Undo: make dive-import undoable

On desktop, replace all add_imported_dives() calls by a new undo-command.
This was rather straight forward, as all the preparation work was done
in previous commits.

By using an undo-command, a full UI-reset can be avoided, making the UI
react smoother.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

9 files changed, 122 insertions, 25 deletions

diff --git a/desktop-widgets/command.cpp b/desktop-widgets/command.cpp
index 2bff1aad0..1fc6fbe1c 100644
--- a/desktop-widgets/command.cpp
+++ b/desktop-widgets/command.cpp
@@ -11,6 +11,13 @@ void addDive(dive *d, bool autogroup, bool newNumber)
 	execute(new AddDive(d, autogroup, newNumber));
 }
 
+void importDives(struct dive_table *dives, struct trip_table *trips,
+		 bool prefer_imported, bool downloaded, bool merge_all_trips,
+		 const QString &source)
+{
+	execute(new ImportDives(dives, trips, prefer_imported, downloaded, merge_all_trips, source));
+}
+
 void deleteDive(const QVector<struct dive*> &divesToDelete)
 {
 	execute(new DeleteDive(divesToDelete));
diff --git a/desktop-widgets/command.h b/desktop-widgets/command.h
index 71ef2f9da..83bde3b3a 100644
--- a/desktop-widgets/command.h
+++ b/desktop-widgets/command.h
@@ -21,6 +21,9 @@ void addDive(dive *d, bool autogroup, bool newNumber); // If d->dive_trip is nul
 						       // distance are added to a trip. dive d is consumed (the structure is reset)!
 						       // If newNumber is true, the dive is assigned a new number, depending on the
 						       // insertion position.
+void importDives(struct dive_table *dives, struct trip_table *trips,
+		 bool prefer_imported, bool downloaded, bool merge_all_trips,
+		 const QString &source);
 void deleteDive(const QVector<struct dive*> &divesToDelete);
 void shiftTime(const QVector<dive *> &changedDives, int amount);
 void renumberDives(const QVector<QPair<dive *, int>> &divesToRenumber);
diff --git a/desktop-widgets/command_divelist.cpp b/desktop-widgets/command_divelist.cpp
index c8ec5d082..6d2eafc6d 100644
--- a/desktop-widgets/command_divelist.cpp
+++ b/desktop-widgets/command_divelist.cpp
@@ -43,7 +43,7 @@ void processByTrip(std::vector<std::pair<dive_trip *, dive *>> &dives, Function
 
 // This helper function removes a dive, takes ownership of the dive and adds it to a DiveToAdd structure.
 // If the trip the dive belongs to becomes empty, it is removed and added to the tripsToAdd vector.
-// It is crucial that dives are added in reverse order of deletion, so the the indices are correctly
+// It is crucial that dives are added in reverse order of deletion, so that the indices are correctly
 // set and that the trips are added before they are used!
 DiveToAdd DiveListBase::removeDive(struct dive *d, std::vector<OwningTripPtr> &tripsToAdd)
 {
@@ -558,6 +558,87 @@ void AddDive::undoit()
 	MainWindow::instance()->refreshDisplay(false);
 }
 
