Dive list: implement proper Qt-model semantics for DiveTripModel

Previously, each dive-list modifying function would lead to a
full model reset. Instead, implement proper Qt-model semantics
using beginInsertRows()/endInsertRows(), beginRemoveRows()/
endRemoveRows(), dataChange().

To do so, a DiveListNotifer singleton is generatated, which
broadcasts all changes to the dive-list. Signals are sent by
the commands and received by the DiveTripModel. Signals are
batched by dive-trip. This seems to be an adequate compromise
for the two kinds of list-views (tree and list). In the common
usecase mostly dives of a single trip are affected.

Thus, batching of dives is performed in two positions:
- At command-level to batch by trip
- In DiveTripModel to feed batches of contiguous elements
  to Qt's begin*/end*-functions.

This is conceptually simple, but rather complex code. To avoid
repetition of complex loops, the batching is implemented in
templated-functions, which are passed lambda-functions, which
are called for each batch.

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

core/CMakeLists.txt

@@ -123,6 +123,7 @@ set(SUBSURFACE_CORE_LIB_SRCS
 	#Subsurface Qt have the Subsurface structs QObjectified for easy access via QML.
 	subsurface-qt/DiveObjectHelper.cpp
 	subsurface-qt/CylinderObjectHelper.cpp
+	subsurface-qt/DiveListNotifier.cpp
 
 	${SERIAL_FTDI}
 	${PLATFORM_SRC}

core/subsurface-qt/DiveListNotifier.cpp

@@ -0,0 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "DiveListNotifier.h"
+
+DiveListNotifier diveListNotifier;

core/subsurface-qt/DiveListNotifier.h

@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// The DiveListNotifier emits signals when the dive-list changes (dives/trips created/deleted/moved)
+// Note that vectors are passed by reference, so this will only work for signals inside the UI thread!
+
+#ifndef DIVELISTNOTIFIER_H
+#define DIVELISTNOTIFIER_H
+
+#include "core/dive.h"
+
+#include <QObject>
+
+class DiveListNotifier : public QObject {
+	Q_OBJECT
+signals:
+
+	// Note that there are no signals for trips being added / created / time-shifted,
+	// because these events never happen without a dive being added / created / time-shifted.
+
+	// We send one divesAdded, divesDeleted, divesChanged and divesTimeChanged signal per trip
+	// (non-associated dives being considered part of the null trip). This is ideal for the
+	// tree-view, but might be not-so-perfect for the list view, if trips intermingle or
+	// the deletion spans multiple trips. But most of the time only dives of a single trip
+	// will be affected and trips don't overlap, so these considerations are moot.
+	// Notes:
+	// - The dives are always sorted by start-time.
+	// - The "trip" arguments are null for top-level-dives.
+	void divesAdded(dive_trip *trip, bool addTrip, const QVector<dive *> &dives);
+	void divesDeleted(dive_trip *trip, bool deleteTrip, const QVector<dive *> &dives);
+	void divesChanged(dive_trip *trip, const QVector<dive *> &dives);
+	void divesMovedBetweenTrips(dive_trip *from, dive_trip *to, bool deleteFrom, bool createTo, const QVector<dive *> &dives);
+	void divesTimeChanged(dive_trip *trip, timestamp_t delta, const QVector<dive *> &dives);
+};
+
+// The DiveListNotifier class has no state and no constructor.
+// We can simply define it as a global object.
+extern DiveListNotifier diveListNotifier;
+
+#endif

desktop-widgets/command_divelist.cpp

@@ -4,9 +4,41 @@
 #include "desktop-widgets/mainwindow.h"
 #include "desktop-widgets/divelistview.h"
 #include "core/divelist.h"
+#include "core/subsurface-qt/DiveListNotifier.h"
 
 namespace Command {
 
+// Generally, signals are sent in batches per trip. To avoid writing the same loop
+// again and again, this template takes a vector of trip / dive pairs, sorts it
+// by trip and then calls a function-object with trip and a QVector of dives in that trip.
+// Input parameters:
+//	- dives: a vector of trip,dive pairs, which will be sorted and processed in batches by trip.
+//	- action: a function object, taking a trip-pointer and a QVector of dives, which will be called for each batch.
+template<typename Function>
+void processByTrip(std::vector<std::pair<dive_trip *, dive *>> &dives, Function action)
+{
+	// Use std::tie for lexicographical sorting of trip, then start-time
+	std::sort(dives.begin(), dives.end(),
+		  [](const std::pair<dive_trip *, dive *> &e1, const std::pair<dive_trip *, dive *> &e2)
+		  { return std::tie(e1.first, e1.second->when) < std::tie(e2.first, e2.second->when); });
+
+	// Then, process the dives in batches by trip
+	size_t i, j; // Begin and end of batch
+	for (i = 0; i < dives.size(); i = j) {
+		dive_trip *trip = dives[i].first;
+		for (j = i + 1; j < dives.size() && dives[j].first == trip; ++j)
+			; // pass
+		// Copy dives into a QVector. Some sort of "range_view" would be ideal, but Qt doesn't work this way.
+		QVector<dive *> divesInTrip(j - i);
+		for (size_t k = i; k < j; ++k)
+			divesInTrip[k - i] = dives[k].second;
+
+		// Finally, emit the signal
+		action(trip, divesInTrip);
+	}
+}
+
+
 // This helper function removes a dive, takes ownership of the dive and adds it to a DiveToAdd structure.
 // It is crucial that dives are added in reverse order of deletion, so the the indices are correctly
 // set and that the trips are added before they are used!
@@ -26,6 +58,7 @@ static DiveToAdd removeDive(struct dive *d)
 	}
 
 	res.dive.reset(unregister_dive(res.idx));	// Remove dive from backend
+
 	return res;
 }
 
