Switching focus to a Popup window and taking a screenshot

I'm writing a testscript in selenium 2 that takes a screenshot o开发者_Python百科f a popup. The popup window is a pdf.

After clicking the link, I'm using the code

try {
File scrFile = ((TakesScreenshot)driver).getScreenshotAs(OutputType.FILE);
FileUtils.copyFile(scrFile, new File("c:\\tmp\\screenshot.png"));
} catch (IOException e) {
    e.printStackTrace();
}
}

To take a screenshot, however, that only takes a shot of the main page and not the popup window. Is there a way to have selenium 2, change focus to the new popup, take the screenshot, and then close the popup and switch back to the main window?

You have to switch the focus of the driver with something like this:

String mainWindow = driver.getWindowHandle();
for (String handle : driver.getWindowHandles()) {
    if (!handle.equals(mainWindow)) {
        driver.switchTo().window(handle)
        //put your screenshot call here
        driver.close();
        driver.switchTo().window(mainWindow);
    }
}

This of course will take a screenshot of all other windows if you got more of them. Then you need to know the exact window handle and just switcht to that.