I want to be able to take a screenshot of a portion or all of the screen using Java. The generally accepted method of doing this to use the Robot class, but that doesn't work in this case. I have multiple transparent JavaFX stages on the screen, and any screenshot taken with the Robot class seems to treat them as completely opaque.
I have also tried having the program simulate the presses of Ctrl+PrtSc. I can't seem to get it to actually put the screenshot into the clipboard before the method finishes though, even if I attempt to have it wait until there is a picture in the clipboard.
Is there any more direct way of getting a screenshot? Anything specific to Swing/AWT, unfortunately, will not work.
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I wrote a Java application that uses the java.awt.Robot to take screen captures of the screen and was wondering if capturing a program using DirectX/OpenGL would be possible?
Each time I try to do this, I get a black screen
Don't know if this is really a solution but seems there's more possible ways to get the screenshot information using a "FrameGrabber" or some related class from JavaCV possibly: http://code.google.com/p/javacv/
Some of the final output shown on the screen could be calculated on a graphics card that has shaders set to act on the image data before it gets put into a display buffer for what's shown so it's possible some effects would be impossible to capture without an analog loopback (go from video out to video in on a capture card).
Related post How to take screenshots fast in Java?
OpenGL is a drawing API, not an all purpose interface to the graphics system. There were times, when taking screenshots with OpenGL was indeed possible through some dirty hacks. However recently I tried to re-implement this on modern OS to see if it still works, and no, it doesn't anymore.
Yes it is possible. But maybe only in limited circiumstances.
I've successfully captured the contents on OpenGL (jogl) windows on linux and windows using the Robot createScreenCapture.
Some specific information about the implementation that may be different for you:
The call to createScreenCapture was done from within the OpenGL
application.
The application used heavyweight GLCanvas
It used Java 6
Make sure you pass it the correct coordinates. You can get the screen coordinates to use from the GraphicsEnvironment
Uhh... a hard one ;o)
I had a try with some other screenshot utils and got a black screen, too. Looks like DirectX is passing the graphics directly to the monitor output. I am wondering if that could be accessed within a java application.
I want to make a transparent overlay for a foreign project to show live video. Sample of overlay is given in the image link below. In image you can see a overlay at right bottom corner showing face of a person, I also want to achieve same functionality using JMF to show face and then display the face in overlay using swing.
Sample Overley Imahe: http://www.ovostudios.com/images/vidsamsolo.jpg
Can someone help achieving this functionality?
If you're just starting the project and haven't actually got the JMF part up and running yet, then you might want to take a look at some alternatives before committing to it.
If you want to go ahead with Swing, to get the general overlay behaviour you want, you'll need to make use of Frame.setUndecorated() to turn off window borders and buttons, and Window.setAlwaysOnTop() to make sure the window stays on top of other windows. For the transparency, see this tutorial. However, I'm not sure whether transparency and video will work nicely together, so good luck!
You might also want to write a custom focus handler for the window so that it cannot be focused, although it is probably impossible for the overlay to be properly 'phantom' whereby clicks just pass through the overlay to the underlying desktop. That kind of behaviour might only be possible by using low-level graphics techniques i.e. by not creating a window at all, but by drawing directly onto the screen. That might require a native library.
I'd like to "capture" a screenshot of what a java applet would currently look like if it were loaded, effectively screenshoting an applet without the use of a vdu.
The purpose of this is to display the image to a user that doesn't have a JVM. Lets assume the applet is a digital clock and has no requirement on user input. So what could be done is set up a pc connected to a vdu, open the applet, schedule a script to take a screenshot and upload the image. Clients could then access what the applet would look like at any given time without the requirement on a jvm.
It'd be such a hassle to have a pc running all the time etc. Surely this could be done somehow without a display.
Would it be possible to create a virtual display in a jvm that can render an applet and then take a screen capture?
If this were possible then perhaps a really high resolution display could be virtualized to create a very high resolution screenshot.
The ScreenImage class should handle this.
Look at java.awt.Robot#createScreenCapture(java.awt.Rectangle)
If this would work, i would wonder, remind the sandbox, and as the above link stated "This will work whether you have an AWT or Swing application."
If you use a "rendering-engine" (composing each pixel to something paintable before repaint()'ing) within you applet, you could use this information and create an image.
Is it possible to get image contents of an obstructed window without bringing it to the front? Also, is it possible to send mouse clicks to a specific locations of such window? I want to do this in Java, using JNA, running Windows XP (if it is possible, would it also work on Windows 7?). If that can be done, would you mind telling me what functions will be needed and where can I read about it, because I have never worked with JNA yet. Thank you.
I am developing a screen capturing utility in Java & I want to capture any background window, when I click on that particular window. But I am not getting how to add mouseClicked event to background window. Can somebody please help me?
I may be way off base but if the other window is not a Java window then it should be outside the Java sandbox. To interact with it requires a native API which is anathema to Java.
Quite obviously as it is you can't interact with other application windows. It can be any random window in your case I presume. Therefore, your mouselistener approach is not correct.
Rather, try to approach it like fetching pixel information displayed on the screen. There is an awt package java.awt.Robot or something that could be used for your purpose. If you want to implement capturing of active window then see if there are java APIs to interact with O.S. and get information of current active window and it's pixel co-ordinates. The co-ordinates could then be supplied to the rectangle attribute that is used with java.awt.Robot APIs to define screen capture area.
If that window is not part of your application you can't do much with it.
Otherwise you just have to add the mouse listener to that window too.
What's your situation?
java.awt.Robot has a method createScreenCapture(Rectangle screenRect) to capture screenshots.
http://java.sun.com/j2se/1.5.0/docs/api/java/awt/Robot.html
however, to get the current active window you would have to use OS specific extensions (mostly via JNI)