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diff --git a/src/data/delimitedstringvalidator.h b/src/data/delimitedstringvalidator.h
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+/*
+    TikZiT - a GUI diagram editor for TikZ
+    Copyright (C) 2018 Aleks Kissinger
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+/*!
+  * A string validator which keeps curly braces matched. Used in various places
+  * to ensure the user doesn't make non-parseable .tikz or .tikzstyles files.
+  *
+  * Its validation function will return Acceptable if all curly braces are matched
+  * properly, Intermediate if all braces are matched except for possibly some opening
+  * curly braces, and Invalid if there are unmatched closing curly braces.
+  */
+
+#ifndef DELIMITEDSTRINGVALIDATOR_H
+#define DELIMITEDSTRINGVALIDATOR_H
+
+
+#include <QObject>
+#include <QValidator>
+
+
+class DelimitedStringValidator : public QValidator
+{
+    Q_OBJECT
+public:
+    DelimitedStringValidator(QObject *parent);
+    QValidator::State validate(QString &input, int &/*pos*/) const override;
+
+    /*!
+     * \brief fixup adds curly braces until all braces are matched (if possible)
+     * \param input
+     */
+    void fixup(QString &input) const override;
+private:
+    /*!
+     * \brief braceDepth computes the final (non-escaped) curly-brace depth of a given string
+     * \param input a string
+     * \return the final brace depth, or -1 if the depth *ever* drops below 0
+     */
+    int braceDepth(QString input) const;
+};
+
+#endif // DELIMITEDSTRINGVALIDATOR_H