[Okular-devel] [Bug 263314] New: Okular doesn't work too well with graphics tablets

[Martin Zuther]

https://bugs.kde.org/show_bug.cgi?id=263314

           Summary: Okular doesn't work too well with graphics tablets
           Product: okular
           Version: 0.11.1
          Platform: Ubuntu Packages
        OS/Version: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: NOR
         Component: general
        AssignedTo: okular-devel at kde.org
        ReportedBy: code at mzuther.de


Version:           0.11.1 (using KDE 4.5.1) 
OS:                Linux

At first, thanks for making such a great free PDF-and-what-not viewer!

I am using a professional graphics tablet (Wacom Intuos3 A5) instead of a
mouse.  Most of the time when I left-click on a document's hyperlink in Okular,
nothing happens at all.  Only occasionally, Okular follows the link.  The same
happens if I right-click on a hyperlink -- most of the time I get the "Add
bookmark / Previous bookmark / Next bookmark" popup, and only rarely the
expected "Follow link / Copy link address" popup comes up.

This problem is probably not related to the tablet's driver, as using the
tablet's mouse works as expected all of the time.  Only when I use the tablet
pen, I get the described behaviour.

I think there are two "culprits" here.  The graphics tablet registers mouse
clicks by either tipping the pen's tip on the tablet surface (left click) or by
holding the pen just above the tablet surface and clicking on one of two pen
buttons (right and middle click).  As the tablet has a very high resolution, it
registers even minute pen movements, so it is almost impossible to do a click
without moving the pen to a veeeery near location (think in micrometers).  But
this might be enough to signal "I don't want to follow the hyperlink, let's
scroll the document" to Okular.

The second culprit, although not as likely, is that graphics tablets report
absolute movement, not relative movement.  That means that a mouse might say
"The mouse pointer has moved 1.1 inches to the left and 0.1 inches to the top"
whereas a graphics reports "The mouse pointer has moved to position 8.8 / 1.2
inches from the top / left position" (although I honestly don't know whether
the zero position actually lies at "top / left" or whether the Linux driver
translates absolute to relative positions -- in Windows XP, which I rarely use,
this distinction unfortunately DOES matter a lot).

Reproducible: Always

Steps to Reproduce:
Open a PDF containing hyperlinks in Okular.  Find a professional (i.e. high
resolution!) graphics tablet and try left- and right-clicking on a hyperlink
with the pen.

Depending on the cause of the problem, you *might* simulate this using a mouse
by clicking on the hyperlink without releasing the button, then moving the
mouse just the tiniest bit (but you'll have to see the pointer move) and
finally releasing the mouse button.

Actual Results:  
The link is either not followed (left button) or the wrong popup comes up ("Add
bookmark / Previous bookmark / Next bookmark", right button).

Expected Results:  
The link is followed (left button) or the correct popup comes up ("Follow link
/ Copy link address", right button).

OS: Linux (x86_64) release 2.6.35-24-generic
Compiler: cc
Graphics tablet: Wacom Intuos3 A5

-- 
Configure bugmail: https://bugs.kde.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.