On 10.12.2013 18:22, Anton V. Tarasov wrote:
Hi Jim, Sergey and All,
Please review the fix that adds support of Retina displays to
JLightweightFrame (which javafx SwingNode is based on).
webrev: http://cr.openjdk.java.net/~ant/JDK-8029455/webrev.1
jira: https://bugs.openjdk.java.net/browse/JDK-8029455
(After the fix goes into jdk9 it should be ported to 8u20 as
well, because the functionality is essential for SwingNode.)
The general idea of the fix is as follows.
A BufferedImage instance, being created in the context in which
the scale factor is determined and is different from one, is
automatically created with appropriately extended size. The image
itself becomes a scaled image (a "scale" private field is set on
it). By the "context" I mean the circumstances where the
BufferedImage is related to a JLightweightFrame, a
GraphicsConfiguration, a SurfaceData, or a GraphicsDevice which
determine the scale factor.
Here are the related changes:
-
http://cr.openjdk.java.net/~ant/JDK-8029455/webrev.1/src/share/classes/java/awt/image/BufferedImage.java.udiff.html
-
http://cr.openjdk.java.net/~ant/JDK-8029455/webrev.1/src/share/classes/sun/awt/image/OffScreenImage.java.udiff.html
-
http://cr.openjdk.java.net/~ant/JDK-8029455/webrev.1/src/share/classes/sun/swing/JLightweightFrame.java.udiff.html
(the resizeBuffer method)
-
http://cr.openjdk.java.net/~ant/JDK-8029455/webrev.1/src/macosx/classes/sun/lwawt/LWLightweightFramePeer.java.udiff.html
-
http://cr.openjdk.java.net/~ant/JDK-8029455/webrev.1/src/share/classes/sun/awt/image/BufferedImageGraphicsConfig.java.udiff.html
-
http://cr.openjdk.java.net/~ant/JDK-8029455/webrev.1/src/macosx/classes/sun/java2d/opengl/CGLGraphicsConfig.java.udiff.html
The "scale" value of a BufferedImage is used when 1)
BufferedImageGraphicsConfig is created 2)
BufImgSurfaceData.getDefaultScale() is called:
-
http://cr.openjdk.java.net/~ant/JDK-8029455/webrev.1/src/share/classes/sun/awt/image/BufferedImageGraphicsConfig.java.udiff.html
-
http://cr.openjdk.java.net/~ant/JDK-8029455/webrev.1/src/share/classes/sun/awt/image/BufImgSurfaceData.java.udiff.html
The former is used in the
GraphicsConfiguration.createCompatibleImage() calls, and the
latter is used in SurfaceManager.getImageScale(Image):
-
http://cr.openjdk.java.net/~ant/JDK-8029455/webrev.1/src/share/classes/sun/awt/image/SurfaceManager.java.udiff.html
A scaled BufferedImage is supported by the
SunGraphics2D.drawImage() primitives. Here's the pattern of how
the image may be created and drawn:
int scale = <get the scale factor from the context>;
BufferedImage img = new BufferedImage(width * scale, height *
scale, ...);
img.setScale(scale); // an accessor is currently used instead
<...>
g2d.drawImage(img, x, y, ...); // 1) draw the image with
auto-scale
g2d.drawImage(img, x, y, dw, dh, ...) // 2) draw the image into a
specified rect
In the first case, if the BufferedImage is created with an
extended size, the "scale" value of the image matters, it should
be drawn as a HiDPI image.
In the second case, if the BufferedImage is created with an
extended size, the "scale" value of the image doesn't matter (it
may not be evidently set) as the image will anyway be scaled from
its physical bounds into provided logical bounds. This all should
(as I suppose) provide backward compatibility for buffered images
that were created in their logical bounds or without setting the
"scale" field. For instance, the
AquaPainter.paintFromSingleCachedImage(...) method creates &
draws an image as follows:
int scale = ((SunGraphics2D) g).surfaceData.getDefaultScale();
int imgW = bounds.width * scale;
int imgH = bounds.height * scale;
BufferedImage img = new BufferedImage(imgW, imgH, ...);
<paint into the img>
g.drawImage(img, bounds.x, bounds.y, bounds.width, bounds.height,
null);
Here, the img.scale value is not set (I didn't modify this code),
and SunGraphics2D doesn't treat the image as a HiDPI image,
however it is drawn as expected. An alternative way to draw the
image would be:
int scale = ((SunGraphics2D) g).surfaceData.getDefaultScale();
int imgW = bounds.width * scale;
int imgH = bounds.height * scale;
BufferedImage img = new BufferedImage(imgW, imgH, ...);
img.setScale(scale);
<paint into the img>
g.drawImage(img, bounds.x, bounds.y, ...);
The result would be the same.
