diff --git a/javafx-template/src/main/java/app/AppController.java b/javafx-template/src/main/java/app/AppController.java
index 1cbbd295aac1d9594c7610f135965215c8bbebbb..d47da69d76a9dbbfd1678a5d6787a9f53466b019 100644
--- a/javafx-template/src/main/java/app/AppController.java
+++ b/javafx-template/src/main/java/app/AppController.java
@@ -100,6 +100,11 @@ public class AppController {
// TODO clear operand
}
+ @FXML
+ void handleSwap() {
+ // TODO clear operand
+ }
+
private void performOperation(UnaryOperator<Double> op) {
// TODO
}
diff --git a/javafx-template/src/main/java/app/Calc.java b/javafx-template/src/main/java/app/Calc.java
index 6102e31383fcdb96fa94197a73a7774bfcbd70a1..8ff70b8fedecadf649989648439d43499a485763 100644
--- a/javafx-template/src/main/java/app/Calc.java
+++ b/javafx-template/src/main/java/app/Calc.java
@@ -7,10 +7,13 @@ import java.util.function.UnaryOperator;
public class Calc {
- private List<Double> operandStack = new ArrayList<>();
+ private final List<Double> operandStack;
- public Calc(Double... operands) {
- operandStack.addAll(List.of(operands));
+ public Calc(double... operands) {
+ operandStack = new ArrayList<>(operands.length + 2);
+ for (var d : operands) {
+ operandStack.add(d);
+ }
}
/**
@@ -20,29 +23,24 @@ public class Calc {
return operandStack.size();
}
- /**
- * Pushes a new operand into the n'th place from the top.
- * @param n the place to push
- * @param d the new operand
- */
- public void pushOperand(int n, double d) {
- operandStack.add(operandStack.size() - n, d);
- }
-
/**
* Pushes a new operand onto top of the stack.
* @param d the new operand
*/
public void pushOperand(double d) {
- pushOperand(0, d);
+ operandStack.add(d);
}
/**
* @param n the place (from the top) to peek
* @return the n'th operand from the top
+ * @throws IllegalArgumentException if n is larger than the operand count
*/
public double peekOperand(int n) {
- return operandStack.get(operandStack.size() - n - 1);
+ if (n > getOperandCount()) {
+ throw new IllegalArgumentException("Cannot peek at position " + n + " when the operand count is " + getOperandCount());
+ }
+ return operandStack.get(getOperandCount() - n - 1);
}
/**
@@ -52,30 +50,26 @@ public class Calc {
return peekOperand(0);
}
- /**
- * Removes and returns the n'th operand from the top.
- * @param n the place from the top to remove
- * @return the n'th operand from the top
- */
- public double popOperand(int n) {
- return operandStack.remove(operandStack.size() - n - 1);
- }
-
/**
* Removes and returns the top operand.
* @return the top operand
+ * @throws IllegalStateException if the stack is empty
*/
public double popOperand() {
- return popOperand(0);
+ if (getOperandCount() == 0) {
+ throw new IllegalStateException("Cannot pop from an empty stack");
+ }
+ return operandStack.remove(operandStack.size() - 1);
}
-
+
/**
* Performs the provided operation in the top operand, and
* replaces it with the result.
* @param op the operation to perform
* @return the result of performing the operation
+ * @throws IllegalStateException if the operand stack is empty
*/
- public double performOperation(UnaryOperator<Double> op) {
+ public double performOperation(UnaryOperator<Double> op) throws IllegalStateException {
// TODO
return 0.0;
}
@@ -85,8 +79,12 @@ public class Calc {
* replaces them with the result.
