fix: add 'isWaylandSession'

Author: JNightRider

jme3-core/src/main/java/com/jme3/system/JmeSystem.java

@@ -190,6 +190,17 @@ public static Platform getPlatform() {
         return systemDelegate.getPlatform();
     }
 
+    /**
+     * Detects if you are in a Wayland session.
+     *
+     * @return {@code true} if you are in a Wayland session, otherwise it will
+     * be {@code false}
+     */
+    public static boolean isWaylandSession() {
+        checkDelegate();
+        return systemDelegate.isWaylandSession();
+    }
+    
     public static JmeContext newContext(AppSettings settings, JmeContext.Type contextType) {
         checkDelegate();
         return systemDelegate.newContext(settings, contextType);

jme3-core/src/main/java/com/jme3/system/JmeSystemDelegate.java

@@ -309,6 +309,14 @@ public Platform getPlatform() {
         }
     }
 
+    public boolean isWaylandSession() {
+        // The following matches the test GLFW does to enable the Wayland backend.
+        if ("wayland".equalsIgnoreCase(System.getenv("XDG_SESSION_TYPE")) && System.getenv("WAYLAND_DISPLAY") != null) {
+            return true;
+        }
+        return false;
+    }
+    
     public String getBuildInfo() {
         StringBuilder sb = new StringBuilder();
         sb.append("Running on ").append(getFullName()).append("\n");