Drawing a variable number of rectangles every x seconds (Dynamic Objects)

[xdn]

I have a stream of images on top of which rectangles are shown to mark certain regions/objects. As new regions/objects show up and others disappear, I need to add/destroy rectangles. Technically there is an upper limit to the number of rectangles but I'd rather have them created dynamically.

At a later point, the user is supposed to be able to interact with the rectangles (click them mostly) so I cannot draw them into the image but need them to be separate objects on top of it.

[wysota]

I have a stream of images on top of which rectangles are shown to mark certain regions/objects. As new regions/objects show up and others disappear, I need to add/destroy rectangles. Technically there is an upper limit to the number of rectangles but I'd rather have them created dynamically.

You have to remember creating/destroying is always slower than showing/hiding. It's a trade-off decision you have to make.

As for keeping all the rectangles -- you can create a property that will hold a list of items.