2 User Interface
2.12 Undo/Redo
UNDO stack REDO stack
Det = Peak
RBW = 1MHz
CF = 1 GHz
When you press Undo, the top item on the Undo stack is removed, the action
represented by that item is undone, and the item is placed on the Redo stack. So
pressing Undo once in the above case would undo the setting of the peak detector,
and the stacks would look like this:
UNDO stack REDO stack
RBW = 1MHz Det = Peak
CF = 1 GHz
Now pressing Undo again would undo the RBW = 1 MHz action, and the stacks
would look like this:
UNDO stack REDO stack
CF = 1 GHz RBW = 1MHz
Det = Peak
Now pressing Redo would Redo the RBW = 1 MHz action, and the stacks would
again look like this:
UNDO stack REDO stack
RBW = 1MHz Det = Peak
CF = 1 GHz
Also, whenever you set a value, the Redo stack is cleared; you can’t redo an action
once you have interrupted the original flow of actions. Think of the Undo stack as the
past, and the Redo stack as the future; if you have items in both stacks it means you
have gone back to a time in the past; if you then do something you have changed
the future, so the old future (the Redo stack) gets cleared.
138 Short Range Comms & IoT Mode User's &Programmer's Reference