From 692d51e286a72aee300e3c4e4bdafab77f2b4f5a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Th=C3=BCm?= <thomas.thuem@uni-ulm.de>
Date: Sun, 13 Dec 2020 00:33:06 +0100
Subject: [PATCH 1/8] feat: Add multiplication and its generalization called
 expression

Resolves #1
---
 .../de/uulm/sp/swt/profcalculator/Add.java    | 10 +++------
 .../sp/swt/profcalculator/Expression.java     | 15 +++++++++++++
 .../sp/swt/profcalculator/Multiplication.java | 18 ++++++++++++++++
 .../sp/swt/profcalculator/ProfCalculator.java | 21 ++++++++++++-------
 4 files changed, 50 insertions(+), 14 deletions(-)
 create mode 100644 ProfCalculator/src/de/uulm/sp/swt/profcalculator/Expression.java
 create mode 100644 ProfCalculator/src/de/uulm/sp/swt/profcalculator/Multiplication.java

diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Add.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Add.java
index d557740..fca66f5 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Add.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Add.java
@@ -1,9 +1,8 @@
 package de.uulm.sp.swt.profcalculator;
 
-public class Add {
+// TODO rename class Add into Addition
+public class Add extends Expression {
 	
-	public Value l, r;
-
 	public Add(Value l, Value r) {
 		this.l = l;
 		this.r = r;
@@ -16,8 +15,5 @@ public String toString() {
 	public int evaluate() {
 		return l.getValue() + r.getValue();
 	}
-
-	public String computeEquation() {
-		return toString() + " = " + evaluate();
-	}
+	
 }
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Expression.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Expression.java
new file mode 100644
index 0000000..0075ceb
--- /dev/null
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Expression.java
@@ -0,0 +1,15 @@
+package de.uulm.sp.swt.profcalculator;
+
+public abstract class Expression {
+
+	// TODO rename l and r to left and right
+	public Value l;
+	public Value r;
+
+	public abstract int evaluate();
+
+	public String computeEquation() {
+		return toString() + " = " + evaluate();
+	}
+
+}
\ No newline at end of file
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Multiplication.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Multiplication.java
new file mode 100644
index 0000000..6fa8cc8
--- /dev/null
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Multiplication.java
@@ -0,0 +1,18 @@
+package de.uulm.sp.swt.profcalculator;
+
+public class Multiplication extends Expression {
+
+	public Multiplication(Value l, Value r) {
+		this.l = l;
+		this.r = r;
+	}
+
+	public String toString() {
+		return l.toString() + " * " + r.toString();
+	}
+
+	public int evaluate() {
+		return l.getValue() * r.getValue();
+	}
+	
+}
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java
index 0e2930e..e73ad8f 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java
@@ -16,13 +16,14 @@ public class ProfCalculator	extends Application implements EventHandler<ActionEv
 
 	private final static Value DEFAULT_VALUE = new Value(0);
 
-	private Add addition = new Add(DEFAULT_VALUE, DEFAULT_VALUE);
+	private Expression expression = new Add(DEFAULT_VALUE, DEFAULT_VALUE);
 
 	private Label errorLabel = new Label();
 
 	private TextField inputField = new TextField();
 
-	private Button addButton = new Button("+");
+	private Button additionButton = new Button("+");
+	private Button multiplicationButton = new Button("*");
 
 	private Label resultLabel = new Label();
 
@@ -31,13 +32,14 @@ public void start(Stage stage) throws Exception {
 		stage.setTitle("Professorial Calculator");
 		errorLabel.setTextFill(Color.web("#AA0000"));
 
-		VBox layout = new VBox(10, errorLabel, inputField, addButton, resultLabel);
+		VBox layout = new VBox(10, errorLabel, inputField, additionButton, multiplicationButton, resultLabel);
 		layout.setPadding(new Insets(20, 80, 20, 80));
 		Scene scene = new Scene(layout);
 
 		stage.setScene(scene);
 		stage.show();
-		addButton.setOnAction(this);
+		additionButton.setOnAction(this);
+		multiplicationButton.setOnAction(this);
 		updateGUI();
 	}
 
