[Skim-app-users] clarification regarding line and freehand notes

[Ed Morehouse]

It has been reported in the bug tracker that line and freehand notes are no
longer visible in Skim with OSX versions 10.11.x. Christiaan, the
developer, has characterized this as a PDFKit rendering bug and marked it as
"open-wont-fix":

http://sourceforge.net/p/skim-app/bugs/1059/

I would like to know whether anyone on the list has any insight into the
cause of this bug. For example, did Apple change the library calls by which
it creates these note types? I noticed that in Apple's own PDF viewer,
Preview, these annotation types work fine and that lines now come with a
control point so that they may be curved.

Is there any hope of getting working (and even curving) lines back in Skim?
For the type of documents that I work with they are very important and
losing them would force me to move to different document annotation software.

thanks,

-Ed


------------------------------------------------------------------------------

[Christiaan Hofman]

Post by Ed Morehouse
It has been reported in the bug tracker that line and freehand notes are no
longer visible in Skim with OSX versions 10.11.x. Christiaan, the
developer, has characterized this as a PDFKit rendering bug and marked it as
http://sourceforge.net/p/skim-app/bugs/1059/
I would like to know whether anyone on the list has any insight into the
cause of this bug. For example, did Apple change the library calls by which
it creates these note types? I noticed that in Apple's own PDF viewer,
Preview, these annotation types work fine and that lines now come with a
control point so that they may be curved.
Is there any hope of getting working (and even curving) lines back in Skim?
For the type of documents that I work with they are very important and
losing them would force me to move to different document annotation software.
thanks,
-Ed

Yes, Apple apparently changed the drawing code for these annotations. They apparently failed to implement the proper coordinate transformations needed to draw the line in the correct location.

I find it weird that Preview does draw them in the correct location. But I do know that Preview overrides the drawing code for certain annotations. The fact that they have curved lines strongly suggests that they do so in this case, as curves are not really supported by the PDF format. IMHO it is very bad behavior to add custom stuff to an open format such as PDF. Moreover the kind of hacking that is needed to override this is something Apple itself strongly discourages, and it is not the way to go. Bugs should be fixed where they are, not worked around by third parties (we had lots of problems doing that with scrolling bugs in PDFKit.)

As for fixing, this is Apple’s responsibility, they should really have done that in 10.11.2, as they know about the bug.

But if Apple won’t fix this bug, I may be forced to add a workaround. But I really don’t want that, because it would be a pretty messy one, and moreover I really don’t want to have a messy legacy override that would still be there when the bug will be fixed in the future (something that may be impossible to avoid).

Christiaan

[Ed Morehouse]

Post by Ed Morehouse
It has been reported in the bug tracker that line and freehand notes are

nolonger visible in Skim with OSX versions 10.11.x.  Christiaan,
thedeveloper, has characterized this as a PDFKit rendering bug and marked it
as"open-wont-fix":http://sourceforge.net/p/skim-app/bugs/1059/I would like
to know whether anyone on the list has any insight into thecause of this
bug.  For example, did Apple change the library calls by whichit creates
these note types?  I noticed that in Apple's own PDF viewer,Preview, these
annotation types work fine and that lines now come with acontrol point so
that they may be curved.Is there any hope of getting working (and even
curving) lines back in Skim? For the type of documents that I work with they
are very important andlosing them would force me to move to different
document annotation software.thanks,-Ed

Post by Ed Morehouse
Yes, Apple apparently changed the drawing code for these annotations. They

apparently failed to implement the proper coordinate transformations needed
to draw the line in the correct location.

Post by Ed Morehouse
I find it weird that Preview does draw them in the correct location. But I

do know that Preview overrides the drawing code for certain annotations. The
fact that they have curved lines strongly suggests that they do so in this
case, as curves are not really supported by the PDF format. IMHO it is very
bad behavior to add custom stuff to an open format such as PDF. Moreover the
kind of hacking that is needed to override this is something Apple itself
strongly discourages, and it is not the way to go. Bugs should be fixed
where they are, not worked around by third parties (we had lots of problems
doing that with scrolling bugs in PDFKit.)

Post by Ed Morehouse
As for fixing, this is Apple’s responsibility, they should really have

done that in 10.11.2, as they know about the bug.

Post by Ed Morehouse
But if Apple won’t fix this bug, I may be forced to add a workaround. But

I really don’t want that, because it would be a pretty messy one, and
moreover I really don’t want to have a messy legacy override that would
still be there when the bug will be fixed in the future (something that may
be impossible to avoid).

