improve Containers->Contents selection connection

create selected_container_changed signal/slot
change Containers to QObject for signals/slots
transform selection to source index in Containers
transform back to proxy index in Contents
default AdFilter::only_show_containers to false

src/ad_filter.h

@@ -15,7 +15,7 @@ class AdFilter : public QSortFilterProxyModel {
 public:
     explicit AdFilter(AdModel *model, QAction *advanced_view_toggle);
 
-    bool only_show_containers;
+    bool only_show_containers = false;
 
 private slots:
     void on_advanced_view_toggled(bool checked);

src/containers_tree.cpp

@@ -15,4 +15,22 @@ proxy(model, advanced_view_toggle)
     view->hideColumn(AdModel::Column::Category);
     view->hideColumn(AdModel::Column::Description);
     view->hideColumn(AdModel::Column::DN);
+
+    connect(
+        view->selectionModel(), &QItemSelectionModel::selectionChanged,
+        this, &ContainersTree::on_selection_changed);
 };
+
+void ContainersTree::on_selection_changed(const QItemSelection &selected, const QItemSelection &) {
+    // Transform selected index into source index and pass it on
+    // to selected_container_changed() signal
+    const QList<QModelIndex> indexes = selected.indexes();
+
+    if (indexes.size() > 0) {
+        QModelIndex index = indexes[0];
+        QModelIndex source_index = proxy.mapToSource(index);
+
+        emit selected_container_changed(source_index);
+    }
+}
+

src/containers_tree.h

@@ -4,16 +4,26 @@
 
 #include "ad_filter.h"
 
+#include <QObject>
+
 class QTreeView;
 class AdModel;
 class QAction;
+class QModelIndex;
 
 // Shows names of AdModel as a tree
-class ContainersTree {
+class ContainersTree : public QObject {
+Q_OBJECT
 
 public:
     ContainersTree(QTreeView *view, AdModel *model, QAction *advanced_view_toggle);
 
+signals:
+    void selected_container_changed(const QModelIndex &selected);
+
+private slots:
+    void on_selection_changed(const QItemSelection &selected, const QItemSelection &);
+
 private:
     QTreeView *view;
     AdFilter proxy;

src/contents_list.cpp

@@ -24,38 +24,9 @@ proxy(model, advanced_view_toggle)
 
 // Both contents and containers share the same source model, but have different proxy's to it
 // So need to map from containers proxy to source then back to proxy of contents
-void ContentsList::set_root_index_from_selection(const QItemSelection &selected, const QItemSelection &) {
-
-    const QList<QModelIndex> indexes = selected.indexes();
-
-    if (indexes.size() == 0) {
-        return;
-    }
-
-    // Map from proxy model of given index to source model of this view (if needed)
-    QModelIndex source_index = indexes[0];
-    {
-        auto proxy_model = qobject_cast<const QSortFilterProxyModel *>(source_index.model());
-        if (proxy_model != nullptr) {
-            source_index = proxy_model->mapToSource(source_index);
-        }
-    }
-
-    // Map from source model of this view to proxy model of this view (if needed)
-    QModelIndex contents_index = source_index;
-    {
-        auto proxy_model = qobject_cast<const QSortFilterProxyModel *>(view->model());
-        if (proxy_model != nullptr) {
-            contents_index = proxy_model->mapFromSource(contents_index);
-        }
-    }
-
-    if (!view->model()->checkIndex(contents_index)) {
-        printf("ContentsList::set_root_index_from_selection received bad index!\n");
-        return;
-    }
-
-    view->setRootIndex(contents_index);
+void ContentsList::on_selected_container_changed(const QModelIndex &source_index) {
+    QModelIndex index = proxy.mapFromSource(source_index);
+    view->setRootIndex(index);
 
     // NOTE: have to hide columns after model update
     view->hideColumn(AdModel::Column::DN);

src/contents_list.h

@@ -25,7 +25,7 @@ public:
     void dropEvent(QDropEvent *event) override;
 
 public slots:
-    void set_root_index_from_selection(const QItemSelection &selected, const QItemSelection &);
+    void on_selected_container_changed(const QModelIndex &source_index);
 
 private:
     QPoint drag_start_position;

src/main.cpp

@@ -61,8 +61,8 @@ int main(int argc, char **argv) {
 
     // Set root index of contents view to selection of containers view
     QObject::connect(
-        ui.containers_view->selectionModel(), &QItemSelectionModel::selectionChanged,
-        &contents_list, &ContentsList::set_root_index_from_selection);
+        &containers_tree, &ContainersTree::selected_container_changed,
+        &contents_list, &ContentsList::on_selected_container_changed);
     
     // Connect menubar "New" submenu's to entry creation dialogs
     QObject::connect(