Undo / Redo

[toloudis]

Use Case

The codebase needs to be ready to support Undo

Solution

Create Command stack.
Make most numeric updates happen via Commands (e.g. when slider has stopped sliding). Add Undo capability to Command class. Command can remember previous value. Need to be able to update UI after undo.
TBD: determine which operations can not be undone and cause the undo stack to be thrown out and started over.
TBD: when input is changed via spin box, how much of it is undo-able? (e.g. On lose focus?)