dlt-plugins

Out-of-tree plugins for dlt-viewer.

Building

just build           # debug build in build/debug (also: just build debug)
just build release   # release build in build/release
                     # both copy the plugins to build/plugins
just install         # install the release plugins
just format          # clang-format all sources
just lint            # clang-tidy all sources
just clean           # remove build/

or with plain CMake:

cmake -S . -B build
cmake --build build

The plugins link against dlt-viewer's libqdlt and use the same Qt major version (detected from libqdlt). qdlt is located in this order:

1. -DDLT_VIEWER_SOURCE_DIR=/path/to/dlt-viewer: a built checkout; the library is taken from DLT_VIEWER_BUILD_DIR (default <source>/build).
2. pkg-config module qdlt.
3. An installed dlt-viewer (include/qdlt and libqdlt) in the default search paths or CMAKE_PREFIX_PATH.

Built plugins end up in <build dir>/out/plugins (with just, also copied to build/plugins). Either point the viewer at that directory (Settings → Plugins path) or install them with cmake --install build (target directory: DLT_PLUGIN_INSTALL_DIR, by default <prefix>/lib/dlt-viewer/plugins) and point the viewer there; system plugin directories belong to the package.

CI

.github/workflows/build.yml builds libqdlt from dlt-viewer's master (or the ref given when run by hand) and the plugins against it, with Qt 5 and Qt 6 on Ubuntu 24.04 and 26.04, warnings as errors. It also runs weekly, to catch dlt-viewer changes that break the plugins.

Debug output

Qt sends qDebug() output to the systemd journal when stderr is not a terminal. Run the viewer with QT_FORCE_STDERR_LOGGING=1 (or check journalctl --user) to see messages such as Load plugin "UI Tweaks".

Adding a plugin

Create plugins/<name>/ with a CMakeLists.txt that calls

dlt_add_plugin(myplugin myplugin.h myplugin.cpp)

and add it with add_subdirectory() in the root CMakeLists.txt. dlt_add_plugin() links plugin_utils and qdlt, and adds the plugin's directory to the include path, so includes are written as "tweaks/foo.h".

The plugin class derives from plugin_utils::ControlPlugin and passes its PluginInfo:

constexpr plugin_utils::PluginInfo kInfo{
    .name = "My Plugin"_L1,
    .version = "0.1.0"_L1,
    .description = "What it does"_L1,
    .settings_group = "myplugin"_L1,
};

MyPlugin::MyPlugin() : ControlPlugin(kInfo) {}

For a settings dock, derive from plugin_utils::ConfigurablePlugin instead, fill the form in buildSettingsForm(), and also declare Q_INTERFACES(QDltPluginViewerInterface); without it the viewer never asks for the dock.

Use snake_case file names. Avoid names starting with ui_: AUTOUIC treats ui_*.h includes as headers generated from .ui files.

plugin_utils

Shared helpers linked into every plugin: plugin metadata and settings, a base class for plugins that act on the main window, and one that adds a settings dock built from a form of checkboxes, spin boxes, text fields and combo boxes bound to the plugin's settings, next to the plugin's own view if it has one.

Plugins

• plugins/uitweaks: small UI fixes, each can be turned off in its dock
  • hide the filter index range and filter append widgets
  • keep the app and context ID columns wide enough
  • fit the payload column to the table width
  • more entries in the Recent menus
  • dark text on filter colors
  • soft marker color palette with shades in the filter dialog
  • start on the Filter tab
  • unclip the filter dialog's type buttons (temporary, until fixed upstream)
• plugins/dltproxy: forwards selected app IDs from a DLT source to a local port, for an ECU in the project to connect to
• plugins/testoverview: lists the test suites and tests a test framework logs, found by configurable start/end token patterns, with their results; goes to a suite or test, or limits the log to it. Its "Tests" toolbar button shows it; it reads the log, on its own thread, only while shown.

Tools

• tools/dlt-filter-proxy: the proxy as a standalone program; also builds on its own with cmake -S tools/dlt-filter-proxy -B build/proxy