Dive list: split DiveTripModel into distinct models (tree and list)

The DiveTripModel was used to represent both, trip and list views.
Thus many functions had conditionals checking for the current mode
and both modes had to be represented by the same data structure.

Instead, split the model in two and derive them from a base class,
which implements common functions and defines an interface.

The model can be switched by a call to resetModel(), which invalidates
any pointer obtained by instance(). This is quite surprising
behavior. To handle it, straighten out the control flow:

DiveListView --> MultiFilterSortModel --> DiveTripModelBase

Before, DiveListView accessed DiveTripModelBase directly.

A goal of this commit is to enable usage of the same model by mobile
and desktop.

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

1 files changed, 65 insertions, 57 deletions

diff --git a/desktop-widgets/divelistview.cpp b/desktop-widgets/divelistview.cpp
index c340b556b..3ba9ba58f 100644
--- a/desktop-widgets/divelistview.cpp
+++ b/desktop-widgets/divelistview.cpp
@@ -28,20 +28,20 @@
 #include "desktop-widgets/simplewidgets.h"
 
 DiveListView::DiveListView(QWidget *parent) : QTreeView(parent), mouseClickSelection(false),
-	currentLayout(DiveTripModel::TREE), dontEmitDiveChangedSignal(false), selectionSaved(false),
-	initialColumnWidths(DiveTripModel::COLUMNS, 50)	// Set up with default length 50
+	currentLayout(DiveTripModelBase::TREE), dontEmitDiveChangedSignal(false), selectionSaved(false),
+	initialColumnWidths(DiveTripModelBase::COLUMNS, 50)	// Set up with default length 50
 {
 	setItemDelegate(new DiveListDelegate(this));
 	setUniformRowHeights(true);
-	setItemDelegateForColumn(DiveTripModel::RATING, new StarWidgetsDelegate(this));
+	setItemDelegateForColumn(DiveTripModelBase::RATING, new StarWidgetsDelegate(this));
 	setModel(MultiFilterSortModel::instance());
 
 	setSortingEnabled(true);
 	setContextMenuPolicy(Qt::DefaultContextMenu);
 	setSelectionMode(ExtendedSelection);
 	header()->setContextMenuPolicy(Qt::ActionsContextMenu);
-	connect(DiveTripModel::instance(), &DiveTripModel::selectionChanged, this, &DiveListView::diveSelectionChanged);
-	connect(DiveTripModel::instance(), &DiveTripModel::newCurrentDive, this, &DiveListView::currentDiveChanged);
+
+	resetModel();
 
 	// Update selection if all selected dives were hidden by filter
 	connect(MultiFilterSortModel::instance(), &MultiFilterSortModel::filterFinished, this, &DiveListView::filterFinished);
@@ -53,7 +53,7 @@ DiveListView::DiveListView(QWidget *parent) : QTreeView(parent), mouseClickSelec
 
 	installEventFilter(this);
 
-	for (int i = DiveTripModel::NR; i < DiveTripModel::COLUMNS; i++)
+	for (int i = DiveTripModelBase::NR; i < DiveTripModelBase::COLUMNS; i++)
 		calculateInitialColumnWidth(i);
 	setColumnWidths();
 }
@@ -63,7 +63,7 @@ DiveListView::~DiveListView()
 	QSettings settings;
 	settings.beginGroup("ListWidget");
 	// don't set a width for the last column - location is supposed to be "the rest"
-	for (int i = DiveTripModel::NR; i < DiveTripModel::COLUMNS - 1; i++) {
+	for (int i = DiveTripModelBase::NR; i < DiveTripModelBase::COLUMNS - 1; i++) {
 		if (isColumnHidden(i))
 			continue;
 		// we used to hardcode them all to 100 - so that might still be in the settings
@@ -72,41 +72,50 @@ DiveListView::~DiveListView()
 		else
 			settings.setValue(QString("colwidth%1").arg(i), columnWidth(i));
 	}
-	settings.remove(QString("colwidth%1").arg(DiveTripModel::COLUMNS - 1));
+	settings.remove(QString("colwidth%1").arg(DiveTripModelBase::COLUMNS - 1));
 	settings.endGroup();
 }
 
