I was working in these days (including this change for X11) to add a feature to press a key, drag the mouse, and release the key to change some value (e.g. zoom, brush size, etc. the same actions that can be activated with the mouse wheel).
This feature was requested in several places before:
There are some mockups to change two different values with the same keyboard modifier + dragging up/down (changes one value, e.g. ink) and left/right changes other value (brush size). This will be possible. (For ink we have to add a new mouse wheel action, but it should be doable.)
I was working in these days (including this change for X11) to add a feature to press a key, drag the mouse, and release the key to change some value (e.g. zoom, brush size, etc. the same actions that can be activated with the mouse wheel).
This feature was requested in several places before:
There are some mockups to change two different values with the same keyboard modifier + dragging up/down (changes one value, e.g. ink) and left/right changes other value (brush size). This will be possible. (For ink we have to add a new mouse wheel action, but it should be doable.)