Multi-monitor scenario will be handled under JDK-8173972.
https://bugs.openjdk.java.net/browse/JDK-8173972
Regards,
Prem
*From:*Phil Race
*Sent:* Tuesday, January 31, 2017 5:24 AM
*To:* Prem Balakrishnan; Alexander Scherbatiy
*Cc:* Sergey Bylokhov; awt-dev@openjdk.java.net
*Subject:* Re: Review Request JDK:-8162959 [HiDPI] screenshot
artifacts using AWT Robot
I like
3. createMultiresolutionScreenCapture(Rectangle rect);
-phil.
On 01/30/2017 01:11 AM, Prem Balakrishnan wrote:
Hi Phil,
Thank you for the review.
>Is Robot only capable of a screen capture from the default screen
? I hope not.
Robot.createScreenCapture() can be used to capture screenshots on
Multi-Monitor as well.
To capture screen on Multi-Monitor user should calculate the total
width of multiple
screens, based on the position of secondary monitor(i.e.,
Right/Left) with respect to
main monitor and pass it to createScreenCapture() method.
>So I would expect that where there are two screens with different
DPI settings/transforms
>the logic in here will be sensitive to the target screen.
I tried with MacBookPro (macOS Sierra version 10.12 , Retina ) by
connecting a secondary monitor non-Retina display.
keeping secondary monitor to the right/left of main display and
targeted rectangle on each sides, expected results are obtained.
The current patch addresses most common scenario of single HiDPI
monitor setup and dual monitor (Hi-DPI, non-HiDPI) setup.
As “Handling multi monitor setup with different DPI settings”
requires additional effort to make it work on all platforms, I
propose to fix it separately.
>And what happens if the target rectangle overlaps the edge
between two screens ?
I tried this scenario with Mac connecting non-retina secondary
monitor, OS doesn’t allow user to place a window in between two
screens.
>The more significant API change is that the isHiDPI parameter is
a misnomer.
>It really means something else and I think what we should do is
delete it
>and change the method name to something else.
Thank you for the Draft.
From my point of view, I think we should maintain the method name
“createScreenCapture()”, because two functions doing the same task
should have the same name so that method will have maximum
proximal visibility i.e., developer will easily know that there
exists two method variants to take screenshots.
(At least the method name should start with create….);
Some of the signatures we can choose from:
1. createScreenCapture(int x, int y, int width, int height);
2. createScreenCapture(Point pt, Dimension d);
3. createMultiresolutionScreenCapture(Rectangle rect);
4. createMultiImageScreenCapture(Rectangle rect);
Request your feedback on the same.
Once we finalize the signature and behavior, I shall update the
patch and send it for review.
Regards,
Prem
*From:*Philip Race
*Sent:* Wednesday, January 25, 2017 11:44 PM
*To:* Alexandr Scherbatiy
*Cc:* Prem Balakrishnan; Sergey Bylokhov; awt-dev@openjdk.java.net
<mailto:awt-dev@openjdk.java.net>
*Subject:* Re: Review Request JDK:-8162959 [HiDPI] screenshot
artifacts using AWT Robot
I'd like to propose some revision to the API and also have a
question about the implementation.
The question about the implementation concerns this code :-
465 AffineTransform tx = GraphicsEnvironment.
466
getLocalGraphicsEnvironment().getDefaultScreenDevice().
467 getDefaultConfiguration().getDefaultTransform();
468 double uiScaleX = tx.getScaleX();
469 double uiScaleY = tx.getScaleY();
Is Robot only capable of a screen capture from the default screen
? I hope not.
So I would expect that where there are two screens with different
DPI settings/transforms
the logic in here will be sensitive to the target screen.
And what happens if the target rectangle overlaps the edge between
two screens ?
Regarding the API, I think that it needs to explain that it is
"not 'hi dpi" per se,
rather that it is the non-default transform that matters.
Additionally the doc should properly link to the class names, not
just write them
as words.
The more significant API change is that the isHiDPI parameter is a
misnomer.
It really means something else and I think what we should do is
delete it
and change the method name to something else.
Here is my draft :
/**
* Creates an image containing pixels read from the screen.
* This image does not include the mouse cursor.
* This method should be used in case there is a scaling
transform from
* user space to screen (device) space.
* Typically this means that the display is a high resolution screen,
* although strictly it means any case in which there is such a
transform.
* Returns a {@link java.awt.image.BufferedImage} for a
non-scaled display and
* a {@link java.awt.image.MultiResolutionImage} where there is a
scaling
* transform.
* <p>
* The {@code MultiResolutionImage} will have two image variants:
* <ul>
* <li> Base Image with user specified size. This is scaled from
the screen.
* <li> Native device resolution image with device size pixels.
