It Should Be Mostly Relative
I’ve been using a PowerBook with (and without) an external display lately, an experience that has brought to my attention that how windows are sized and positioned when moving between display setups could be better.
Window heights, widths, and positions should be stored as relative values (i.e., “Window 1 is 75% of available height, 50% of available width, 0% from top, 10% from left, on primary display) to make the transition from one monitor setup to another smoother.
There is software which functions better using an exact size, such as text editors and terminal emulators; the designers would make the call to override relative sizing. Even if relative sizing wasn’t used, relative positioning could be useful to maintain spatial relationships.
Of course, as soon as one of those windows has a maximum or minimum size greater/less than the specified percentage of the new display… then all bets are off - your spatial relationships are somewhat blown and the window won’t possibly fit. But probably still a better solution than the current deal?
There are a number problems related to relative sizing and positioning, but I think the benfits would outweight the detriments.