How i can detect arrow keys with arsd.terminal?

[Adam D. Ruppe]

On Friday, 11 April 2025 at 13:51:59 UTC, Zoda wrote:
> i want to detect arrow keys with 
> arsd.terminal.RealTimeConsoleInput,
> how can i do that?

The secret is kinda tucked away but here's the enum that defines 
these keys as magic characters:

https://opendlang.org/library/arsd.terminal.KeyboardEvent.Key.html

You can use that in a switch along with other characters in a 
getch loop:

```
import arsd.terminal;

void main() {
         auto terminal = Terminal(ConsoleOutputType.linear);
         auto rtti = RealTimeConsoleInput(&terminal, 
ConsoleInputFlags.raw);
         loop: while(true) {
                 switch(rtti.getch()) {
                         case 'q': // other characters work as 
chars in the switch
                                 break loop;
                         case KeyboardEvent.Key.F1: // also f-keys 
via that enum
                                 terminal.writeln("You pressed 
F1!");
                         break;
                         case KeyboardEvent.Key.LeftArrow: // 
arrow keys, etc.
                                 terminal.writeln("left");
                         break;
                         case KeyboardEvent.Key.RightArrow:
                                 terminal.writeln("right");
                         break;
                         default: {}
                 }
         }
}
```

See other notes at the top of this page:
https://opendlang.org/library/arsd.terminal.KeyboardEvent.html


If you also need to check for things like shift+arrows, that may 
be possible (depends on your terminal) but will require you write 
a full event loop with the `nextEvent` function and it is quite a 
bit more involved.

https://opendlang.org/library/arsd.terminal.RealTimeConsoleInput.nextEvent.html


Note that if you want to just get a line of text from an editor, 
that's what Terminal.getline is for, has some features similar to 
gnu readline. It can be extensively customized as well to add tab 
complete, syntax highlighting, and more by subclassing 
LineGetter. You can also run your own event loop and filter the 
events you forward to the linegetter and custom responding to 
others for maximum control, but that gets quite involved.