color item icon backgrounds in the UI from visuals.toml

src/ui/ItemIconCache.h

@@ -8,38 +8,76 @@
 #include <QPixmap>
 #include <QString>
 
-// Rasterizes and caches per-item icon SVGs (REQ-UI-ITEM-ICON). Item icons are
-// self-contained, full-color SVGs loaded from a directory, one file per item type
-// named after the item's id (e.g. "iron_ore.svg"). Shared by the recipe-selection
-// dialog (REQ-UI-RECIPE-ICON) and the game world's belt/port item rendering so the
-// rasterization is not duplicated.
+class QPainter;
+class QRectF;
+struct VisualsConfig;
+
+// Rasterizes and caches per-item icon SVGs, and composes them onto the item's colored
+// square (REQ-UI-ITEM-ICON). Item icons are self-contained, full-color SVGs loaded from
+// a directory, one file per item type named after the item's id (e.g. "iron_ore.svg").
 //
-// A missing icon file is not an error: hasIcon() returns false for it and the caller
-// falls back (a colored square in the world, a name caption in the dialog).
+// The square is the item's `fill` and `outline` from visuals.toml with the icon inset
+// within it, and it backs the icon both in the game world and wherever the UI displays
+// an item as an item: the recipe-selection dialog's option buttons (REQ-UI-RECIPE-ICON),
+// the selection panel's item chips (REQ-UI-SINGLE-SELECTION, REQ-UI-HQ-PANEL), and the
+// recipe summary (REQ-UI-RECIPE-SUMMARY). Defined here once rather than per widget, in
+// two forms: paintItem() for the world's fractional geometry, getSquarePixmap() for
+// widgets that want a ready-made pixmap.
+//
+// The bare icon of getPixmap() has one remaining use: the inline building_block icon
+// that stands in for the word "Blocks" beside a number (REQ-UI-BLOCKS-ICON), which is a
+// decoration on a line of text rather than an item display and takes no square.
+//
+// A missing icon file is not an error: hasIcon() returns false for it and the item shows
+// its colored square alone.
 class ItemIconCache
 {
 public:
-    // iconDir is the directory holding the "<item_id>.svg" icon files
-    // (typically "<configDir>/../icons/items").
-    explicit ItemIconCache(const QString& iconDir);
+    // iconDir is the directory holding the "<item_id>.svg" icon files (typically
+    // "<configDir>/../icons/items"). visuals supplies the per-item square colors and
+    // must outlive the cache; its contents may be replaced on a restart (REQ-CFG-RELOAD),
+    // which is what clearPixmapCache() is for.
+    ItemIconCache(const QString& iconDir, const VisualsConfig* visuals);
 
     // True if an icon SVG file exists for the given item id. Loads the file's bytes
     // on first query and remembers the result (including absence) so repeated calls
     // are cheap.
     bool hasIcon(const std::string& itemId);
 
-    // Returns the item's icon rasterized to a transparent sizePx*sizePx pixmap,
-    // cached per (item id, size) so it is rendered once and reused across frames and
-    // only re-rasterized when the target size changes (REQ-UI-ITEM-ICON). Returns a
-    // null pixmap if the item has no icon file (callers should gate on hasIcon()).
+    // Paints the item's colored square into rect and its icon inset within it
+    // (REQ-UI-ITEM-ICON). Takes the rect as a QRectF so the world can keep painting at
+    // sub-pixel geometry. An item with no visuals entry gets no square, one with no icon
+    // file no icon; with neither, this paints nothing.
+    void paintItem(QPainter& painter, const QRectF& rect, const std::string& itemId);
+
+    // The same composition rasterized to a sizePx*sizePx pixmap for widget use, cached
+    // per (item id, size) so it is rendered once and reused. Returns a null pixmap only
+    // when the item has neither a visuals entry nor an icon file, which is the one case
+    // in which a caller has nothing to show and falls back to text.
+    QPixmap getSquarePixmap(const std::string& itemId, int sizePx);
+
+    // Returns the item's icon alone, without its square, rasterized to a transparent
+    // sizePx*sizePx pixmap and cached per (item id, size) so it is rendered once and
+    // reused across frames (REQ-UI-ITEM-ICON). Returns a null pixmap if the item has no
+    // icon file (callers should gate on hasIcon()).
     QPixmap getPixmap(const std::string& itemId, int sizePx);
 
+    // Drops every rasterized pixmap. Called when the visuals are reloaded on a restart
+    // (REQ-CFG-RELOAD), because the composed squares carry the colors they were painted
+    // with; they are re-rasterized on next use.
+    void clearPixmapCache();
+
 private:
     // Returns the raw SVG bytes for an item id, loading and caching them on first
     // access. An absent file caches an empty QByteArray so it is not retried.
     const QByteArray& getSvg(const std::string& itemId);
+    // Shared rasterize-and-cache step. cacheKey distinguishes the bare and squared
+    // variants of one item within the single pixmap cache.
+    QPixmap getPixmap(const std::string& cacheKey, const std::string& itemId,
+                      int sizePx, bool withSquare);
 
     QString                            m_iconDir;
+    const VisualsConfig*               m_visuals;  // Not owned; lives in MainWindow.
     std::map<std::string, QByteArray>  m_svgById;
     std::map<std::pair<std::string, int>, QPixmap> m_pixmapCache;
 };