terminal cursor style is changed when running tcell

[moson-mo]

When changing the cursor style in the terminal (f.e.: echo -e -n "\x1b[3 q" for blinking-underline)
and running tcell, it is changed back to the (default) blinking block.

Steps to reproduce:

1. execute echo -e -n "\x1b[3 q" to change the cursor style in terminal
2. run the following go program

package main

import (
	"fmt"
	"os"

	"github.com/gdamore/tcell/v2"
)

func main() {
	tcell.SetEncodingFallback(tcell.EncodingFallbackASCII)
	s, e := tcell.NewScreen()
	if e != nil {
		fmt.Fprintf(os.Stderr, "%v\n", e)
		os.Exit(1)
	}
	if e = s.Init(); e != nil {
		fmt.Fprintf(os.Stderr, "%v\n", e)
		os.Exit(1)
	}
	s.ShowCursor(0, 0)
	s.Show()
	s.Fini()
}

3. back in the terminal you'll noticed that the style is changed back to the default one.

This happens since commit 761abf6
It's probably because of the default value of 0 for cursorStyle in tScreen.
I guess to fix this it would be needed to get the current setting when tcell is starting and assigning it to cursorStyle. No clue if/how that is possible though.

ref: moson-mo/pacseek#19

[gdamore]

There is no way (that I am aware of) to query the existing cursor style. So we can't save and restore it.

One thing we could do is conditionalize the "restoring" of the cursor style upon whether an application changes it or not.

If this bothers you greatly, you might see if your terminal emulator can support changing the "default". The value 0 is the "default" -- so terminals should restore the cursor to whatever the user preference for the default is.

[moson-mo]

Hi @gdamore
thanks for your quick reply. I guess setting the default style is the terminal itself is the way to go indeed.
Just tried it with xfce4-terminal and it works fine that way.

Closing this.

btw. thank you for this awesome project.