How do you detect and return to scroll position in VSA (to return to the last read Label)?

MIT App Inventor Help
1

I'm presenting a large group of labels to the user, all in a vertical scroll arrangement. To the user it appears like a chapter in a book in which the user is scrolling down through the chapter while reading it.

I'd like them to return to the same spot when they later restart the app. I don't see any VSA properties which indicate position or location. Any ideas of how to do this? How to know where the user was?

2

If you search you will find these:


3

Thanks...will check them out.

4

Is there a specific reason for using a large group of labels?

blocks

5

Thanks Chris. Yes I do need the labels because the purpose of the app is to separately adjust the font size, color, etc for each paragraph (based on importance). So I have almost 200 labels that I'm working with. It's working great and I am pleased with it. I just want to be able to return the reader to their prior approximate scroll position when they restart the app.

6

Unlike Buttons and other components, Labels do not have Events or Methods. If Labels had a Events or Methods you might be able to focus on one of the Labels.

You might try

  1. LabelPlus - Additional methods for the Label component

The extension provides Methods that you might be able to use to Focus on a Label using a RequestFocus Method and a LostFocus Event Block. Experiment, you may be able to use these Methods/Events to return to a Label.

  1. Make a List of your Existing Labels. Use the List to 'find' the last used Label possibly. You would have to experiment to find out if this is practical.

When you are successful, let us know. If not let us know what you tried.

  1. Use a different method. Possibly use the LabelPlus scrolling feature and conventional search for last read text when the user returns.
1 Like
7

Another solution would be HTML + CSS + a little Javascript if the adjustments are to be made on-the-fly.