@@ -45,8 +47,13 @@ public void start(Stage stage) throws Exception {
 	public void handle(ActionEvent event) {
 		try {
 			int newValue = Integer.parseInt(inputField.getText());
-			int oldResult = addition.evaluate();
-			addition = new Add(new Value(oldResult), new Value(newValue));
+			int oldResult = expression.evaluate();
+			if (event.getSource() == additionButton) {
+				expression = new Add(new Value(oldResult), new Value(newValue));
+			}
+			else if (event.getSource() == multiplicationButton) {
+				expression = new Multiplication(new Value(oldResult), new Value(newValue));
+			}
 			updateGUI();
 			inputField.requestFocus();
 		} catch (NumberFormatException e) {
@@ -55,7 +62,7 @@ public void handle(ActionEvent event) {
 	}
 
 	private void updateGUI() {
-		resultLabel.setText(addition.computeEquation());
+		resultLabel.setText(expression.computeEquation());
 		inputField.setText("");
 		errorLabel.setText("");
 	}

From db6d74acfa00a38172133d21ab0794e446f3b3b6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Th=C3=BCm?= <thomas.thuem@uni-ulm.de>
Date: Sun, 13 Dec 2020 00:37:49 +0100
Subject: [PATCH 2/8] refactor: Rename class Add and its fields

---
 .../de/uulm/sp/swt/profcalculator/Add.java    | 19 -------------------
 .../uulm/sp/swt/profcalculator/Addition.java  | 18 ++++++++++++++++++
 .../sp/swt/profcalculator/Expression.java     |  5 ++---
 .../sp/swt/profcalculator/Multiplication.java | 10 +++++-----
 .../sp/swt/profcalculator/ProfCalculator.java |  4 ++--
 5 files changed, 27 insertions(+), 29 deletions(-)
 delete mode 100644 ProfCalculator/src/de/uulm/sp/swt/profcalculator/Add.java
 create mode 100644 ProfCalculator/src/de/uulm/sp/swt/profcalculator/Addition.java

diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Add.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Add.java
deleted file mode 100644
index fca66f5..0000000
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Add.java
+++ /dev/null
@@ -1,19 +0,0 @@
-package de.uulm.sp.swt.profcalculator;
-
-// TODO rename class Add into Addition
-public class Add extends Expression {
-	
-	public Add(Value l, Value r) {
-		this.l = l;
-		this.r = r;
-	}
-
-	public String toString() {
-		return l.toString() + " + " + r.toString();
-	}
-
-	public int evaluate() {
-		return l.getValue() + r.getValue();
-	}
-	
-}
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Addition.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Addition.java
new file mode 100644
index 0000000..f7c3840
--- /dev/null
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Addition.java
@@ -0,0 +1,18 @@
+package de.uulm.sp.swt.profcalculator;
+
+public class Addition extends Expression {
+	
+	public Addition(Value left, Value right) {
+		this.left = left;
+		this.right = right;
+	}
+
+	public String toString() {
+		return left.toString() + " + " + right.toString();
+	}
+
+	public int evaluate() {
+		return left.getValue() + right.getValue();
+	}
+	
+}
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Expression.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Expression.java
index 0075ceb..8dba35d 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Expression.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Expression.java
@@ -2,9 +2,8 @@
 
 public abstract class Expression {
 
-	// TODO rename l and r to left and right
-	public Value l;
-	public Value r;
+	public Value left;
+	public Value right;
 
 	public abstract int evaluate();
 
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Multiplication.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Multiplication.java
index 6fa8cc8..e56f4a3 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Multiplication.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Multiplication.java
@@ -2,17 +2,17 @@
 
 public class Multiplication extends Expression {
 
-	public Multiplication(Value l, Value r) {
-		this.l = l;
-		this.r = r;
+	public Multiplication(Value left, Value right) {
+		this.left = left;
+		this.right = right;
 	}
 
 	public String toString() {
-		return l.toString() + " * " + r.toString();
+		return left.toString() + " * " + right.toString();
 	}
 
 	public int evaluate() {
-		return l.getValue() * r.getValue();
+		return left.getValue() * right.getValue();
 	}
 	
