[kaleidescape] Update readiness_state when Thing is offline (#20485)

* Update readiness_state when Thing is offline

Signed-off-by: Michael Lobstein <michael.lobstein@gmail.com>

Author: mlobstein

bundles/org.openhab.binding.kaleidescape/README.md

@@ -17,7 +17,7 @@ The supported Thing types are:
 - `player` Any KPlayer, M Class [M300, M500, M700] or Cinema One 1st Gen player
 - `cinemaone` Cinema One (2nd Gen)
 - `alto`
-- `strato` Includes Strato, Strato S, Strato C, Strato V or Strato M
+- `strato` Includes Strato, Strato S, Strato C, Strato V, Strato M, or Strato E
 
 The binding supports either a TCP/IP connection or direct serial port connection (19200-8-N-1) to the Kaleidescape component.
 
@@ -94,7 +94,7 @@ The following channels are available:
 | ui#cinemascape_mode        | String      | Identifies the CinemaScape mode currently active                                                                                |
 | ui#ui_state                | String      | Provides information about which screen is visible in the Kaleidescape user interface                                           |
 | ui#child_mode_state        | String      | Indicates if the onscreen display is displaying the child user interface                                                        |
-| ui#readiness_state         | String      | Indicates the system's current idle mode (Not available on Premiere system players)                                             |
+| ui#readiness_state         | String      | Indicates the system's current idle mode or if the Thing is offline (Not available on Premiere system players)                  |
 | ui#highlighted_selection   | String      | Specifies the handle of the movie or album currently selected on the user interface                                             |
 | ui#user_defined_event      | String      | Will contain custom event messages generated by scripts, sent from another component, or system events                          |
 | ui#user_input              | String      | Indicates if the user is being prompted for input, what type of input, and any currently entered characters                     |

bundles/org.openhab.binding.kaleidescape/src/main/java/org/openhab/binding/kaleidescape/internal/handler/KaleidescapeHandler.java

@@ -294,11 +294,15 @@ private synchronized boolean openConnection() {
      * Close the connection with the Kaleidescape component
      */
     private synchronized void closeConnection() {
+        if (getThing().getChannel(SYSTEM_READINESS_STATE) != null) {
+            updateState(SYSTEM_READINESS_STATE, new StringType("Offline"));
+        }
+
         if (connector.isConnected()) {
             connector.close();
-            connector.removeEventListener(this);
             logger.debug("closeConnection(): disconnected");
         }
+        connector.removeEventListener(this);
     }
 
     @Override