[Bug 1016777] Re: dotty missing labels and context menu is broken

[Emden R. Gansner]

I can describe why this is happening, but I still can't replicate it on
our versions of ubuntu, so I'm not sure how best to provide a fix. When
given a graph, dotty calls dot -Txdot to get the necessary rendering
information. By default, fontname is set to "Times-Roman". When using an
X11 interface, dotty maps this to '-*-times-
medium-r-*--%d-*-*-*-*-*-*-1', where the %d will be replaced with the
desired font size. When text is written, dotty calls XLoadQueryFont
(display,fontname). If the call fails with the requested font size,
dotty increments and decrements the size to see if a nearby font can be
found.  If this fails, dotty draws a tiny box for the text.

So on the systems having problems, the call XLoadQueryFont (display
,"-*-times-medium-r-*--14-*-*-*-*-*-*-1") is failing. So, why is the
match failing on these systems?

As a workaround, the mapping I mentioned is defined in the text file share/graphviz/lefty/dotty.lefty, so a user could fix Times-Roman to map to an available X11 font. One could also set a specific fontname attribute in the graph. This problem with this is that names that XLoadQueryFont will accept won't be handled well by the font resolution in pango. For me, pango maps the request for times-medium to a sans serif font. As long as the font metrics are not too far off, this probably won't matter too much. But why is dotty still being used? If one just wants a single command for drawing and displaying a graph, why not use  
  dot -Tx11 ?

For the record, the right-button menus work fine for me on Ubuntu 12.04
with Graphviz 2.36.

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https://bugs.launchpad.net/bugs/1016777

Title:
  dotty missing labels and context menu is broken

Status in “graphviz” package in Ubuntu:
  Confirmed

Bug description:
  Dotty on Ubuntu 12.04 doesn't really work.

  Load a dot graph in dotty (for example, "dotty example.dot" using the
  attached graph, taken from the Graphviz homepage).  There are two
  problems:

  1)  The text labels are not drawn, they just show up as dots.
  2)  The right-click menu doesn't work.  It shows up and entries are highlighted as you hover over them, but nothing happens when you select them.

  This is with graphviz 2.26.3-10ubuntu1 on Precise.

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