Merge pull request #6672 from bdach/negative-numbers-exist

Fix `TextBox` not allowing minus sign to be input in numerical type textboxes

Author: peppy

osu.Framework/Graphics/UserInterface/TextBox.cs

@@ -103,20 +103,22 @@ private bool canAddCharacter(char character)
                 // discard control/special characters.
                 return false;
 
-            var currentNumberFormat = CultureInfo.CurrentCulture.NumberFormat;
-
-            switch (InputProperties.Type)
+            if (InputProperties.Type.IsNumerical())
             {
-                case TextInputType.Decimal:
-                    return char.IsAsciiDigit(character) || currentNumberFormat.NumberDecimalSeparator.Contains(character);
+                bool validNumericalCharacter = false;
 
-                case TextInputType.Number:
-                case TextInputType.NumericalPassword:
-                    return char.IsAsciiDigit(character);
+                var currentNumberFormat = CultureInfo.CurrentCulture.NumberFormat;
 
-                default:
-                    return true;
+                validNumericalCharacter |= char.IsAsciiDigit(character);
+                validNumericalCharacter |= selectionLeft == 0 && currentNumberFormat.NegativeSign.Contains(character);
+
+                if (InputProperties.Type == TextInputType.Decimal)
+                    validNumericalCharacter |= currentNumberFormat.NumberDecimalSeparator.Contains(character);
+
+                return validNumericalCharacter;
             }
+
+            return true;
         }
 
         private bool readOnly;

osu.Framework/Input/TextInputType.cs

@@ -66,6 +66,20 @@ public static bool IsPassword(this TextInputType type)
             }
         }
 
+        public static bool IsNumerical(this TextInputType type)
+        {
+            switch (type)
+            {
+                case TextInputType.Number:
+                case TextInputType.NumericalPassword:
+                case TextInputType.Decimal:
+                    return true;
+
+                default:
+                    return false;
+            }
+        }
+
         public static bool SupportsIme(this TextInputType type) => type == TextInputType.Name || type == TextInputType.Text;
     }
 }