Method undo

texteditor/buffer.go:824–835

Undo undo undoes next group of items on the undo stack

()

// undo undoes next group of items on the undo stack
func (tb *Buffer) undo() []*text.Edit {
	autoSave := tb.batchUpdateStart()
	defer tb.batchUpdateEnd(autoSave)
	tbe := tb.Lines.Undo()
	if tbe == nil || tb.Undos.Pos == 0 { // no more undo = fully undone
		tb.SetChanged(false)
		tb.notSaved = false
		tb.AutoSaveDelete()
	}
	tb.signalMods()
	return tbe
}

// redo redoes next group of items on the undo stack,
// and returns the last record, nil if no more