+void DiveListView::resetModel()
+{
+	MultiFilterSortModel::instance()->resetModel(currentLayout);
+	// If the model was reset, we have to reconnect the signals and tell
+	// the filter model to update its source model.
+	connect(DiveTripModelBase::instance(), &DiveTripModelBase::selectionChanged, this, &DiveListView::diveSelectionChanged);
+	connect(DiveTripModelBase::instance(), &DiveTripModelBase::newCurrentDive, this, &DiveListView::currentDiveChanged);
+}
+
 void DiveListView::calculateInitialColumnWidth(int col)
 {
 	const QFontMetrics metrics(defaultModelFont());
 	int em = metrics.width('m');
 	int zw = metrics.width('0');
 
-	QString header_txt = DiveTripModel::instance()->headerData(col, Qt::Horizontal, Qt::DisplayRole).toString();
+	QString header_txt = DiveTripModelBase::instance()->headerData(col, Qt::Horizontal, Qt::DisplayRole).toString();
 	int width = metrics.width(header_txt);
 	int sw = 0;
 	switch (col) {
-	case DiveTripModel::NR:
-	case DiveTripModel::DURATION:
+	case DiveTripModelBase::NR:
+	case DiveTripModelBase::DURATION:
 		sw = 8*zw;
 		break;
-	case DiveTripModel::DATE:
+	case DiveTripModelBase::DATE:
 		sw = 14*em;
 		break;
-	case DiveTripModel::RATING:
+	case DiveTripModelBase::RATING:
 		sw = static_cast<StarWidgetsDelegate*>(itemDelegateForColumn(col))->starSize().width();
 		break;
-	case DiveTripModel::SUIT:
-	case DiveTripModel::SAC:
+	case DiveTripModelBase::SUIT:
+	case DiveTripModelBase::SAC:
 		sw = 7*em;
 		break;
-	case DiveTripModel::PHOTOS:
+	case DiveTripModelBase::PHOTOS:
 		sw = 5*em;
 		break;
-	case DiveTripModel::BUDDIES:
+	case DiveTripModelBase::BUDDIES:
 		sw = 50*em;
 		break;
-	case DiveTripModel::LOCATION:
+	case DiveTripModelBase::LOCATION:
 		sw = 50*em;
 		break;
 	default:
@@ -126,7 +135,7 @@ void DiveListView::setColumnWidths()
 	/* if no width are set, use the calculated width for each column;
 	 * for that to work we need to temporarily expand all rows */
 	expandAll();
-	for (int i = DiveTripModel::NR; i < DiveTripModel::COLUMNS; i++) {
+	for (int i = DiveTripModelBase::NR; i < DiveTripModelBase::COLUMNS; i++) {
 		if (isColumnHidden(i))
 			continue;
 		QVariant width = settings.value(QString("colwidth%1").arg(i));
@@ -143,7 +152,7 @@ void DiveListView::setColumnWidths()
 int DiveListView::lastVisibleColumn()
 {
 	int lastColumn = -1;
-	for (int i = DiveTripModel::NR; i < DiveTripModel::COLUMNS; i++) {
+	for (int i = DiveTripModelBase::NR; i < DiveTripModelBase::COLUMNS; i++) {
 		if (isColumnHidden(i))
 			continue;
 		lastColumn = i;
@@ -249,11 +258,11 @@ void DiveListView::rememberSelection()
 	Q_FOREACH (const QModelIndex &index, selection.indexes()) {
 		if (index.column() != 0) // We only care about the dives, so, let's stick to rows and discard columns.
 			continue;
-		struct dive *d = index.data(DiveTripModel::DIVE_ROLE).value<struct dive *>();
+		struct dive *d = index.data(DiveTripModelBase::DIVE_ROLE).value<struct dive *>();
 		if (d) {
 			selectedDives.insert(d->divetrip, get_divenr(d));
 		} else {
-			struct dive_trip *t = index.data(DiveTripModel::TRIP_ROLE).value<dive_trip *>();
+			struct dive_trip *t = index.data(DiveTripModelBase::TRIP_ROLE).value<dive_trip *>();
 			if (t)
 				selectedDives.insert(t, -1);
 		}
@@ -289,7 +298,7 @@ void DiveListView::selectTrip(dive_trip_t *trip)
 		return;
 
