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, 9 insertions, 8 deletions

diff --git a/qt-models/filtermodels.cpp b/qt-models/filtermodels.cpp
index 785d36123..4e4134033 100644
--- a/qt-models/filtermodels.cpp
+++ b/qt-models/filtermodels.cpp
@@ -88,13 +88,14 @@ MultiFilterSortModel::MultiFilterSortModel(QObject *parent) : QSortFilterProxyMo
 {
 	setFilterKeyColumn(-1); // filter all columns
 	setFilterCaseSensitivity(Qt::CaseInsensitive);
-	setSourceModel(DiveTripModel::instance());
 }
 
-void MultiFilterSortModel::setLayout(DiveTripModel::Layout layout)
+void MultiFilterSortModel::resetModel(DiveTripModelBase::Layout layout)
 {
-	DiveTripModel *tripModel = DiveTripModel::instance();
-	tripModel->setLayout(layout);	// Note: setLayout() resets the whole model
+	DiveTripModelBase::resetModel(layout);
+	// DiveTripModelBase::resetModel() generates a new instance.
+	// Thus, the source model must be reset.
+	setSourceModel(DiveTripModelBase::instance());
 }
 
 bool MultiFilterSortModel::showDive(const struct dive *d) const
@@ -143,14 +144,14 @@ bool MultiFilterSortModel::showDive(const struct dive *d) const
 bool MultiFilterSortModel::filterAcceptsRow(int source_row, const QModelIndex &source_parent) const
 {
 	QModelIndex index0 = sourceModel()->index(source_row, 0, source_parent);
-	struct dive *d = sourceModel()->data(index0, DiveTripModel::DIVE_ROLE).value<struct dive *>();
+	struct dive *d = sourceModel()->data(index0, DiveTripModelBase::DIVE_ROLE).value<struct dive *>();
 
 	// For dives, simply check the hidden_by_filter flag
 	if (d)
 		return !d->hidden_by_filter;
 
 	// Since this is not a dive, it must be a trip
-	dive_trip *trip = sourceModel()->data(index0, DiveTripModel::TRIP_ROLE).value<dive_trip *>();
+	dive_trip *trip = sourceModel()->data(index0, DiveTripModelBase::TRIP_ROLE).value<dive_trip *>();
 
 	if (!trip)
 		return false; // Oops. Neither dive nor trip, something is seriously wrong.
@@ -189,7 +190,7 @@ void MultiFilterSortModel::myInvalidate()
 	invalidateFilter();
 
 	// Tell the dive trip model to update the displayed-counts
-	DiveTripModel::instance()->filterFinished();
+	DiveTripModelBase::instance()->filterFinished();
 	emit filterFinished();
 
 #if !defined(SUBSURFACE_MOBILE)
@@ -218,7 +219,7 @@ void MultiFilterSortModel::stopFilterDiveSite()
 bool MultiFilterSortModel::lessThan(const QModelIndex &i1, const QModelIndex &i2) const
 {
 	// Hand sorting down to the source model.
-	return DiveTripModel::instance()->lessThan(i1, i2);
+	return DiveTripModelBase::instance()->lessThan(i1, i2);
 }
 
 void MultiFilterSortModel::filterDataChanged(const FilterData& data)