+ImportDives::ImportDives(struct dive_table *dives, struct trip_table *trips,
+			 bool prefer_imported, bool downloaded, bool merge_all_trips,
+			 const QString &source)
+{
+	setText(tr("import %n dive(s) from %1", "", dives->nr).arg(source));
+
+	struct dive_table dives_to_add = { 0 };
+	struct dive_table dives_to_remove = { 0 };
+	struct trip_table trips_to_add = { 0 };
+	process_imported_dives(dives, trips, prefer_imported, downloaded, merge_all_trips,
+			       &dives_to_add, &dives_to_remove, &trips_to_add);
+
+	// Add trips to the divesToAdd.trips structure
+	divesToAdd.trips.reserve(trips_to_add.nr);
+	for (int i = 0; i < trips_to_add.nr; ++i)
+		divesToAdd.trips.emplace_back(trips_to_add.trips[i]);
+
+	// Add dives to the divesToAdd.dives structure
+	divesToAdd.dives.reserve(dives_to_add.nr);
+	for (int i = 0; i < dives_to_add.nr; ++i) {
+		OwningDivePtr divePtr(dives_to_add.dives[i]);
+		divePtr->selected = false; // See above in AddDive::AddDive()
+		dive_trip *trip = divePtr->divetrip;
+		divePtr->divetrip = nullptr; // See above in AddDive::AddDive()
+		int idx = dive_table_get_insertion_index(&dive_table, divePtr.get());
+
+		// Note: The dives are added in reverse order of the divesToAdd array.
+		// This, and the fact that we populate the array in chronological order
+		// means that wo do *not* have to manipulated the indices.
+		// Yes, that's all horribly subtle.
+		divesToAdd.dives.push_back({ std::move(divePtr), trip, idx });
+	}
+
+	// Add dive to be deleted to the divesToRemove structure
+	divesToRemove.reserve(dives_to_remove.nr);
+	for (int i = 0; i < dives_to_remove.nr; ++i)
+		divesToRemove.push_back(dives_to_remove.dives[i]);
+}
+
+bool ImportDives::workToBeDone()
+{
+	return !divesToAdd.dives.empty();
+}
+
+void ImportDives::redoit()
+{
+	// Remember selection so that we can undo it
+	currentDive = current_dive;
+
+	// Add new dives
+	std::vector<dive *> divesToRemoveNew = addDives(divesToAdd);
+
+	// Remove old dives
+	divesToAdd = removeDives(divesToRemove);
+
+	// Select the newly added dives
+	restoreSelection(divesToRemoveNew, divesToRemoveNew.back());
+
+	// Remember dives to remove
+	divesToRemove = std::move(divesToRemoveNew);
+
+	mark_divelist_changed(true);
+}
+
+void ImportDives::undoit()
+{
+	// Add new dives
+	std::vector<dive *> divesToRemoveNew = addDives(divesToAdd);
+
+	// Remove old dives
+	divesToAdd = removeDives(divesToRemove);
+
+	// Remember dives to remove
+	divesToRemove = std::move(divesToRemoveNew);
+
+	// ...and restore the selection
+	restoreSelection(selection, currentDive);
+
+	mark_divelist_changed(true);
+}
+
 DeleteDive::DeleteDive(const QVector<struct dive*> &divesToDeleteIn) : divesToDelete(divesToDeleteIn.toStdVector())
 {
 	setText(tr("delete %n dive(s)", "", divesToDelete.size()));
diff --git a/desktop-widgets/command_divelist.h b/desktop-widgets/command_divelist.h
index 77116c302..8cf8986e3 100644
--- a/desktop-widgets/command_divelist.h
+++ b/desktop-widgets/command_divelist.h
@@ -104,6 +104,26 @@ private:
 	dive *			currentDive;
 };
 
+class ImportDives : public DiveListBase {
+public:
+	// Note: dives and trips are consumed - after the call they will be empty.
+	ImportDives(struct dive_table *dives, struct trip_table *trips,
+		    bool prefer_imported, bool downloaded, bool merge_all_trips,
+		    const QString &source);
+private:
+	void undoit() override;
+	void redoit() override;
+	bool workToBeDone() override;
+
+	// For redo and undo
+	DivesAndTripsToAdd	divesToAdd;
+	std::vector<dive *>	divesToRemove;
+
+	// For undo
+	std::vector<dive *>	selection;
+	dive *			currentDive;
+};
+
 class DeleteDive : public DiveListBase {
 public:
 	DeleteDive(const QVector<dive *> &divesToDelete);
diff --git a/desktop-widgets/divelogimportdialog.cpp b/desktop-widgets/divelogimportdialog.cpp
index f8e44067d..638cf6094 100644
--- a/desktop-widgets/divelogimportdialog.cpp
+++ b/desktop-widgets/divelogimportdialog.cpp
@@ -1011,9 +1011,8 @@ void DiveLogImportDialog::on_buttonBox_accepted()
 		}
 	}
 
-	add_imported_dives(&table, &trips, false, false, true);
-	Command::clear();
-	MainWindow::instance()->refreshDisplay();
+	QString source = fileNames.size() == 1 ? fileNames[0] : tr("multiple files");
+	Command::importDives(&table, &trips, false, false, true, source);
 }
 
