Fixes #1358. Attribute.Foreground / Attribute.Background now working with CursesDriver

[BDisp]

To allowing some test on some specifics ConsoleDriver features, the initialization should be done in the Init method (ConsoleDriver) and in the Setup (IMainLoopDriver), instead in the constructors.

[BDisp]

282 The active test run was aborted. Reason: Test host process crashed : Error opening terminal: unknown.

I don't know what going here.

[tznind]

282 The active test run was aborted. Reason: Test host process crashed : Error opening terminal: unknown.

I don't know what going here.

Looks like there are a lot of failed calls to xclip right before the crash message (although that could be coincidence). The issue manifested in 9abcdec right? What exactly does that commit do? Is it possible that that commit makes some tests use the 'real' driver when previously they used FakeDriver?

The error message seems to crop up a lot in real life (i.e. outside of CI) and be associated with the variable $TERM not being defined (also here)

It is also the commit that introduces MakeAttribute_Testing_Almost_All_Drivers which is explicitly going to construct the Terminal.Gui.CursesDriver. Is that the first time any test has constructed that class? maybe it doesn't construct properly given some environmental considerations. Since the error message seems to crop up quite often if you search for it is it possible it is coming from ncurses itself?

[BDisp]

In the last commit I didn't see any error caused by the xclip, only in the previous.
I run all the unit tests on Windows, Linux and Mac without any problems.

Normally I need to export TERM environment variable on Docker images. Maybe the server is not prepared to run a real terminal in Linux.

Is that the first time any test has constructed that class?

Yes, is the first time and maybe the environment is not properly prepared to run a terminal in the server image. But I'll need some help for this, please. Thanks.

[tznind]

Ok I have enabled GitHub Actions in my fork of the repo (actions are disabled by default in forks) and have created a minimum repro of the issue:

tznind#19

Its a PR from a branch to main in my repo because the build test workflow seemed to want that in order to run.

I'll do a bit of exploring but I've also noticed that Console.WriteLine throws NotImplementedException in the CI container so it might be that it's simply not designed to run a real console session as you say.

[BDisp]

I'll do a bit of exploring but I've also noticed that Console.WriteLine throws NotImplementedException in the CI container so it might be that it's simply not designed to run a real console session as you say.

With the WindowsDriver and NetDriver, using windows console, you can't create an handle to a real console session. This the reason why I removed this initialization from the drivers constructors to the Init method. So we must avoid using Console functions.
The CursesDriver is the only that give no error creating a handle to a window and we need to call The Init and the End methods, because ncurses need to load the libraries to deal with the colors functions.

[tznind]

Yup, seems as soon as you call Init ncurses crashes hard (in CI container). It might be that we just cant test this functionality this way and scrap the test?

I tried setting environment variable TERM but didn't help and felt hacky anyway.

[BDisp]

It looks like it will have to be. Do you think I should also discard all changes to the drivers?

[tznind]

It looks like it will have to be. Do you think I should also discard all changes to the drivers?

Its up to you, I think the important thing is to fix the Foreground/Background color issue itself which is what this PR does.

I think changing Constructor/Init logic is something else and if it was only done to delay the 'error creating a handle' exception then we probably don't need/want that behaviour change.

[tznind]

Great stuff! I had a little play around with your InvertColors scenario to make it cooler. If you don't like it you can ignore it:

List<Label> labels = new List<Label> ();
var foreColors = Enum.GetValues (typeof (Color)).Cast<Color> ().ToArray ();
for (int y = 0; y < foreColors.Length; y++) {

	var fore = foreColors [y];
	var back = foreColors [(y + 1) % foreColors.Length];
	var color = Application.Driver.MakeAttribute (fore, back);

	var label = new Label ($"{fore} on {back}") {
		ColorScheme = new ColorScheme (),
		Y = y
	};
	label.ColorScheme.Normal = color;
	Win.Add (label);
	labels.Add (label);
}

var button = new Button ("Invert color!") {
	X = Pos.Center (),
	Y = foreColors.Length+1,
};
button.Clicked += () => {

	foreach(var label in labels) {
		var color = label.ColorScheme.Normal;
		color = Application.Driver.MakeAttribute (color.Background, color.Foreground);

		label.ColorScheme.Normal = color;
		label.Text = $"{color.Foreground} on {color.Background}";
		label.SetNeedsDisplay ();

	}
};

[tig]

Nice!