<AWT Dev> [9] Review Request: JDK-8029455 JLightweightFrame: support scaled painting

[Anton V. Tarasov]

Hi all,

Please look at the new version:

http://cr.openjdk.java.net/~ant/JDK-8029455/webrev.2

It contains the following changes:

- All the scale related stuff is moved to the new class: 
OffScreenHiDPIImage.java

- JViewport and RepaintManager no longer cache buffers.

- JLightweightFrame has new method: createHiDPIImage(w, h).

- JViewport, RepaintManager and AbstractRegionPainter goes the new path 
to create a HiDPI buffered image.

- A new internal property is added: "swing.jlf.hidpiImageEnabled". False 
by default. It makes JLF.createImage(w, h) forward the call to 
JLF.createHiDPIImage(w, h). This can be used by a third party code in 
case it creates a buffered image via Component.createImage(w, h) and 
uses the image so that it can benefit from being a HiDPI image on a 
Retina display.

For instance, SwingSet2 has an animating Bezier curve demo. Switching 
the property on makes the curve auto scale smoothly. Please, look at the 
screenshots:

-- http://cr.openjdk.java.net/~ant/JDK-8029455/RoughtCurve.png
-- http://cr.openjdk.java.net/~ant/JDK-8029455/SmoothCurve.png

- SunGraphics2D now draws a HiDPI buffered image the same way it draws a 
VolatileImage.

- I've removed the copyArea() method from the BufImgSurfaceData, and 
modified the original version. The only question I have is: do I need to 
check for "instanceof OffScreenHiDPIImage.SurfaceData" in case when 
"transformState == TRANSFORM_TRANSLATESCALE"? If this method is invoked 
with some other SD, and the transform is SCALE, will it do the job with 
the coordinates conversion done?

- I've left the new methods in FramePeer default... May yet we implement 
them in other peers when we really need it?

- CPlatformLWWindow.getGraphicsDevice() checks for an intersection + 
scale. This heuristic actually may fail when a Window is moved b/w three 
or four displays so that it intersects them all at some time. JFX will 
set a new scale factor in between and AWT may pick up a wrong device. I 
don't know any simple solution for that. For two monitors this will work.

Thanks,
Anton.