 	QAbstractItemModel *m = model();
-	QModelIndexList match = m->match(m->index(0, 0), DiveTripModel::TRIP_ROLE, QVariant::fromValue(trip), 2, Qt::MatchRecursive);
+	QModelIndexList match = m->match(m->index(0, 0), DiveTripModelBase::TRIP_ROLE, QVariant::fromValue(trip), 2, Qt::MatchRecursive);
 	QItemSelectionModel::SelectionFlags flags;
 	if (!match.count())
 		return;
@@ -314,7 +323,7 @@ void DiveListView::clearTripSelection()
 
 	// we want to make sure no trips are selected
 	Q_FOREACH (const QModelIndex &index, selectionModel()->selectedRows()) {
-		dive_trip_t *trip = index.data(DiveTripModel::TRIP_ROLE).value<dive_trip *>();
+		dive_trip_t *trip = index.data(DiveTripModelBase::TRIP_ROLE).value<dive_trip *>();
 		if (!trip)
 			continue;
 		selectionModel()->select(index, QItemSelectionModel::Deselect);
@@ -343,7 +352,7 @@ QList<dive_trip_t *> DiveListView::selectedTrips()
 {
 	QList<dive_trip_t *> ret;
 	Q_FOREACH (const QModelIndex &index, selectionModel()->selectedRows()) {
-		dive_trip_t *trip = index.data(DiveTripModel::TRIP_ROLE).value<dive_trip *>();
+		dive_trip_t *trip = index.data(DiveTripModelBase::TRIP_ROLE).value<dive_trip *>();
 		if (!trip)
 			continue;
 		ret.push_back(trip);
@@ -374,7 +383,7 @@ void DiveListView::selectDive(int i, bool scrollto, bool toggle)
 	if (i == -1)
 		return;
 	QAbstractItemModel *m = model();
-	QModelIndexList match = m->match(m->index(0, 0), DiveTripModel::DIVE_IDX, i, 2, Qt::MatchRecursive);
+	QModelIndexList match = m->match(m->index(0, 0), DiveTripModelBase::DIVE_IDX, i, 2, Qt::MatchRecursive);
 	if (match.isEmpty())
 		return;
 	QModelIndex idx = match.first();
@@ -411,7 +420,7 @@ void DiveListView::selectDives(const QList<int> &newDiveSelection)
 			selectDive(newSelection);
 	}
 	QAbstractItemModel *m = model();
-	QModelIndexList idxList = m->match(m->index(0, 0), DiveTripModel::DIVE_IDX, get_divenr(current_dive), 2, Qt::MatchRecursive);
+	QModelIndexList idxList = m->match(m->index(0, 0), DiveTripModelBase::DIVE_IDX, get_divenr(current_dive), 2, Qt::MatchRecursive);
 	if (!idxList.isEmpty()) {
 		QModelIndex idx = idxList.first();
 		if (idx.parent().isValid())
@@ -462,7 +471,7 @@ bool DiveListView::eventFilter(QObject *, QEvent *event)
 
 void DiveListView::sortIndicatorChanged(int i, Qt::SortOrder order)
 {
-	DiveTripModel::Layout newLayout = i == (int)DiveTripModel::NR ? DiveTripModel::TREE : DiveTripModel::LIST;
+	DiveTripModelBase::Layout newLayout = i == (int)DiveTripModelBase::NR ? DiveTripModelBase::TREE : DiveTripModelBase::LIST;
 	/* No layout change? Just re-sort, and scroll to first selection, making sure all selections are expanded */
 	if (currentLayout == newLayout) {
 		sortByColumn(i, order);
@@ -470,12 +479,12 @@ void DiveListView::sortIndicatorChanged(int i, Qt::SortOrder order)
 		// clear the model, repopulate with new indexes.
 		rememberSelection();
 		unselectDives();
-		if (currentLayout == DiveTripModel::TREE)
+		if (currentLayout == DiveTripModelBase::TREE)
 			backupExpandedRows();
 		currentLayout = newLayout;
-		MultiFilterSortModel::instance()->setLayout(newLayout);
+		resetModel();
 		sortByColumn(i, order);
-		if (newLayout == DiveTripModel::TREE)
+		if (newLayout == DiveTripModelBase::TREE)
 			restoreExpandedRows();
 		restoreSelection();
 	}
@@ -489,8 +498,7 @@ void DiveListView::setSortOrder(int i, Qt::SortOrder order)
 
