Auto-switching Audio Widget? I use a lot of audio apps on my HTC One, like Doggcatcher, Google Music, Tunein Radio, Pandora, NPR, etc. Most, if not all, of these apps have a 4x1 widget which controls playback. These are very helpful, but I have to devote 1-2 homescreen pages to these widgets, even though only one of them is relevant to me at a time.

Is there a way to reserver a 4x1 block of space on the homescreen, and have that space filled with the 4x1 widget of whatever app is currently outputting audio to the system?

This is kind of similar to the HTC One Sense's lockscreen implementation, where it has a generic widget that shows play, previous, and next buttons that control whatever app is currently playing audio, and shows the title of the currently playing track.



I think this would be a good idea, and would be very useful to me. Is there anything out there that can support this functionality?

An alternate solution might be a generic audio widget that just shows the title track, with play, previous, and next controls, just like the HTC One lockscreen widget above. It's not ideal, as I like the app-specific functions (thumbs-up, etc.), but it would scratch the itch.
And a third variant is a kind of "1x1 multi-widget", capable of holding other widgets, and expanding to their size when opened. There are several of those "widget folders" available, see e.g. Widget Folder or Widget Container (there might be more of them, but those are the two I was able to find short-term). Then each of your widgets consumes just 1x1 when not used, and the one you use opens on top of them.

To make it more plastic and better understandable:

 
Widget Container: All closed, weather opened (click images to enlarge)

The first screenshot shows 4 closed "widget containers" (the green ones). In the second screenshot, the "Weather Container" was opened, and here covers  4x4, i.e. the entire screen.

Admitted, not the most beautiful, but a practical solution to your problem ;)