update plant action

lib/presentation/screens/actions/plant/widget_plant_supply.dart

   final changeSelectedSupply = Get.put(ChangeSupply());
   final changeSupplyUsing = Get.put(ChangeSupplyUsing());
   final changeUnit = Get.put(ChangeUnit());
-  final changeQuantity = Get.put(ChangeValueQuantity());
   final changeButton = Get.put(ChangeButtonInForm());
 
   @override
     changeSelectedSupply.initValue();
     changeSupplyUsing.init(widget.currentItems);
     changeUnit.initValue();
-    changeQuantity.changeQuantity("");
     changeButton.resetValue();
   }
 
                           ..tbSuppliesName = editedSupplyUsing.supplyName
                           ..unit = editedSupplyUsing.supplyUnit;
                         changeSelectedSupply.change(editedSupply);
-                        changeQuantity.changeQuantity(editedSupplyUsing.quantity
-                            .formatNumtoStringDecimal());
                         changeUnit
                             .updateListByUnitName(editedSupplyUsing.supplyUnit);
                         changeUnit.updateSelected(editedSupplyUsing.supplyUnit);
                         _dosageController.text = editedSupplyUsing.dosage;
+                        _quantityController.text = editedSupplyUsing.quantity
+                            .formatNumtoStringDecimal();
                       },
                       child: Card(
                           child: Stack(
             .toList(),
         onChanged: (value) {
           var currentQuantity = _quantityController.text;
-          changeQuantity.changeQuantity(currentQuantity);
-          num assignValue = changeQuantity.quantity.parseDoubleThousand();
+          num assignValue = currentQuantity.parseDoubleThousand();
           if (assignValue != null) {
             var oldSelected = data.selectedUnit;
             if (oldSelected == value) {
                   oldUnit: oldSelected,
                   newUnit: value);
             }
-            changeQuantity
-                .changeQuantity(assignValue.formatNumtoStringDecimal());
+            _quantityController.text = assignValue.formatNumtoStringDecimal();
           }
           changeUnit.updateSelected(value);
         },
   }
 
   _quantityField() {
-    return GetBuilder<ChangeValueQuantity>(builder: (_) {
-      WidgetsBinding.instance.addPostFrameCallback((timeStamp) {
-        var quantityValue = changeQuantity.quantity;
-        _quantityController.text = quantityValue;
-      });
-
-      return TextFormField(
-        keyboardType: TextInputType.numberWithOptions(decimal: true),
-        inputFormatters: [
-          ThousandsFormatter(
-              formatter: NumberFormat("#,###.##", "es"), allowFraction: true)
-        ],
-        decoration: InputDecoration(labelText: "Tổng lượng sử dụng"),
-        controller: _quantityController,
-      );
-    });
+    return TextFormField(
+      keyboardType: TextInputType.numberWithOptions(decimal: true),
+      inputFormatters: [
+        ThousandsFormatter(
+            formatter: NumberFormat("#,###.##", "es"), allowFraction: true)
+      ],
+      decoration: InputDecoration(labelText: "Tổng lượng sử dụng"),
+      controller: _quantityController,
+      onSaved: (newValue) {
+        print(newValue);
+      },
+      onChanged: (v) {
+        print(v);
+      },
+    );
   }
 
   _buttonInForm() {
                         borderRadius: new BorderRadius.circular(8.0)),
                     onPressed: () {
                       var currentSupply = changeSelectedSupply.currentSupply;
-                      changeQuantity.changeQuantity(_quantityController.text);
-                      var quantityWithCurrentSupplyUnit =
-                          UtilAction.convertUnit(
-                              inputValue:
-                                  changeQuantity.quantity.parseDoubleThousand(),
-                              oldUnit: changeUnit.selectedUnit,
-                              newUnit: changeSelectedSupply.currentSupply.unit);
                       if (currentSupply.id != null) {
+                        var quantityWithCurrentSupplyUnit =
+                            UtilAction.convertUnit(
+                                inputValue: _quantityController.text
+                                    .parseDoubleThousand(),
+                                oldUnit: changeUnit.selectedUnit,
+                                newUnit:
+                                    changeSelectedSupply.currentSupply.unit);
                         SuppliesUsing newSup = SuppliesUsing()
                           ..dosage = _dosageController.text
                           ..quantity = quantityWithCurrentSupplyUnit
                     onPressed: () {
                       var currentSupply = changeSelectedSupply.currentSupply;
                       if (currentSupply.id != null) {
-                        changeQuantity.changeQuantity(_quantityController.text);
                         var quantityWithCurrentSupplyUnit =
                             UtilAction.convertUnit(
-                                inputValue: changeQuantity.quantity
+                                inputValue: _quantityController.text
                                     .parseDoubleThousand(),
                                 oldUnit: changeUnit.selectedUnit,
                                 newUnit:
     _quantityController.text = "";
     changeUnit.initValue();
     changeSelectedSupply.initValue();
-    changeQuantity.changeQuantity("");
   }
 
   _hidenKeyboard(BuildContext context) {
   }
 }
 
-class ChangeValueQuantity extends GetxController {
-  String quantity = "";
-  void changeQuantity(String newQuantity) {
-    quantity = newQuantity;
-    update();
-  }
-}
-
 class ChangeButtonInForm extends GetxController {
   bool isEdit;
   void resetValue() {