give the selection cards their own parts instead of label blobs

src/ui/selection/ItemChipRow.cpp

@@ -0,0 +1,78 @@
+#include "ItemChipRow.h"
+
+#include <QGridLayout>
+
+#include "ItemChip.h"
+#include "ItemIconCache.h"
+
+namespace
+{
+
+// Size the item icon is drawn at inside a chip, in device-independent pixels.
+const int kChipIconSizePx = 18;
+
+// Chips per row. Two fit the panel's capped width side by side; a third would force the
+// counts to shrink.
+const int kChipsPerRow = 2;
+
+}  // namespace
+
+
+ItemChipRow::ItemChipRow(ItemIconCache* itemIcons, QWidget* parent)
+    : QWidget(parent)
+    , m_itemIcons(itemIcons)
+{
+    m_layout = new QGridLayout(this);
+    m_layout->setContentsMargins(0, 0, 0, 0);
+    m_layout->setSpacing(4);
+}
+
+void ItemChipRow::setEntries(const std::vector<Entry>& entries)
+{
+    std::vector<std::string> itemIds;
+    itemIds.reserve(entries.size());
+    for (const Entry& entry : entries)
+    {
+        itemIds.push_back(entry.itemId);
+    }
+
+    // Only the set of items changing is a structural change; the counts change every
+    // tick and must not cost a widget rebuild.
+    if (itemIds != m_itemIds)
+    {
+        m_itemIds = std::move(itemIds);
+        rebuildChips(entries);
+    }
+
+    for (std::size_t index = 0; index < entries.size(); ++index)
+    {
+        m_chips[index]->setCount(entries[index].countText);
+        m_chips[index]->setSubLine(entries[index].subLine);
+    }
+    setVisible(!entries.empty());
+}
+
+void ItemChipRow::rebuildChips(const std::vector<Entry>& entries)
+{
+    for (ItemChip* chip : m_chips)
+    {
+        m_layout->removeWidget(chip);
+        chip->deleteLater();
+    }
+    m_chips.clear();
+
+    for (std::size_t index = 0; index < entries.size(); ++index)
+    {
+        const std::string& itemId = entries[index].itemId;
+        // A missing icon file is not an error (REQ-UI-ITEM-ICON): the chip is then laid
+        // out around its count alone.
+        const QPixmap icon = m_itemIcons->hasIcon(itemId)
+            ? m_itemIcons->getPixmap(itemId, kChipIconSizePx)
+            : QPixmap();
+
+        ItemChip* chip = new ItemChip(icon, this);
+        m_layout->addWidget(chip, static_cast<int>(index) / kChipsPerRow,
+                            static_cast<int>(index) % kChipsPerRow);
+        m_chips.push_back(chip);
+    }
+}