@@ -38,8 +71,9 @@ static dive *addDive(DiveToAdd &d)
 		insert_trip_dont_merge(d.tripToAdd.release()); // Return ownership to backend
 	if (d.trip)
 		add_dive_to_trip(d.dive.get(), d.trip);
-	dive *res = d.dive.release();			// Give up ownership of dive
+	dive *res = d.dive.release();		// Give up ownership of dive
-	add_single_dive(d.idx, res);			// Return ownership to backend
+	add_single_dive(d.idx, res);		// Return ownership to backend
+
 	return res;
 }
 
@@ -55,6 +89,22 @@ static std::vector<DiveToAdd> removeDives(std::vector<dive *> &divesToDelete)
 		res.push_back(removeDive(d));
 	divesToDelete.clear();
 
+	// We send one dives-deleted signal per trip (see comments in DiveListNotifier.h).
+	// Therefore, collect all dives in a array and sort by trip.
+	std::vector<std::pair<dive_trip *, dive *>> dives;
+	dives.reserve(res.size());
+	for (const DiveToAdd &entry: res)
+		dives.push_back({ entry.trip, entry.dive.get() });
+
+	// Send signals.
+	processByTrip(dives, [&](dive_trip *trip, const QVector<dive *> &divesInTrip) {
+		// Now, let's check if this trip is supposed to be deleted, by checking if it was marked
+		// as "add it". We could be smarter here, but let's just check the whole array for brevity.
+		bool deleteTrip = trip &&
+				  std::find_if(res.begin(), res.end(), [trip](const DiveToAdd &entry)
+					       { return entry.tripToAdd.get() == trip; }) != res.end();
+		emit diveListNotifier.divesDeleted(trip, deleteTrip, divesInTrip);
+	});
 	return res;
 }
 
@@ -67,10 +117,34 @@ static std::vector<dive *> addDives(std::vector<DiveToAdd> &divesToAdd)
 	std::vector<dive *> res;
 	res.reserve(divesToAdd.size());
 
+	// At the end of the function, to send the proper dives-added signals,
+	// we the the list of added trips. Create this list now.
+	std::vector<dive_trip *> addedTrips;
+	for (const DiveToAdd &entry: divesToAdd) {
+		if (entry.tripToAdd)
+			addedTrips.push_back(entry.tripToAdd.get());
+	}
+
+	// Now, add the dives
 	for (auto it = divesToAdd.rbegin(); it != divesToAdd.rend(); ++it)
 		res.push_back(addDive(*it));
 	divesToAdd.clear();
 
+	// We send one dives-deleted signal per trip (see comments in DiveListNotifier.h).
+	// Therefore, collect all dives in a array and sort by trip.
+	std::vector<std::pair<dive_trip *, dive *>> dives;
+	dives.reserve(res.size());
+	for (dive *d: res)
+		dives.push_back({ d->divetrip, d });
+
+	// Send signals.
+	processByTrip(dives, [&](dive_trip *trip, const QVector<dive *> &divesInTrip) {
+		// Now, let's check if this trip is supposed to be created, by checking if it was marked
+		// as "add it". We could be smarter here, but let's just check the whole array for brevity.
+		bool createTrip = trip && std::find(addedTrips.begin(), addedTrips.end(), trip) != addedTrips.end();
+		// Finally, emit the signal
+		emit diveListNotifier.divesAdded(trip, createTrip, divesInTrip);
+	});
 	return res;
 }
 
@@ -85,6 +159,20 @@ static void renumberDives(QVector<QPair<int, int>> &divesToRenumber)
 			continue;
 		std::swap(d->number, pair.second);
 	}
+
+	// Emit changed signals per trip.
+	// First, collect all dives and sort by trip
+	std::vector<std::pair<dive_trip *, dive *>> dives;
+	dives.reserve(divesToRenumber.size());
+	for (const auto &pair: divesToRenumber) {
+		dive *d = get_dive_by_uniq_id(pair.first);
+		dives.push_back({ d->divetrip, d });
+	}
+
+	// Send signals.
+	processByTrip(dives, [&](dive_trip *trip, const QVector<dive *> &divesInTrip) {
+		emit diveListNotifier.divesChanged(trip, divesInTrip);
+	});
 }
 
 // This helper function moves a dive to a trip. The old trip is recorded in the
@@ -121,9 +209,17 @@ static OwningTripPtr moveDiveToTrip(DiveToTrip &diveToTrip)
 // a no-op.
 static void moveDivesBetweenTrips(DivesToTrip &dives)
 {
-	// first bring back the trip(s)
+	// We collect an array of created trips so that we can instruct
-	for (OwningTripPtr &trip: dives.tripsToAdd)
+	// the model to create a new entry
-		insert_trip_dont_merge(trip.release()); // Return ownership to backend
+	std::vector<dive_trip *> createdTrips;
+	createdTrips.reserve(dives.tripsToAdd.size());
+
+	// First, bring back the trip(s)
+	for (OwningTripPtr &trip: dives.tripsToAdd) {
+		dive_trip *t = trip.release();	// Give up ownership
+		createdTrips.push_back(t);
+		insert_trip_dont_merge(t);	// Return ownership to backend
+	}
 	dives.tripsToAdd.clear();
 
 	for (DiveToTrip &dive: dives.divesToMove) {
@@ -133,6 +229,60 @@ static void moveDivesBetweenTrips(DivesToTrip &dives)
 			dives.tripsToAdd.push_back(std::move(tripToAdd));
 	}
 