 void DiveListView::reload()
 {
-	// A side-effect of setting the layout is reloading the model data
-	MultiFilterSortModel::instance()->setLayout(currentLayout);
+	resetModel();
 
 	if (amount_selected && current_dive != NULL)
 		selectDive(get_divenr(current_dive), true);
@@ -519,15 +527,15 @@ void DiveListView::reloadHeaderActions()
 			QString title = QString("%1").arg(model()->headerData(i, Qt::Horizontal).toString());
 			QString settingName = QString("showColumn%1").arg(i);
 			QAction *a = new QAction(title, header());
-			bool showHeaderFirstRun = !(i == DiveTripModel::MAXCNS ||
-						    i == DiveTripModel::GAS ||
-						    i == DiveTripModel::OTU ||
-						    i == DiveTripModel::TEMPERATURE ||
-						    i == DiveTripModel::TOTALWEIGHT ||
-						    i == DiveTripModel::SUIT ||
-						    i == DiveTripModel::CYLINDER ||
-						    i == DiveTripModel::SAC ||
-						    i == DiveTripModel::TAGS);
+			bool showHeaderFirstRun = !(i == DiveTripModelBase::MAXCNS ||
+						    i == DiveTripModelBase::GAS ||
+						    i == DiveTripModelBase::OTU ||
+						    i == DiveTripModelBase::TEMPERATURE ||
+						    i == DiveTripModelBase::TOTALWEIGHT ||
+						    i == DiveTripModelBase::SUIT ||
+						    i == DiveTripModelBase::CYLINDER ||
+						    i == DiveTripModelBase::SAC ||
+						    i == DiveTripModelBase::TAGS);
 			bool shown = s.value(settingName, showHeaderFirstRun).toBool();
 			a->setCheckable(true);
 			a->setChecked(shown);
@@ -608,9 +616,9 @@ void DiveListView::selectionChanged(const QItemSelection &selected, const QItemS
 		if (index.column() != 0)
 			continue;
 		const QAbstractItemModel *model = index.model();
-		struct dive *dive = model->data(index, DiveTripModel::DIVE_ROLE).value<struct dive *>();
+		struct dive *dive = model->data(index, DiveTripModelBase::DIVE_ROLE).value<struct dive *>();
 		if (!dive) // it's a trip!
-			deselect_dives_in_trip(model->data(index, DiveTripModel::TRIP_ROLE).value<dive_trip *>());
+			deselect_dives_in_trip(model->data(index, DiveTripModelBase::TRIP_ROLE).value<dive_trip *>());
 		else
 			deselect_dive(dive);
 	}
@@ -619,11 +627,11 @@ void DiveListView::selectionChanged(const QItemSelection &selected, const QItemS
 			continue;
 
 		const QAbstractItemModel *model = index.model();
-		struct dive *dive = model->data(index, DiveTripModel::DIVE_ROLE).value<struct dive *>();
+		struct dive *dive = model->data(index, DiveTripModelBase::DIVE_ROLE).value<struct dive *>();
 		if (!dive) { // it's a trip!
 			if (model->rowCount(index)) {
 				QItemSelection selection;
-				select_dives_in_trip(model->data(index, DiveTripModel::TRIP_ROLE).value<dive_trip *>());
+				select_dives_in_trip(model->data(index, DiveTripModelBase::TRIP_ROLE).value<dive_trip *>());
 				selection.select(index.child(0, 0), index.child(model->rowCount(index) - 1, 0));
 				selectionModel()->select(selection, QItemSelectionModel::Select | QItemSelectionModel::Rows);
 				selectionModel()->setCurrentIndex(index, QItemSelectionModel::Select | QItemSelectionModel::NoUpdate);
@@ -725,8 +733,8 @@ void DiveListView::merge_trip(const QModelIndex &a, int offset)
 	int i = a.row() + offset;
 	QModelIndex b = a.sibling(i, 0);
 
