removing some old redundant operations

app/src/main/kotlin/com/simplemobiletools/calculator/helpers/CalculatorImpl.kt

@@ -2,7 +2,6 @@ package com.simplemobiletools.calculator.helpers
 
 import android.content.Context
 import com.simplemobiletools.calculator.R
-import com.simplemobiletools.calculator.operation.PercentOperation
 import com.simplemobiletools.commons.extensions.toast
 import net.objecthunter.exp4j.ExpressionBuilder
 
@@ -106,8 +105,7 @@ class CalculatorImpl(calculator: Calculator, private val context: Context) {
 
     // handle percents manually, it doesn't seem to be possible via net.objecthunter:exp4j. "%" is used only for modulo there
     private fun handlePercent() {
-        val operation = PercentOperation(baseValue, getSecondValue(), lastOperation)
+        val result = calculatePercentage(baseValue, getSecondValue(), lastOperation)
-        val result = operation.getResult()
         showNewFormula("${baseValue.format()}${getSign(lastOperation)}${getSecondValue().format()}%")
         inputDisplayedFormula = result.format()
         showNewResult(result.format())
@@ -168,6 +166,28 @@ class CalculatorImpl(calculator: Calculator, private val context: Context) {
         }
     }
 
+    private fun calculatePercentage(baseValue: Double, secondValue: Double, sign: String): Double {
+        return when (sign) {
+            MULTIPLY -> {
+                val partial = 100 / secondValue
+                baseValue / partial
+            }
+            DIVIDE -> {
+                val partial = 100 / secondValue
+                baseValue * partial
+            }
+            PLUS -> {
+                val partial = baseValue / (100 / secondValue)
+                baseValue.plus(partial)
+            }
+            MINUS -> {
+                val partial = baseValue / (100 / secondValue)
+                baseValue.minus(partial)
+            }
+            else -> baseValue / (100 * secondValue)
+        }
+    }
+
     private fun showNewResult(value: String) {
         callback!!.showNewResult(value, context)
     }

app/src/main/kotlin/com/simplemobiletools/calculator/operation/DivideOperation.kt

@@ -1,9 +0,0 @@
-package com.simplemobiletools.calculator.operation
-
-import com.simplemobiletools.calculator.operation.base.BinaryOperation
-import com.simplemobiletools.calculator.operation.base.Operation
-
-class DivideOperation(baseValue: Double, secondValue: Double) : BinaryOperation(baseValue, secondValue), Operation {
-
-    override fun getResult() = baseValue / secondValue
-}

app/src/main/kotlin/com/simplemobiletools/calculator/operation/MinusOperation.kt

@@ -1,9 +0,0 @@
-package com.simplemobiletools.calculator.operation
-
-import com.simplemobiletools.calculator.operation.base.BinaryOperation
-import com.simplemobiletools.calculator.operation.base.Operation
-
-class MinusOperation(baseValue: Double, secondValue: Double) : BinaryOperation(baseValue, secondValue), Operation {
-
-    override fun getResult() = baseValue - secondValue
-}

app/src/main/kotlin/com/simplemobiletools/calculator/operation/MultiplyOperation.kt

@@ -1,9 +0,0 @@
-package com.simplemobiletools.calculator.operation
-
-import com.simplemobiletools.calculator.operation.base.BinaryOperation
-import com.simplemobiletools.calculator.operation.base.Operation
-
-class MultiplyOperation(baseValue: Double, secondValue: Double) : BinaryOperation(baseValue, secondValue), Operation {
-
-    override fun getResult() = baseValue * secondValue
-}

app/src/main/kotlin/com/simplemobiletools/calculator/operation/OperationFactory.kt

@@ -1,19 +0,0 @@
-package com.simplemobiletools.calculator.operation
-
-import com.simplemobiletools.calculator.helpers.*
-import com.simplemobiletools.calculator.operation.base.Operation
-
-object OperationFactory {
-
-    fun forId(id: String, baseValue: Double, secondValue: Double): Operation? {
-        return when (id) {
-            PLUS -> PlusOperation(baseValue, secondValue)
-            MINUS -> MinusOperation(baseValue, secondValue)
-            DIVIDE -> DivideOperation(baseValue, secondValue)
-            MULTIPLY -> MultiplyOperation(baseValue, secondValue)
-            POWER -> PowerOperation(baseValue, secondValue)
-            ROOT -> RootOperation(baseValue, secondValue)
-            else -> null
-        }
-    }
-}

app/src/main/kotlin/com/simplemobiletools/calculator/operation/PercentOperation.kt

