Merge pull request #26 from trubitsyn/master

Polymorphic calculator operations

app/src/main/java/com/simplemobiletools/calculator/CalculatorImpl.java

@@ -1,5 +1,8 @@
 package com.simplemobiletools.calculator;
 
+import com.simplemobiletools.calculator.operation.OperationFactory;
+import com.simplemobiletools.calculator.operation.base.Operation;
+
 public class CalculatorImpl {
     private String mDisplayedValue;
     private String mDisplayedFormula;
@@ -110,60 +113,19 @@ public class CalculatorImpl {
     }
 
     public void calculateResult() {
-        if (!mIsFirstOperation)
+        if (!mIsFirstOperation) {
             updateFormula();
-
-        switch (mLastOperation) {
-            case Constants.PLUS:
-                updateResult(mBaseValue + mSecondValue);
-                break;
-            case Constants.MINUS:
-                updateResult(mBaseValue - mSecondValue);
-                break;
-            case Constants.MULTIPLY:
-                updateResult(mBaseValue * mSecondValue);
-                break;
-            case Constants.DIVIDE:
-                divideNumbers();
-                break;
-            case Constants.MODULO:
-                moduloNumbers();
-                break;
-            case Constants.POWER:
-                powerNumbers();
-                break;
-            case Constants.ROOT:
-                updateResult(Math.sqrt(mBaseValue));
-                break;
-            default:
-                break;
         }
+
+        Operation operation = OperationFactory.forId(mLastOperation, mBaseValue, mSecondValue);
+
+        if (operation != null) {
+            updateResult(operation.getResult());
+        }
+
         mIsFirstOperation = false;
     }
 
-    private void divideNumbers() {
-        double resultValue = 0;
-        if (mSecondValue != 0)
-            resultValue = mBaseValue / mSecondValue;
-
-        updateResult(resultValue);
-    }
-
-    private void moduloNumbers() {
-        double resultValue = 0;
-        if (mSecondValue != 0)
-            resultValue = mBaseValue % mSecondValue;
-
-        updateResult(resultValue);
-    }
-
-    private void powerNumbers() {
-        double resultValue = Math.pow(mBaseValue, mSecondValue);
-        if (Double.isInfinite(resultValue) || Double.isNaN(resultValue))
-            resultValue = 0;
-        updateResult(resultValue);
-    }
-
     public void handleOperation(String operation) {
         if (mLastKey.equals(Constants.DIGIT))
             handleResult();

app/src/main/java/com/simplemobiletools/calculator/operation/DivideOperation.java

@@ -0,0 +1,20 @@
+package com.simplemobiletools.calculator.operation;
+
+import com.simplemobiletools.calculator.operation.base.BinaryOperation;
+import com.simplemobiletools.calculator.operation.base.Operation;
+
+public class DivideOperation extends BinaryOperation implements Operation {
+
+    public DivideOperation(double baseValue, double secondValue) {
+        super(baseValue, secondValue);
+    }
+
+    @Override
+    public double getResult() {
+        double result = 0;
+        if (secondValue != 0) {
+            result = baseValue / secondValue;
+        }
+        return result;
+    }
+}

app/src/main/java/com/simplemobiletools/calculator/operation/MinusOperation.java

@@ -0,0 +1,15 @@
+package com.simplemobiletools.calculator.operation;
+
+import com.simplemobiletools.calculator.operation.base.BinaryOperation;
+import com.simplemobiletools.calculator.operation.base.Operation;
+
+public class MinusOperation extends BinaryOperation implements Operation {
+    protected MinusOperation(double baseValue, double secondValue) {
+        super(baseValue, secondValue);
+    }
+
+    @Override
+    public double getResult() {
+        return baseValue - secondValue;
+    }
+}

app/src/main/java/com/simplemobiletools/calculator/operation/ModuloOperation.java

@@ -0,0 +1,19 @@
+package com.simplemobiletools.calculator.operation;
+
+import com.simplemobiletools.calculator.operation.base.BinaryOperation;
+import com.simplemobiletools.calculator.operation.base.Operation;
+
+public class ModuloOperation extends BinaryOperation implements Operation {
+    protected ModuloOperation(double baseValue, double secondValue) {
+        super(baseValue, secondValue);
+    }
+
+    @Override
+    public double getResult() {
+        double result = 0;
+        if (secondValue != 0) {
+            result = baseValue % secondValue;
+        }
+        return result;
+    }
+}

app/src/main/java/com/simplemobiletools/calculator/operation/MultiplyOperation.java

