Data Visualization Plugins

[Bartimaeus-]

Creating a discussion topic for plugin support for data visualization widgets to extend PlotJuggler's capabilities. This might include widgets such as a dial gauge, bar indicator, "red light/green light" indicator, etc. This is a topic that I've discussed a bit with Davide and may spend some time trying to develop. Davide made it clear that any PR would need to be fully aligned with the way he wants it to be implemented in order to be accepted, and the purpose of this discussion is to capture the requirements and outline the implementation for early feedback.

Known Requirements/Feedback:
From Davide:

This kind of configurability of the widget is something I have been thinking about in the last 2 years or so.

I definitely don't have time to work on this, but for me the most interesting "variation" of a widget would be one displaying an image.

To implement this "the right way, many things need to happen:

• Ability to "morph" a PlotWidget into another one.
• This new kind of widget should be implemented as plugins, to allow modular extensibility.
• I would think about 3-4 typical use cases (gauge, images, etc.)

The plugin must:

• react to new data, where drag and drop must be always the first option.
• react to time slider moved
• be configurable

[Bartimaeus-]

The term "DataViewer" is used to refer to this new type of plugin, and was chosen to follow the "DataLoader", "DataStreamer", "VideoViewer" plugin naming convention. Alternate naming will be adopted if directed by the maintainer.

Plugin Elements

• DataViewers should maintain a consistent user experience within PlotJuggler
• The DataViewer class inherits from the PlotJugglerPlugin class
• Existing conventions for performing actions and workflows should be used when possible

The image below outlines the required GUI elements of a DataViewer:

DataViewer Layout and Management

• One widget type per plugin for plugins bundled with PlotJuggler (custom plugins can do whatever they want)

PlotWidget as a Plugin
One major change proposed is changing the original PlotWidget itself into one or more DataVisPlugins that come by default with PlotJuggler:

This would bring the following benefits:

• Simpler main application level code than treating the PlotWidget as a special case
• Makes development for the DataViewerPlugin simpler by starting with something to use as a framework.
• Helps ensure that all connections to/from main application and other plugins are considered

Additional Use Cases:
Use cases for the following will be considered:
-Dial Gauge Widget
-Bar Gauge Widget (horizontal and vertical)
-Image Viewer Widget
-User Input Widgets (stretch goal)

Image Viewer Widget
The image viewer allows for a lot of user flexibility and quick creation of custom interfaces using image assets
-Allow user to display images based on input data
-Image scaling and rotation may be allowed to enable advanced widget behavior
-Behavior defined via Lua script
Example-- battery status display (each icon would be a separate image file)

The free software DashWare has a similar type of widget component that they call a Digit:

DashWare_Digit_Gauge.mp4

example Lua script:

if (value == 0) then
return "0_percent.jpg"
end
if (value <= 25) then
return "25_percent.jpg"
if(value <= 50) then
return "50_percent.jpg"
end
--(continue for all cases)

User Input Widgets
These widgets would not be DataViewers, but they would share the same place in the DockedWidgets area. Their purpose would be to allow user-defined actions to occur based on user input to the widget. This would effectively let users configure PlotJuggler as a basic human machine interface
Example use cases:
-Stream data from PJ to external device/program to make changes and observe output
-Trigger changes in DataViewer plugins (ex: change curve filter parameters such as scaling values using a slider to allow dynamic scaling of values)
Screenshot from: https://qwt.sourceforge.io/controlscreenshots.html