 }
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java
index e73ad8f..d6a3151 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java
@@ -16,7 +16,7 @@ public class ProfCalculator	extends Application implements EventHandler<ActionEv
 
 	private final static Value DEFAULT_VALUE = new Value(0);
 
-	private Expression expression = new Add(DEFAULT_VALUE, DEFAULT_VALUE);
+	private Expression expression = new Addition(DEFAULT_VALUE, DEFAULT_VALUE);
 
 	private Label errorLabel = new Label();
 
@@ -49,7 +49,7 @@ public void handle(ActionEvent event) {
 			int newValue = Integer.parseInt(inputField.getText());
 			int oldResult = expression.evaluate();
 			if (event.getSource() == additionButton) {
-				expression = new Add(new Value(oldResult), new Value(newValue));
+				expression = new Addition(new Value(oldResult), new Value(newValue));
 			}
 			else if (event.getSource() == multiplicationButton) {
 				expression = new Multiplication(new Value(oldResult), new Value(newValue));

From b3dd5b033e4405984665b2bc290c37a4d431f47c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Th=C3=BCm?= <thomas.thuem@uni-ulm.de>
Date: Wed, 16 Dec 2020 18:39:50 +0100
Subject: [PATCH 3/8] refactor: Push down fields from class Expression

---
 ProfCalculator/src/de/uulm/sp/swt/profcalculator/Addition.java | 3 +++
 .../src/de/uulm/sp/swt/profcalculator/Expression.java          | 3 ---
 .../src/de/uulm/sp/swt/profcalculator/Multiplication.java      | 3 +++
 3 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Addition.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Addition.java
index f7c3840..298a3b3 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Addition.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Addition.java
@@ -2,6 +2,9 @@
 
 public class Addition extends Expression {
 	
+	public Value left;
+	public Value right;
+
 	public Addition(Value left, Value right) {
 		this.left = left;
 		this.right = right;
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Expression.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Expression.java
index 8dba35d..f0e4d17 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Expression.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Expression.java
@@ -2,9 +2,6 @@
 
 public abstract class Expression {
 
-	public Value left;
-	public Value right;
-
 	public abstract int evaluate();
 
 	public String computeEquation() {
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Multiplication.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Multiplication.java
index e56f4a3..b7b896b 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Multiplication.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Multiplication.java
@@ -2,6 +2,9 @@
 
 public class Multiplication extends Expression {
 
+	public Value left;
+	public Value right;
+
 	public Multiplication(Value left, Value right) {
 		this.left = left;
 		this.right = right;

From 63d059b7c6d3f8f6dd6a3dfba116a6ce64ee0111 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Th=C3=BCm?= <thomas.thuem@uni-ulm.de>
Date: Wed, 16 Dec 2020 18:45:35 +0100
Subject: [PATCH 4/8] feat: Show complete computation as formula

---
 .../src/de/uulm/sp/swt/profcalculator/Addition.java       | 8 ++++----
 .../src/de/uulm/sp/swt/profcalculator/Multiplication.java | 8 ++++----
 .../src/de/uulm/sp/swt/profcalculator/ProfCalculator.java | 7 +++----
 .../src/de/uulm/sp/swt/profcalculator/Value.java          | 6 ++++--
 4 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Addition.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Addition.java
index 298a3b3..a994ff0 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Addition.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Addition.java
@@ -2,10 +2,10 @@
 
 public class Addition extends Expression {
 	
-	public Value left;
-	public Value right;
+	public Expression left;
+	public Expression right;
 
-	public Addition(Value left, Value right) {
+	public Addition(Expression left, Expression right) {
 		this.left = left;
 		this.right = right;
 	}
@@ -15,7 +15,7 @@ public String toString() {
 	}
 
 	public int evaluate() {
-		return left.getValue() + right.getValue();
+		return left.evaluate() + right.evaluate();
 	}
 	