Post by Ed Morehouse
Christiaan

hi Christiaan,

Thank you for your reply and explanation. I understand your point of view
and agree that bugs should be fixed at the source. But I do not know how
much hope there is of Apple addressing this one in a timely fashion. As I
understand it, they have been fairly unresponsive about fixing similar
reported bugs in the past. As far as I can tell, the documentation for
PDFKit hasn't been updated since 2007, although I suspect that the library
has changed somewhat since then (for example, with the addition of curved
lines):

https://developer.apple.com/library/mac/documentation/GraphicsImaging
/Reference/PDFKit_Ref/

I have no right or desire to request that you make changes in Skim to work
around Apple's bugs. But a significant loss of functionality is bound to
negatively affect users who have come to rely on it, so I just wanted to
know what was the cause and whether we can expect a fix.

In any case, thank you for all your work on Skim and BibDesk. They have
been invaluable tools for me, and I'm sure, for many other people as well.

cheers,

-Ed
------------------------------------------------------------------------------

[Christiaan Hofman]

BTW, is it correct that you also see this problem for line, circle, and box notes, in particular on cropped and/or rotated pages?

Christiaan

Post by Ed Morehouse
It has been reported in the bug tracker that line and freehand notes are

nolonger visible in Skim with OSX versions 10.11.x. Christiaan,
thedeveloper, has characterized this as a PDFKit rendering bug and marked it
as"open-wont-fix":http://sourceforge.net/p/skim-app/bugs/1059/I would like
to know whether anyone on the list has any insight into thecause of this
bug. For example, did Apple change the library calls by whichit creates
these note types? I noticed that in Apple's own PDF viewer,Preview, these
annotation types work fine and that lines now come with acontrol point so
that they may be curved.Is there any hope of getting working (and even
curving) lines back in Skim? For the type of documents that I work with they
are very important andlosing them would force me to move to different
document annotation software.thanks,-Ed

Post by Ed Morehouse
Yes, Apple apparently changed the drawing code for these annotations. They

apparently failed to implement the proper coordinate transformations needed
to draw the line in the correct location.

Post by Ed Morehouse
I find it weird that Preview does draw them in the correct location. But I

do know that Preview overrides the drawing code for certain annotations. The
fact that they have curved lines strongly suggests that they do so in this
case, as curves are not really supported by the PDF format. IMHO it is very
bad behavior to add custom stuff to an open format such as PDF. Moreover the
kind of hacking that is needed to override this is something Apple itself
strongly discourages, and it is not the way to go. Bugs should be fixed
where they are, not worked around by third parties (we had lots of problems
doing that with scrolling bugs in PDFKit.)

Post by Ed Morehouse
As for fixing, this is Apple’s responsibility, they should really have

done that in 10.11.2, as they know about the bug.

Post by Ed Morehouse
But if Apple won’t fix this bug, I may be forced to add a workaround. But

I really don’t want that, because it would be a pretty messy one, and
moreover I really don’t want to have a messy legacy override that would
still be there when the bug will be fixed in the future (something that may
be impossible to avoid).

Post by Ed Morehouse
Christiaan

hi Christiaan,
Thank you for your reply and explanation. I understand your point of view
and agree that bugs should be fixed at the source. But I do not know how
much hope there is of Apple addressing this one in a timely fashion. As I
understand it, they have been fairly unresponsive about fixing similar
reported bugs in the past. As far as I can tell, the documentation for
PDFKit hasn't been updated since 2007, although I suspect that the library
has changed somewhat since then (for example, with the addition of curved
https://developer.apple.com/library/mac/documentation/GraphicsImaging <https://developer.apple.com/library/mac/documentation/GraphicsImaging>
/Reference/PDFKit_Ref/
I have no right or desire to request that you make changes in Skim to work
around Apple's bugs. But a significant loss of functionality is bound to
negatively affect users who have come to rely on it, so I just wanted to
know what was the cause and whether we can expect a fix.
In any case, thank you for all your work on Skim and BibDesk. They have
been invaluable tools for me, and I'm sure, for many other people as well.
cheers,
-Ed

[Ed Morehouse]

Post by Christiaan Hofman
BTW, is it correct that you also see this problem for line, circle, and

box notes, in particular on cropped and/or rotated pages?

Post by Christiaan Hofman
Christiaan

Hi Christiaan,

I'm not sure what you mean, the circle and box notes seem fine to me, it's
just the line and freehand notes that are no longer visible. Cropping or
rotating doesn't seem to have any effect. For what it's worth, I'm on Skim
1.4.16 and OSX 10.11.2.

-Ed
------------------------------------------------------------------------------

[Marc H. Scholl]


 same here (on same system config): only lines and freehand don’t show, all the other graphics annotations are fine.

—Marc

Post by Christiaan Hofman

Post by Christiaan Hofman
BTW, is it correct that you also see this problem for line, circle, and

box notes, in particular on cropped and/or rotated pages?

Post by Christiaan Hofman
Christiaan

Hi Christiaan,
I'm not sure what you mean, the circle and box notes seem fine to me, it's
just the line and freehand notes that are no longer visible. Cropping or
rotating doesn't seem to have any effect. For what it's worth, I'm on Skim
1.4.16 and OSX 10.11.2.
-Ed
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