@@ -1,35 +0,0 @@
-package com.simplemobiletools.calculator.operation
-
-import com.simplemobiletools.calculator.helpers.DIVIDE
-import com.simplemobiletools.calculator.helpers.MINUS
-import com.simplemobiletools.calculator.helpers.MULTIPLY
-import com.simplemobiletools.calculator.helpers.PLUS
-import com.simplemobiletools.calculator.operation.base.BinaryOperation
-import com.simplemobiletools.calculator.operation.base.Operation
-
-class PercentOperation(baseValue: Double, secondValue: Double, val sign: String) : BinaryOperation(baseValue, secondValue), Operation {
-
-    override fun getResult(): Double {
-        return when (sign) {
-            MULTIPLY -> {
-                val partial = 100 / secondValue
-                baseValue / partial
-            }
-            DIVIDE -> {
-                val partial = 100 / secondValue
-                baseValue * partial
-            }
-            PLUS -> {
-                val partial = baseValue / (100 / secondValue)
-                baseValue.plus(partial)
-            }
-            MINUS -> {
-                val partial = baseValue / (100 / secondValue)
-                baseValue.minus(partial)
-            }
-            else -> {
-                baseValue / (100 * secondValue)
-            }
-        }
-    }
-}

app/src/main/kotlin/com/simplemobiletools/calculator/operation/PlusOperation.kt

@@ -1,9 +0,0 @@
-package com.simplemobiletools.calculator.operation
-
-import com.simplemobiletools.calculator.operation.base.BinaryOperation
-import com.simplemobiletools.calculator.operation.base.Operation
-
-class PlusOperation(baseValue: Double, secondValue: Double) : BinaryOperation(baseValue, secondValue), Operation {
-
-    override fun getResult() = baseValue + secondValue
-}

app/src/main/kotlin/com/simplemobiletools/calculator/operation/PowerOperation.kt

@@ -1,18 +0,0 @@
-package com.simplemobiletools.calculator.operation
-
-import com.simplemobiletools.calculator.operation.base.BinaryOperation
-import com.simplemobiletools.calculator.operation.base.Operation
-import kotlin.math.pow
-
-class PowerOperation(baseValue: Double, secondValue: Double) : BinaryOperation(baseValue, secondValue), Operation {
-
-    override fun getResult(): Double {
-        val result = baseValue.pow(secondValue)
-
-        return if (java.lang.Double.isInfinite(result) || java.lang.Double.isNaN(result))
-            0.0
-        else {
-            result
-        }
-    }
-}

app/src/main/kotlin/com/simplemobiletools/calculator/operation/RootOperation.kt

@@ -1,10 +0,0 @@
-package com.simplemobiletools.calculator.operation
-
-import com.simplemobiletools.calculator.operation.base.BinaryOperation
-import com.simplemobiletools.calculator.operation.base.Operation
-import kotlin.math.sqrt
-
-class RootOperation(baseValue: Double, secondValue: Double) : BinaryOperation(baseValue, secondValue), Operation {
-
-    override fun getResult() = sqrt(secondValue) * baseValue
-}

app/src/main/kotlin/com/simplemobiletools/calculator/operation/base/BinaryOperation.kt

@@ -1,3 +0,0 @@
-package com.simplemobiletools.calculator.operation.base
-
-open class BinaryOperation protected constructor(protected val baseValue: Double, protected val secondValue: Double)

app/src/main/kotlin/com/simplemobiletools/calculator/operation/base/Operation.kt

@@ -1,5 +0,0 @@
-package com.simplemobiletools.calculator.operation.base
-
-interface Operation {
-    fun getResult(): Double
-}

app/src/main/kotlin/com/simplemobiletools/calculator/operation/base/UnaryOperation.kt

@@ -1,5 +0,0 @@
-package com.simplemobiletools.calculator.operation.base
-
-import java.math.BigDecimal
-
-open class UnaryOperation protected constructor(protected var value: BigDecimal)