fix: Don't show un-necessary alert dialog on nutrient page (#1648)

* don't show un-necessary alert dialog on
nutrition page

* made isEdited function private

* return  true to let will pop scope pop to previous
screen

* added comments for better understanding

* localizations.okay instead of localizations.close

packages/smooth_app/lib/pages/product/nutrition_page_loaded.dart

@@ -111,6 +111,7 @@ class _NutritionPageLoadedState extends State<NutritionPageLoaded> {
           ),
         ),
       ),
+      //return a boolean to decide whether to return to previous page or not
       onWillPop: () => _showCancelPopup(localizations),
     );
   }
@@ -360,28 +361,40 @@ class _NutritionPageLoadedState extends State<NutritionPageLoaded> {
         label: Text(appLocalizations.nutrition_page_add_nutrient),
       );
 
-  Future<bool> _showCancelPopup(AppLocalizations localizations) async =>
-      await showDialog<bool>(
-        context: context,
-        builder: (BuildContext context) => AlertDialog(
-          shape: const RoundedRectangleBorder(
-            borderRadius: ROUNDED_BORDER_RADIUS,
-          ),
-          title: Text(localizations.general_confirmation),
-          content: Text(localizations.nutrition_page_close_confirmation),
-          actions: <TextButton>[
-            TextButton(
-              child: Text(localizations.cancel.toUpperCase()),
-              onPressed: () => Navigator.pop(context, false),
-            ),
-            TextButton(
-              child: Text(localizations.close.toUpperCase()),
-              onPressed: () => Navigator.pop(context, true),
+  Future<bool> _showCancelPopup(AppLocalizations localizations) async {
+    //if no changes made then returns true to the onWillPop
+    // allowing it to let the user return back to previous screen
+    if (!_isEdited()) {
+      return true;
+    }
+    return await showDialog<bool>(
+          context: context,
+          builder: (BuildContext context) => AlertDialog(
+            shape: const RoundedRectangleBorder(
+              borderRadius: ROUNDED_BORDER_RADIUS,
             ),
-          ],
-        ),
-      ) ??
-      false;
+            title: Text(localizations.general_confirmation),
+            content: Text(localizations.nutrition_page_close_confirmation),
+            actions: <TextButton>[
+              TextButton(
+                child: Text(localizations.cancel.toUpperCase()),
+                // returns false to onWillPop after the alert dialog is closed with cancel button
+                //blocking return to the previous screen
+                onPressed: () => Navigator.pop(context, false),
+              ),
+              TextButton(
+                child: Text(localizations.okay.toUpperCase()),
+                // returns true to onWillPop after the alert dialog is closed with close button
+                //letting return to the previous screen
+                onPressed: () => Navigator.pop(context, true),
+              ),
+            ],
+          ),
+        ) ??
+        // in case alert dialog is closed, a false is return
+        // blocking the return to the previous screen
+        false;
+  }
 
   Future<void> _validateAndSave(final AppLocalizations localizations,
       final LocalDatabase localDatabase) async {
@@ -437,4 +450,20 @@ class _NutritionPageLoadedState extends State<NutritionPageLoaded> {
       Navigator.of(context).pop(true);
     }
   }
+
+  bool _isEdited() {
+    for (final String key in _controllers.keys) {
+      final TextEditingController controller = _controllers[key]!;
+      if (_nutritionContainer.getValue(key) != null) {
+        if (_numberFormat.format(_nutritionContainer.getValue(key)) !=
+            controller.value.text) {
+          //if any controller is not equal to the value in the container
+          // then the form is edited, return true
+          return true;
+        }
+      }
+    }
+    //else form is not edited just return false
+    return false;
+  }
 }