Contributing Guidelines

Code Structure

├── AUTHORS                      # Author information
├──                 # Changelog
├──              # Contributing guidelines
├── COPYING                      # Main license
├── COPYING.*                    # Other licenses
├── data                         # Data files to be installed
│   ├── COPYING                  # License information
│   ├── org.zrythm.Zrythm.gschema.xml # GSettings schema
│   └── zrythm.desktop           # Desktop file
├── doc                          # Documentation
│   ├── *.h                      # Doxygen pages
│   ├──          # Doxygen conf
│   ├──         # Doxygen mcss conf
│   ├── group_defs.dox           # TODO
│   └── m.css                    # m.css theme for html docs
├── ext                          # External libs
│   ├── audio_decoder            # Audio decoder by rgareus
│   ├── libcyaml                 # Yaml serialization
│   ├── midilib                  # MIDI file serialization
│   ├── README                   # Disclaimer
│   └── zix                      # Data struct utils
├── git-packaging-hooks          # Git hooks for packaging
├── inc                          # Include dir
│   ├── actions                  # Actions (undo, quit, etc.)
│   ├── audio                    # Audio-related headers
│   ├── gui                      # Gui-related headers
│   │   ├── backend              # Backend for serialization
│   │   └── widgets              # Gui widgets
│   ├── plugins                  # Plugin handling
│   │   ├── lv2                  # LV2 plugin handling
│   │   └── vst                  # VST plugin handling
│   ├── settings                 # Settings
│   ├── utils                    # Various utils
│   └── zrythm.h                 # Main zrythm struct
├──                  # Meson conf
├── meson.options                # Meson options
├── plugins                      # Bundled plugins
├── po                           # I18n
│   ├── *.po                     # Translations
│   ├── LINGUAS                  # Languages
│   ├── POTFILES                 # List of translatable files
│   └── zrythm.pot               # Source strings
├──                    # Main README file
├── resources                    # Bundled resources
│   ├── fonts                    # Fonts FIXME move to data
│   ├── # Gtk resources generator
│   ├── icons                    # Icons
│   ├── samples                  # Samples FIXME move to data
│   ├── theme                    # Parent GTK theme
│   ├── theme.css                # Zrythm GTK theme
│   └── ui                       # GTK ui files for widgets
├── scripts                      # various scripts
│   ├── # Prints the translatable files
│   ├──    # Commands to run after install
├── src                          # Source (.c) counterparts of inc
├── tests                        # Automated tests
├── THANKS                       # Thanks notice
├── THIRDPARTY_LICENSE           # Linked library license information
├── tools                        # TODO
└── TRANSLATORS                  # List of translators


Use gdb build/src/zrythm

There is also

G_DEBUG=fatal_warnings,signals,actions G_ENABLE_DIAGNOSTIC=1 gdb _build/src/zrythm

G_DEBUG will trigger break points at GTK warning messages and G_ENABLE_DIAGNOSTIC is used to break at deprecation warnings for GTK+3 (must all be fixed before porting to GTK+4).

Tests and Coverage

To run the test suite, use

meson _build -Denable_tests

followed by

meson test -C _build

To get a coverage report use

meson _build -Denable_tests=true -Denable_coverage=true

followed by the test command above, followed by

gcovr -r .

or for html output

gcovr -r . --html -o coverage.html

OBS Packaging

Binary packages are created on OBS (Open Build System) using git hooks. See the README in git-packaging-hooks and the packaging branch.


These are some guidelines for contributing code. They are not strict rules.


  • Document how to use the function in the header file
  • Document how the function works (if it's not obvious from the code) in the source file
  • Document each logical block within a function (what it does so one can understand what the function does at each step by only reading the comments)

Coding Style

GNU style is preferable.

Include Order

In alphabetic order:

  1. Standard C library headers
  2. Local headers
  3. GTK and GLib headers
  4. Any other headers

Line Length

Please keep lines within 60 characters. This works nicely with 8 files open simultaneously in a tiled editor like vim.


  • Generally, backend files should have a *_new() function to create a new instance or an *_init() function to initialize an existing instance, depending on if they are to be created dynamically or not.
  • Widgets should have a *_new() function if they should be created dynamically. They should have a *_setup() function to initialize them or "set them up" and a *_refresh() function to refresh their internal state. *_setup() is to be called only once after the instance is created and *_refresh() to be called multiple times as needed.
  • Zrythm has a UI event system that redraws only the relevant widgets based on the type of event.


If you contributed significant (for copyright purposes) amounts of code, you may add your copyright notice (name, year and optionally email/website) at the top of the file, otherwise you agree to assign all copyrights to Alexandros Theodotou, the main author.

All your changes should be licensed under the AGPLv3+ like the rest of the project, or at least a compatible Free Software license of your choice.

Common Problems

Getting random GUI related errors with no trace in valgrind or GTK warnings

This might happen when calling GTK code or g_idle_add() from non-GUI threads. GTK runs in a single GUI thread. Any GTK-related code must be run from the GUI thread only.

Submitting Patches

You can use whatever method you like for sending patches. There's Savannah, mailing lists and IRC.


Use the enable profiling option when running meson, then build and run the program normally. The program must end gracefully (ie, not Ctrl-C). When the program ends, run

gprof build/src/zrythm > results

and check the results file for the profiling results.


Zrythm is translated on Weblate:

Alternatively, you can edit the PO files directly and submit a patch.


Test Zrythm and report bugs, ideas and suggestions on Savannah.



Copyright (C) 2018-2019 Alexandros Theodotou

Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved. This file is offered as-is, without any warranty.