@@ -0,0 +1,15 @@
+package com.simplemobiletools.calculator.operation;
+
+import com.simplemobiletools.calculator.operation.base.BinaryOperation;
+import com.simplemobiletools.calculator.operation.base.Operation;
+
+public class MultiplyOperation extends BinaryOperation implements Operation {
+    protected MultiplyOperation(double baseValue, double secondValue) {
+        super(baseValue, secondValue);
+    }
+
+    @Override
+    public double getResult() {
+        return baseValue * secondValue;
+    }
+}

app/src/main/java/com/simplemobiletools/calculator/operation/OperationFactory.java

@@ -0,0 +1,31 @@
+package com.simplemobiletools.calculator.operation;
+
+import android.support.annotation.Nullable;
+
+import com.simplemobiletools.calculator.Constants;
+import com.simplemobiletools.calculator.operation.base.Operation;
+
+public class OperationFactory {
+
+    @Nullable
+    public static Operation forId(String id, double baseValue, double secondValue) {
+        switch (id) {
+            case Constants.PLUS:
+                return new PlusOperation(baseValue, secondValue);
+            case Constants.MINUS:
+                return new MinusOperation(baseValue, secondValue);
+            case Constants.DIVIDE:
+                return new DivideOperation(baseValue, secondValue);
+            case Constants.MULTIPLY:
+                return new MultiplyOperation(baseValue, secondValue);
+            case Constants.MODULO:
+                return new ModuloOperation(baseValue, secondValue);
+            case Constants.POWER:
+                return new PowerOperation(baseValue, secondValue);
+            case Constants.ROOT:
+                return new RootOperation(baseValue);
+            default:
+                return null;
+        }
+    }
+}

app/src/main/java/com/simplemobiletools/calculator/operation/PlusOperation.java

@@ -0,0 +1,16 @@
+package com.simplemobiletools.calculator.operation;
+
+import com.simplemobiletools.calculator.operation.base.BinaryOperation;
+import com.simplemobiletools.calculator.operation.base.Operation;
+
+public class PlusOperation extends BinaryOperation implements Operation {
+
+    protected PlusOperation(double baseValue, double secondValue) {
+        super(baseValue, secondValue);
+    }
+
+    @Override
+    public double getResult() {
+        return baseValue + secondValue;
+    }
+}

app/src/main/java/com/simplemobiletools/calculator/operation/PowerOperation.java

@@ -0,0 +1,20 @@
+package com.simplemobiletools.calculator.operation;
+
+import com.simplemobiletools.calculator.operation.base.BinaryOperation;
+import com.simplemobiletools.calculator.operation.base.Operation;
+import com.simplemobiletools.calculator.operation.base.UnaryOperation;
+
+public class PowerOperation extends BinaryOperation implements Operation {
+
+    protected PowerOperation(double baseValue, double secondValue) {
+        super(baseValue, secondValue);
+    }
+
+    @Override
+    public double getResult() {
+        double result = Math.pow(baseValue, secondValue);
+        if (Double.isInfinite(result) || Double.isNaN(result))
+            result = 0;
+        return result;
+    }
+}

app/src/main/java/com/simplemobiletools/calculator/operation/RootOperation.java

@@ -0,0 +1,16 @@
+package com.simplemobiletools.calculator.operation;
+
+import com.simplemobiletools.calculator.operation.base.Operation;
+import com.simplemobiletools.calculator.operation.base.UnaryOperation;
+
+public class RootOperation extends UnaryOperation implements Operation {
+
+    protected RootOperation(double value) {
+        super(value);
+    }
+
+    @Override
+    public double getResult() {
+        return Math.sqrt(value);
+    }
+}

app/src/main/java/com/simplemobiletools/calculator/operation/base/BinaryOperation.java

@@ -0,0 +1,11 @@
+package com.simplemobiletools.calculator.operation.base;
+
+public class BinaryOperation {
+    protected double baseValue;
+    protected double secondValue;
+
+    protected BinaryOperation(double baseValue, double secondValue) {
+        this.baseValue = baseValue;
+        this.secondValue = secondValue;
+    }
+}

app/src/main/java/com/simplemobiletools/calculator/operation/base/Operation.java

@@ -0,0 +1,5 @@
+package com.simplemobiletools.calculator.operation.base;
+
+public interface Operation {
+    double getResult();
+}

app/src/main/java/com/simplemobiletools/calculator/operation/base/UnaryOperation.java

@@ -0,0 +1,10 @@
+package com.simplemobiletools.calculator.operation.base;
+
+public class UnaryOperation {
+
+    protected double value;
+
+    protected UnaryOperation(double value) {
+        this.value = value;
+    }
+}