Move to menu package

This is because shift is frequently called at iteration so using less getters is a noticable change
Also because you type less :)))))

Author: coderFlameyosFlow

src/main/java/me/flame/menus/menu/IterationDirection.java

@@ -0,0 +1,199 @@
+package me.flame.menus.menu;
+
+/**
+ * Iteration direction of a {@link Page} or {@link Menu}
+ * @author Mqzn (Mqzen), FlameyosFlow (Mostly Mqzen)
+ */
+@SuppressWarnings("unused")
+public enum IterationDirection {
+    HORIZONTAL {
+        @Override
+        public Slot shift(Slot oldPos, int maxRows) {
+            int oldCol = oldPos.col;
+            int oldRow = oldPos.row;
+
+            if (oldCol == 9 && oldRow < maxRows) {
+                oldCol = 1;
+                oldRow++;
+            } else {
+                oldCol++;
+            }
+
+            return new Slot(oldRow, oldCol);
+        }
+    },
+
+    VERTICAL {
+        @Override
+        public Slot shift(Slot oldPos, int maxRows) {
+            int oldCol = oldPos.col;
+            int oldRow = oldPos.row;
+
+            if (oldCol < 9 && oldRow == maxRows) {
+                oldCol++;
+                oldRow = 1;
+            } else {
+                oldRow++;
+            }
+
+            return new Slot(oldRow, oldCol);
+        }
+    },
+
+    UPWARDS_ONLY {
+        @Override
+        public Slot shift(Slot oldPos, int maxRows) {
+            return new Slot(oldPos.row - 1, oldPos.col);
+        }
+    },
+
+    DOWNWARDS_ONLY {
+        @Override
+        public Slot shift(Slot oldPos, int maxRows) {
+            return new Slot(oldPos.row + 1, oldPos.col);
+        }
+    },
+
+    RIGHT_ONLY {
+        @Override
+        public Slot shift(Slot oldPos, int maxRows) {
+            int col = oldPos.col + 1;
+            if (col > 9) {
+                return Slot.NaS;
+            }
+            return new Slot(oldPos.row, col);
+        }
+    },
+
+    LEFT_ONLY {
+        @Override
+        public Slot shift(Slot oldPos, int maxRows) {
+            int col = oldPos.col - 1;
+            if (col < 0) {
+                return Slot.NaS;
+            }
+            return new Slot(oldPos.row, col);
+        }
+    },
+
+    RIGHT_UPWARDS_ONLY {
+        @Override
+        public Slot shift(Slot oldPos, int maxRows) {
+            Slot upwardSlot = UPWARDS_ONLY.shift(oldPos, maxRows);
+            int row = upwardSlot.row;
+
+            Slot rightSlot = RIGHT_ONLY.shift(oldPos, maxRows);
+            int col = rightSlot.col;
+
+            return new Slot(row, col);
+        }
+    },
+
+    RIGHT_DOWNWARDS_ONLY {
+        @Override
+        public Slot shift(Slot oldPos, int maxRows) {
+            Slot downwardSlot = DOWNWARDS_ONLY.shift(oldPos, maxRows);
+            int row = downwardSlot.row;
+
+            Slot rightSlot = RIGHT_ONLY.shift(oldPos, maxRows);
+            int col = rightSlot.col;
+
+            return new Slot(row, col);
+        }
+    },
+
+    LEFT_UPWARDS {
+        @Override
+        public Slot shift(Slot oldPos, int maxRows) {
+            Slot upwardSlot = UPWARDS_ONLY.shift(oldPos, maxRows);
+            int row = upwardSlot.row;
+
+            Slot leftSlot = LEFT_ONLY.shift(oldPos, maxRows);
+            int col = leftSlot.col;
+
+            return new Slot(row, col);
+        }
+    },
+
+    LEFT_DOWNWARDS {
+        @Override
+        public Slot shift(Slot oldPos, int maxRows) {
+            Slot downwardSlot = DOWNWARDS_ONLY.shift(oldPos, maxRows);
+            int row = downwardSlot.row;
+
+            Slot leftSlot = LEFT_ONLY.shift(oldPos, maxRows);
+            int col = leftSlot.col;
+
+            return new Slot(row, col);
+        }
+    },
+
+    BACKWARDS_HORIZONTAL {
+        @Override
+        public Slot shift(Slot oldPos, int maxRows) {
+            int oldCol = oldPos.col;
+            int oldRow = oldPos.row;
+
+            if (oldCol == 1 && oldRow >= 1) {
+                oldCol = 9;
+                oldRow--;
+            } else {
+                oldCol--;
+            }
+
+            return new Slot(oldRow, oldCol);
+        }
+    },
+
+    BACKWARDS_VERTICAL {
+        @Override
+        public Slot shift(Slot oldPos, int maxRows) {
+            int oldCol = oldPos.col;
+            int oldRow = oldPos.row;
+
+            if (oldCol > 1 && oldRow < 6) {
+                oldCol--;
+                oldRow = 6;
+            } else {
+                oldRow--;
+            }
+
+            return new Slot(oldRow, oldCol);
+        }
+    };
+
+    /**
+     * Shifting the slot "oldPos" by "maxRows" to the next slot.
+     *
+     * @param  oldPos   the old position to shift FROM
+     * @param  maxRows  the maximum amount of rows the menu may have
+     * @return          the shifted position that can AND will depend on the {@link IterationDirection} direction
+     *                  <p>How different directions work:</p>
+     *                  <p></p>
+     *                  HORIZONTAL: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, etc.
+     *                  <p></p>
+     *                  VERTICAL: 0, 9, 18, 27, 36, 45, 1, 10, etc.
+     *                  <p></p>
+     *                  UPWARDS_ONLY: 45, 36, 27, 18, 9, 0.
+     *                  <p></p>
+     *                  DOWNWARDS_ONLY: 0, 9, 18, 27, 36, 45.
+     *                  <p></p>
+     *                  RIGHT_ONLY: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.
+     *                  <p></p>
+     *                  LEFT_ONLY: 9, 8, 7, 6, 5, 4, 3, 2, 1, 0
+     *                  <p></p>
+     *                  RIGHT_UPWARDS_ONLY: 45, 37, 29, 21, 13, 5, 0.
+     *                  <p></p>
+     *                  RIGHT_DOWNWARDS_ONLY: 0, 10, 20, 30, 40, 50.
+     *                  <p></p>
+     *                  LEFT_UPWARDS: 53, 44, 35, 26, 17, 8, 0.
+     *                  <p></p>
+     *                  LEFT_DOWNWARDS: 7, 16, 25, 34, 40, 48.
+     *                  <p></p>
+     *                  BACKWARDS_HORIZONTAL: 53, 52, 51, 50, 49, etc.
+     *                  <p></p>
+     *                  BACKWARDS_VERTICAL: 53, 44, 35, 26, 17, 17, 8, 52, etc.
+     *
+     */
+    public abstract Slot shift(Slot oldPos, int maxRows);
+}