+	// We send one signal per from-trip/to-trip pair.
+	// First, collect all dives in a struct and sort by from-trip/to-trip.
+	struct DiveMoved {
+		dive_trip *from;
+		dive_trip *to;
+		dive *d;
+	};
+	std::vector<DiveMoved> divesMoved;
+	divesMoved.reserve(dives.divesToMove.size());
+	for (const DiveToTrip &entry: dives.divesToMove)
+		divesMoved.push_back({ entry.trip, entry.dive->divetrip, entry.dive });
+
+	// Sort lexicographically by from-trip, to-trip and by start-time.
+	// Use std::tie() for lexicographical sorting.
+	std::sort(divesMoved.begin(), divesMoved.end(), [] ( const DiveMoved &d1, const DiveMoved &d2)
+		  { return std::tie(d1.from, d1.to, d1.d->when) < std::tie(d2.from, d2.to, d2.d->when); });
+
+	// Now, process the dives in batches by trip
+	// TODO: this is a bit different from the cases above, so we don't use the processByTrip template,
+	// but repeat the loop here. We might think about generalizing the template, if more of such
+	// "special cases" appear.
+	size_t i, j; // Begin and end of batch
+	for (i = 0; i < divesMoved.size(); i = j) {
+		dive_trip *from = divesMoved[i].from;
+		dive_trip *to = divesMoved[i].to;
+		for (j = i + 1; j < divesMoved.size() && divesMoved[j].from == from && divesMoved[j].to == to; ++j)
+			; // pass
+		// Copy dives into a QVector. Some sort of "range_view" would be ideal, but Qt doesn't work this way.
+		QVector<dive *> divesInTrip(j - i);
+		for (size_t k = i; k < j; ++k)
+			divesInTrip[k - i] = divesMoved[k].d;
+
+		// Check if the from-trip was deleted: If yes, it was recorded in the tripsToAdd structure
+		bool deleteFrom = from &&
+				  std::find_if(dives.tripsToAdd.begin(), dives.tripsToAdd.end(),
+					       [from](const OwningTripPtr &trip) { return trip.get() == from; }) != dives.tripsToAdd.end();
+		// Check if the to-trip has to be created. For this purpose, we saved an array of trips to be created.
+		bool createTo = false;
+		if (to) {
+			// Check if the element is there...
+			auto it = std::find(createdTrips.begin(), createdTrips.end(), to);
+
+			// ...if it is - remove it as we don't want the model to create the trip twice!
+			if (it != createdTrips.end()) {
+				createTo = true;
+				// erase/remove would be more performant, but this is irrelevant in the big scheme of things.
+				createdTrips.erase(it);
+			}
+		}
+
+		// Finally, emit the signal
+		emit diveListNotifier.divesMovedBetweenTrips(from, to, deleteFrom, createTo, divesInTrip);
+	}
+
 	// Reverse the tripsToAdd and the divesToAdd, so that on undo/redo the operations
 	// will be performed in reverse order.
 	std::reverse(dives.tripsToAdd.begin(), dives.tripsToAdd.end());
@@ -144,11 +294,11 @@ AddDive::AddDive(dive *d)
 	setText(tr("add dive"));
 	d->maxdepth.mm = 0;
 	fixup_dive(d);
-	diveToAdd.trip = d->divetrip;
+	d->divetrip = nullptr;	// TODO: consider autogroup == true
-	d->divetrip = nullptr;
+	int idx = dive_get_insertion_index(d);
-	diveToAdd.idx = dive_get_insertion_index(d);
+	d->number = get_dive_nr_at_idx(idx);
-	d->number = get_dive_nr_at_idx(diveToAdd.idx);
+
-	diveToAdd.dive.reset(clone_dive(d));
+	divesToAdd.push_back({ OwningDivePtr(clone_dive(d)), nullptr, d->divetrip, idx });
 }
 
 bool AddDive::workToBeDone()
@@ -158,22 +308,27 @@ bool AddDive::workToBeDone()
 
 void AddDive::redo()
 {
-	diveToRemove = addDive(diveToAdd);
+	int idx = divesToAdd[0].idx;
+	divesToRemove = addDives(divesToAdd);
 	mark_divelist_changed(true);
 
 	// Finally, do the UI stuff:
 	MainWindow::instance()->dive_list()->unselectDives();
-	MainWindow::instance()->dive_list()->selectDive(diveToAdd.idx, true);
+	MainWindow::instance()->dive_list()->selectDive(idx, true);
-	MainWindow::instance()->refreshDisplay();
+
+	// Exit from edit mode, but don't recalculate dive list
+	// TODO: Remove edit mode
+	MainWindow::instance()->refreshDisplay(false);
 }
 
 void AddDive::undo()
 {
 	// Simply remove the dive that was previously added
-	diveToAdd = removeDive(diveToRemove);
+	divesToAdd = removeDives(divesToRemove);
 
-	// Finally, do the UI stuff:
+	// Exit from edit mode, but don't recalculate dive list
-	MainWindow::instance()->refreshDisplay();
+	// TODO: Remove edit mode
+	MainWindow::instance()->refreshDisplay(false);
 }
 
 DeleteDive::DeleteDive(const QVector<struct dive*> &divesToDeleteIn) : divesToDelete(divesToDeleteIn.toStdVector())
@@ -189,20 +344,13 @@ bool DeleteDive::workToBeDone()
 void DeleteDive::undo()
 {
 	divesToDelete = addDives(divesToAdd);
-
 	mark_divelist_changed(true);
-
-	// Finally, do the UI stuff:
-	MainWindow::instance()->refreshDisplay();
 }
 
 void DeleteDive::redo()
 {
 	divesToAdd = removeDives(divesToDelete);
 	mark_divelist_changed(true);
-
-	// Finally, do the UI stuff:
-	MainWindow::instance()->refreshDisplay();
 }
 
 
@@ -212,20 +360,30 @@ ShiftTime::ShiftTime(const QVector<dive *> &changedDives, int amount)
 	setText(tr("shift time of %n dives", "", changedDives.count()));
 }
 
-void ShiftTime::undo()
+void ShiftTime::redo()
 {
 	for (dive *d: diveList)
 		d->when -= timeChanged;
 
