ROS 2 version of rqt_bag has missing icons

[clalancette]

Prior to ros-visualization/qt_gui_core#250 being merged, icons didn't work at all on Linux. Once that PR is merged, icons work for the most part, but there are a few missing in rqt_bag (see the attached file for a screenshot).

From the tooltips, these missing icons look like "Zoom In", "Zoom Out", "Zoom Home", and "Toggle Thumbnails"

[emersonknapp]

This is related to ros-visualization/rqt#249 - though from what I can tell, the Tango theme doesn't provide the icons that are missing:

• zoom-in
• zoom-out
• zoom-original
• insert-image

I don't know the historical context - maybe original rqt apps were depending on Adwaita theme instead? This seems to have those icons under those exact names, at least in its "legacy" listings.

[emersonknapp]

Oh - this issue is true on Noetic, too. I think it's an Ubuntu Focal+ problem, not a ROS2 problem.