 }
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Multiplication.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Multiplication.java
index b7b896b..758447d 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Multiplication.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Multiplication.java
@@ -2,10 +2,10 @@
 
 public class Multiplication extends Expression {
 
-	public Value left;
-	public Value right;
+	public Expression left;
+	public Expression right;
 
-	public Multiplication(Value left, Value right) {
+	public Multiplication(Expression left, Expression right) {
 		this.left = left;
 		this.right = right;
 	}
@@ -15,7 +15,7 @@ public String toString() {
 	}
 
 	public int evaluate() {
-		return left.getValue() * right.getValue();
+		return left.evaluate() * right.evaluate();
 	}
 	
 }
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java
index d6a3151..47ee734 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java
@@ -16,7 +16,7 @@ public class ProfCalculator	extends Application implements EventHandler<ActionEv
 
 	private final static Value DEFAULT_VALUE = new Value(0);
 
-	private Expression expression = new Addition(DEFAULT_VALUE, DEFAULT_VALUE);
+	private Expression expression = DEFAULT_VALUE;
 
 	private Label errorLabel = new Label();
 
@@ -47,12 +47,11 @@ public void start(Stage stage) throws Exception {
 	public void handle(ActionEvent event) {
 		try {
 			int newValue = Integer.parseInt(inputField.getText());
-			int oldResult = expression.evaluate();
 			if (event.getSource() == additionButton) {
-				expression = new Addition(new Value(oldResult), new Value(newValue));
+				expression = new Addition(expression, new Value(newValue));
 			}
 			else if (event.getSource() == multiplicationButton) {
-				expression = new Multiplication(new Value(oldResult), new Value(newValue));
+				expression = new Multiplication(expression, new Value(newValue));
 			}
 			updateGUI();
 			inputField.requestFocus();
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Value.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Value.java
index 85e75c7..dc30780 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Value.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Value.java
@@ -1,6 +1,6 @@
 package de.uulm.sp.swt.profcalculator;
 
-public class Value {
+public class Value extends Expression {
 
 	Integer value;
 
@@ -12,7 +12,9 @@ public String toString() {
 		return value.toString();
 	}
 
-	public int getValue() {
+	@Override
+	public int evaluate() {
 		return value.intValue();
 	}
+
 }

From 5cf747293a539f944187d00ad150418d18b10a2e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Th=C3=BCm?= <thomas.thuem@uni-ulm.de>
Date: Wed, 16 Dec 2020 18:47:10 +0100
Subject: [PATCH 5/8] refactor: Move classes into a new subpackage for
 expressions

---
 .../src/de/uulm/sp/swt/profcalculator/ProfCalculator.java     | 4 ++++
 .../sp/swt/profcalculator/{ => expressions}/Addition.java     | 2 +-
 .../sp/swt/profcalculator/{ => expressions}/Expression.java   | 2 +-
 .../swt/profcalculator/{ => expressions}/Multiplication.java  | 2 +-
 .../uulm/sp/swt/profcalculator/{ => expressions}/Value.java   | 2 +-
 5 files changed, 8 insertions(+), 4 deletions(-)
 rename ProfCalculator/src/de/uulm/sp/swt/profcalculator/{ => expressions}/Addition.java (87%)
 rename ProfCalculator/src/de/uulm/sp/swt/profcalculator/{ => expressions}/Expression.java (75%)
 rename ProfCalculator/src/de/uulm/sp/swt/profcalculator/{ => expressions}/Multiplication.java (87%)
 rename ProfCalculator/src/de/uulm/sp/swt/profcalculator/{ => expressions}/Value.java (82%)

diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java
index 47ee734..0bda3d8 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java
@@ -1,5 +1,9 @@
 package de.uulm.sp.swt.profcalculator;
 
