Enum zng_ext_undo::UndoFullOp

pub enum UndoFullOp<'r> {
    Init {
        redo: &'r mut bool,
    },
    Op(UndoOp),
    Info {
        info: &'r mut Option<Arc<dyn UndoInfo>>,
    },
    Merge {
        next_data: &'r mut dyn Any,
        prev_timestamp: DInstant,
        within_undo_interval: bool,
        merged: &'r mut bool,
    },
}

Represents a full undo/redo action.

This can be used to implement undo and redo in a single closure. See UNDO.register_full_op and UNDO.run_full_op for more details.

Variants

Init

Initialize data in the execution context.

This is called once before the initial Op(UndoOp::Redo) call, it can be used to skip registering no-ops.

Fields

redo: &'r mut bool

If the op must actually be executed.

This is true by default, if set to false the OP will be dropped without ever executing and will not be registered for undo.

Op(UndoOp)

Normal undo/redo.

Info

Collect display info.

Fields

info: &'r mut Option<Arc<dyn UndoInfo>>

Set this to respond.

If not set the info will be some generic “action” text.

Merge

Try merge the next_data onto self data (at the undone state).

Fields

next_data: &'r mut dyn Any

Closure data for the next undo action.

The data can be from any full undo closure action, only merge if the data indicates that it comes from actions that can be covered by the self closure.

prev_timestamp: DInstant

Timestamp of the previous action registered.

within_undo_interval: bool

If the prev_timestamp is within the UNDO.undo_interval. Undo actions can choose to ignore this and merge anyway.

merged: &'r mut bool

Set this to true if the next action can be dropped because the self closure now also implements it.

Trait Implementations

impl<'r> Debug for UndoFullOp<'r>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.