stdin.js

"use strict";

const MASK_CHAR = "×";
function passwordify(input, maskChar) {
    maskChar = maskChar || MASK_CHAR;

    function ignore() {}
    function mask(node) {
        node.textContent = node.textContent.replace(/./g, maskChar);
    }

    let editor = input.QueryInterface(Ci.nsIDOMNSEditableElement)
                      .editor;

    editor.addEditActionListener({
        QueryInterface: XPCOMUtils.generateQI([Ci.nsIEditActionListener]),
        DidCreateNode: ignore,
        DidDeleteNode: ignore,
        DidDeleteSelection: ignore,
        DidDeleteText: ignore,
        DidInsertNode: ignore,
        DidInsertText: mask,
        DidJoinNodes: ignore,
        DidSplitNode: ignore,
        WillCreateNode: ignore,
        WillDeleteNode: ignore,
        WillDeleteSelection: ignore,
        WillDeleteText: ignore,
        WillInsertNode: mask,
        WillInsertText: ignore,
        WillJoinNodes: ignore,
        WillSplitNode: ignore
    });
}