added trig and advanced functions

src/main/java/rocks/zipcode/calcskin/CalcEngine.java

@@ -20,4 +20,35 @@ public class CalcEngine {
     public double divide(double v, double v1) {
         return v/v1;
     }
+
+    public double squared(double v){
+        return Math.pow(v,2);
+    }
+
+    public double exponent(double v, double y){
+        return Math.pow(v,y);
+    }
+
+    public double inverse(double v){
+        return 1/v;
+    }
+
+    public double squareRoot(double v) {
+        return Math.sqrt(v);
+    }
+
+    public double calcSin(double x) {
+        double answer = Math.sin(x);
+        return answer;
+    }
+
+    public double calcCos(double x) {
+        double answer = Math.cos(x);
+        return answer;
+    }
+
+    public double calcTan(double x) {
+        double answer = Math.tan(x);
+        return answer;
+    }
 }

src/main/java/rocks/zipcode/calcskin/CalcSkin.java

@@ -24,10 +24,10 @@ public class CalcSkin extends Application {
         launch(args);
     }
     private static final String[][] template = {
-            { "7", "8", "9", "/" },
-            { "4", "5", "6", "*" },
-            { "1", "2", "3", "-" },
-            { "0", "c", "=", "+" }
+            { "7", "8", "9", "/", "x^2", "SINE"},
+            { "4", "5", "6", "*", "√", "COSINE"},
+            { "1", "2", "3", "-", "1/x","TAN" },
+            { "0", "c", "=", "+", "x^y" }
     };
 
     private final Map<String, Button> accelerators = new HashMap<>();
@@ -36,7 +36,7 @@ public class CalcSkin extends Application {
     private DoubleProperty currentValue = new SimpleDoubleProperty();
     private CalcEngine calcEngine = new CalcEngine();
 
-    private enum Op { NOOP, ADD, SUBTRACT, MULTIPLY, DIVIDE }
+    private enum Op { NOOP, ADD, SUBTRACT, MULTIPLY, DIVIDE, SQUARED, SROOT, INVERSE, EXPONENT, SINE, COSINE, TAN }
 
     private Op curOp   = Op.NOOP;
     private Op stackOp = Op.NOOP;
@@ -84,7 +84,7 @@ public class CalcSkin extends Application {
         screen.setStyle("-fx-background-color: aquamarine;");
         screen.setAlignment(Pos.CENTER_RIGHT);
         screen.setEditable(false);
-        screen.textProperty().bind(Bindings.format("%.0f", currentValue));
+        screen.textProperty().bind(Bindings.format("%.2f", currentValue));
         return screen;
     }
 
@@ -127,6 +127,13 @@ public class CalcSkin extends Application {
             case "-": triggerOp.set(Op.SUBTRACT); break;
             case "*": triggerOp.set(Op.MULTIPLY); break;
             case "/": triggerOp.set(Op.DIVIDE);   break;
+            case "x^2": triggerOp.set(Op.SQUARED); break;
+            case "√": triggerOp.set(Op.SROOT); break;
+            case "1/x": triggerOp.set(Op.INVERSE); break;
+            case "x^y": triggerOp.set(Op.EXPONENT); break;
+            case "SINE": triggerOp.set(Op.SINE); break;
+            case "COSINE": triggerOp.set(Op.COSINE); break;
+            case "TAN": triggerOp.set(Op.TAN); break;
         }
         return triggerOp;
     }
@@ -181,10 +188,18 @@ public class CalcSkin extends Application {
             @Override
             public void handle(ActionEvent actionEvent) {
                 switch (stackOp) {
+                    case NOOP:
                     case ADD:      currentValue.set(calcEngine.add(previousValue.get(), currentValue.get())); break;
                     case SUBTRACT: currentValue.set(calcEngine.subtract(previousValue.get(), currentValue.get())); break;
                     case MULTIPLY: currentValue.set(calcEngine.multiply(previousValue.get(), currentValue.get())); break;
                     case DIVIDE:   currentValue.set(calcEngine.divide(previousValue.get(), currentValue.get())); break;
+                    case SQUARED: currentValue.set(calcEngine.squared(previousValue.get())); break;
+                    case SROOT: currentValue.set(calcEngine.squareRoot(currentValue.get())); break;
+                    case INVERSE: currentValue.set(calcEngine.inverse(previousValue.get())); break;
+                    case EXPONENT: currentValue.set(calcEngine.exponent(previousValue.get(), currentValue.get())); break;
+                    case SINE: currentValue.set(calcEngine.calcSin(previousValue.get())); break;
+                    case COSINE: currentValue.set(calcEngine.calcCos(previousValue.get())); break;
+                    case TAN: currentValue.set(calcEngine.calcTan(previousValue.get())); break;
                 }
             }
         });