Add new validator to ignore special characters

Author: CORDEA

library/src/main/java/co/kyash/vtl/validators/NoSpecialCharacterValidator.kt

@@ -0,0 +1,45 @@
+package co.kyash.vtl.validators
+
+import android.content.Context
+import co.kyash.vtl.VtlValidationFailureException
+import io.reactivex.Completable
+import io.reactivex.schedulers.Schedulers
+
+/**
+ * Validation error when the text contains special characters.
+ */
+class NoSpecialCharacterValidator(
+        private val errorMessage: String
+) : VtlValidator {
+    companion object {
+        private const val VS15 = '\uFE0E'
+        private const val VS16 = '\uFE0F'
+
+        private const val ZERO_WIDTH_JOINER = '\u200D'
+        private const val ENCLOSING_KEYCAP = '\u20E3'
+    }
+
+    override fun validateAsCompletable(context: Context, text: String?): Completable =
+            Completable.fromRunnable {
+                if (!validate(text)) {
+                    throw VtlValidationFailureException(errorMessage)
+                }
+            }.subscribeOn(Schedulers.computation())
+
+    override fun validate(text: String?): Boolean {
+        if (text.isNullOrBlank()) {
+            return true
+        }
+        return text.none {
+            val type = Character.getType(it).toByte()
+            it == VS15
+                    || it == VS16
+                    || it == ZERO_WIDTH_JOINER
+                    || it == ENCLOSING_KEYCAP
+                    || type == Character.SURROGATE
+                    || type == Character.OTHER_SYMBOL
+        }
+    }
+
+    override fun getErrorMessage(): String? = errorMessage
+}