OpenCPN Developer Manual

Design overview

Supported platforms

The installer supports four platforms:

  • Windows

  • Macos

  • Debian

  • Flatpak

The PR contains patches to make the mingw builds usable. However, the core installer makes no difference between mingw or msvc builds.

The combination of Debian and Flatpak is aimed to cover the fragmented Linux ecosystem. While Flatpak can be used on all Linux distros, having Debian packages available makes sense for space-constrained embedded systems like the Raspberry.

Catalog and tarballs

These are the groundwork for the installer code. The catalog is the complete list of available plugins presented to user. When user selects a plugin, the catalog provides info so the plugin can be downloaded. See [Catalog](Catalog) and [Tarballs](Tarballs)

Installations

Plugins are installed in the user writable [installation paths](Installation-paths).

After installation, a list of installed files is left in the [user configuration directory](Terminology#_user_config_path), in the sub directory plugins/install_data. This list is used when uninstalling. If the list does not exist the installer assumes the plugin has been installed using other means and will not change it in any way.

Main modules affected

  • pluginmanager.cpp has been patched to:

    • Load plugins from the [User install dir](terminology#_user_install_path) on all platforms. This makeś Macos and Windows work in a similar way as Linux.

    • Support uninstallation of plugins in user install directories.

    • Support a dynamic set of plugins. Prior to this PR, the set of plugins loaded at startup never changed.

  • The two new modules download\_mgr and catalog\_mgr handles the download and catalog manager UI dialogs.

  • The PluginHandler module is the backend side of plugins, mostly downloading and installing. Here is also code to handle the plugin metadata.

  • The PluginPaths module handles mapping of various paths to platform- specific values.

  • OCPNPlatform has been patched to provide an extended set of platform paths, mostly to support loading plugins from user directories.

Build chain

The flatpak/ directory contains all necessary pieces to build a flatpak version of opencpn. This has been incorporated to be able to test flatpaked plugins.

The ci/ directory contains changes to build mingw and also support for deploying packages to cloudsmith.io. Build scripts has been refactored to be usable also in other builders like circleci.com