+import de.uulm.sp.swt.profcalculator.expressions.Addition;
+import de.uulm.sp.swt.profcalculator.expressions.Expression;
+import de.uulm.sp.swt.profcalculator.expressions.Multiplication;
+import de.uulm.sp.swt.profcalculator.expressions.Value;
 import javafx.application.Application;
 import javafx.event.ActionEvent;
 import javafx.event.EventHandler;
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Addition.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Addition.java
similarity index 87%
rename from ProfCalculator/src/de/uulm/sp/swt/profcalculator/Addition.java
rename to ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Addition.java
index a994ff0..99a7a8a 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Addition.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Addition.java
@@ -1,4 +1,4 @@
-package de.uulm.sp.swt.profcalculator;
+package de.uulm.sp.swt.profcalculator.expressions;
 
 public class Addition extends Expression {
 	
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Expression.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Expression.java
similarity index 75%
rename from ProfCalculator/src/de/uulm/sp/swt/profcalculator/Expression.java
rename to ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Expression.java
index f0e4d17..c2624ac 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Expression.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Expression.java
@@ -1,4 +1,4 @@
-package de.uulm.sp.swt.profcalculator;
+package de.uulm.sp.swt.profcalculator.expressions;
 
 public abstract class Expression {
 
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Multiplication.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Multiplication.java
similarity index 87%
rename from ProfCalculator/src/de/uulm/sp/swt/profcalculator/Multiplication.java
rename to ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Multiplication.java
index 758447d..c1f3e2d 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Multiplication.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Multiplication.java
@@ -1,4 +1,4 @@
-package de.uulm.sp.swt.profcalculator;
+package de.uulm.sp.swt.profcalculator.expressions;
 
 public class Multiplication extends Expression {
 
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Value.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Value.java
similarity index 82%
rename from ProfCalculator/src/de/uulm/sp/swt/profcalculator/Value.java
rename to ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Value.java
index dc30780..41c5a07 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Value.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Value.java
@@ -1,4 +1,4 @@
-package de.uulm.sp.swt.profcalculator;
+package de.uulm.sp.swt.profcalculator.expressions;
 
 public class Value extends Expression {
 

From 37d0dac91b2dab40a69d2bc5ce0a8f67d221a070 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Th=C3=BCm?= <thomas.thuem@uni-ulm.de>
Date: Wed, 16 Dec 2020 19:11:44 +0100
Subject: [PATCH 6/8] feat: Add brackets to expressions when needed

---
 .../sp/swt/profcalculator/ProfCalculator.java |  2 ++
 .../profcalculator/expressions/Addition.java  |  4 +--
 .../expressions/Expression.java               |  6 +++++
 .../expressions/Multiplication.java           |  4 +--
 .../expressions/NecessaryBrackets.java        | 25 +++++++++++++++++++
 .../swt/profcalculator/expressions/Value.java |  2 +-
 6 files changed, 38 insertions(+), 5 deletions(-)
 create mode 100644 ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/NecessaryBrackets.java

diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java
index 0bda3d8..51994b5 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java
@@ -3,6 +3,7 @@
 import de.uulm.sp.swt.profcalculator.expressions.Addition;
 import de.uulm.sp.swt.profcalculator.expressions.Expression;
 import de.uulm.sp.swt.profcalculator.expressions.Multiplication;
+import de.uulm.sp.swt.profcalculator.expressions.NecessaryBrackets;
 import de.uulm.sp.swt.profcalculator.expressions.Value;
 import javafx.application.Application;
 import javafx.event.ActionEvent;
@@ -57,6 +58,7 @@ public void handle(ActionEvent event) {
 			else if (event.getSource() == multiplicationButton) {
 				expression = new Multiplication(expression, new Value(newValue));
 			}
+			expression = new NecessaryBrackets(expression);
 			updateGUI();
 			inputField.requestFocus();
 		} catch (NumberFormatException e) {
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Addition.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Addition.java
index 99a7a8a..290f903 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Addition.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Addition.java
@@ -10,8 +10,8 @@ public Addition(Expression left, Expression right) {
 		this.right = right;
 	}
 
-	public String toString() {
-		return left.toString() + " + " + right.toString();
+	public String toString(Expression parent) {
+		return left.toString(this) + " + " + right.toString(this);
 	}
 
 	public int evaluate() {
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Expression.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Expression.java
index c2624ac..2047d49 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Expression.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Expression.java
@@ -4,6 +4,12 @@ public abstract class Expression {
 
 	public abstract int evaluate();
 