 	// Changing times may have unsorted the dive table
 	sort_table(&dive_table);
-	mark_divelist_changed(true);
+
+	// We send one dives-deleted signal per trip (see comments in DiveListNotifier.h).
+	// Therefore, collect all dives in a array and sort by trip.
+	std::vector<std::pair<dive_trip *, dive *>> dives;
+	dives.reserve(diveList.size());
+	for (dive *d: diveList)
+		dives.push_back({ d->divetrip, d });
+
+	// Send signals.
+	processByTrip(dives, [&](dive_trip *trip, const QVector<dive *> &divesInTrip) {
+		emit diveListNotifier.divesTimeChanged(trip, timeChanged, divesInTrip);
+	});
 
 	// Negate the time-shift so that the next call does the reverse
 	timeChanged = -timeChanged;
 
-	// Finally, do the UI stuff:
+	mark_divelist_changed(true);
-	MainWindow::instance()->refreshDisplay();
 }
 
 bool ShiftTime::workToBeDone()
@@ -233,10 +391,10 @@ bool ShiftTime::workToBeDone()
 	return !diveList.isEmpty();
 }
 
-void ShiftTime::redo()
+void ShiftTime::undo()
 {
-	// Same as undo(), since after undo() we reversed the timeOffset
+	// Same as redo(), since after redo() we reversed the timeOffset
-	undo();
+	redo();
 }
 
 
@@ -249,9 +407,6 @@ void RenumberDives::undo()
 {
 	renumberDives(divesToRenumber);
 	mark_divelist_changed(true);
-
-	// Finally, do the UI stuff:
-	MainWindow::instance()->refreshDisplay();
 }
 
 bool RenumberDives::workToBeDone()
@@ -275,9 +430,6 @@ void TripBase::redo()
 	moveDivesBetweenTrips(divesToMove);
 
 	mark_divelist_changed(true);
-
-	// Finally, do the UI stuff:
-	MainWindow::instance()->refreshDisplay();
 }
 
 void TripBase::undo()
@@ -393,10 +545,6 @@ void SplitDives::redo()
 	divesToUnsplit[1] = addDive(splitDives[1]);
 	unsplitDive = removeDive(diveToSplit);
 	mark_divelist_changed(true);
-
-	// Finally, do the UI stuff:
-	MainWindow::instance()->refreshDisplay();
-	MainWindow::instance()->refreshProfile();
 }
 
 void SplitDives::undo()
@@ -408,10 +556,6 @@ void SplitDives::undo()
 	splitDives[1] = removeDive(divesToUnsplit[1]);
 	splitDives[0] = removeDive(divesToUnsplit[0]);
 	mark_divelist_changed(true);
-
-	// Finally, do the UI stuff:
-	MainWindow::instance()->refreshDisplay();
-	MainWindow::instance()->refreshProfile();
 }
 
 MergeDives::MergeDives(const QVector <dive *> &dives)
@@ -503,10 +647,6 @@ void MergeDives::redo()
 	renumberDives(divesToRenumber);
 	diveToUnmerge = addDive(mergedDive);
 	unmergedDives = removeDives(divesToMerge);
-
-	// Finally, do the UI stuff:
-	MainWindow::instance()->refreshDisplay();
-	MainWindow::instance()->refreshProfile();
 }
 
 void MergeDives::undo()
@@ -514,10 +654,6 @@ void MergeDives::undo()
 	divesToMerge = addDives(unmergedDives);
 	mergedDive = removeDive(diveToUnmerge);
 	renumberDives(divesToRenumber);
-
-	// Finally, do the UI stuff:
-	MainWindow::instance()->refreshDisplay();
-	MainWindow::instance()->refreshProfile();
 }
 
 } // namespace Command

desktop-widgets/command_divelist.h

@@ -47,10 +47,12 @@ private:
 	bool workToBeDone() override;
 
 	// For redo
-	DiveToAdd	diveToAdd;
+	// Note: we use a vector even though we add only a single dive, so
+	// that we can reuse the multi-dive functions of the other commands.
+	std::vector<DiveToAdd>	divesToAdd;
 
 	// For undo
-	dive		*diveToRemove;
+	std::vector<dive *>	divesToRemove;
 };
 
 class DeleteDive : public Base {

desktop-widgets/divelistview.cpp

@@ -668,11 +668,6 @@ void DiveListView::merge_trip(const QModelIndex &a, int offset)
 	if (trip_a == trip_b || !trip_a || !trip_b)
 		return;
 	Command::mergeTrips(trip_a, trip_b);
-	rememberSelection();
-	reload(currentLayout, false);
-	restoreSelection();
-	mark_divelist_changed(true);
-	//TODO: emit a signal to signalize that the divelist changed?
 }
 
 void DiveListView::mergeTripAbove()
@@ -696,11 +691,6 @@ void DiveListView::removeFromTrip()
 			divesToRemove.append(d);
 	}
 	Command::removeDivesFromTrip(divesToRemove);
-
-	rememberSelection();
-	reload(currentLayout, false);
-	restoreSelection();
-	mark_divelist_changed(true);
 }
 
 void DiveListView::newTripAbove()
@@ -717,10 +707,6 @@ void DiveListView::newTripAbove()
 			dives.append(d);
 	}
 	Command::createTrip(dives);
-
-	reload(currentLayout, false);
-	mark_divelist_changed(true);
-	restoreSelection();
 }
 
 void DiveListView::addToTripBelow()
@@ -765,9 +751,6 @@ void DiveListView::addToTrip(int delta)
 		}
 	}
 	Command::addDivesToTrip(dives, trip);
-
-	reload(currentLayout, false);
-	restoreSelection();
 }
 
 void DiveListView::markDiveInvalid()
@@ -783,9 +766,6 @@ void DiveListView::markDiveInvalid()
 		// now mark the dive invalid... how do we do THAT?
 		// d->invalid = true;
 	}
-	if (amount_selected == 0) {
-		MainWindow::instance()->cleanUpEmpty();
-	}
 	mark_divelist_changed(true);
 	MainWindow::instance()->refreshDisplay();
 	if (prefs.display_invalid_dives == false) {
@@ -802,26 +782,12 @@ void DiveListView::deleteDive()
 		return;
 
