I use the Unified Transform tool a lot and it's a great tool but there are some
issues with the user interface that I find very challenging.
Firstly that if I click on another layer in the layers list, the transform can
be instantly cancelled. When I am doing a transform, it can be multiple layers
that I am aligning the new layer over, and I might need to turn a lower order
layer off or on to use as the background to the layer being transformed.
Secondly there seems to be too many ways to trigger a transform. There is a
button called Transform in the dialog box, which is fine. But there also seems
to be an expectation that you should be able to press a key on the keyboard to
start the transform operation. And this is not just one key, it seems to be a
whole lot of different keys that will trigger it. This is similar to the way
that with some tools, such as Crop, the transform will be triggered if you only
so much as click outside the crop rectangle accidentally.
That seems to be the default behaviour of Gimp and if it is, I wonder if the
person who implemented these features has ever got the understanding that it
might be possible to accidentally click in the wrong place or press the wrong
key and then have the transform triggered unnecessarily. You may say that this
is only a minor inconvenience where a transform only takes seconds to complete
and can be undone. That may be true in a lot of cases but I have worked with
layers in images where a transform has taken 15, 30 or even 60 minutes to
complete, and that's on a 1 year old computer with 32 GB of RAM and a 200 GB SSD
based tile cache which is never more than half used.
I couldn't see any way in the preferences to change this "press any key or click
anywhere outside the rectangle" behaviour and neither could I see how it is
inconvenient to move the mouse over click the specific button to trigger the