+	public abstract String toString(Expression parent);
+
+	public String toString() {
+		return toString(null);
+	}
+
 	public String computeEquation() {
 		return toString() + " = " + evaluate();
 	}
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Multiplication.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Multiplication.java
index c1f3e2d..7256be3 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Multiplication.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Multiplication.java
@@ -10,8 +10,8 @@ public Multiplication(Expression left, Expression right) {
 		this.right = right;
 	}
 
-	public String toString() {
-		return left.toString() + " * " + right.toString();
+	public String toString(Expression parent) {
+		return left.toString(this) + " * " + right.toString(this);
 	}
 
 	public int evaluate() {
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/NecessaryBrackets.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/NecessaryBrackets.java
new file mode 100644
index 0000000..177b051
--- /dev/null
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/NecessaryBrackets.java
@@ -0,0 +1,25 @@
+package de.uulm.sp.swt.profcalculator.expressions;
+
+public class NecessaryBrackets extends Expression {
+
+	private Expression expression;
+
+	public NecessaryBrackets(Expression expression) {
+		this.expression = expression;
+	}
+	
+	@Override
+	public String toString(Expression parent) {
+		String childString = expression.toString(parent);
+		if (parent instanceof Multiplication && expression instanceof Addition) {
+			childString = "(" + childString + ")";
+		}
+		return childString;
+	}
+
+	@Override
+	public int evaluate() {
+		return expression.evaluate();
+	}
+
+}
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Value.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Value.java
index 41c5a07..c9f9ed6 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Value.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Value.java
@@ -8,7 +8,7 @@ public Value(int value) {
 		this.value = value;
 	}
 
-	public String toString() {
+	public String toString(Expression parent) {
 		return value.toString();
 	}
 

From ab3454cdfaf7e1855d5be4fbed9877cc7372f0e5 Mon Sep 17 00:00:00 2001
From: Simon Schall <simon-1.schall@uni-ulm.de>
Date: Sat, 17 Jul 2021 20:30:27 +0200
Subject: [PATCH 7/8] add Subtraction to Calculator

---
 .../sp/swt/profcalculator/ProfCalculator.java |  8 ++++++-
 .../expressions/NecessaryBrackets.java        |  2 +-
 .../expressions/Subtraction.java              | 24 +++++++++++++++++++
 3 files changed, 32 insertions(+), 2 deletions(-)
 create mode 100644 ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Subtraction.java

diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java
index 51994b5..5d4cca7 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java
@@ -4,6 +4,7 @@
 import de.uulm.sp.swt.profcalculator.expressions.Expression;
 import de.uulm.sp.swt.profcalculator.expressions.Multiplication;
 import de.uulm.sp.swt.profcalculator.expressions.NecessaryBrackets;
+import de.uulm.sp.swt.profcalculator.expressions.Subtraction;
 import de.uulm.sp.swt.profcalculator.expressions.Value;
 import javafx.application.Application;
 import javafx.event.ActionEvent;
@@ -29,6 +30,7 @@ public class ProfCalculator	extends Application implements EventHandler<ActionEv
 
 	private Button additionButton = new Button("+");
 	private Button multiplicationButton = new Button("*");
+	private Button subtractionButton = new Button("-");
 
 	private Label resultLabel = new Label();
 
@@ -37,7 +39,7 @@ public void start(Stage stage) throws Exception {
 		stage.setTitle("Professorial Calculator");
 		errorLabel.setTextFill(Color.web("#AA0000"));
 
-		VBox layout = new VBox(10, errorLabel, inputField, additionButton, multiplicationButton, resultLabel);
+		VBox layout = new VBox(10, errorLabel, inputField, additionButton, subtractionButton, multiplicationButton, resultLabel);
 		layout.setPadding(new Insets(20, 80, 20, 80));
 		Scene scene = new Scene(layout);
 
