It is not possible to move the cursor outside the active buffer using ANSI commands #5042

DevTester425 · 2024-04-22T07:44:25Z

DevTester425
Apr 22, 2024

Please describe the solution how to move the cursor to position 1;1 if term.buffer.active.baseY > 0.
If this cannot be done by ANSI commands, describe any method.

Details

Browser and browser version: all
OS version: all
xterm.js version: 5.1.0

Steps to reproduce

run code

<!doctype html>
  <html>
    <head>
      <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/xterm@5.1.0/css/xterm.min.css" />
      <script src="https://cdn.jsdelivr.net/npm/xterm@5.1.0/lib/xterm.min.js"></script>
    </head>
    <body>
      <div id="terminal"></div>
      <script>
        (async () => {
            var term = new Terminal({
                rows: 10
            });
            term.open(document.getElementById('terminal'));
            await write(term, '\r\n1\r\n2\r\n3\r\n4\r\n5\r\n6\r\n7\r\n8\r\n9\r\n10\r\n11\r\n12\r\n13\r\n14\r\n15');
            term.scrollToTop();
            await write(term, '\u001b[1;1H');
 
            async function write(term, data) {
                return new Promise((resolve) => {
                    term.write(data, resolve)
                })
            }
        })()
      </script>
    </body>
  </html>

Result

Answered by Tyriar

Apr 22, 2024

This is by design, once there's content to scroll you cannot change it outside of clearing it entirely.

View full answer

Tyriar · 2024-04-22T08:50:13Z

Tyriar
Apr 22, 2024
Maintainer

This is by design, once there's content to scroll you cannot change it outside of clearing it entirely.

5 replies

DevTester425 Apr 23, 2024
Author

Thanks for the answer.
This behavior is different from the behavior of terminals.
Is there no way to achieve this?

jerch Apr 23, 2024
Maintainer

This behavior is different from the behavior of terminals.

Nope, thats exactly as all xterm-like terminal emulators behave.

Is there no way to achieve this?

Not an easy one. The hard one would be to fork the repo and expand the cursor logic to the full scrollbuffer yourself. We wont do that, as its not how it is intended to work in terminals.

DevTester425 Apr 24, 2024
Author

Thanks for the answer.
How about the approach of resizing the terminal every time the content doesn't fit in the active buffer?
See the code below.

<!doctype html>
  <html>
    <head>
      <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/xterm@5.1.0/css/xterm.min.css" />
      <script src="https://cdn.jsdelivr.net/npm/xterm@5.1.0/lib/xterm.min.js"></script>
    </head>
    <body>
      <div id="terminal"></div>
      <script>
        (async () => {
            var term = new Terminal({
              rows: 10
            });
            term.open(document.getElementById('terminal'));
            
            for (let i = 0; i < 100; i++) {
              await write(term, '\r\n' + (i + 1));
            }
            await write(term, '\u001b[1;1H');

            async function write(term, data) {
                return new Promise((resolve) => {
                  term.write(data, resolve);
                  if (term.buffer.active.baseY > 0) {
                    term.resize(term.cols, term.rows + term.buffer.active.baseY);
                  }
                })
            }
            })()
      </script>
    </body>
  </html>

Tyriar Apr 24, 2024
Maintainer

You could do that, but you're going to run into performance problems eventually if it gets big enough

DevTester425 Apr 24, 2024
Author

Thanks for the answer.

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It is not possible to move the cursor outside the active buffer using ANSI commands #5042

DevTester425 Apr 22, 2024

Details

Steps to reproduce

Replies: 1 comment · 5 replies

Tyriar Apr 22, 2024 Maintainer

DevTester425 Apr 23, 2024 Author

jerch Apr 23, 2024 Maintainer

DevTester425 Apr 24, 2024 Author

Tyriar Apr 24, 2024 Maintainer

DevTester425 Apr 24, 2024 Author

DevTester425
Apr 22, 2024

Replies: 1 comment 5 replies

Tyriar
Apr 22, 2024
Maintainer

DevTester425 Apr 23, 2024
Author

jerch Apr 23, 2024
Maintainer

DevTester425 Apr 24, 2024
Author

Tyriar Apr 24, 2024
Maintainer

DevTester425 Apr 24, 2024
Author