From dc97c40b700a71ce7b5dfef5231374846c7e479b Mon Sep 17 00:00:00 2001
From: tibbi <tibor@kaputa.sk>
Date: Thu, 5 Nov 2020 23:04:53 +0100
Subject: [PATCH] do not allow prepending some numbers with zero

---
 .../calculator/helpers/CalculatorImpl.kt      | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/app/src/main/kotlin/com/simplemobiletools/calculator/helpers/CalculatorImpl.kt b/app/src/main/kotlin/com/simplemobiletools/calculator/helpers/CalculatorImpl.kt
index d07c2643..a49c04cb 100644
--- a/app/src/main/kotlin/com/simplemobiletools/calculator/helpers/CalculatorImpl.kt
+++ b/app/src/main/kotlin/com/simplemobiletools/calculator/helpers/CalculatorImpl.kt
@@ -79,6 +79,17 @@ class CalculatorImpl(calculator: Calculator, val context: Context) {
             inputDisplayedFormula = ""
         }
 
+        val valueToCheck = if (inputDisplayedFormula.startsWith("-")) {
+            inputDisplayedFormula.substring(1)
+        } else {
+            inputDisplayedFormula
+        }
+
+        val value = valueToCheck.substring(valueToCheck.indexOfAny(operations, 0, false) + 1)
+        if (value == "0" && number.toString().areDigitsOnly()) {
+            inputDisplayedFormula = inputDisplayedFormula.dropLast(1)
+        }
+
         inputDisplayedFormula += number
         setValue(inputDisplayedFormula)
     }
@@ -287,7 +298,13 @@ class CalculatorImpl(calculator: Calculator, val context: Context) {
     }
 
     private fun zeroClicked() {
-        val value = inputDisplayedFormula
+        val valueToCheck = if (inputDisplayedFormula.startsWith("-")) {
+            inputDisplayedFormula.substring(1)
+        } else {
+            inputDisplayedFormula
+        }
+
+        val value = valueToCheck.substring(valueToCheck.indexOfAny(operations, 0, false) + 1)
         if (value != "0") {
             addDigit(0)
         }