Support feature DEC Locator Mode

[christianparpart]

trafficstars

Accidentally already advertised (needs to be fixed), the DEC Locator Mode might (or might not?) be interesting to support. I am not sure what apps can make use of it yet. And finding documentation apart from how to enable/disable it I didn't find quickly. It's still worth looking into it.

[j4james]

If you have the DEC STD 070 manual, it's documented in section 13 (Text Locator Extension). There are also a bunch of tests in Vttest (see menu 11.8.5.8) that you can use to check your implementation.

[j4james]

If you want some more example to test with, here are a couple of drawing apps:

• https://github.com/saitoha/libsixel/tree/examples/examples/drawing
• https://github.com/aiju/sixeldraw

I haven't tried these myself, by they claim to work with Sixel and DEC locator mode.

[christianparpart]

@j4james For the Nth time I'm trying to revive my DEC text locator PR, every time I realize that it's not actually too trivial so each time I start over again by reading parts of the spec at least. Sad facts first. :-)

Now, I thought I might shortcut and interactively get an impression by using vttest on xterm. However, I simply can't get xterm to show me anything in vttest on 11.8.5.8.

My ~/.Xresources looks like that:

XTerm*.mainMenu.label:          File
XTerm*.vtMenu.label:            Options
XTerm*.fontMenu.label:          View
XTerm*.geometry: 100x30
XTerm*faceName: JetBrains Mono Nerd Font Mono
XTerm*faceSize: 14
XTerm*decTerminalID: vt340
XTerm*numColorRegisters: 256

Not really much in it. Do you happen to know if there's anything missing or haven't you n/ever tried on Xterm or another TE?

I thought maybe you know it, thanks anyways, Christian.

[christianparpart]

Turns out my xterm doesn't respond with 29 on DA1 but only ^[[?63;1;2;4;6;9;15;16;22;28c. Hmm...

[j4james]

If I remember correctly, you need to build XTerm with the --enable-dec-locator option set.