remove everything related to factorials, we dont even have it

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

@@ -129,11 +129,6 @@ class CalculatorImpl(calculator: Calculator, val context: Context) {
         calculateResult()
     }
 
-    private fun handleFactorial() {
-        baseValue = getDisplayedNumberAsDouble()
-        calculateResult()
-    }
-
     private fun calculateResult(update: Boolean = true) {
         if (update) {
             updateFormula()
@@ -185,7 +180,7 @@ class CalculatorImpl(calculator: Calculator, val context: Context) {
             handlePercent()
             lastKey = tempOp
             lastOperation = tempOp
-        } else if (lastKey == DIGIT && operation != ROOT && operation != FACTORIAL) {
+        } else if (lastKey == DIGIT && operation != ROOT) {
             handleResult()
             if (inputDisplayedFormula.last() != '+' &&
                 inputDisplayedFormula.last() != '-' &&
@@ -205,9 +200,6 @@ class CalculatorImpl(calculator: Calculator, val context: Context) {
         if (operation == ROOT) {
             handleRoot()
             resetValue = false
-        } else if (operation == FACTORIAL) {
-            handleFactorial()
-            resetValue = false
         }
     }
 
@@ -318,7 +310,6 @@ class CalculatorImpl(calculator: Calculator, val context: Context) {
         PERCENT -> "%"
         POWER -> "^"
         ROOT -> "√"
-        FACTORIAL -> "!"
         else -> ""
     }
 

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

@@ -12,7 +12,6 @@ const val ROOT = "root"
 const val DECIMAL = "decimal"
 const val CLEAR = "clear"
 const val RESET = "reset"
-const val FACTORIAL = "factorial"
 
 const val NAN = "NaN"
 const val ZERO = "zero"

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

@@ -86,7 +86,7 @@ class MyWidgetProvider : AppWidgetProvider(), Calculator {
 
     override fun onReceive(context: Context, intent: Intent) {
         when (val action = intent.action) {
-            DECIMAL, ZERO, ONE, TWO, THREE, FOUR, FIVE, SIX, SEVEN, EIGHT, NINE, EQUALS, CLEAR, RESET, PLUS, MINUS, MULTIPLY, DIVIDE, PERCENT, POWER, ROOT, FACTORIAL -> myAction(action, context)
+            DECIMAL, ZERO, ONE, TWO, THREE, FOUR, FIVE, SIX, SEVEN, EIGHT, NINE, EQUALS, CLEAR, RESET, PLUS, MINUS, MULTIPLY, DIVIDE, PERCENT, POWER, ROOT -> myAction(action, context)
             else -> super.onReceive(context, intent)
         }
     }
@@ -111,7 +111,7 @@ class MyWidgetProvider : AppWidgetProvider(), Calculator {
             EQUALS -> calc!!.handleEquals()
             CLEAR -> calc!!.handleClear()
             RESET -> calc!!.handleReset()
-            PLUS, MINUS, MULTIPLY, DIVIDE, PERCENT, POWER, ROOT, FACTORIAL -> calc!!.handleOperation(action)
+            PLUS, MINUS, MULTIPLY, DIVIDE, PERCENT, POWER, ROOT -> calc!!.handleOperation(action)
         }
     }
 

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

@@ -1,21 +0,0 @@
-package com.simplemobiletools.calculator.operation
-
-import com.simplemobiletools.calculator.operation.base.Operation
-import com.simplemobiletools.calculator.operation.base.UnaryOperation
-import java.math.BigDecimal
-
-class FactorialOperation(value: BigDecimal) : UnaryOperation(value), Operation {
-
-    override fun getResult(): BigDecimal {
-        return if (value.compareTo(BigDecimal.ZERO) == 0 || value.compareTo(BigDecimal.ONE) == 0 ){
-            BigDecimal.ONE
-        } else{
-            var result = BigDecimal.ONE
-            val base = value.toInt()
-            for(i in 1..base){
-                result = result.multiply(BigDecimal(i))
-            }
-            result
-        }
-    }
-}

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

@@ -15,7 +15,6 @@ object OperationFactory {
             PERCENT -> PercentOperation(baseValue, secondValue)
             POWER -> PowerOperation(baseValue, secondValue)
             ROOT -> RootOperation(baseValue)
-            FACTORIAL -> FactorialOperation(baseValue)
             else -> null
         }
     }