I'm testing 18.04 beta on Arch Linux. After I select a rectangular region, spectacle shows a message on bottom of the screen saying that I can use double click or press enter to take the screenshot. Double click only works if applied in selected region. Double click outside selected region does nothing. Double click on selected region after double click outside it also does nothing.
Thanks for the report, can confirm. In general the rectangular region selector seems to have many issues, maybe we should replace it entirely some day instead of putting more work into it… > Double click outside selected region does nothing. The first click (press down) will already start a new selection rectangle, but as the button is released immediately, this rectangle is invalid. We still show the old rectangle, but remember the invalid one. I guess if on button release the rectangle is too small, it should simply be discarded.
> Double click only works if applied in selected region. Double click outside selected region does nothing. This is intentional. Whether it should stay that way, I'm not 100% sure, but I think it's fine. It makes a certain amount of sense that only double clicking on the selection would accept the selection like when double clicking a file to open it. > Double click on selected region after double click outside it also does nothing. This seems to be fixed.