 	int i;
-	int lastDiveNr = -1;
 	QVector<struct dive*> deletedDives;
 	for_each_dive (i, d) {
-		if (!d->selected)
+		if (d->selected)
-			continue;
+			deletedDives.append(d);
-		deletedDives.append(d);
-		lastDiveNr = i;
 	}
-	// the actual dive deletion is happening in the redo command that is implicitly triggered
 	Command::deleteDive(deletedDives);
-	if (amount_selected == 0) {
-		MainWindow::instance()->cleanUpEmpty();
-	}
-	mark_divelist_changed(true);
-	MainWindow::instance()->refreshDisplay();
-	if (lastDiveNr != -1) {
-		clearSelection();
-		selectDive(lastDiveNr);
-		rememberSelection();
-	}
 }
 
 void DiveListView::contextMenuEvent(QContextMenuEvent *event)

desktop-widgets/mainwindow.cpp

@@ -36,6 +36,8 @@
 #include "core/settings/qPrefPartialPressureGas.h"
 #include "core/settings/qPrefTechnicalDetails.h"
 
+#include "core/subsurface-qt/DiveListNotifier.h"
+
 #include "desktop-widgets/about.h"
 #include "desktop-widgets/command.h"
 #include "desktop-widgets/divecomputermanagementdialog.h"
@@ -492,8 +494,6 @@ void MainWindow::refreshDisplay(bool doRecreateDiveList)
 	dive_list()->setFocus();
 	WSInfoModel::instance()->updateInfo();
 	ui.actionAutoGroup->setChecked(autogroup);
-	if (amount_selected == 0)
-		cleanUpEmpty();
 }
 
 void MainWindow::recreateDiveList()

desktop-widgets/simplewidgets.cpp

@@ -172,9 +172,6 @@ void RenumberDialog::buttonClicked(QAbstractButton *button)
 			}
 		}
 		Command::renumberDives(renumberedDives);
-
-		mark_divelist_changed(true);
-		MainWindow::instance()->dive_list()->restoreSelection();
 	}
 }
 

desktop-widgets/tab-widgets/maintab.cpp

@@ -809,7 +809,6 @@ void MainTab::acceptChanges()
 		acceptingEdit = false;
 		ui.editDiveSiteButton->setEnabled(!ui.location->text().isEmpty());
 		emit addDiveFinished();
-		MainWindow::instance()->dive_list()->reload(DiveTripModel::CURRENT, true);
 		DivePlannerPointsModel::instance()->setPlanMode(DivePlannerPointsModel::NOTHING);
 		int scrolledBy = MainWindow::instance()->dive_list()->verticalScrollBar()->sliderPosition();
 		MainWindow::instance()->dive_list()->verticalScrollBar()->setSliderPosition(scrolledBy);

qt-models/divetripmodel.cpp

@@ -5,6 +5,7 @@
 #include "core/divelist.h"
 #include "core/qthelper.h"
 #include "core/subsurface-string.h"
+#include "core/subsurface-qt/DiveListNotifier.h"
 #include <QIcon>
 #include <QDebug>
 
@@ -431,6 +432,12 @@ DiveTripModel::DiveTripModel(QObject *parent) :
 	QAbstractItemModel(parent),
 	currentLayout(TREE)
 {
+	// Stay informed of changes to the divelist
+	connect(&diveListNotifier, &DiveListNotifier::divesAdded, this, &DiveTripModel::divesAdded);
+	connect(&diveListNotifier, &DiveListNotifier::divesDeleted, this, &DiveTripModel::divesDeleted);
+	connect(&diveListNotifier, &DiveListNotifier::divesChanged, this, &DiveTripModel::divesChanged);
+	connect(&diveListNotifier, &DiveListNotifier::divesMovedBetweenTrips, this, &DiveTripModel::divesMovedBetweenTrips);
+	connect(&diveListNotifier, &DiveListNotifier::divesTimeChanged, this, &DiveTripModel::divesTimeChanged);
 }
 
 int DiveTripModel::columnCount(const QModelIndex&) const
@@ -627,6 +634,11 @@ QVariant DiveTripModel::headerData(int section, Qt::Orientation orientation, int
 	return ret;
 }
 
+DiveTripModel::Item::Item(dive_trip *t, const QVector<dive *> &divesIn) : trip(t),
+	dives(divesIn.toStdVector())
+{
+}
+
 DiveTripModel::Item::Item(dive_trip *t, dive *d) : trip(t),
 	dives({ d })
 {
@@ -637,6 +649,108 @@ DiveTripModel::Item::Item(dive *d) : trip(nullptr),
 {
 }
 
