src/java.desktop/unix/native/libawt_xawt/awt/awt_GraphicsEnv.c

*** 2080,2084 ****
--- 2080,2119 ----
  }
  
  /**
   * End DisplayMode/FullScreen support
   */
+ 
+ int getScale(const char *name) {
+     char *uiScale = getenv(name);
+     if (uiScale != NULL) {
+         double scale = strtod(uiScale, NULL);
+         if (errno == ERANGE || scale < 1) {
+             return -1;
+         }
+         return (int) scale;
+     }
+     return -1;
+ }
+ 
+ /*
+  * Class:     sun_awt_X11GraphicsDevice
+  * Method:    getNativeScaleFactor
+  * Signature: (I)I
+  */
+ JNIEXPORT jint JNICALL
+ Java_sun_awt_X11GraphicsDevice_getNativeScaleFactor
+     (JNIEnv *env, jobject this, jint screen) {
+ 
+     // for debug purposes
+     static int scale = -2.0;
+ 
+     if (scale == -2) {
+         scale = getScale("J2D_UISCALE");
+     }
+ 
+     if (scale >= 1) {
+         return scale;
+     }
+ 
+     return getScale("GDK_SCALE");
+ }