Struggling to find a suitable way to implement scrolling and updating data in a loop

[EddRobinson]

I'll try and explain this the best way I can.
I basically have a background thread that every 10ms sends a load of commands through the serial port and then receives a lot of data back which is decoded and displayed in my program.

I have a List that stores the received data and then displays it in labels. But, I'm having an issue finding the best way to have it constantly updating but also have the list in a scroll-able view.

I originally had a FrameView that displayed all the data and that was refreshing every 10ms and working perfectly, but struggled to implement scrolling.

I've recently switched to a ListView, which was near perfect, scrolling was working and everything was displaying, except it only updated when there was mouse movement / keyboard input. Not ideal.

Using the SetSourceAsync Task, I've managed to achieve the constant update of the values needed, but it interferes with the scrolling and constantly moves back to the top of the list (so you can't scroll down).

I'm unsure what else try or have I overlooked a simple way of implementing this?

Many thanks in advanced

[BDisp]

You must update inside the Application.Mainloop.Invoke to use the main thread.

[EddRobinson]

I am, that's how I managed to get the data to constantly update as required.

The issue is then, that it interferes with the scrolling

[BDisp]

Ok. If you are using a ListView add new items to the source and use the MoveEnd method to scroll to end. You must not update the ListView source but add news items to the List. Don't forget to use SetNeedsDisplay method.

[BDisp]

You must to add the ListView with the source into the initial window and not in the thread.

[EddRobinson]

Awesome dude, thank you very much.

Is there a way for automatic Text Wrapping using ListView?

[BDisp]

No, you have to implement yourself by using the TextFormatter.WordWrap, using a custom class with an override ToString(). Also by subclassing the IListDataSource in the ListView. Currently ListView has the limitation to have a height length of one. Another option is using the TextView with word wrap enabled.

[tznind]

In the past I have struggled to get TextView working nicely with scrolling text, see this PR that I abandonned if you want to go down this route and get a headstart: #1838

One way to handle the multi line issue is to render on one line (e.g. with ListView or TableView) and then have a key to pop out the full message into a modal dialog.

There was a cool application written recently by @aaronhudon for lumber packing which had scrolling data using TableView. If your data has timestamps or warning levels or other stuff you want to store in a tabular format then it could be nice:

#2387

Also since it sounds like you are getting into creating a project in Terminal.Gui I thought I would give a shout out shameless plug to the designer (incase you didn't know about it): https://github.com/gui-cs/TerminalGuiDesigner . It speeds up building dialogs and popups and stuff quite a bit and can give you a headstart on making cool apps.

I have seen several users wanting a solution for scrolling readonly text UI. Maybe we should put the time into developing a dedicated view for it. Either by subclassing TextView or just from scratch.

[EddRobinson]

No, you have to implement yourself by using the TextFormatter.WordWrap, using a custom class with an override ToString(). Also by subclassing the IListDataSource in the ListView. Currently ListView has the limitation to have a height length of one. Another option is using the TextView with word wrap enabled.

It's fine, I have implemented a workaround that works for my use case using ListView, so I'm happy.

In the past I have struggled to get TextView working nicely with scrolling text, see this PR that I abandonned if you want to go down this route and get a headstart: #1838

One way to handle the multi line issue is to render on one line (e.g. with ListView or TableView) and then have a key to pop out the full message into a modal dialog.

There was a cool application written recently by @aaronhudon for lumber packing which had scrolling data using TableView. If your data has timestamps or warning levels or other stuff you want to store in a tabular format then it could be nice:

#2387

Also since it sounds like you are getting into creating a project in Terminal.Gui I thought I would give a shout out shameless plug to the designer (incase you didn't know about it): https://github.com/gui-cs/TerminalGuiDesigner . It speeds up building dialogs and popups and stuff quite a bit and can give you a headstart on making cool apps.

I have seen several users wanting a solution for scrolling readonly text UI. Maybe we should put the time into developing a dedicated view for it. Either by subclassing TextView or just from scratch.

Thankyou for the useful links. Scrolling readonly text UI would have been perfect for me, I have ended up using 3 listviews and 1 textview for my project, and 2 of those 4 views are essentially "read only".

[EddRobinson]

Another thing. So I have my ListView displaying a string list, I'm unsure how to "do stuff" when I click on something in that List.

I can see from the API reference that I need to create an event - OpenSelectedItem.

But I'm not entirely sure how to make it all function. Maybe it's my experience level (2 years in University and currently on an Industrial Year), but I'm having a hard time following a lot of the documentation

[BDisp]

What you need to do is subscribe the OpenSelectedItem event by setting like this:

myListView.OpenSelectedItem += (e) => { doSomething };

In v2 is:

myListView.OpenSelectedItem += (s, e) => { doSomething };

There is also another event that is SelectedItemChanged.

[EddRobinson]

Ahhh, many thanks.

[BDisp]

You welcome. You also can use a method like this:

myListView.OpenSelectedItem += DoSomething();

private void DoSomething(object s, ListViewItemEventArgs e)
{
  ...
}