* @param op the operation to perform
* @return the result of performing the operation
+ * @throws IllegalStateException if the operand count is less than two
*/
- public double performOperation(BinaryOperator<Double> op) {
+ public double performOperation(BinaryOperator<Double> op) throws IllegalStateException {
+ if (getOperandCount() < 2) {
+ throw new IllegalStateException("Too few operands (" + getOperandCount() + ") on the stack");
+ }
var op1 = popOperand();
var op2 = popOperand();
var result = op.apply(op1, op2);
diff --git a/javafx-template/src/main/resources/app/App.fxml b/javafx-template/src/main/resources/app/App.fxml
index 41f4e4f1816de5e5e8134f3f6c45307279f7e554..7356474389da1d59fbedba33e5186b44f993c4f3 100644
--- a/javafx-template/src/main/resources/app/App.fxml
+++ b/javafx-template/src/main/resources/app/App.fxml
@@ -15,7 +15,7 @@
<!-- multi-line button label with XML entity for newline -->
<Button text="E n t e r" onAction="#handleEnter"
- GridPane.rowIndex="2" GridPane.columnIndex="3" GridPane.rowSpan="4"/>
+ GridPane.rowIndex="2" GridPane.columnIndex="3" GridPane.rowSpan="3"/>
<Button text="7" onAction="#handleDigit"
GridPane.rowIndex="2" GridPane.columnIndex="0"/>
@@ -23,24 +23,29 @@
GridPane.rowIndex="2" GridPane.columnIndex="1"/>
<Button text="9" onAction="#handleDigit"
GridPane.rowIndex="2" GridPane.columnIndex="2"/>
+
<Button text="4" onAction="#handleDigit"
GridPane.rowIndex="3" GridPane.columnIndex="0"/>
<Button text="5" onAction="#handleDigit"
GridPane.rowIndex="3" GridPane.columnIndex="1"/>
<Button text="6" onAction="#handleDigit"
GridPane.rowIndex="3" GridPane.columnIndex="2"/>
+
<Button text="1" onAction="#handleDigit"
GridPane.rowIndex="4" GridPane.columnIndex="0"/>
<Button text="2" onAction="#handleDigit"
GridPane.rowIndex="4" GridPane.columnIndex="1"/>
<Button text="3" onAction="#handleDigit"
GridPane.rowIndex="4" GridPane.columnIndex="2"/>
+
<Button text="0" onAction="#handleDigit"
GridPane.rowIndex="5" GridPane.columnIndex="0"/>
<Button text="." onAction="#handlePoint"
GridPane.rowIndex="5" GridPane.columnIndex="1"/>
<Button text="C" onAction="#handleClear"
GridPane.rowIndex="5" GridPane.columnIndex="2"/>
+ <Button text="~" onAction="#handleSwap"
+ GridPane.rowIndex="5" GridPane.columnIndex="3"/>
<Button text="+" onAction="#handleOpAdd"
GridPane.rowIndex="6" GridPane.columnIndex="0"/>
diff --git a/javafx-template/src/test/java/app/CalcTest.java b/javafx-template/src/test/java/app/CalcTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..9a7c0df0cc7517529e1b579ed515ddc89a8e8eda
--- /dev/null
+++ b/javafx-template/src/test/java/app/CalcTest.java
@@ -0,0 +1,39 @@
+package app;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+public class CalcTest {
+
+ private static void checkCalc(Calc calc, double... operands) {
+ Assertions.assertEquals(operands.length, calc.getOperandCount(), "Wrong operand count");
+ for (int i = 0; i < operands.length; i++) {
+ Assertions.assertEquals(operands[i], calc.peekOperand(i), "Wrong value at #" + i + " of operand stack");
+ }
+ }
+
+ @Test
+ public void testCalc() {
+ checkCalc(new Calc());
+ checkCalc(new Calc(1.0), 1.0);
+ checkCalc(new Calc(3.14, 1.0), 1.0, 3.14);
+ }
+
+ @Test
+ public void testPushOperand() {
+ Calc calc = new Calc();
+ calc.pushOperand(1.0);
+ checkCalc(calc, 1.0);
+ calc.pushOperand(3.14);
+ checkCalc(calc, 3.14, 1.0);
+ }
+
+ @Test
+ public void testPopOperand() {
+ Calc calc = new Calc(1.0, 3.14);
+ Assertions.assertEquals(3.14, calc.popOperand());
+ checkCalc(calc, 1.0);
+ Assertions.assertEquals(1.0, calc.popOperand());
+ checkCalc(calc);
+ }
+}