Check isNotEmpty before insert prefix or suffix.

Author: joutvhu

CHANGELOG.md

@@ -2,3 +2,7 @@
 
 - Initial library
 - Support NumberTextInputFormatter, CurrencyTextInputFormatter and PercentageTextInputFormatter.
+
+## 1.0.0+1
+
+- Check isNotEmpty before insert prefix or suffix.

README.md

@@ -7,7 +7,7 @@ Number Text Input Formatter for Flutter.
 ```yaml
 # Add into pubspec.yaml
 dependencies:
-  number_text_input_formatter: ^1.0.0
+  number_text_input_formatter: ^1.0.0+1
 ```
 
 ## Usage

lib/src/editor.dart

@@ -15,6 +15,10 @@ abstract class TextValueEditor {
 
   String get text;
 
+  bool get isEmpty;
+
+  bool get isNotEmpty;
+
   TextEditingValue get inputValue;
 
   MutableTextRange? get selection;
@@ -55,6 +59,12 @@ class DefaultTextValueEditor implements TextValueEditor {
   @override
   int get length => codeUnits.length;
 
+  @override
+  bool get isEmpty => codeUnits.isEmpty;
+
+  @override
+  bool get isNotEmpty => codeUnits.isNotEmpty;
+
   DefaultTextValueEditor(this.inputValue)
       : selection = MutableTextRange.fromTextSelection(inputValue.selection),
         composingRegion = MutableTextRange.fromComposingRange(inputValue.composing),
@@ -195,11 +205,17 @@ class LookupTextValueEditor implements TextValueEditor {
     return editor[index];
   }
 
+  @override
+  String get text => editor.text;
+
   @override
   int get length => editor.length;
 
   @override
-  String get text => editor.text;
+  bool get isEmpty => editor.isEmpty;
+
+  @override
+  bool get isNotEmpty => editor.isNotEmpty;
 
   int get currentCode => editor[index];
 

lib/src/filter.dart

@@ -249,17 +249,19 @@ class TextNumberFilter {
   }
 
   void afterFilter() {
-    if (decimalPoint != null) {
-      if (decimalDigits == 0) {
-        insertDecimalDigits();
-      }
-    } else {
-      if (hasDecimalPoint) {
-        insertDecimalPoint();
+    if (editor.isNotEmpty) {
+      if (decimalPoint != null) {
+        if (decimalDigits == 0) {
+          insertDecimalDigits();
+        }
+      } else {
+        if (hasDecimalPoint) {
+          insertDecimalPoint();
+        }
       }
-    }
 
-    groupDigits();
+      groupDigits();
+    }
   }
 
   void insertDecimalDigits() {

lib/src/formatter.dart

@@ -117,11 +117,13 @@ class NumberTextInputFormatter extends TextInputFormatter {
         ..prepare({'removing': oldValue.text.length - 1 == newValue.text.length})
         ..filter();
 
-    if (prefix != null) {
-      state.prefix(prefix!);
-    }
-    if (suffix != null) {
-      state.suffix(suffix!);
+    if (state.isNotEmpty) {
+      if (prefix != null) {
+        state.prefix(prefix!);
+      }
+      if (suffix != null) {
+        state.suffix(suffix!);
+      }
     }
 
     return state.finalize();

pubspec.yaml

@@ -1,6 +1,6 @@
 name: number_text_input_formatter
 description: Number Text Input Formatter for Flutter
-version: 1.0.0
+version: 1.0.0+1
 
 homepage: https://github.com/joutvhu/number_text_input_formatter
 repository: https://github.com/joutvhu/number_text_input_formatter.git