On Mon, 25 Aug 2025 19:38:15 GMT, Alexey Ivanov <aiva...@openjdk.org> wrote:
>>> However, the fix resets the known range of pages to the full range of the >>> document. Is it because the native code doesn't care about the range and >>> it's handled in Java side? >> >> It looks like the operating system does not expect the page range selected >> by the user here, but the number of pages in the document, even though it is >> queried as page range. >> >> >>> Wouldn't it be easier then to always return NO from knowsPageRange? The >>> fTotalPages field can be dropped from the PrinterView class. >> >> Here we can only guess what exactly the operating system is doing in this >> case. For example, if the number of pages is not known, e.g. in streaming >> mode, the operating system must start with the first page and iterate >> through the pages until it reaches the desired page. >> So I would let the operating system know the number of pages. It may help it >> to choose a more appropriate printing strategy. >> >> >>> But why didn't the old code work? If a range is set to 2-3, we know exactly >>> the number of pages to print, and this number is 2. >> >> To answer this question, we need to look at the code of the operating >> system. But it seems that the operating system needs the total number of >> pages here, not the range selected by the user. >> The documentation page does not describe it in detail either. >> >>> Does it work correctly if mDocument.getNumberOfPages() in CPrinterJob.java >>> returns a certain number instead of UNKNOWN_NUMBER_OF_PAGES? >> >> I tried both variants and it does not work. > >> > Does it work correctly if mDocument.getNumberOfPages() in CPrinterJob.java >> > returns a certain number instead of UNKNOWN_NUMBER_OF_PAGES? >> >> I tried both variants and it does not work. > > You didn't answer the question, so I had to write a test which also uses > `Pageable` and returns the number of pages. > > No, it doesn't work as expected *without* your suggested fix. > > Yes, it does behave as expected *with* the fix. We're good. > Wouldn't it be easier then to always return `NO` from `knowsPageRange`? The > `fTotalPages` field can be dropped from the `PrinterView` class. Returning `NO` doesn't work at all. I had to test it myself. I get an error message dialog displayed: *Error while printing.* Yet I still think the `fTotalPages` field can be dropped from the `PrinterView` class. It serves no real purpose and its value is often incorrect. For example, if the total number of pages returned by `Pageable` is 10, the value of `fTotalPages` is set to 10 too, even if the range 10-10 is requested. I tested that setting `aRange->length` to `NSIntegerMax` always works. Therefore, the code can be simplified by getting rid of `fTotalPages`. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/11266#discussion_r2298973332
