The question in short
I would like to click-and-drag single glyphs in a server-hosted scatter, and make sure that the (x,y) coordinates of the glyph are updated on server side.
(for full clarity this is not a use of the “Pan” tool. This mpld3 example shows the click-and-drag behaviour I refer to, and the image below comes from this SO question)

Context of the question
As Bokeh introduced a few interesting widgets (Tables, Sliders,…) I am seeking to move a professional application from a desktop environment based on Matplotib+PyQt, to a Heroku + Flask + Bokeh-server solution. To do this, I need to be able to click-and-drag elements of a chart like in the mpld3 example linked above, or in this matplotlib example). This is a “bokeh for webapp” question (and to be clear, being able to have basic pyqt-like widgets on the web without having to deal directly with stuff like extjs is absolutely amazing).
Reference documentation
This issue has been touched on already here in this group, but I need some help wrapping these elements together.



