Stream.concat(Stream.of(itemStack), Arrays.stream(itemStacks)).toArray(ItemStack[]::new);
+ return simulateMultiAdd(allStacks);
+ }
+ }
+
+ /**
+ * Simulates adding {@link ItemStack}s to this {@link VirtualInventory}
+ * and then returns if all {@link ItemStack}s would fit.
+ *
+ * @return If all provided {@link ItemStack}s would fit if added.
+ */
+ public boolean canHold(@NotNull ItemStack itemStack, @NotNull ItemStack... itemStacks) {
+ if (itemStacks.length == 0) {
+ return simulateSingleAdd(itemStack) == 0;
+ } else {
+ ItemStack[] allStacks = Stream.concat(Stream.of(itemStack), Arrays.stream(itemStacks)).toArray(ItemStack[]::new);
+ return Arrays.stream(simulateMultiAdd(allStacks)).allMatch(i -> i == 0);
+ }
+ }
+
/**
* Returns the amount of items that wouldn't fit in the inventory when added.
*
@@ -448,7 +508,7 @@ public class VirtualInventory implements ConfigurationSerializable {
* @param itemStack The {@link ItemStack} to use
* @return How many items wouldn't fit in the inventory when added
*/
- public int simulateAdd(ItemStack itemStack) {
+ private int simulateSingleAdd(ItemStack itemStack) {
int amountLeft = itemStack.getAmount();
// find all slots where the item partially fits
@@ -471,21 +531,16 @@ public class VirtualInventory implements ConfigurationSerializable {
/**
* Simulates adding multiple {@link ItemStack}s to this {@link VirtualInventory}
* and returns the amount of {@link ItemStack}s that did not fit.
- * This method should only be used for simulating the addition of multiple {@link ItemStack}s.
- * For a single {@link ItemStack} use {@link #simulateAdd(ItemStack)}
- * Note: This method does not add any {@link ItemStack}s to the {@link VirtualInventory}.
*
* @param itemStacks The {@link ItemStack} to be used in the simulation
* @return An array of integers representing the leftover amount for each {@link ItemStack} provided.
* The size of this array is always equal to the amount of {@link ItemStack}s provided as method parameters.
*/
- public int[] simulateMultiAdd(List itemStacks) {
- if (itemStacks.size() < 2) throw new IllegalArgumentException("Illegal amount of ItemStacks in List");
-
+ private int[] simulateMultiAdd(ItemStack... itemStacks) {
VirtualInventory copiedInv = new VirtualInventory(null, size, getItems(), stackSizes.clone());
- int[] result = new int[itemStacks.size()];
- for (int index = 0; index != itemStacks.size(); index++) {
- result[index] = copiedInv.addItem(null, itemStacks.get(index));
+ int[] result = new int[itemStacks.length];
+ for (int index = 0; index != itemStacks.length; index++) {
+ result[index] = copiedInv.addItem(null, itemStacks[index]);
}
return result;