I have the standalone viewer setup with left mouse button "Select clipboard region" and with the latest release (12.4) turned on "Click left/right edge to go to previous/next picture" with a 20% edge.
Left click on the left/right side goes to the next/previous picture, as expected.
Left click on the left/right with no other pictures in the folder, does nothing. Also as expected I guess, although some feedback would be appreciated.
Left click and drag, in the middle of the picture selects a region, as expected
Left click and drag to select, on the 20% edge of the screen, does not what I was expecting. I was expecting to select a region. Instead, when there are more pictures in the folder, it goes to show the next/prev picture. When there are no more pictures in the folder, Directory Opus does absolutely nothing and just sits there, making me doubt my left mouse button.
In that last one, I expected Directory Opus to register that I am moving the mouse after the initial click (inside of the 20% edge) and switch to "Select clipboard region"-mode.
Is it possible to change this behaviour?