I agree that GOP is basically a natural analogy to a tracking area already, so that might be a good place to look. Perhaps this can be rolled into the name canvas mechanism whereby a named canvas will receive mouse events when GOP is enabled?

On Mar 17, 2019, at 1:38 PM, Dan Wilcox <danomatika@gmail.com> wrote:

That's a similar concept to Cocoa's NSTrackingArea. It's basically a rectangle in a view that you attach which then receives mouse enter, leave, move, down, up, & drag events. You can update the position and size whenever.

https://developer.apple.com/documentation/appkit/nstrackingarea?language=objc

I could imagine something similar in Pd, say a [mousearea] object. Also, updating [cnv] with similar functionality would be useful. [mousearea] could be used for arbitrary areas for control interaction and drawing of other objects while [cnv] could be used to create simple graphical regions for things like piano keys. I know there have been different approaches in this area, so it might be helpful to take a look (DesireData, PurrData, etc).

I think this would complement a general, canvas wide set of [mouse] objects. I started by following the existing approach and split functionality into [mouse], [mouseup], and [mousemotion]. Another approach would be to use a single [mouse] object with a status symbol in addition to x & y.