fix: add 'isWaylandSession'|SystemDelegate

Author: JNightRider

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

@@ -159,13 +159,13 @@ public boolean isDeviceRumbleSupported() {
         return false;
     }
 
-    @Override
-    public void rumble(float amountHigh, float amountLow, float duration) {
-    }
-
-    public final AssetManager newAssetManager(URL configFile) {
-        return new DesktopAssetManager(configFile);
-    }
+    @Override
+    public void rumble(float amountHigh, float amountLow, float duration) {
+    }
+
+    public final AssetManager newAssetManager(URL configFile) {
+        return new DesktopAssetManager(configFile);
+    }
 
     public final AssetManager newAssetManager() {
         return new DesktopAssetManager(null);
@@ -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");