Added ASCII display header

include/ascii_display.h

@@ -0,0 +1,80 @@
+/*
+ * sadplay - AdLib music player with graphics.
+ * 
+ * ascii_display.h - ASCII display interface.
+ * 
+ * Copyright (C) 2025 Marco Confalonieri <marco at marcoconfalonieri.it>
+ *
+ * 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/>.
+ */
+
+#ifndef _SADPLAY_ASCII_DISPLAY_H_
+#define _SADPLAY_ASCII_DISPLAY_H_
+
+#include "display.h"
+
+/**
+ * The display class represents an abstract view for the application.
+ */
+class ascii_display: public display {
+    public:
+        /**
+         * Constructor.
+         */
+        ascii_display();
+
+        /**
+         * Destructor.
+         */
+        ~ascii_display();
+
+        /**
+         * Initializes the view.
+         *
+         * @return  true if correctly initialized
+         */
+        bool initialize();
+
+        /**
+         * Updates the channel bar.
+         */
+        void update_channel_bar();
+
+        /**
+         * Returns the channel bar instance.
+         * 
+         * @return  the channel bar
+         */
+        channel_bar* get_channel_bar();
+
+        /**
+         * Returns the maximum number of supported channels.
+         * 
+         * @return the number of supported channels
+         */
+        int get_max_channels();
+
+    private:
+        /**
+         * Number of channels.
+         */
+        static const int ONE_CHANNEL;
+
+        /**
+         * Frequency limits
+         */
+        static const double FREQ_LIMIT[];
+};
+
+#endif // _SADPLAY_ASCII_DISPLAY_H_