# HG changeset patch
# User kcr
# Date 1406052904 25200
# Node ID 8af594af405db839e812aee61ca5296555dc6ead
# Parent  9a099138d2956f0d9ef42659023e81d5deb507d5
RT-37974: FX exits with GTK error when DISPLAY not set, should throw HeadlessException

diff --git a/modules/graphics/src/main/java/com/sun/glass/ui/gtk/GtkApplication.java b/modules/graphics/src/main/java/com/sun/glass/ui/gtk/GtkApplication.java
--- a/modules/graphics/src/main/java/com/sun/glass/ui/gtk/GtkApplication.java
+++ b/modules/graphics/src/main/java/com/sun/glass/ui/gtk/GtkApplication.java
@@ -61,6 +61,11 @@
     private final InvokeLaterDispatcher invokeLaterDispatcher;
 
     GtkApplication() {
+        // Check whether the Display is valid and throw an exception if not
+        if (!isDisplayValid()) {
+            throw new RuntimeException("Unable to open DISPLAY");
+        }
+
         boolean isEventThread = AccessController
                 .doPrivileged((PrivilegedAction<Boolean>) () -> Boolean.getBoolean("javafx.embed.isEventThread"));
         if (!isEventThread) {
@@ -71,6 +76,10 @@
         }
     }
 
+    private static boolean isDisplayValid() {
+        return _isDisplayValid();
+    }
+
     private void initDisplay() {
         Map ds = getDeviceDetails();
         if (ds != null) {
@@ -109,7 +118,7 @@
     protected void runLoop(final Runnable launchable) {
         final boolean isEventThread = AccessController
             .doPrivileged((PrivilegedAction<Boolean>) () -> Boolean.getBoolean("javafx.embed.isEventThread"));
-        
+
         if (isEventThread) {
             init();
             setEventThread(Thread.currentThread());
@@ -119,7 +128,7 @@
         
         final boolean noErrorTrap = AccessController
             .doPrivileged((PrivilegedAction<Boolean>) () -> Boolean.getBoolean("glass.noErrorTrap"));
-        
+
         final Thread toolkitThread =
             AccessController.doPrivileged((PrivilegedAction<Thread>) () -> new Thread(() -> {
                 init();
@@ -143,6 +152,8 @@
         return true;
     }
 
+    private static native boolean _isDisplayValid();
+
     private native void _terminateLoop();
     
     private native void _init(long eventProc, boolean disableGrab);
diff --git a/modules/graphics/src/main/native-glass/gtk/GlassApplication.cpp b/modules/graphics/src/main/native-glass/gtk/GlassApplication.cpp
--- a/modules/graphics/src/main/native-glass/gtk/GlassApplication.cpp
+++ b/modules/graphics/src/main/native-glass/gtk/GlassApplication.cpp
@@ -67,6 +67,17 @@
 
 /*
  * Class:     com_sun_glass_ui_gtk_GtkApplication
+ * Method:    _isDisplayValid
+ * Signature: ()Z
+ */
+JNIEXPORT jboolean JNICALL Java_com_sun_glass_ui_gtk_GtkApplication__1isDisplayValid
+  (JNIEnv * env, jclass clazz)
+{
+    return is_display_valid();
+}
+
+/*
+ * Class:     com_sun_glass_ui_gtk_GtkApplication
  * Method:    _init
  * Signature: ()V
  */
diff --git a/modules/graphics/src/main/native-glass/gtk/glass_general.cpp b/modules/graphics/src/main/native-glass/gtk/glass_general.cpp
--- a/modules/graphics/src/main/native-glass/gtk/glass_general.cpp
+++ b/modules/graphics/src/main/native-glass/gtk/glass_general.cpp
@@ -118,11 +118,29 @@
     gdk_threads_init();
 }
 
+static jboolean displayValid = JNI_FALSE;
+
+jboolean
+is_display_valid() {
+    return displayValid;
+}
+
 JNIEXPORT jint JNICALL
 JNI_OnLoad(JavaVM *jvm, void *reserved)
 {
     JNIEnv *env;
     jclass clazz;
+    Display* display;
+
+    display = XOpenDisplay(NULL);
+    if (display != NULL) {
+        XCloseDisplay(display);
+        displayValid = JNI_TRUE;
+    }
+//    else {
+//        // TODO: we should be able to just return JNI_ERR but that causes a
+//        // subsequent GTK error (maybe due to some cleanup function running)
+//    }
 
     if (jvm->GetEnv((void **)&env, JNI_VERSION_1_6)) {
          return JNI_ERR; /* JNI version not supported */
@@ -328,17 +346,23 @@
         env->CallStaticVoidMethod(clazz, mid_lock);
 
         if (!env->CallStaticBooleanMethod(clazz, mid_getAndSetInitializationNeededFlag)) {
-            init_threads();
+            if (displayValid) {
+                init_threads();
+            }
         }
 
         env->CallStaticVoidMethod(clazz, mid_unlock);
     } else {
         env->ExceptionClear();
-        init_threads();
+        if (displayValid) {
+            init_threads();
+        }
     }
 
-    gdk_threads_enter();
-    gtk_init(NULL, NULL);
+    if (displayValid) {
+        gdk_threads_enter();
+        gtk_init(NULL, NULL);
+    }
 
     return JNI_VERSION_1_6;
 }
diff --git a/modules/graphics/src/main/native-glass/gtk/glass_general.h b/modules/graphics/src/main/native-glass/gtk/glass_general.h
--- a/modules/graphics/src/main/native-glass/gtk/glass_general.h
+++ b/modules/graphics/src/main/native-glass/gtk/glass_general.h
@@ -241,6 +241,8 @@
 
     gboolean check_and_clear_exception(JNIEnv *env);
 
+    jboolean is_display_valid();
+
     gsize get_files_count(gchar **uris);
 
     jobject uris_to_java(JNIEnv *env, gchar **uris, gboolean files);