Added a menu iterator

Author: Mqzn

src/main/java/me/flame/menus/menu/iterator/MenuIterator.java

@@ -0,0 +1,197 @@
+package me.flame.menus.menu.iterator;
+
+import me.flame.menus.menu.BaseMenu;
+import me.flame.menus.menu.Slot;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ *
+ * @author Mqzen
+ * @date 28/8/2023
+ *
+ * A special class made to iterate over complex menus.
+ */
+public final class MenuIterator {
+
+	@NotNull
+	private Slot currentPosition;
+
+	@NotNull
+	private final IterationDirection direction;
+
+	@NotNull
+	private final BaseMenu<?> menu;
+
+	public MenuIterator(int startingRow, int startingCol,
+											@NotNull IterationDirection direction,
+											@NotNull BaseMenu<?> menu) {
+		this.menu = menu;
+		this.currentPosition = new Slot(startingRow, startingCol);
+		this.direction = direction;
+	}
+
+	public Slot nextSlot(boolean emptyOnly) {
+
+
+		if(!emptyOnly) {
+			Slot newPos = direction.shift(currentPosition, menu.getRows());
+			currentPosition = newPos;
+			return newPos;
+		}
+
+		while(menu.getOptionalItem(currentPosition).isPresent()) {
+			currentPosition = direction.shift(currentPosition, menu.getRows());
+		}
+
+		//when it becomes empty
+		return currentPosition;
+	}
+
+	public Slot nextSlot() {
+		return nextSlot(false);
+	}
+
+	public enum IterationDirection {
+
+
+		HORIZONTAL() {
+			@Override
+			Slot shift(Slot oldPos, int maxRows) {
+
+				int oldCol = oldPos.getColumn();
+				int oldRow = oldPos.getRow();
+
+				if(oldCol == 8 && oldRow < maxRows-1) {
+					oldRow++;
+					oldCol = 0;
+				}else {
+					oldCol++;
+				}
+
+				return new Slot(oldRow, oldCol);
+			}
+		},
+
+		VERTICAL() {
+			@Override
+			Slot shift(Slot oldPos, int maxRows) {
+				int oldCol = oldPos.getColumn();
+				int oldRow = oldPos.getRow();
+
+				if(oldCol < 8 && oldRow == maxRows-1) {
+					oldCol++;
+					oldRow = 0;
+				}else {
+					oldRow++;
+				}
+
+				return new Slot(oldRow, oldCol);
+			}
+		},
+
+		UPWARDS_ONLY {
+
+			@Override
+			Slot shift(Slot oldPos, int maxRows) {
+				int row = oldPos.getRow()-1;
+				if(row < 0) {
+					row = oldPos.getRow();
+				}
+				return new Slot(row, oldPos.getColumn());
+			}
+		},
+
+		DOWNWARDS_ONLY {
+			@Override
+			Slot shift(Slot oldPos, int maxRows) {
+				int row = oldPos.getRow()+1;
+				if(row > maxRows) {
+					row = oldPos.getRow();
+				}
+				return new Slot(row, oldPos.getColumn());
+			}
+
+		},
+
+		RIGHT_ONLY {
+			@Override
+			Slot shift(Slot oldPos, int maxRows) {
+				int col = oldPos.getColumn()+1;
+				if(col > 8) {
+					col = oldPos.getColumn();
+				}
+				return new Slot(oldPos.getRow(), col);
+			}
+		},
+
+
+		LEFT_ONLY{
+			@Override
+			Slot shift(Slot oldPos, int maxRows) {
+				int col = oldPos.getColumn()-1;
+				if(col < 0) {
+					col = oldPos.getColumn();
+				}
+				return new Slot(oldPos.getRow(), col);
+			}
+		},
+
+
+		RIGHT_UPWARDS_ONLY {
+			@Override
+			Slot shift(Slot oldPos, int maxRows) {
+				Slot upwardSlot = UPWARDS_ONLY.shift(oldPos, maxRows);
+				int row = upwardSlot.getRow();
+
+				Slot rightSlot = RIGHT_ONLY.shift(oldPos, maxRows);
+				int col = rightSlot.getColumn();
+
+				return new Slot(row, col);
+			}
+		},
+
+
+		RIGHT_DOWNWARDS_ONLY {
+			@Override
+			Slot shift(Slot oldPos, int maxRows) {
+				Slot downwardSlot = DOWNWARDS_ONLY.shift(oldPos, maxRows);
+				int row = downwardSlot.getRow();
+
+				Slot rightSlot = RIGHT_ONLY.shift(oldPos, maxRows);
+				int col = rightSlot.getColumn();
+
+				return new Slot(row, col);
+			}
+		},
+
+		LEFT_UPWARDS {
+			@Override
+			Slot shift(Slot oldPos, int maxRows) {
+				Slot upwardSlot = UPWARDS_ONLY.shift(oldPos, maxRows);
+				int row = upwardSlot.getRow();
+
+				Slot leftSlot = LEFT_ONLY.shift(oldPos, maxRows);
+				int col = leftSlot.getColumn();
+
+				return new Slot(row, col);
+			}
+		},
+
+		LEFT_DOWNWARDS {
+			@Override
+			Slot shift(Slot oldPos, int maxRows) {
+				Slot downwardSlot = DOWNWARDS_ONLY.shift(oldPos, maxRows);
+				int row = downwardSlot.getRow();
+
+				Slot leftSlot = LEFT_ONLY.shift(oldPos, maxRows);
+				int col = leftSlot.getColumn();
+
+				return new Slot(row, col);
+			}
+		};
+
+		abstract Slot shift(Slot oldPos, int maxRows);
+	}
+
+
+}