restore expand state after item is no longer filtered out, fixes #1262

src/librssguard/core/feedsproxymodel.cpp

@@ -322,6 +322,25 @@ bool FeedsProxyModel::lessThan(const QModelIndex& left, const QModelIndex& right
 
 bool FeedsProxyModel::filterAcceptsRow(int source_row, const QModelIndex& source_parent) const {
   bool should_show = filterAcceptsRowInternal(source_row, source_parent);
+
+  if (should_show && m_hiddenIndices.contains(QPair<int, QModelIndex>(source_row, source_parent))) {
+    qDebugNN << LOGSEC_CORE << "Item"
+             << QUOTE_W_SPACE(m_sourceModel
+                                ->data(m_sourceModel->index(source_row, 0, source_parent), Qt::ItemDataRole::EditRole)
+                                .toString())
+             << "was previously hidden and now shows up, expand.";
+
+    const_cast<FeedsProxyModel*>(this)->m_hiddenIndices.removeAll(QPair<int, QModelIndex>(source_row, source_parent));
+
+    // Now, item now should be displayed and previously it was not.
+    // Expand!
+    emit indexNotFilteredOutAnymore(m_sourceModel->index(source_row, 0, source_parent));
+  }
+
+  if (!should_show) {
+    const_cast<FeedsProxyModel*>(this)->m_hiddenIndices.append(QPair<int, QModelIndex>(source_row, source_parent));
+  }
+
   return should_show;
 }
 

src/librssguard/core/feedsproxymodel.h

@@ -56,7 +56,7 @@ class FeedsProxyModel : public QSortFilterProxyModel {
     void invalidateReadFeedsFilter(bool set_new_value = false, bool show_unread_only = false);
 
   signals:
-    void expandAfterFilterIn(QModelIndex source_idx) const;
+    void indexNotFilteredOutAnymore(QModelIndex source_idx) const;
 
     // There was some drag/drop operation, notify view about this.
     void requireItemValidationAfterDragDrop(const QModelIndex& source_index);
@@ -79,6 +79,7 @@ class FeedsProxyModel : public QSortFilterProxyModel {
     bool m_showNodeLabels;
     bool m_showNodeImportant;
     QList<RootItem::Kind> m_priorities;
+    QList<QPair<int, QModelIndex>> m_hiddenIndices;
 };
 
 #endif // FEEDSPROXYMODEL_H

src/librssguard/gui/feedsview.cpp

@@ -42,6 +42,7 @@ FeedsView::FeedsView(QWidget* parent)
   m_proxyModel->setView(this);
 
   // Connections.
+  connect(&m_expansionDelayer, &QTimer::timeout, this, &FeedsView::reloadDelayedExpansions);
   connect(m_sourceModel, &FeedsModel::itemExpandRequested, this, &FeedsView::onItemExpandRequested);
   connect(m_sourceModel, &FeedsModel::itemExpandStateSaveRequested, this, &FeedsView::onItemExpandStateSaveRequested);
   connect(header(), &QHeaderView::sortIndicatorChanged, this, &FeedsView::saveSortState);
@@ -49,7 +50,7 @@ FeedsView::FeedsView(QWidget* parent)
           &FeedsProxyModel::requireItemValidationAfterDragDrop,
           this,
           &FeedsView::validateItemAfterDragDrop);
-  connect(m_proxyModel, &FeedsProxyModel::expandAfterFilterIn, this, &FeedsView::expandItemDelayed);
+  connect(m_proxyModel, &FeedsProxyModel::indexNotFilteredOutAnymore, this, &FeedsView::reloadItemExpandState);
   connect(this, &FeedsView::expanded, this, &FeedsView::onIndexExpanded);
   connect(this, &FeedsView::collapsed, this, &FeedsView::onIndexCollapsed);
 
@@ -818,6 +819,24 @@ void FeedsView::onIndexCollapsed(const QModelIndex& idx) {
   }
 }
 
+void FeedsView::reloadDelayedExpansions() {
+  qDebugNN << LOGSEC_GUI << "Reloading delayed feed list expansions.";
+
+  m_expansionDelayer.stop();
+  m_dontSaveExpandState = true;
+
+  for (const QPair<QModelIndex, bool>& exp : m_delayedItemExpansions) {
+    auto idx = m_proxyModel->mapFromSource(exp.first);
+
+    if (idx.isValid()) {
+      setExpanded(idx, exp.second);
+    }
+  }
+
+  m_dontSaveExpandState = false;
+  m_delayedItemExpansions.clear();
+}
+
 void FeedsView::onItemExpandStateSaveRequested(RootItem* item) {
   saveExpandStates(item);
 }
@@ -862,25 +881,22 @@ void FeedsView::loadAllExpandStates() {
                                             .toInt()));
 }
 
-void FeedsView::expandItemDelayed(const QModelIndex& source_idx) {
-  // QTimer::singleShot(100, this, [=] {
+void FeedsView::reloadItemExpandState(const QModelIndex& source_idx) {
   //  Model requests to expand some items as they are visible and there is
   //  a filter active, so they maybe were not visible before.
-  QModelIndex pidx = m_proxyModel->mapFromSource(source_idx);
 
-  // NOTE: These changes are caused by filtering mechanisms
-  // and we don't want to store the values.
-  m_dontSaveExpandState = true;
+  RootItem* it = m_sourceModel->itemForIndex(source_idx);
 
-#if QT_VERSION >= 0x050D00 // Qt >= 5.13.0
-  expandRecursively(pidx);
-#else
-  setExpanded(pidx, true);
-#endif
+  if (it == nullptr) {
+    return;
+  }
 
-  m_dontSaveExpandState = false;
+  const QString setting_name = it->hashCode();
+  const bool expand =
+    qApp->settings()->value(GROUP(CategoriesExpandStates), setting_name, it->childCount() > 0).toBool();
 
-  //});
+  m_delayedItemExpansions.append({source_idx, expand});
+  m_expansionDelayer.start(300);
 }
 
 QMenu* FeedsView::initializeContextMenuCategories(RootItem* clicked_item) {

src/librssguard/gui/feedsview.h

@@ -8,6 +8,7 @@
 #include "gui/toolbars/feedstoolbar.h"
 
 #include <QStyledItemDelegate>
+#include <QTimer>
 
 class FeedsProxyModel;
 class Feed;
@@ -107,7 +108,8 @@ class RSSGUARD_DLLSPEC FeedsView : public BaseTreeView {
     void onIndexExpanded(const QModelIndex& idx);
     void onIndexCollapsed(const QModelIndex& idx);
 
-    void expandItemDelayed(const QModelIndex& source_idx);
+    void reloadDelayedExpansions();
+    void reloadItemExpandState(const QModelIndex& source_idx);
     void markSelectedItemReadStatus(RootItem::ReadStatus read);
     void markAllItemsReadStatus(RootItem::ReadStatus read);
 
@@ -146,6 +148,8 @@ class RSSGUARD_DLLSPEC FeedsView : public BaseTreeView {
     FeedsModel* m_sourceModel;
     FeedsProxyModel* m_proxyModel;
     bool m_dontSaveExpandState;
+    QList<QPair<QModelIndex, bool>> m_delayedItemExpansions;
+    QTimer m_expansionDelayer;
 
     // QTreeView interface
   protected: