Item template structure

Signed-off-by: Rogiel <rogiel@rogiel.com>

src/main/java/com/l2jserver/util/calculator/Formula.java

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+package com.l2jserver.util.calculator;
+
+import java.util.List;
+
+import com.l2jserver.util.calculator.operation.AddOperation;
+import com.l2jserver.util.calculator.operation.CalculatorOperation;
+import com.l2jserver.util.calculator.operation.SetOperation;
+import com.l2jserver.util.calculator.operation.SubtractOperation;
+import com.l2jserver.util.factory.CollectionFactory;
+
+public class Formula {
+	private List<CalculatorOperation<Integer>> operations = CollectionFactory
+			.newList(null);
+
+	public void addOperation(int order, CalculatorOperation<Integer> operation) {
+		operations.set(order, operation);
+	}
+
+	public void add(int order, int value) {
+		addOperation(order, new AddOperation(value));
+	}
+
+	public void subtract(int order, int value) {
+		addOperation(order, new SubtractOperation(value));
+	}
+
+	public void set(int order, int value) {
+		addOperation(order, new SetOperation(value));
+	}
+
+	public int calculate() {
+		int value = 0;
+		for (CalculatorOperation<Integer> operation : operations) {
+			value = operation.calculate(value);
+		}
+		return value;
+	}
+}

src/main/java/com/l2jserver/util/calculator/operation/AddOperation.java

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+package com.l2jserver.util.calculator.operation;
+
+public class AddOperation implements CalculatorOperation<Integer> {
+	private Integer value;
+
+	public AddOperation(Integer value) {
+		this.value = value;
+	}
+
+	@Override
+	public Integer calculate(Integer value) {
+		return value + this.value;
+	}
+}

src/main/java/com/l2jserver/util/calculator/operation/CalculatorOperation.java

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+package com.l2jserver.util.calculator.operation;
+
+public interface CalculatorOperation<T extends Number> {
+	T calculate(T value);
+}

src/main/java/com/l2jserver/util/calculator/operation/MultiplyOperation.java

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+package com.l2jserver.util.calculator.operation;
+
+public class MultiplyOperation implements CalculatorOperation<Integer> {
+	private Integer value;
+
+	public MultiplyOperation(Integer value) {
+		this.value = value;
+	}
+
+	@Override
+	public Integer calculate(Integer value) {
+		return value * this.value;
+	}
+}

src/main/java/com/l2jserver/util/calculator/operation/SetOperation.java

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+package com.l2jserver.util.calculator.operation;
+
+public class SetOperation implements CalculatorOperation<Integer> {
+	private Integer value;
+
+	public SetOperation(Integer value) {
+		this.value = value;
+	}
+
+	@Override
+	public Integer calculate(Integer value) {
+		return this.value;
+	}
+}

src/main/java/com/l2jserver/util/calculator/operation/SubtractOperation.java

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+package com.l2jserver.util.calculator.operation;
+
+public class SubtractOperation implements CalculatorOperation<Integer> {
+	private Integer value;
+
+	public SubtractOperation(Integer value) {
+		this.value = value;
+	}
+
+	@Override
+	public Integer calculate(Integer value) {
+		return value - this.value;
+	}
+}