-
http://cr.openjdk.java.net/~ant/JDK-8029455/webrev.1/src/share/classes/sun/java2d/SunGraphics2D.java.sdiff.html
The following changes:
-
http://cr.openjdk.java.net/~ant/JDK-8029455/webrev.1/src/macosx/classes/sun/lwawt/macosx/CPlatformLWView.java.udiff.html
are defined by this logic. Running Swing via JLightweightFrame
(JLF) makes it "display agnostic". Swing is painted to an
off-screen buffer and it's the host (e.g. SwingNode) that renders
the buffer on a particular device. So, the host should detect the
scale of the current display and set it on JLF.
Does it mean that all methods related to the
Component.getLocationOnScreen() does not work?
However, AWT in order to paint to a volatile image requires
CGraphicsDevice and CGLSurfaceData to be created. By default AWT
creates CGraphicsDevice instances matching all the detected
display devices (CGraphicsEnvironment.initDevices()). But, as JLF
doesn't have any platform window behind it, AWT can't match JLF
to the exact device it's currently displayed on.
Why? You can try to check it youseft via
CGLGraphicsConfig.getBounds()+Peer.getBounds();
So, on the one hand, AWT doesn't know which device is current and
what is the current scale (the host passes this value), but from
the other hand, AWT has a list of all the CGraphicsDevice
instances.
I tried to leverage from that fact. The
CPlatformLWView.getGraphicsDevice() method takes the current
scale from the JLF instance, and then tries to match it to an
existent device from the list. In case it can't find a device
with the specified scale (which should not actually happen,
unless the host passes an arbitrary scale value, which is not the
case for SwingNode) it takes a default device and changes its
scale forcedly. I'm not sure if I should create a new dummy
device instance instead. The scale factor of the device (which is
then propagated to CGLSurfaceData on its creation) is the only
info that JLF will take from the device to create a scaled
volatile image.
The following changes:
-
http://cr.openjdk.java.net/~ant/JDK-8029455/webrev.1/src/share/classes/javax/swing/JViewport.java.udiff.html
-
http://cr.openjdk.java.net/~ant/JDK-8029455/webrev.1/src/share/classes/javax/swing/RepaintManager.java.udiff.html
were made to map a backing store image to a scale factor.
The JViewPort.paint(...) method calls SunGraphics2D.copyArea(...)
on scrolling. The method was not implemented for a graphics with
a scale transform and a BufImgSurfaceData (it threw exceptions).
I took that code, copied it to the
BufImgSurfaceData.copyArea(...) and added a general translation
for the coords:
-
http://cr.openjdk.java.net/~ant/JDK-8029455/webrev.1/src/share/classes/sun/awt/image/BufImgSurfaceData.java.udiff.html
It works, but I'm not sure the implementation is eligible (I
don't know the details of the Blit class, at least it warns not
to use the same source and dest).
The rest of the changes (not covered here) should be clear.
Testing:
- Using jfc/SwingSet2 and jfc/Java2D demos (in a standalone mode
& embedded into SwingNode [1]).
- Testing both Nimbus and Aqua L&F.
- Setting swing.volatileImageBufferEnabled=false/true for all
combinations.
Currently, I see no regressions and no visual issues comparing a
standalone mode and a SwingSet mode.
At the end, I suspect there may be some intersection b/w this fix
and the fix which introduced MultiResolutionToolkitImage.
Unfortunately, I didn't yet read that review saga... Please tell
me if I should incorporate anything from that fix.
Thanks,
Anton.
[1] There's a SwingSet part of the fix which I'm going to post to
the jfx alias separately.