src/share/classes/javax/swing/JViewport.java

*** 37,46 ****
--- 37,49 ----
  import javax.swing.border.*;
  import javax.accessibility.*;
  
  
  import java.io.Serializable;
+ import sun.awt.image.OffScreenImage;
+ import sun.awt.image.SurfaceManager;
+ import sun.java2d.SunGraphics2D;
  
  
  /**
   * The "viewport" or "porthole" through which you see the underlying
   * information. When you scroll, what moves is the viewport. It is like
*** 752,771 ****
          // blit garbage into the exposed areas.
          Rectangle viewBounds = getView().getBounds();
          if (!isOpaque()) {
              g.clipRect(0, 0, viewBounds.width, viewBounds.height);
          }
  
!         if (backingStoreImage == null) {
              // Backing store is enabled but this is the first call to paint.
              // Create the backing store, paint it and then copy to g.
              // The backing store image will be created with the size of
              // the viewport. We must make sure the clip region is the
              // same size, otherwise when scrolling the backing image
              // the region outside of the clipped region will not be painted,
              // and result in empty areas.
              backingStoreImage = createImage(width, height);
              Rectangle clip = g.getClipBounds();
              if (clip.width != width || clip.height != height) {
                  if (!isOpaque()) {
                      g.setClip(0, 0, Math.min(viewBounds.width, width),
                                Math.min(viewBounds.height, height));
--- 755,784 ----
          // blit garbage into the exposed areas.
          Rectangle viewBounds = getView().getBounds();
          if (!isOpaque()) {
              g.clipRect(0, 0, viewBounds.width, viewBounds.height);
          }
+         int scale = g instanceof SunGraphics2D ?
+                     ((SunGraphics2D)g).surfaceData.getDefaultScale() : 1;        
  
!         if (backingStoreImage == null ||
!             SurfaceManager.getImageScale(backingStoreImage) != scale)
!         {
              // Backing store is enabled but this is the first call to paint.
              // Create the backing store, paint it and then copy to g.
              // The backing store image will be created with the size of
              // the viewport. We must make sure the clip region is the
              // same size, otherwise when scrolling the backing image
              // the region outside of the clipped region will not be painted,
              // and result in empty areas.
+             Window w = SwingUtilities.getWindowAncestor(this);            
+             if (w instanceof JLightweightFrame) {
+                 backingStoreImage = ((JLightweightFrame)w).createHiDPIImage(width, height);
+                 ((OffScreenImage)backingStoreImage).setReturnLayoutSize(true);
+             } else {            
                  backingStoreImage = createImage(width, height);
+             }
              Rectangle clip = g.getClipBounds();
              if (clip.width != width || clip.height != height) {
                  if (!isOpaque()) {
                      g.setClip(0, 0, Math.min(viewBounds.width, width),
                                Math.min(viewBounds.height, height));