@@ -45,6 +47,7 @@ public void start(Stage stage) throws Exception {
 		stage.show();
 		additionButton.setOnAction(this);
 		multiplicationButton.setOnAction(this);
+		subtractionButton.setOnAction(this);
 		updateGUI();
 	}
 
@@ -58,6 +61,9 @@ public void handle(ActionEvent event) {
 			else if (event.getSource() == multiplicationButton) {
 				expression = new Multiplication(expression, new Value(newValue));
 			}
+			else if (event.getSource() == subtractionButton) {
+				expression = new Subtraction(expression, new Value(newValue));
+			}
 			expression = new NecessaryBrackets(expression);
 			updateGUI();
 			inputField.requestFocus();
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/NecessaryBrackets.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/NecessaryBrackets.java
index 177b051..d88e79f 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/NecessaryBrackets.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/NecessaryBrackets.java
@@ -11,7 +11,7 @@ public NecessaryBrackets(Expression expression) {
 	@Override
 	public String toString(Expression parent) {
 		String childString = expression.toString(parent);
-		if (parent instanceof Multiplication && expression instanceof Addition) {
+		if (parent instanceof Multiplication && (expression instanceof Addition || expression instanceof Subtraction)) {
 			childString = "(" + childString + ")";
 		}
 		return childString;
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Subtraction.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Subtraction.java
new file mode 100644
index 0000000..fdc8584
--- /dev/null
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Subtraction.java
@@ -0,0 +1,24 @@
+package de.uulm.sp.swt.profcalculator.expressions;
+
+public class Subtraction extends Expression{
+	
+	public Expression left;
+	public Expression right;
+	
+	public Subtraction(Expression left, Expression right) {
+		this.left = left;
+		this.right = right;
+	}
+
+	@Override
+	public int evaluate() {
+		return left.evaluate() - right.evaluate();
+	}
+
+	@Override
+	public String toString(Expression parent) {
+		// TODO Auto-generated method stub
+		return left.toString(this) + "-" + right.toString(this);
+	}
+
+}

From 4844f88bfd04823bfd435ee844ae119979c758c2 Mon Sep 17 00:00:00 2001
From: Simon Schall <simon-1.schall@uni-ulm.de>
Date: Sat, 17 Jul 2021 21:28:16 +0200
Subject: [PATCH 8/8] implement a second mode

beside using brackets, user can now also decide to evaluate the
expression immediatley
---
 .../de/uulm/sp/swt/profcalculator/Mode.java   |  6 +++
 .../sp/swt/profcalculator/ProfCalculator.java | 39 ++++++++++++++++++-
 .../profcalculator/expressions/Evaluate.java  | 25 ++++++++++++
 .../expressions/Expression.java               |  3 +-
 4 files changed, 70 insertions(+), 3 deletions(-)
 create mode 100644 ProfCalculator/src/de/uulm/sp/swt/profcalculator/Mode.java
 create mode 100644 ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Evaluate.java

diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Mode.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Mode.java
new file mode 100644
index 0000000..a6f306e
--- /dev/null
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/Mode.java
@@ -0,0 +1,6 @@
+package de.uulm.sp.swt.profcalculator;
+
+public enum Mode {
+	BRACKET,
+	EVALUATE
+}
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java
index 5d4cca7..9a315ab 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/ProfCalculator.java
@@ -1,6 +1,7 @@
 package de.uulm.sp.swt.profcalculator;
 
 import de.uulm.sp.swt.profcalculator.expressions.Addition;
+import de.uulm.sp.swt.profcalculator.expressions.Evaluate;
 import de.uulm.sp.swt.profcalculator.expressions.Expression;
 import de.uulm.sp.swt.profcalculator.expressions.Multiplication;
 import de.uulm.sp.swt.profcalculator.expressions.NecessaryBrackets;
@@ -13,12 +14,16 @@
 import javafx.scene.Scene;
 import javafx.scene.control.Button;
 import javafx.scene.control.Label;
+import javafx.scene.control.RadioButton;
 import javafx.scene.control.TextField;
+import javafx.scene.control.ToggleGroup;
 import javafx.scene.layout.VBox;
 import javafx.scene.paint.Color;
 import javafx.stage.Stage;
 
 public class ProfCalculator	extends Application implements EventHandler<ActionEvent> {
+	
+	private Mode mode = Mode.BRACKET;
 
 	private final static Value DEFAULT_VALUE = new Value(0);
 