-	dive_trip_t *trip_a = a.data(DiveTripModel::TRIP_ROLE).value<dive_trip *>();
-	dive_trip_t *trip_b = b.data(DiveTripModel::TRIP_ROLE).value<dive_trip *>();
+	dive_trip_t *trip_a = a.data(DiveTripModelBase::TRIP_ROLE).value<dive_trip *>();
+	dive_trip_t *trip_b = b.data(DiveTripModelBase::TRIP_ROLE).value<dive_trip *>();
 	if (trip_a == trip_b || !trip_a || !trip_b)
 		return;
 	Command::mergeTrips(trip_a, trip_b);
@@ -757,7 +765,7 @@ void DiveListView::removeFromTrip()
 
 void DiveListView::newTripAbove()
 {
-	struct dive *d = contextMenuIndex.data(DiveTripModel::DIVE_ROLE).value<struct dive *>();
+	struct dive *d = contextMenuIndex.data(DiveTripModelBase::DIVE_ROLE).value<struct dive *>();
 	if (!d) // shouldn't happen as we only are setting up this action if this is a dive
 		return;
 	//TODO: port to c-code.
@@ -783,7 +791,7 @@ void DiveListView::addToTripAbove()
 void DiveListView::addToTrip(int delta)
 {
 	// d points to the row that has (mouse-)pointer focus, and there are nr rows selected
-	struct dive *d = contextMenuIndex.data(DiveTripModel::DIVE_ROLE).value<struct dive *>();
+	struct dive *d = contextMenuIndex.data(DiveTripModelBase::DIVE_ROLE).value<struct dive *>();
 	int nr = selectionModel()->selectedRows().count();
 	QModelIndex t;
 	dive_trip_t *trip = NULL;
@@ -792,7 +800,7 @@ void DiveListView::addToTrip(int delta)
 	// check if its sibling is a trip.
 	for (int i = 1; i <= nr; i++) {
 		t = contextMenuIndex.sibling(contextMenuIndex.row() + (delta > 0 ? i: i * -1), 0);
-		trip = t.data(DiveTripModel::TRIP_ROLE).value<dive_trip *>();
+		trip = t.data(DiveTripModelBase::TRIP_ROLE).value<dive_trip *>();
 		if (trip)
 			break;
 	}
@@ -815,7 +823,7 @@ void DiveListView::addToTrip(int delta)
 void DiveListView::markDiveInvalid()
 {
 	int i;
-	struct dive *d = contextMenuIndex.data(DiveTripModel::DIVE_ROLE).value<struct dive *>();
+	struct dive *d = contextMenuIndex.data(DiveTripModelBase::DIVE_ROLE).value<struct dive *>();
 	if (!d)
 		return;
 	for_each_dive (i, d) {
@@ -834,7 +842,7 @@ void DiveListView::markDiveInvalid()
 
 void DiveListView::deleteDive()
 {
-	struct dive *d = contextMenuIndex.data(DiveTripModel::DIVE_ROLE).value<struct dive *>();
+	struct dive *d = contextMenuIndex.data(DiveTripModelBase::DIVE_ROLE).value<struct dive *>();
 	if (!d)
 		return;
 
@@ -852,17 +860,17 @@ void DiveListView::contextMenuEvent(QContextMenuEvent *event)
 	QAction *collapseAction = NULL;
 	// let's remember where we are
 	contextMenuIndex = indexAt(event->pos());
-	struct dive *d = contextMenuIndex.data(DiveTripModel::DIVE_ROLE).value<struct dive *>();
-	dive_trip_t *trip = contextMenuIndex.data(DiveTripModel::TRIP_ROLE).value<dive_trip *>();
+	struct dive *d = contextMenuIndex.data(DiveTripModelBase::DIVE_ROLE).value<struct dive *>();
+	dive_trip_t *trip = contextMenuIndex.data(DiveTripModelBase::TRIP_ROLE).value<dive_trip *>();
 	QMenu popup(this);
-	if (currentLayout == DiveTripModel::TREE) {
+	if (currentLayout == DiveTripModelBase::TREE) {
 		// verify if there is a node that`s not expanded.
 		bool needs_expand = false;
 		bool needs_collapse = false;
 		uint expanded_nodes = 0;
 		for(int i = 0, end = model()->rowCount(); i < end; i++) {
 			QModelIndex idx = model()->index(i, 0);
-			if (idx.data(DiveTripModel::DIVE_ROLE).value<struct dive *>())
+			if (idx.data(DiveTripModelBase::DIVE_ROLE).value<struct dive *>())
 				continue;
 
 			if (!isExpanded(idx)) {