moon
/
enigma-bbs
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Experimental UTF-8 -> CP437 (aka nix -> ansi) override to work around terms such as NR that report 'xterm' but want CP437

This commit is contained in:
Bryan Ashby 2019-01-12 10:31:03 -07:00
parent 372494e376
commit d5bd2d5adf
1 changed files with 72 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

73
core/connect.js
View File

@ -56,6 +56,74 @@ function ansiDiscoverHomePosition(client, cb) {
client.term.write(`${ansi.goHome()}${ansi.queryPos()}`); // go home, query pos
}
function ansiAttemptDetectUTF8(client, cb) {
//
// Trick to attempt and detect UTF-8. While there is a lot more than
// just UTF-8 and CP437, many those are the main concerns, when it comes
// terminals that for example tell us they are "xterm" but still want CP437.
//
// Try to detect UTF-8 by discovering the cursor position, writing some
// multi-byte UTF-8, and checking the position again. If the term is really
// UTF-8, we should get a proper position, otherwise we'll be further out.
//
// We currently only do this if the term hasn't already been ID'd as a
// "*nix" terminal -- that is, xterm, etc.
//
if(!client.term.isNixTerm()) {
return cb(null);
}
let posStage = 1;
let initialPosition;
let giveUpTimer;
const giveUp = () => {
client.removeListener('cursor position report', cprListener);
clearTimeout(giveUpTimer);
return cb(null);
};
const ASCIIPortion = ' Character encoding detection ';
const cprListener = (pos) => {
switch(posStage) {
case 1 :
posStage = 2;
initialPosition = pos;
clearTimeout(giveUpTimer);
giveUpTimer = setTimeout( () => {
return giveUp();
}, 2000);
client.once('cursor position report', cprListener);
client.term.rawWrite(`\u9760${ASCIIPortion}\u9760`); // Unicode skulls on each side
client.term.rawWrite(ansi.queryPos());
break;
case 2 :
{
clearTimeout(giveUpTimer);
const len = pos[1] - initialPosition[1];
if(!isNaN(len) && len >= ASCIIPortion.length + 6) { // CP437 displays 3 chars each Unicode skull
client.log.info('Terminal identified as UTF-8 but does not appear to be. Overriding to "ansi".');
client.setTermType('ansi');
}
}
return cb(null);
}
};
giveUpTimer = setTimeout( () => {
return giveUp();
}, 2000);
client.once('cursor position report', cprListener);
client.term.rawWrite(ansi.goHome() + ansi.queryPos());
}
function ansiQueryTermSizeIfNeeded(client, cb) {
if(client.term.termHeight > 0 || client.term.termWidth > 0) {
return cb(null);
@ -164,7 +232,7 @@ function connectEntry(client, nextMenu) {
// We still don't have something good for term height/width.
// Default to DOS size 80x25.
//
// :TODO: Netrunner is currenting hitting this and it feels wrong. Why is NAWS/ENV/CPR all failing???
// :TODO: Netrunner is currently hitting this and it feels wrong. Why is NAWS/ENV/CPR all failing???
client.log.warn( { reason : err.message }, 'Failed to negotiate term size; Defaulting to 80x25!');
term.termHeight = 25;
@ -175,6 +243,9 @@ function connectEntry(client, nextMenu) {
return callback(null);
});
},
function checkUtf8IfNeeded(callback) {
return ansiAttemptDetectUTF8(client, callback);
}
],
() => {
prepareTerminal(term);