Cannot Scroll Inside Flutter Dropdown Popup (Overlay) to Select Option - Appium FlutterDriver Java

[VarshiniProcessDrive]

Hello,
I'm automating a Flutter app using Appium FlutterDriver (Java). I'm able to scroll the main form and click on a dropdown, but I can't scroll inside the dropdown popup to select an option that’s not initially visible.

Problem:
Once the dropdown opens, it shows a scrollable list of options (e.g., "gst_rate_18"), but when I attempt to scroll using flutter:scrollUntilVisible, nothing happens or it fails silently.

Map<String, Object> scrollParams = new HashMap<>();
scrollParams.put("item", finder.byValueKey(targetKey));  // e.g., "gst_rate_18"
scrollParams.put("dxScroll", 0);
scrollParams.put("dyScroll", -25);

// Attempt to scroll within dropdown popup container
driver.executeScript("flutter:scrollUntilVisible", finder.byValueKey(containerKey), scrollParams);

I wait for the dropdown to appear, and I even retry locating the containerKey, which I assume is the dropdown list’s container.

Question:

How can I scroll inside a dropdown popup in Flutter to select an off-screen item (e.g., "gst_rate_18") using Appium Flutter Driver in Java?
Do Flutter dropdowns render with a widget that is not scrollable by default or not exposed to flutter:scrollUntilVisible?
Is there a recommended workaround or widget type I should target for such dropdowns?

Any help, sample code, or guidance is appreciated! Thanks in advance!

[Alpaca00]

Hello, most likely the issue is with the container key, which is not scrollable.

This is from the method documentation:
The scrollable must locate the scrolling widget that contains the item. Typically find.byType('ListView') or find.byType('CustomScrollView').

// Attempt to scroll within dropdown popup container
driver.executeScript("flutter:scrollUntilVisible", finder.byValueKey(containerKey), scrollParams);

You need to either add key directly to the View widget or find the appropriate widget using find.byType in the widget tree to anchor to