feat: Increase the default value from zero every second

Resolves #6

Author: tthuem

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.CounterValue;
 import de.uulm.sp.swt.profcalculator.expressions.Expression;
 import de.uulm.sp.swt.profcalculator.expressions.Multiplication;
 import de.uulm.sp.swt.profcalculator.expressions.NecessaryBrackets;
@@ -21,9 +22,7 @@
 
 public class ProfCalculator	extends Application implements EventHandler<ActionEvent> {
 
-	private final static Value DEFAULT_VALUE = new Value(0);
-
-	private Expression expression = DEFAULT_VALUE;
+	private Expression expression = new CounterValue(this);
 
 	private GUIFactory guiFactory = new BlueFontGUIFactory();
 
@@ -72,7 +71,7 @@ else if (event.getSource() == multiplicationButton) {
 		}
 	}
 
-	private void updateGUI() {
+	public void updateGUI() {
 		resultLabel.setText(expression.computeEquation());
 		inputField.setText("");
 		errorLabel.setText("");

ProfCalculator/src/de/uulm/sp/swt/profcalculator/expressions/CounterValue.java

@@ -0,0 +1,32 @@
+package de.uulm.sp.swt.profcalculator.expressions;
+
+import de.uulm.sp.swt.profcalculator.ProfCalculator;
+import javafx.application.Platform;
+
+public class CounterValue extends Value implements Runnable {
+	
+	ProfCalculator calc;
+
+	public CounterValue(ProfCalculator calc) {
+		super(0);
+		this.calc = calc;
+		new Thread(this).start();
+	}
+
+	@Override
+	public void run() {
+		while (value < 10) {
+			try {
+				Thread.sleep(1000);
+			} catch (InterruptedException e) {
+			}
+			value++;
+			Platform.runLater(new Runnable() {
+				public void run() {
+					calc.updateGUI();
+				}
+			});
+		}
+	}
+	
+}