 TagDragDelegate::TagDragDelegate(QObject *parent) : QStyledItemDelegate(parent)
diff --git a/desktop-widgets/downloadfromdivecomputer.cpp b/desktop-widgets/downloadfromdivecomputer.cpp
index 547c740c8..ff703d98e 100644
--- a/desktop-widgets/downloadfromdivecomputer.cpp
+++ b/desktop-widgets/downloadfromdivecomputer.cpp
@@ -521,25 +521,12 @@ void DownloadFromDCWidget::on_ok_clicked()
 	}
 
 	if (table->nr > 0) {
-		MainWindow::instance()->diveList->unselectDives();
-		// remember the last downloaded dive (on most dive computers this will be the chronologically
-		// first new dive) and select it again after processing all the dives
-		int uniqId = table->dives[table->nr - 1]->id;
-		add_imported_dives(table, trips, preferDownloaded(), true, false);
-		Command::clear();
-		// after add_imported_dives does any merging or resorting needed, we need
-		// to recreate the model for the dive list so we can select the newest dive
-		MainWindow::instance()->recreateDiveList();
-		int idx = get_idx_by_uniq_id(uniqId);
-		// this shouldn't be necessary - but there are reports that somehow existing dives stay selected
-		// (but not visible as selected)
-		MainWindow::instance()->diveList->unselectDives();
-		MainWindow::instance()->diveList->selectDive(idx, true);
+		auto data = thread.data();
+		Command::importDives(table, trips, preferDownloaded(), true, false, data->devName());
 	}
 
-	if (ostcFirmwareCheck && currentState == DONE) {
+	if (ostcFirmwareCheck && currentState == DONE)
 		ostcFirmwareCheck->checkLatest(this, thread.data()->internalData());
-	}
 	accept();
 }
 
diff --git a/desktop-widgets/mainwindow.cpp b/desktop-widgets/mainwindow.cpp
index 474ce0f55..2e4342511 100644
--- a/desktop-widgets/mainwindow.cpp
+++ b/desktop-widgets/mainwindow.cpp
@@ -1714,9 +1714,8 @@ void MainWindow::importFiles(const QStringList fileNames)
 		fileNamePtr = QFile::encodeName(fileNames.at(i));
 		parse_file(fileNamePtr.data(), &table, &trips);
 	}
-	add_imported_dives(&table, &trips, false, false, true);
-	Command::clear();
-	refreshDisplay();
+	QString source = fileNames.size() == 1 ? fileNames[0] : tr("multiple files");
+	Command::importDives(&table, &trips, false, false, true, source);
 }
 
 void MainWindow::loadFiles(const QStringList fileNames)
diff --git a/desktop-widgets/subsurfacewebservices.cpp b/desktop-widgets/subsurfacewebservices.cpp
index 58806a75b..e6ef6668e 100644
--- a/desktop-widgets/subsurfacewebservices.cpp
+++ b/desktop-widgets/subsurfacewebservices.cpp
@@ -4,6 +4,7 @@
 #include "core/webservice.h"
 #include "core/settings/qPrefCloudStorage.h"
 #include "desktop-widgets/mainwindow.h"
+#include "desktop-widgets/command.h"
 #include "desktop-widgets/usersurvey.h"
 #include "core/divelist.h"
 #include "desktop-widgets/mapwidget.h"
@@ -771,8 +772,7 @@ void DivelogsDeWebServices::buttonClicked(QAbstractButton *button)
 		struct dive_table table = { 0 };
 		struct trip_table trips = { 0 };
 		parse_file(QFile::encodeName(zipFile.fileName()), &table, &trips);
-		add_imported_dives(&table, &trips, false, false, true);
-		MainWindow::instance()->refreshDisplay();
+		Command::importDives(&table, &trips, false, false, true, QStringLiteral("divelogs.de"));
 
 		/* store last entered user/pass in config */
 		QSettings s;
diff --git a/qt-models/diveimportedmodel.cpp b/qt-models/diveimportedmodel.cpp
index ac7e26c26..566bda173 100644
--- a/qt-models/diveimportedmodel.cpp
+++ b/qt-models/diveimportedmodel.cpp
@@ -141,6 +141,7 @@ void DiveImportedModel::repopulate(dive_table_t *table, trip_table_t *trips)
 	endResetModel();
 }
 
+// Note: this function is only used from mobile - perhaps move it there or unify.
 void DiveImportedModel::recordDives()
 {
 	if (diveTable->nr == 0)