The grids docker has input field for user to put spacing value. this input field only takes in pixels. I think we also should provide a way to have grids and guides in mm, cm and in units. this will be useful for mainly comic creators while setting up templates or pages. to reproduce 1) Open Krita, show ruler and change the ruler units to anything other than px 2) open a new document, and show grids, you'll notice that grids are pixel based 3) open the grid docker, and put 1cm in spacing input field of the grid tab, you'll get an error.
Not sure whether its doable, though it is desirable. WISHGROUP: Small Usability Fixes
I think the bug report can be extended to make all the input boxes unit aware. Since it is not the just the input boxes in the grid docker are not aware of other units, it is other input boxes as well. For example the input boxes for the rectangle, ellipse (selection as well as shape) tool or the input box for the brush are all pixel only. Some use cases for making them unit aware as as follows 1) You want to illustrate a book cover and need a rectangular shape to denote the spine of the book cover, currently you will have to input accurate pixel value to draw the rectangle. 2) You are designing a line art which will be printed and want to have a brush size in print value example a 2 inch flat brush. Ideally the input box should take value in inch and convert it to pixel for the user. One example of these type of input boxes can be found in inkscape, the input boxes that appear on the tool bar above when you use shape tools in inkscape behave this way
The need of more units in grid docker is indisputable but I'm not sure about other places. The Grids docker is used sparingly - most probably just once per document - while the brush size input field is used all the time, and user probably just clicks somewhere around the area. Also please correct me if I'm wrong but isn't it the case that every time Krita uses a "unit aware input", it's just a numeric box and then a combobox with units?