#90 [WIP] merged metadata management for channel state, decoder states and audio metadata into a new metadata class. The new metadata class is maintained for each decoding audio channel, or in the future, a decoding TDMA channel. Audio playback, recording and streaming all use the same metadata object for the channel. The list of channel processing gui panels have been deleted and channel processing status will now reside in a table where each table row is a metadata instance from the processing channel. The channel processing manager is responsible for adding/removing the channel's metadata instance to/from the metadata table. This allows the channel processing table to be the controller for the messages, events and channel spectrum views, keyed to the selected table row metadata.

I still have to clean up the gui components and wire in the table selection listeners.

src/util/StringUtils.java

@@ -0,0 +1,41 @@
+/*******************************************************************************
+ * sdrtrunk
+ * Copyright (C) 2014-2017 Dennis Sheirer
+ *
+ * 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 <http://www.gnu.org/licenses/>
+ *
+ ******************************************************************************/
+package util;
+
+public class StringUtils
+{
+    /**
+     * Compares string a to b and returns true if a is non-null and non-empty, b is non-null and non-empty, and
+     * a is equal to b.
+     * @param a string to compare
+     * @param b string to compare
+     */
+    public static boolean isEqual(String a, String b)
+    {
+        return !isEmpty(a) && !isEmpty(b) && a.equals(b);
+    }
+
+    /**
+     * Checks the string for null or empty condition
+     */
+    public static boolean isEmpty(String a)
+    {
+        return a == null || a.isEmpty();
+    }
+}