No Image Open error when running ImageJ commands

[hinerm]

1. Open napari
2. Open brick
3. Run Gaussian Blur... command (highlighted in yellow)
4. Get No Image error

I'm assuming this command needs to be run from the ImageJ GUI because it needs an ImageWindow? We probably don't want to show any Ij1 commands then right..?

[gselzer]

I'm assuming this command needs to be run from the ImageJ GUI because it needs an ImageWindow? We probably don't want to show any Ij1 commands then right..?

@hinerm so what we can do is use the LegacyImageMap to set the current ImagePlus to the current active layer on the fly, so that these things would work. I think I started doing this on the active-layer-to-active-ij-window branch with this commit. I never did finish that work, though...

[ctrueden]

@gselzer What if the napari user opens, say, three different images into napari, i.e. three image layers? Then they try running a plugin such as Image Calculator, which allows to select which images you want to operate upon? We want to ensure that all three of these napari images are available as options in the ImageJ plugin's dialog box. We could always sync all image layers from Python to Java just prior to executing a command... but what about interactive GUI mode? Should GUI mode behave differently than headless mode? It would be strange for a bunch of ImageWindows to appear every time you run a command from the napari-imagej widget, wouldn't it?

[gselzer]

I'm closing this, as #207 has been merged.