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Revision as of 17:25, 23 January 2012 by Lcc (talk | contribs) (Ideas)
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Lines of descendants chart
DescendantsLines, example Gramps data, inc_marriages and inc_places.
Shakespeare family tree, DescendantsLines
Shakespeare family tree, DescendantsLines, including event places

DescendantsLines is an in-development addon for Gramps which generates a graphical descendants tree using orthogonal edges and routing ("square edges").


2007: Adam Sampson has written a standalone python script for parsing data.gramps (GRAMPS XML). [1]

2010: this script needs some updates for avoiding minor issues.

A modified script is available on the addons repository. [2]


  1. No option for name display format
  2. Partial quoting of xml-syntax-like data. Data which resembles xml syntax (tags, etc) may cause error.
  3. Script ignores role on event (was added in 2007)
  4. Script ignores localized date handlers (using ISO date format, date quality in english)
  5. Memory limitation with a large database (DOM parsing)
  6. The last pixel column of each secondary line of each entry is wrong coloured (red instead black)
  7. The addon DescendantsLines does not use the Gramps document interface. (perhaps the Gramps document interface options should be hidden)
  8. DestinationOption does not have the usual error handling and user checking (e.g. for overwriting files)


  1. Create the directory $GRAMPSHOME/gramps/gramps34/plugins/DescendantsLines/ .
  2. Copy the files and from svn to the directory $GRAMPSHOME/gramps/gramps34/plugins/DescendantsLines/ .
  3. Open Gramps and generate the report -- Reports -> Graphical Reports -> Descendants Lines. Choose the output path on "Destination" (default $GRAMPSHOME/DescendantsLines.png). The "Filename" option will contain an empty file after the report is run.
  4. The script currently runs in "debug mode" so it generates copious terminal output such as "Unknown event type: ..." or "Unknown spouse: ...". These warnings are harmless.


The options for the addon DescendantsLines are:

  • S_DOWN - The length of the vertical edges from descendant to spouse-bar
  • S_UP - The length of the vertical edges from spouse-bar to spouse
  • S_VPAD - Length of vertical padding spacing between spouse and spouse-bar (?)
  • FL_PAD - Length of padding spacing between S_UP edges (vertical edges from spouse-bar to spouse) and O_DOWN edges (vertical edges from spouse-bar to child-bar)
  • OL_PAD
  • O_DOWN - The length of the vertical edges from spouse-bar to child-bar
  • C_PAD - Length of padding spacing between children
  • F_PAD - Length of padding spacing between families (?)
  • C_UP - The length of the vertical edges from child to child-bar
  • SP_PAD - Length of padding spacing between spouses
  • output_fmt - The output format (PNG or SVG)
  • output_fn - The output filename
  • max_gen - Maximum number of generations to include.
  • inc_places - Whether to include event places in the output
  • inc_marriages - Whether to include marriage information in the output



There is an experimental try for migrating this Gtk/cairo code to a draw plugin working into Gramps (font, style, path, canvas, output formats).

Draft version is available on Addons repository as unstable (beta). [3]

The idea will be to keep the Gramps XML parsing, but with a copy of the active database and use of current report environment (output formats, style, path).


  • Using the library get_event_or_fallback() methods from gen.utils. (done in Gramps-addons)
  • Add a generation limit. (done in Gramps-addons)
  • Make the XML export smaller. Use filter. (done in Gramps-addons)
  • Add option for output format. (done in Gramps-addons trunk)
  • Think of tree compression algorithms.


Pass 1: generate a tmp XML with only data needed for the report, to load it as input

  1. Enable Person selection (Gramps ID) - done
  2. Generate a temp Gramps XML database matching 'IsDescendantFamilyOf' filter rule - done
  3. Input path - done (need to set @prefix@: path_to_SVN/src on
  4. Clean-up - done
  • simple Gramps XML template with events, persons, families objects (only export primary event role reference).
  • 'localized' dates (does not follow last DTD, which uses english and ISO format).

FINISHED - it works fine!

Pass 2: use draw report environment

  1. Generate a plugins/docgen/ file [4]
  2. Move Gtk code to draw report (if possible)
  3. Move cairo code to draw report (if possible)
  4. Output path
  5. Clean-up, pylint, etc ...

Pass 2 (Alternate): use of user-defined (mega)-widgets

  1. Have a look at mega-widget request and implementation [5]
  2. Output path through mega-widget
  3. Clean-up, pylint, etc ...

Pass 2 (Alternate): use a DestinationOption

  1. Use a DestinationOption
  2. Ignore standard Filename option

Command Line Interface

Gramps provides a cli support for running reports and tools [6].

  • use stdin and stdout for command line import/export [7]

Feel free to contribute or improve it.