RStudio shortcuts exist for moving between Source and Console panes .. and showing the Environment/History and Packages/File System panes .. but not moving to them.
Keyboard shortcuts: https://support.rstudio.com/hc/en-us/articles/200711853-Keyboard-Shortcuts
It is a very frequent operation to switch between panes - and it should be supported by keyboard shortcuts: is there a hidden set of shortcuts and/or a way to add custom shortcuts to RStudio for this?