* </ul>
* @param screenRect Rect to capture in screen coordinates
* @return The captured image
* @throws IllegalArgumentException if {@code screenRect} width
and height
* are not greater than zero
* @throws SecurityException if {@code readDisplayPixels} permission
* is not granted
* @see SecurityManager#checkPermission
* @see AWTPermission
*/
public synchronized Image multiImageeScreenCapture(Rectangle
screenRect);
-phil.
On 1/20/17, 3:20 AM, Alexandr Scherbatiy wrote:
On 1/19/2017 3:57 PM, Prem Balakrishnan wrote:
Hi Alex,
Please review updated patch as per review comments.
http://cr.openjdk.java.net/~pkbalakr/8162959/webrev.06/
<http://cr.openjdk.java.net/%7Epkbalakr/8162959/webrev.06/>
Automated test validates both Robot.getPixelColor() and output
of Robot.createScreenCapture() API's.
Jtreg and JCK tests passed on build with fix across all the
platforms(Mac, Windows and Linux) without causing any regression.
src/java.desktop/share/classes/java/awt/Robot.java
> 421 * @param isHiDPI Indicates if HiDPI Display
There should be mention that this argument value is ignored when
a screenshot is taken on non-HiDPI display
Thanks,
Alexandr.
Regards,
Prem
*From:*Alexandr Scherbatiy
*Sent:* Thursday, January 12, 2017 2:39 PM
*To:* Prem Balakrishnan; Sergey Bylokhov; awt-dev@openjdk.java.net
<mailto:awt-dev@openjdk.java.net>; Philip Race
*Subject:* Re: Review Request JDK:-8162959 [HiDPI] screenshot
artifacts using AWT Robot
> 421 * @param isHiDPI Indicates if HiDPI Display
There should be mention that this argument value is ignored when
a screenshot is taken on non-HiDPI display
Please also check the the method Robot.getPixelColor(int x, int y)
also correctly works on Mac OS X, Windows and Linux after the fix.
Thanks,
Alexandr.
On 1/10/2017 11:54 AM, Prem Balakrishnan wrote:
Hi Alex,
Please review updated patch,
http://cr.openjdk.java.net/~pkbalakr/8162959/webrev.05/
<http://cr.openjdk.java.net/%7Epkbalakr/8162959/webrev.05/>
updated imageOption to kCGWindowImageBestResolution which
returns Best Resolution Image while capturing screen using
CGWindowListCreateImage() method.
Regards,
Prem
*From:*Alexandr Scherbatiy
*Sent:* Tuesday, January 10, 2017 1:08 AM
*To:* Prem Balakrishnan; Sergey Bylokhov;
awt-dev@openjdk.java.net <mailto:awt-dev@openjdk.java.net>;
Philip Race
*Subject:* Re: Review Request JDK:-8162959 [HiDPI] screenshot
artifacts using AWT Robot
CGWindowListCreateImage() method which is used to capture a
screenshot on Mac OS X by Robot has imageOption argument which
can have value: kCGWindowImageBestResolution
https://developer.apple.com/reference/coregraphics/1666230-quartz_window_services/window_image_types?language=objc
"When capturing the window, return the best image
resolution. The returned image size may be different than the
screen size."
Could this option help to get a high-resolution CGImageRef
on HiDPI display?
Thanks,
Alexandr.
On 12/27/2016 12:14 PM, Prem Balakrishnan wrote:
Hi Alexander,
Please review updated patch,
http://cr.openjdk.java.net/~pkbalakr/8162959/webrev.04/
<http://cr.openjdk.java.net/%7Epkbalakr/8162959/webrev.04/>
I used wrong bounds while creating images, correct it in
this patch.
Regards,
Prem
*From:*Alexander Scherbatiy
*Sent:* Wednesday, December 14, 2016 5:18 PM
*To:* Prem Balakrishnan; Sergey Bylokhov;
awt-dev@openjdk.java.net
<mailto:awt-dev@openjdk.java.net>; Philip Race
*Subject:* Re: Review Request JDK:-8162959 [HiDPI]
screenshot artifacts using AWT Robot
On 07/12/16 10:24, Prem Balakrishnan wrote:
Hi Alexander,
Please review updated patch as per review comments.
http://cr.openjdk.java.net/~pkbalakr/8162959/webrev.03/
<http://cr.openjdk.java.net/%7Epkbalakr/8162959/webrev.03/>
I used a simple app [1] to create a screenshot of a
frame on Mac OS X:
Rectangle rect = frame.getBounds();
rect.setLocation(frame.getLocationOnScreen());
BufferedImage img = robot.createScreenCapture(rect);
It takes only bottom right quarter of the frame [2].
Is it possible to use some API that makes a screenshot
and returns an NSImage on Mac OS X?
In this case it would be possible to get a high
resolution representation from the NSImage and return it
in the same way as it is updated on Windows and Linux.
