diff --git a/src/demoreadersettings.h b/src/demoreadersettings.h
new file mode 100644
--- /dev/null
+++ b/src/demoreadersettings.h
@@ -0,0 +1,48 @@
+/*
+  Copyright © 2018 Hasan Yavuz Özderya
+
+  This file is part of serialplot.
+
+  serialplot 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.
+
+  serialplot 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 serialplot.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef DEMOREADERSETTINGS_H
+#define DEMOREADERSETTINGS_H
+
+#include <QWidget>
+
+namespace Ui {
+class DemoReaderSettings;
+}
+
+class DemoReaderSettings : public QWidget
+{
+    Q_OBJECT
+
+public:
+    explicit DemoReaderSettings(QWidget *parent = 0);
+    ~DemoReaderSettings();
+
+    unsigned numChannels() const;
+    /// Doesn't signal `numChannelsChanged`.
+    void setNumChannels(unsigned value);
+
+private:
+    Ui::DemoReaderSettings *ui;
+
+signals:
+    void numChannelsChanged(unsigned);
+};
+
+#endif // DEMOREADERSETTINGS_H