src/macosx/native/sun/awt/CGraphicsDevice.m

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this

@@ -154,18 +154,16 @@
  */
 JNIEXPORT jdouble JNICALL
 Java_sun_awt_CGraphicsDevice_nativeGetXResolution
   (JNIEnv *env, jclass class, jint displayID)
 {
-    // TODO: this is the physically correct answer, but we probably want
-    // to use NSScreen API instead...
+     // CGDisplayScreenSize can return 0 if displayID is invalid
     CGSize size = CGDisplayScreenSize(displayID);
     CGRect rect = CGDisplayBounds(displayID);
     // 1 inch == 25.4 mm
     jfloat inches = size.width / 25.4f;
-    jfloat dpi = rect.size.width / inches;
-    return dpi;
+    return inches > 0 ? rect.size.width / inches : 72;
 }
 
 /*
  * Class:     sun_awt_CGraphicsDevice
  * Method:    nativeGetYResolution

@@ -173,18 +171,16 @@
  */
 JNIEXPORT jdouble JNICALL
 Java_sun_awt_CGraphicsDevice_nativeGetYResolution
   (JNIEnv *env, jclass class, jint displayID)
 {
-    // TODO: this is the physically correct answer, but we probably want
-    // to use NSScreen API instead...
+     // CGDisplayScreenSize can return 0 if displayID is invalid
     CGSize size = CGDisplayScreenSize(displayID);
     CGRect rect = CGDisplayBounds(displayID);
     // 1 inch == 25.4 mm
     jfloat inches = size.height / 25.4f;
-    jfloat dpi = rect.size.height / inches;
-    return dpi;
+    return inches > 0 ? rect.size.height / inches : 72;
 }
 
 /*
  * Class:     sun_awt_CGraphicsDevice
  * Method:    nativeGetScreenInsets