Increase the resolution/scale with the default "Save" button on the toolbar

[Icoti]

@banesullivan-kb, I am grateful that you opened this topic because I have exactly the same concern and was postponing the work on my to-do-list.
Thanks also to @Bryan for the explanation.

@banesullivan-kb

I suspect I’ll need to do a few things for a custom “Save” button that increases the scale factor:

1. Add a new button to the toolbar that triggers a Python callback (I’ve seen examples of this done before)
2. Install the browser dependencies server-side and execute export_png with the desired scale_factor
3. Serialize the saved PNG and send it back to the client
4. Download the received PNG

Steps 3 and 4 are the daunting part for me being new to Bokeh and Panel (where I’m using Bokeh) so if anyone feels like chiming in with a snippet on how to tackle those parts, it would be greatly appreciated!

For 2. and 3. I guess that get_screenshot_as_png() could do the job, although I didn’t try it myself yet.

For the download part 4., have a look at that topic in which a html file created with file_html() is downloaded:
https://discourse.bokeh.org/t/download-an-html-version-of-the-app/11033/7