[VisualDatabase] Draw the card grid with a model/view (#7701)

* [VisualDatabase] Draw the card grid with a model/view instead of a widget per card

The visual card database built one CardInfoPictureWithTextOverlayWidget per
card, 100 per page, and tore them down on every search, resize and scroll
page. It also looked each card up again by name from the model row, kept a
shadow QList<ExactCard>, and carried paging state plus a 5 s timer that only
existed to defer the first page.

Replace that with a real view on a flattened model:

- CardDatabaseDisplayModel gains CardInfoRole and cardInfoAt(), so a view can
  get the CardInfoPtr behind a proxy row without a name round trip.
- New CardDatabaseVisualDisplayModel (libcockatrice_models) flattens the
  filtered and sorted proxy into one entry per displayed card picture: the
  preferred printing normally, every printing of the selected sets while set
  filters are active. Proxy changes rebuild it on a 30 ms coalescing timer.
- New CardDatabaseVisualView (QListView IconMode) paints only visible rows
  through the new CardPictureDelegate, keeps the old interaction contract
  (left/right/middle press -> cardClicked, hover -> cardHovered, Ctrl+wheel
  resize, no selection, no focus stealing, scroll to top on a new result) and
  repaints when CardPictureLoader reports an async image.
- CardSizeWidget::enableCtrlScrollResize() also watches scroll-area viewports,
  which is what makes Ctrl+wheel work over a QListView.
- VisualDatabaseDisplayWidget drops the paging, the shadow list, the dead
  members and the 5 s timer.

Behaviour-preserving: no gameplay change, no new user-facing strings.

* [VisualDatabase] Fix the card grid wheel step

QListView hands the delegate's item height to the scroll bar as its single step under ScrollPerPixel, so QAbstractSlider moved wheelScrollLines() whole card rows per notch. Handle the wheel in the view instead: one line is an eighth of the grid cell, so a notch moves about a third of a card row at any card size and still follows the OS line count.

---------

Co-authored-by: Lukas Brübach <Bruebach.Lukas@bdosecurity.de>

cockatrice/src/filters/filter_tree_model.cpp

@@ -11,6 +11,27 @@
 
 class QObject;
 
+namespace
+{
+/**
+ * @brief Visits every filter item below @p node, depth first.
+ */
+template <typename Callback> void forEachFilter(const FilterTreeNode *node, const Callback &callback)
+{
+    if (node == nullptr) {
+        return;
+    }
+
+    if (const auto *filterItem = dynamic_cast<const FilterItem *>(node)) {
+        callback(filterItem);
+    }
+
+    for (int i = 0; i < node->childCount(); ++i) {
+        forEachFilter(node->nodeAt(i), callback);
+    }
+}
+} // namespace
+
 FilterTreeModel::FilterTreeModel(QObject *parent) : QAbstractItemModel(parent)
 {
     fTree = new FilterTree;
@@ -110,46 +131,31 @@ void FilterTreeModel::clearFiltersOfType(CardFilter::Attr filterType)
 QList<const CardFilter *> FilterTreeModel::getFiltersOfType(CardFilter::Attr filterType) const
 {
     QList<const CardFilter *> filters;
-    if (!fTree) {
-        return filters;
-    }
-
-    std::function<void(const FilterTreeNode *)> traverse;
-    traverse = [&](const FilterTreeNode *node) {
-        if (const auto *filterItem = dynamic_cast<const FilterItem *>(node)) {
-            if (filterItem->attr() == filterType) {
-                QString text = filterItem->text();
-                filters.append(new CardFilter(text, filterItem->type(), filterItem->attr()));
-            }
+    forEachFilter(fTree, [&](const FilterItem *filterItem) {
+        if (filterItem->attr() == filterType) {
+            filters.append(new CardFilter(filterItem->text(), filterItem->type(), filterItem->attr()));
         }
-        for (int i = 0; i < node->childCount(); ++i) {
-            traverse(node->nodeAt(i));
-        }
-    };
-
-    traverse(fTree);
+    });
     return filters;
 }
 
+QStringList FilterTreeModel::getFilterTermsOfType(CardFilter::Attr filterType) const
+{
+    QStringList terms;
+    forEachFilter(fTree, [&](const FilterItem *filterItem) {
+        if (filterItem->attr() == filterType) {
+            terms.append(filterItem->text());
+        }
+    });
+    return terms;
+}
+
 QList<const CardFilter *> FilterTreeModel::allFilters() const
 {
     QList<const CardFilter *> filters;
-    if (!fTree) {
-        return filters;
-    }
-
-    std::function<void(const FilterTreeNode *)> traverse;
-    traverse = [&](const FilterTreeNode *node) {
-        if (const auto *filterItem = dynamic_cast<const FilterItem *>(node)) {
-            QString text = filterItem->text();
-            filters.append(new CardFilter(text, filterItem->type(), filterItem->attr()));
-        }
-        for (int i = 0; i < node->childCount(); ++i) {
-            traverse(node->nodeAt(i));
-        }
-    };
-
-    traverse(fTree);
+    forEachFilter(fTree, [&](const FilterItem *filterItem) {
+        filters.append(new CardFilter(filterItem->text(), filterItem->type(), filterItem->attr()));
+    });
     return filters;
 }
 

cockatrice/src/filters/filter_tree_model.h

@@ -28,7 +28,14 @@ public slots:
     void addFilter(const CardFilter *f);
     void removeFilter(const CardFilter *f);
     void clearFiltersOfType(CardFilter::Attr filterType);
+    /**
+     * @brief Copies every active filter of one attribute into new CardFilter objects.
+     *
+     * The caller owns the returned filters. Prefer getFilterTermsOfType() when only
+     * the terms are needed.
+     */
     [[nodiscard]] QList<const CardFilter *> getFiltersOfType(CardFilter::Attr filterType) const;
+    /// @brief Copies every active filter into new CardFilter objects. The caller owns them.
     [[nodiscard]] QList<const CardFilter *> allFilters() const;
 
 private slots:
@@ -48,6 +55,13 @@ public:
     {
         return fTree;
     }
+
+    /**
+     * @brief The texts of every active filter of one attribute, without allocating filters.
+     *
+     * Prefer this over getFiltersOfType() when only the filter terms are needed.
+     */
+    [[nodiscard]] QStringList getFilterTermsOfType(CardFilter::Attr filterType) const;
     [[nodiscard]] int rowCount(const QModelIndex &parent = QModelIndex()) const override;
     [[nodiscard]] int columnCount(const QModelIndex & /*parent*/ = QModelIndex()) const override;
     [[nodiscard]] QVariant data(const QModelIndex &index, int role) const override;