[OpenJDK 2D-Dev] [9] RFR 4987884: PrinterJob carries over some values between calls to print.

[Phil Race]

I've always considered it unfortunate that PrinterJob did not
prohibit print() being called twice from day one.
It is not something I would encourage apps to do and I
would not be surprised to see this as the source of odd bugs.
If I could I would go update all the implementation code to
throw IllegalStateException if you call print() twice but
I suspect it may break code that does this for some reason
that in all probability is historical (like "I'm saving 
CPU/memory/whatever")
So I don't want to put anything in the docs that imply that
it is something that an app might be encouraged to do.

i.e. in the test the app does

aset.add(new PageRanges(1,1));
..
pjob.print(aset);

...
pjob.print();
...

PageRanges is *an example* of what should not be carried over.

So I think this (and the initial v0 fix) is missing the point of the bug
which is "The attribute set passed in a by the app should not be remembered
across calls."

In fact the proposed doc. arguably legitimises the opposite.

1427 * If {@code print(PrintRequestAttributeSet attributes)} is called 
before
1428 * this method for the same PrinterJob, it is expected to 
use/carryover the
1429 * same attributes set passed to
1430 * {@code print(PrintRequestAttributeSet attributes)}


What I was asking for in the bug report was that *any* settings
in that first print(aset) call should not be preserved as internal
state once print(aset) returns. So it seems like a clean-up-before-return
rather than a clean-up-on-reentry.

This requires careful attention to the contract of this method

https://docs.oracle.com/javase/8/docs/api/java/awt/print/PrinterJob.html#print-javax.print.attribute.PrintRequestAttributeSet-

Now since this bug was filed we added the ability to use the native
dialogs with an attribute set, so there may be some additional
or deeper pollution of the native state which may make this harder
to achieve. I don't have a ready answer for that but it does not
mean that we should give up with out a proper study of this ..

-phil.

On 09/29/2016 02:39 AM, Prasanta Sadhukhan wrote:
>
>
> On 9/12/2016 12:33 PM, Prasanta Sadhukhan wrote:
>> Hi All,
>>
>> Updated the spec to clarify that it is expected to use the same 
>> attribute set passed to print(PrintRequestAttributeSet) if it is 
>> called before no-args print() method for same PrinterJob.
>> http://cr.openjdk.java.net/~psadhukhan/4987884/webrev.01/
>>
> Updated PrinterJob spec as opposed to inner class RasterPrinterJob so 
> that javadocs is updated.
> http://cr.openjdk.java.net/~psadhukhan/4987884/webrev.02/
>
> Regards
> Prasanta
>> Regards
>> Prasanta
>> On 8/29/2016 1:41 PM, Prasanta Sadhukhan wrote:
>>> Hi All,
>>>
>>> If we call
>>> -----------------
>>> /        pageFormat = job.pageDialog(pageFormat);//
>>> //        pageFormat.setPaper(paper);//
>>> //        job.setPrintable(p, pageFormat);//
>>> ////
>>> //        try {//
>>> //            job.printDialog();//
>>> //            job.print();//
>>> //        } catch (PrinterException e) {}//
>>> /-------------------
>>> then these attributes are added
>>> Media, OrientationRequested, MediaPrintableArea, Chromaticity, 
>>> PrinterResolution, Copies, SheetCollate, Sides
>>> even if we do not change any fields
>>> and PageRanges attribute is added if we change page selection from 
>>> "All" to "Pages".
>>>
>>> In light of that, I do not think we can remove PageRanges attribute 
>>> from no-args print() method as that will remove user selection.
>>>  Or for that matter, any attributes as those can be set via 
>>> pageDialog or printDialog.
>>>
>>> I guess we need to mark this as "Wont fix" . spec also is not clear 
>>> if we are not supposed to honour any attributes already set, if we 
>>> call no-args print() method.
>>> Any comments?
>>>
>>> Regards
>>> Prasanta
>>> On 7/5/2016 10:52 AM, Prasanta Sadhukhan wrote:
>>>> Hi All,
>>>>
>>>> Please review a fix whereby it is seen that the PageRanges 
>>>> attribute passed to 1st print() call is inadvertently been carried 
>>>> forward to 2nd print
>>>> if some program tries calling in this sequence
>>>> ----------
>>>> /PrinterJob pj = PrinterJob.getPrinterJob();//
>>>> //pj.setPageable(..)//
>>>> //pj.print(..)//
>>>> //pj.setPageable(..)//
>>>> //pj.print(..)
>>>> ------------
>>>> /
>>>> Bug: https://bugs.openjdk.java.net/browse/JDK-4987884/
>>>> /webrev: http://cr.openjdk.java.net/~psadhukhan/4987884/webrev.00//
>>>>
>>>> /This is because no-args print() uses an internal attribute set 
>>>> which is presumed to carry over information not supplied
>>>> by the client directly but created during a call to no-args 
>>>> printDialog() or during call to setPrintable() called via 
>>>> setAttributes().
>>>> but it apparently seems, we should not be remembering PageRange 
>>>> attribute between calls to print() as it will result in wrong page 
>>>> numbers being printed.
>>>>
>>>> Proposed fix to remove the PageRanges attribute from no-args 
>>>> print() between print() calls.
>>>>
>>>> Regards
>>>> Prasanta
>>>
>>
>

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