On 2/6/2015 15:28 PM, Thomas Harre wrote: > If I have understood you correctly, it is safe to assume a checkbox is > selected, if the value is a value from the available Values but not > "Off".
Yes, a PDF in which the "Off" appearance doesn't corresponds with the off state is in violation with the PDF specification. > But to be honest I don't know what is meant by "The appearance for the > off state is optional". > Does this mean it's possible to have checkboxes that can only ever be > selected? No. It means that you can have a check box for which only the appearance of the on state is defined. In that case, there will be no "Off" appearance: it will be just blank. What's the point of this? you might ask. Imagine a paper form that is scanned. There are already appearances of check boxes in the PDF because the PDF mimics the paper form completely. Now somebody adds interactive check boxes that can be selected interactively. In this case, there's no real need to define an appearance for the off state: the check boxes are already there. It's sufficient to create an appearance for the on state. Now when the check box is toggled between the on and off state, you'll see the appearance for the on state when checked, and you see nothing when not checked. In reality you'll always keep seeing the check box of the scanned image. Does that make sense? ------------------------------------------------------------------------------ Dive into the World of Parallel Programming. The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ iText-questions mailing list iText-questions@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/itext-questions iText(R) is a registered trademark of 1T3XT BVBA. Many questions posted to this list can (and will) be answered with a reference to the iText book: http://www.itextpdf.com/book/ Please check the keywords list before you ask for examples: http://itextpdf.com/themes/keywords.php