+bool DiveTripModel::Item::isDive(const dive *d) const
+{
+	return !trip && dives.size() == 1 && dives[0] == d;
+}
+
+dive *DiveTripModel::Item::getDive() const
+{
+	return !trip && dives.size() == 1 ? dives[0] : nullptr;
+}
+
+timestamp_t DiveTripModel::Item::when() const
+{
+	return trip ? trip->when : dives[0]->when;
+}
+
+// Find a range of matching elements in a vector.
+// Input parameters:
+//	v: vector to be searched
+//	first: first element to search
+//	cond: a function that is fed elements and returns an integer:
+//		- >0: matches
+//		-  0: doesn't match
+//		- <0: stop searching, no more elements will be found
+//	      cond is called exactly once per element and from the beginning of the range.
+// Returns a pair [first, last) with usual C++ semantics: last-first is the size of the found range.
+// If no items were found, first and last are set to the size of the vector.
+template <typename Vector, typename Predicate>
+std::pair<int, int> findRangeIf(const Vector &v, int first, Predicate cond)
+{
+	int size = (int)v.size();
+	for (int i = first; i < size; ++i) {
+		int res = cond(v[i]);
+		if (res > 0) {
+			for (int j = i + 1; j < size; ++j) {
+				if (cond(v[j]) <= 0)
+					return { i, j };
+			}
+			return { i, size };
+		} else if (res < 0) {
+			break;
+		}
+	}
+	return { size, size };
+}
+
+// Ideally, Qt's model/view functions are processed in batches of contiguous
+// items. Therefore, this template is used to process actions on ranges of
+// contiguous elements of a vector.
+// Input paremeters:
+//	- items: vector to process, wich must allow random access via [] and the size() function
+//	- cond: a predicate that is tested for each element. contiguous ranges of elements which
+//		test for true are collected. cond is fed an element and should return:
+//		- >0: matches
+//		-  0: doesn't match
+//		- <0: stop searching, no more elements will be found
+//	- action: action that is called with the vector, first and last element of the range.
+template<typename Vector, typename Predicate, typename Action>
+void processRanges(Vector &items, Predicate cond, Action action)
+{
+	// Note: the "i++" is correct: We know that the last element tested
+	// negatively -> we can skip it. Thus we avoid checking any element
+	// twice.
+	for(int i = 0;; i++) {
+		std::pair<int,int> range = findRangeIf(items, i, cond);
+		if (range.first >= (int)items.size())
+			break;
+		int delta = action(items, range.first, range.second);
+		i = range.second + delta;
+	}
+}
+
+// processRangesZip() is a refined version of processRanges(), which operates on two vectors.
+// The vectors are supposed to be sorted equivalently. That is, the first matching
+// item will of the first vector will match to the first item of the second vector.
+// It is supposed that all elements of the second vector will match to an element of
+// the first vector.
+// Input parameters:
+//	- items1: vector to process, wich must allow random access via [] and the size() function
+//	- items2: second vector to process. every item in items2 must match to an item in items1
+//		  in ascending order.
+//	- cond1: a predicate that is tested for each element of items1 with the next unmatched element
+//		 of items2. returns a boolean
+//	- action: action that is called with the vectors, first and last element of the first range
+//		  and first element of the last range.
+template<typename Vector1, typename Vector2, typename Predicate, typename Action>
+void processRangesZip(Vector1 &items1, Vector2 &items2, Predicate cond, Action action)
+{
+	int actItem = 0;
+	processRanges(items1,
+		      [&](typename Vector1::const_reference &e) mutable -> int { // Condition. Marked mutable so that it can change actItem
+			if (actItem >= items2.size())
+				return -1; // No more items -> bail
+			if (!cond(e, items2[actItem]))
+				return 0;
+			++actItem;
+			return 1;
+		      },
+		      [&](Vector1 &v1, int from, int to) { // Action
+		      	return action(v1, items2, from, to, actItem);
+		      });
+}
+
 void DiveTripModel::setupModelData()
 {
 	int i = dive_table.nr;
@@ -727,3 +841,272 @@ bool DiveTripModel::setData(const QModelIndex &index, const QVariant &value, int
 	dive *d = diveOrNull(index);
 	return d ? DiveItem(d).setData(index, value, role) : false;
 }
+
+int DiveTripModel::findTripIdx(const dive_trip *trip) const
+{
+	for (int i = 0; i < (int)items.size(); ++i)
+		if (items[i].trip == trip)
+			return i;
+	return -1;
+}
+
+int DiveTripModel::findDiveIdx(const dive *d) const
+{
+	for (int i = 0; i < (int)items.size(); ++i)
+		if (items[i].isDive(d))
+			return i;
+	return -1;
+}
+
+int DiveTripModel::findDiveInTrip(int tripIdx, const dive *d) const
+{
+	const Item &item = items[tripIdx];
+	for (int i = 0; i < (int)item.dives.size(); ++i)
+		if (item.dives[i] == d)
+			return i;
+	return -1;
+}
+
+int DiveTripModel::findInsertionIndex(timestamp_t when) const
+{
+	for (int i = 0; i < (int)items.size(); ++i) {
+		if (when > items[i].when())
+			return i;
+	}
+	return items.size();
+}
+
+// Add items from vector "v2" to vector "v1" in batches of contiguous objects.
+// The items are inserted at places according to a sort order determined by "comp".
+// "v1" and "v2" are supposed to be ordered accordingly.
+// TODO: We might use binary search with std::lower_bound(), but not sure if it's worth it.
+// Input parameters:
+//	- v1: destination vector
+//	- v2: source vector
+//	- comp: compare-function, which is fed elements from v2 and v1. returns true for "insert here".
+//	- adder: performs the insertion. Perameters: v1, v2, insertion index, from, to range in v2.
+template <typename Vector1, typename Vector2, typename Comparator, typename Inserter>
+void addInBatches(Vector1 &v1, const Vector2 &v2, Comparator comp, Inserter insert)
+{
+	int idx = 0; // Index where dives will be inserted
+	int i, j; // Begin and end of range to insert
+	for (i = 0; i < (int)v2.size(); i = j) {
+		for (; idx < (int)v1.size() && !comp(v2[i], v1[idx]); ++idx)
+			; // Pass
+
+		// We found the index of the first item to add.
+		// Now search how many items we should insert there.
+		if (idx == (int)v1.size()) {
+			// We were at end -> insert the remaining items
+			j = v2.size();
+		} else {
+			for (j = i + 1; j < (int)v2.size() && comp(v2[i], v1[idx]); ++j)
+				; // Pass
+		}
+
+		// Now add the batch
+		insert(v1, v2, idx, i, j);
+
+		// Skip over inserted dives for searching the new insertion position plus one.
+		// If we added at the end, the loop will end anyway.
+		idx += j - i + 1;
+	}
+}
+
+void DiveTripModel::addDivesToTrip(int trip, const QVector<dive *> &dives)
+{
+		// Construct the parent index, ie. the index of the trip.
+		QModelIndex parent = createIndex(trip, 0, noParent);
+
+		// Either this is outside of a trip or we're in list mode.
+		// Thus, add dives at the top-level in batches
+		addInBatches(items[trip].dives, dives,
+			     [](dive *d, dive *d2) { return d->when >= d2->when; }, // comp
+			     [&](std::vector<dive *> &items, const QVector<dive *> &dives, int idx, int from, int to) { // inserter
+				beginInsertRows(parent, idx, idx + to - from - 1);
+				items.insert(items.begin() + idx, dives.begin() + from, dives.begin() + to);
+				endInsertRows();
+			     });
+}
+
+void DiveTripModel::divesAdded(dive_trip *trip, bool addTrip, const QVector<dive *> &divesIn)
+{
+	// The dives come from the backend sorted by start-time. But our model is sorted
+	// reverse-chronologically. Therefore, invert the list.
+	// TODO: Change sorting of the model to reflect core!