[1]
http://cr.openjdk.java.net/~alexsch/8162959/screenshot/RobotScreenshot.java
<http://cr.openjdk.java.net/%7Ealexsch/8162959/screenshot/RobotScreenshot.java>
[2]
http://cr.openjdk.java.net/~alexsch/8162959/screenshot/screenshot.png
<http://cr.openjdk.java.net/%7Ealexsch/8162959/screenshot/screenshot.png>
Thanks,
Alexandr.
Regards,
Prem
*From:*Alexandr Scherbatiy
*Sent:* Monday, November 21, 2016 8:10 PM
*To:* Prem Balakrishnan; Sergey Bylokhov;
awt-dev@openjdk.java.net
<mailto:awt-dev@openjdk.java.net>; Phil Race
*Subject:* Re: Review Request JDK:-8162959 [HiDPI]
screenshot artifacts using AWT Robot
On 11/16/2016 8:46 AM, Prem Balakrishnan wrote:
Hi Alexander,
Please review update patch as per review comments.
http://cr.openjdk.java.net/~pkbalakr/8162959/webrev.02/
<http://cr.openjdk.java.net/%7Epkbalakr/8162959/webrev.02/>
With this patch, Robot.createScreenCapture(Rectangle)
method returns a scaled down image on the HiDPI display.
- The native part on Mac OS X and Linux should be updated
as well.
- 416 * Returns BufferedImage for Non-HiDPI display
and MultiResolutionImage
417 * for HiDPI display with two resolution variants.
There should be added an explanation what is the content
of the first and the second resolution variant.
Thanks,
Alexandr.
Regards,
Prem
*From:*Alexandr Scherbatiy
*Sent:* Thursday, November 03, 2016 4:05 PM
*To:* Prem Balakrishnan; Sergey Bylokhov;
awt-dev@openjdk.java.net <mailto:awt-dev@openjdk.java.net>
*Subject:* Re: Review Request JDK:-8162959 [HiDPI]
screenshot artifacts using AWT Robot
On 11/2/2016 1:57 PM, Prem Balakrishnan wrote:
Hi Alexander,
Please review updated patch.
http://cr.openjdk.java.net/~pkbalakr/8162959/webrev.01/
<http://cr.openjdk.java.net/%7Epkbalakr/8162959/webrev.01/>
Added a new public API “*Image
createHiDPIScreenCapture(Rectangle screenRect)”.*
Returns an ordinary screenshot(BufferedImage) if the UI
scale is 1.
Returns MultiResolutionImage for HiDPI display with two
resolution variants,
1.Low Resolution/base image with user input width and
height, I have used interpolation algorithm for scaling ,
adapted from JavaFX Robot
(http://hg.openjdk.java.net/openjfx/9-dev/rt/rev/89a5de54b7dc),
2.High Resolution image with scaled width and height .
- Please, check that the
Robot.createScreenCapture(Rectangle) method returns a
scaled down image on the HiDPI display
- Probably existing Java methods can be used for an
image scaling.
For example, there is the Image.getScaledInstance(int
width, int height, int hints) method.
Or may be it is better just to create an image with
required size and draw the high-resolution image into it
using a specific scale and rendering hints.
Thanks,
Alexandr.
Regards,
Prem
*From:*Alexander Scherbatiy
*Sent:* Thursday, October 13, 2016 3:21 PM
*To:* Prem Balakrishnan; Sergey Bylokhov;
awt-dev@openjdk.java.net <mailto:awt-dev@openjdk.java.net>
*Subject:* Re: Review Request JDK:-8162959 [HiDPI]
screenshot artifacts using AWT Robot
On 06/10/16 15:28, Prem Balakrishnan wrote:
Hi*,*
**
Please review fix for JDK 9,
*Bug:*https://bugs.openjdk.java.net/browse/JDK-8162959
*Webrev:*http://cr.openjdk.java.net/~pkbalakr/8162959/webrev.00/
<http://cr.openjdk.java.net/%7Epkbalakr/8162959/webrev.00/>
I have adapted the same fix as used for JavaFX Robot
*Bug: *JDK-8162783
<https://bugs.openjdk.java.net/browse/JDK-8162783>.
*Patch:
*http://hg.openjdk.java.net/openjfx/9-dev/rt/rev/89a5de54b7dc
New Public API ” BufferedImage
createScreenCapture(Rectangle screenRect, boolean
isHiDPI)”is added,
Which will have a parameter to specify if HiDPI.
It is better to a add public method which returns
MultiResolution image on HiDPI display and consists of
two resoltion variants
- base image which has size requested by a user
- high-resolution image which creates an original
screen capture
The proposed by your algorithm can be applied to the
base image.
For more details see JDK-8020618 [macosx] java.awt.Robot
makes blurry screen captures on Retina
Thanks,
Alexandr.
Regards,
Prem
