subsurface/desktop-widgets/undocommands.cpp
Berthold Stoeger 403dd5a891 Undo: fix multi-level undo of delete-dive and remove-dive-from-trip
The original undo-code was fundamentally broken. Not only did it leak
resources (copied trips were never freed), it also kept references
to trips or dives that could be changed by other commands. Thus,
anything more than a single undo could lead to crashes.

Two ways of fixing this were considered
1) Don't store pointers, but unique dive-ids and trip-ids.
   Whereas such unique ids exist for dives, they would have to be
   implemented for trips.
2) Don't free objects in the backend.
   Instead, take ownership of deleted objects in the undo-object.
   Thus, all references in previous undo-objects are guaranteed to
   still exist (unless the objects are deleted elsewhere).

After some contemplation, the second method was chosen, because
it is significantly less intrusive. While touching the undo-objects,
clearly separate backend from ui-code, such that they can ultimately
be reused for mobile.

Note that if other parts of the code delete dives, crashes can still
be provoked. Notable examples are split/merge dives. These will have
to be fixed later. Nevertheless, the new code is a significant
improvement over the old state.

While touching the code, implement proper translation string based
on Qt's plural-feature (using %n).

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
2018-10-11 16:22:27 -07:00

159 lines
4.1 KiB
C++

// SPDX-License-Identifier: GPL-2.0
#include "desktop-widgets/undocommands.h"
#include "desktop-widgets/mainwindow.h"
#include "core/divelist.h"
#include "core/subsurface-string.h"
#include "core/gettextfromc.h"
UndoDeleteDive::UndoDeleteDive(const QVector<struct dive*> &divesToDeleteIn) : divesToDelete(divesToDeleteIn)
{
setText(tr("delete %n dive(s)", "", divesToDelete.size()));
}
void UndoDeleteDive::undo()
{
// first bring back the trip(s)
for (auto &trip: tripsToAdd) {
dive_trip *t = trip.release(); // Give up ownership
insert_trip(&t); // Return ownership to backend
}
tripsToAdd.clear();
for (DiveToAdd &d: divesToAdd) {
if (d.trip)
add_dive_to_trip(d.dive.get(), d.trip);
divesToDelete.append(d.dive.get()); // Delete dive on redo
add_single_dive(d.idx, d.dive.release()); // Return ownership to backend
}
mark_divelist_changed(true);
divesToAdd.clear();
// Finally, do the UI stuff:
MainWindow::instance()->refreshDisplay();
}
void UndoDeleteDive::redo()
{
for (dive *d: divesToDelete) {
int idx = get_divenr(d);
if (idx < 0) {
qWarning() << "Deletion of unknown dive!";
continue;
}
// remove dive from trip - if this is the last dive in the trip
// remove the whole trip.
dive_trip *trip = unregister_dive_from_trip(d, false);
if (trip && trip->nrdives == 0) {
unregister_trip(trip); // Remove trip from backend
tripsToAdd.emplace_back(trip); // Take ownership of trip
}
unregister_dive(idx); // Remove dive from backend
divesToAdd.push_back({ OwningDivePtr(d), trip, idx });
// Take ownership for dive
}
divesToDelete.clear();
mark_divelist_changed(true);
// Finally, do the UI stuff:
MainWindow::instance()->refreshDisplay();
}
UndoShiftTime::UndoShiftTime(QVector<int> changedDives, int amount)
: diveList(changedDives), timeChanged(amount)
{
setText(tr("delete %n dive(s)", "", changedDives.size()));
}
void UndoShiftTime::undo()
{
for (int i = 0; i < diveList.count(); i++) {
dive *d = get_dive_by_uniq_id(diveList.at(i));
d->when -= timeChanged;
}
// Changing times may have unsorted the dive table
sort_table(&dive_table);
mark_divelist_changed(true);
// Negate the time-shift so that the next call does the reverse
timeChanged = -timeChanged;
// Finally, do the UI stuff:
MainWindow::instance()->refreshDisplay();
}
void UndoShiftTime::redo()
{
// Same as undo(), since after undo() we reversed the timeOffset
undo();
}
UndoRenumberDives::UndoRenumberDives(const QVector<QPair<int, int>> &divesToRenumberIn) : divesToRenumber(divesToRenumberIn)
{
setText(tr("renumber %n dive(s)", "", divesToRenumber.count()));
}
void UndoRenumberDives::undo()
{
for (auto &pair: divesToRenumber) {
dive *d = get_dive_by_uniq_id(pair.first);
if (!d)
continue;
std::swap(d->number, pair.second);
}
mark_divelist_changed(true);
// Finally, do the UI stuff:
MainWindow::instance()->refreshDisplay();
}
void UndoRenumberDives::redo()
{
// Redo and undo do the same thing!
undo();
}
UndoRemoveDivesFromTrip::UndoRemoveDivesFromTrip(const QVector<dive *> &divesToRemoveIn) : divesToRemove(divesToRemoveIn)
{
setText(tr("remove %n dive(s) from trip", "", divesToRemove.size()));
}
void UndoRemoveDivesFromTrip::undo()
{
// first bring back the trip(s)
for (auto &trip: tripsToAdd) {
dive_trip *t = trip.release(); // Give up ownership
insert_trip(&t); // Return ownership to backend
}
tripsToAdd.clear();
for (auto &pair: divesToAdd)
add_dive_to_trip(pair.first, pair.second);
divesToAdd.clear();
// Finally, do the UI stuff:
MainWindow::instance()->refreshDisplay();
}
void UndoRemoveDivesFromTrip::redo()
{
for (dive *d: divesToRemove) {
// remove dive from trip - if this is the last dive in the trip
// remove the whole trip.
dive_trip *trip = unregister_dive_from_trip(d, false);
if (!trip)
continue; // This was not part of a trip
if (trip->nrdives == 0) {
unregister_trip(trip); // Remove trip from backend
tripsToAdd.emplace_back(trip); // Take ownership of trip
}
divesToAdd.emplace_back(d, trip);
}
mark_divelist_changed(true);
// Finally, do the UI stuff:
MainWindow::instance()->refreshDisplay();
}