+	QVector<dive *> dives = divesIn;
+	std::reverse(dives.begin(), dives.end());
+
+	if (!trip || currentLayout == LIST) {
+		// Either this is outside of a trip or we're in list mode.
+		// Thus, add dives at the top-level in batches
+		addInBatches(items, dives,
+			     [](dive *d, const Item &entry) { return d->when >= entry.when(); }, // comp
+			     [&](std::vector<Item> &items, const QVector<dive *> &dives, int idx, int from, int to) { // inserter
+				beginInsertRows(QModelIndex(), idx, idx + to - from - 1);
+				items.insert(items.begin() + idx, dives.begin() + from, dives.begin() + to);
+				endInsertRows();
+			     });
+	} else if (addTrip) {
+		// We're supposed to add the whole trip. Just insert the trip.
+		int idx = findInsertionIndex(trip->when); // Find the place where we have to insert the thing
+		beginInsertRows(QModelIndex(), idx, idx);
+		items.insert(items.begin() + idx, { trip, dives });
+		endInsertRows();
+	} else {
+		// Ok, we have to add dives to an existing trip
+		// Find the trip...
+		int idx = findTripIdx(trip);
+		if (idx < 0) {
+			// We don't know the trip - this shouldn't happen. We seem to have
+			// missed some signals!
+			qWarning() << "DiveTripModel::divesAdded(): unknown trip";
+			return;
+		}
+
+		// ...and add dives.
+		addDivesToTrip(idx, dives);
+
+		// We have to signal that the trip changed, so that the number of dives in th header is updated
+		QModelIndex tripIndex = createIndex(idx, 0, noParent);
+		dataChanged(tripIndex, tripIndex);
+	}
+}
+
+void DiveTripModel::divesDeleted(dive_trip *trip, bool deleteTrip, const QVector<dive *> &divesIn)
+{
+	// TODO: dives comes sorted by ascending time, but the model is sorted by descending time.
+	// Instead of being smart, simple reverse the input array.
+	QVector<dive *> dives = divesIn;
+	std::reverse(dives.begin(), dives.end());
+
+	if (!trip || currentLayout == LIST) {
+		// Either this is outside of a trip or we're in list mode.
+		// Thus, delete top-level dives. We do this range-wise.
+		processRangesZip(items, dives,
+				 [](const Item &e, dive *d) { return e.getDive() == d; }, // Condition
+				 [&](std::vector<Item> &items, const QVector<dive *> &, int from, int to, int) -> int { // Action
+					beginRemoveRows(QModelIndex(), from, to - 1);
+					items.erase(items.begin() + from, items.begin() + to);
+					endRemoveRows();
+					return from - to; // Delta: negate the number of items deleted
+					 });
+	} else {
+		// Find the trip
+		int idx = findTripIdx(trip);
+		if (idx < 0) {
+			// We don't know the trip - this shouldn't happen. We seem to have
+			// missed some signals!
+			qWarning() << "DiveTripModel::divesDeleted(): unknown trip";
+			return;
+		}
+
+		if (deleteTrip) {
+			// We're supposed to delete the whole trip. Nice, we don't have to
+			// care about individual dives. Just remove the row.
+			beginRemoveRows(QModelIndex(), idx, idx);
+			items.erase(items.begin() + idx);
+			endRemoveRows();
+		} else {
+			// Construct the parent index, ie. the index of the trip.
+			QModelIndex parent = createIndex(idx, 0, noParent);
+
+			// Delete a number of dives in a trip. We do this range-wise.
+			processRangesZip(items[idx].dives, dives,
+					 [](dive *d1, dive *d2) { return d1 == d2; }, // Condition
+					 [&](std::vector<dive *> &diveList, const QVector<dive *> &, int from, int to, int) -> int { // Action
+						beginRemoveRows(parent, from, to - 1);
+						diveList.erase(diveList.begin() + from, diveList.begin() + to);
+						endRemoveRows();
+						return from - to; // Delta: negate the number of items deleted
+					 });
+
+			// We have to signal that the trip changed, so that the number of dives in th header is updated
+			QModelIndex tripIndex = createIndex(idx, 0, noParent);
+			dataChanged(tripIndex, tripIndex);
+		}
+	}
+}
+
+void DiveTripModel::divesChanged(dive_trip *trip, const QVector<dive *> &divesIn)
+{
+	// TODO: dives comes sorted by ascending time, but the model is sorted by descending time.
+	// Instead of being smart, simple reverse the input array.
+	QVector<dive *> dives = divesIn;
+	std::reverse(dives.begin(), dives.end());
+
+	if (!trip || currentLayout == LIST) {
+		// Either this is outside of a trip or we're in list mode.
+		// Thus, these are top-level dives. We do this range-wise.
+
+		// Since we know that the dive list is sorted, we will only ever search for the first element
+		// in dives as this must be the first that we encounter. Once we find a range, increase the
+		// index accordingly.
+		processRangesZip(items, dives,
+				 [](const Item &e, dive *d) { return e.getDive() == d; }, // Condition
+				 [&](const std::vector<Item> &, const QVector<dive *> &, int from, int to, int) -> int { // Action
+					// TODO: We might be smarter about which columns changed!
+					dataChanged(createIndex(from, 0, noParent), createIndex(to - 1, COLUMNS - 1, noParent));
+					return 0; // No items added or deleted
+				 });
+	} else {
+		// Find the trip.
+		int idx = findTripIdx(trip);
+		if (idx < 0) {
+			// We don't know the trip - this shouldn't happen. We seem to have
+			// missed some signals!
+			qWarning() << "DiveTripModel::divesChanged(): unknown trip";
+			return;
+		}
+
+		// Change the dives in the trip. We do this range-wise.
+		processRangesZip(items[idx].dives, dives,
+				 [](dive *d1, dive *d2) { return d1 == d2; }, // Condition
+				 [&](const std::vector<dive *> &, const QVector<dive *> &, int from, int to, int) -> int { // Action
+					// TODO: We might be smarter about which columns changed!
+					dataChanged(createIndex(from, 0, idx), createIndex(to - 1, COLUMNS - 1, idx));
+					return 0; // No items added or deleted
+				 });
+	}
+}
+
+void DiveTripModel::divesMovedBetweenTrips(dive_trip *from, dive_trip *to, bool deleteFrom, bool createTo, const QVector<dive *> &dives)
+{
+	// Move dives between trips. This is an "interesting" problem, as we might
+	// move from trip to trip, from trip to top-level or from top-level to trip.
+	// Moreover, we might have to add a trip first or delete an old trip.
+	// For simplicity, we will simply used the already existing divesAdded() / divesDeleted()
+	// functions. This *is* cheating. But let's just try this and see how graceful
+	// this is handled by Qt and if it gives some ugly UI behavior!
+
+	// But first let's just rule out the trivial cases: same-to-same trip move
+	// and list view (in which case we don't care).
+	if (from == to || currentLayout == LIST)
+		return;
+
+	// Cheating!
+	divesAdded(to, createTo, dives);
+	divesDeleted(from, deleteFrom, dives);
+}
+
+void DiveTripModel::divesTimeChanged(dive_trip *trip, timestamp_t delta, const QVector<dive *> &dives)
+{
+	// As in the case of divesMovedBetweenTrips(), this is a tricky, but solvable, problem.
+	// We have to consider the direction (delta < 0 or delta >0) and that dives at their destination
+	// position have different contiguous batches than at their original position. For now,
+	// cheat and simply do a remove/add pair. Note that for this to work it is crucial the the
+	// order of the dives don't change. This is indeed the case, as all starting-times where
+	// moved by the same delta.
+
+	// Unfortunately, deleting of the dives clears current_dive, so we have to remember it.
+	// TODO: remove this hack!
+	dive *current = current_dive;
+
+	// Cheating!
+	divesDeleted(trip, false, dives);
+	divesAdded(trip, false, dives);
+
+	// Now, restore current_dive
+	// TODO: remove this hack!
+	selected_dive = get_divenr(current);
+}

