Searching for python script islands to layers

[Ofnuts]

1) pdb.gimp_image_select_item(image, operation, item). The API and the UI have different goals, they aren't always identical.

2)

Code:

image.add_layer(pdb.gimp_layer_new_from_drawable(layer.mask,image),0)

But why do you need this? You can work on the mask, it is a drawable and can be used in most calls that you use with a layer. Try this:

• create an empty image (single white layer)
  
• add an alpha channel to that
  
• add a layer mask
  
• put some black on the mask to create transparent holes
  
• remember that at this point your editoing goes to the mask (as stated in the status bar at the bottom)
  
• start the wand tool and click on your layer. The marching ants circle the holes
  
• in the Layers list, click on the Layer preview and check that the status bar tells you that you are now edting the layer and no longer the mask
  
• still with the wand, click on you layer (in the holes or not). The marching ants are along the canvas boundaries
  

This tells you two things:

• the wand doesn't care about opacity
  
• fuzzy select works on a layer mask so if you want to select by opacity you can use the mask directly (note that the mask will be a one bit-per-pixel drawable, so the pixels in the tiles have a single element).
  

3) Sorry, read some doc to fast, I thought I had seen an Opacity criterion. But then see 2)