@@ -31,6 +36,9 @@ public class ProfCalculator	extends Application implements EventHandler<ActionEv
 	private Button additionButton = new Button("+");
 	private Button multiplicationButton = new Button("*");
 	private Button subtractionButton = new Button("-");
+	
+	private RadioButton rbBracket = new RadioButton("Brackets");
+	private RadioButton rbEvaluation = new RadioButton("Immediate Evaluation");
 
 	private Label resultLabel = new Label();
 
@@ -38,8 +46,27 @@ public class ProfCalculator	extends Application implements EventHandler<ActionEv
 	public void start(Stage stage) throws Exception {
 		stage.setTitle("Professorial Calculator");
 		errorLabel.setTextFill(Color.web("#AA0000"));
+		
+		ToggleGroup modus = new ToggleGroup();
+		rbBracket.setToggleGroup(modus);
+		rbBracket.setSelected(true);
+		rbEvaluation.setToggleGroup(modus);
+		
+		rbBracket.setOnAction(new EventHandler<ActionEvent>() {
+			@Override
+			public void handle(ActionEvent e) {
+				mode = Mode.BRACKET;
+			}
+		});
+		
+		rbEvaluation.setOnAction(new EventHandler<ActionEvent>() {
+			@Override
+			public void handle(ActionEvent e) {
+				mode = Mode.EVALUATE;
+			}
+		});
 
-		VBox layout = new VBox(10, errorLabel, inputField, additionButton, subtractionButton, multiplicationButton, resultLabel);
+		VBox layout = new VBox(10, errorLabel, inputField, additionButton, subtractionButton, multiplicationButton, resultLabel, rbBracket, rbEvaluation);
 		layout.setPadding(new Insets(20, 80, 20, 80));
 		Scene scene = new Scene(layout);
 
@@ -64,13 +91,21 @@ else if (event.getSource() == multiplicationButton) {
 			else if (event.getSource() == subtractionButton) {
 				expression = new Subtraction(expression, new Value(newValue));
 			}
-			expression = new NecessaryBrackets(expression);
+			if(mode == Mode.BRACKET) {
+				expression = new NecessaryBrackets(expression);
+			}
+			else {
+				expression = new Evaluate(expression);
+			}
 			updateGUI();
 			inputField.requestFocus();
 		} catch (NumberFormatException e) {
 			errorLabel.setText("\"" + inputField.getText() + "\" is not a valid integer");
 		}
 	}
+	
+	
+	
 
 	private void updateGUI() {
 		resultLabel.setText(expression.computeEquation());
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Evaluate.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Evaluate.java
new file mode 100644
index 0000000..86d9e59
--- /dev/null
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Evaluate.java
@@ -0,0 +1,25 @@
+package de.uulm.sp.swt.profcalculator.expressions;
+
+public class Evaluate extends Expression {
+
+	private Expression expression;
+	
+	public Evaluate(Expression expression) {
+		this.expression = expression;
+	}
+	
+	@Override
+	public String toString(Expression parent) {
+		String childString = expression.toString(parent);
+		if (parent instanceof Multiplication && (expression instanceof Addition || expression instanceof Subtraction)) {
+			childString = String.valueOf(evaluate());
+		}
+		return childString;
+	}
+
+	@Override
+	public int evaluate() {
+		return expression.evaluate();
+	}
+
+}
diff --git a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Expression.java b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Expression.java
index 2047d49..c7f5402 100644
--- a/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Expression.java
+++ b/ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/Expression.java
@@ -1,7 +1,8 @@
 package de.uulm.sp.swt.profcalculator.expressions;
 
-public abstract class Expression {
 
+public abstract class Expression {
+	
 	public abstract int evaluate();
 
 	public abstract String toString(Expression parent);