qt-models/divetripmodel.h

@@ -108,7 +108,12 @@ public:
 	int rowCount(const QModelIndex &parent) const;
 	QModelIndex index(int row, int column, const QModelIndex &parent) const;
 	QModelIndex parent(const QModelIndex &index) const;
-
+private slots:
+	void divesAdded(dive_trip *trip, bool addTrip, const QVector<dive *> &dives);
+	void divesDeleted(dive_trip *trip, bool deleteTrip, const QVector<dive *> &dives);
+	void divesChanged(dive_trip *trip, const QVector<dive *> &dives);
+	void divesTimeChanged(dive_trip *trip, timestamp_t delta, const QVector<dive *> &dives);
+	void divesMovedBetweenTrips(dive_trip *from, dive_trip *to, bool deleteFrom, bool createTo, const QVector<dive *> &dives);
 private:
 	// The model has up to two levels. At the top level, we have either trips or dives
 	// that do not belong to trips. Such a top-level item is represented by the "Item"
@@ -121,11 +126,24 @@ private:
 	// one element, which is the corresponding dive.
 	struct Item {
 		dive_trip		*trip;
-		QVector<dive *>		 dives;
+		std::vector<dive *>	 dives;			// std::vector<> instead of QVector for insert() with three iterators
-		Item(dive_trip *t, dive *d);	// Initialize a trip with one dive
+		Item(dive_trip *t, const QVector<dive *> &dives);
-		Item(dive *d);			// Initialize a top-level dive
+		Item(dive_trip *t, dive *d);			// Initialize a trip with one dive
+		Item(dive *d);					// Initialize a top-level dive
+		bool isDive(const dive *) const;		// Helper function: is this the give dive?
+		dive *getDive() const;				// Helper function: returns top-level-dive or null
+		timestamp_t when() const;			// Helper function: start time of dive *or* trip
 	};
 
+	// Access trips and dives
+	int findTripIdx(const dive_trip *trip) const;
+	int findDiveIdx(const dive *d) const;			// Find _top_level_ dive
+	int findDiveInTrip(int tripIdx, const dive *d) const;	// Find dive inside trip. Second parameter is index of trip
+	int findInsertionIndex(timestamp_t when) const;		// Where to insert item with timestamp "when"
+
+	// Addition and deletion of dives
+	void addDivesToTrip(int idx, const QVector<dive *> &dives);
+
 	dive *diveOrNull(const QModelIndex &index) const;	// Returns a dive if this index represents a dive, null otherwise
 	QPair<dive_trip *, dive *> tripOrDive(const QModelIndex &index) const;
 								// Returns either a pointer to a trip or a dive, or twice null of index is invalid