split the selection panel into one card per kind of selection

src/ui/selection/SelectionContent.h

@@ -0,0 +1,101 @@
+#pragma once
+
+#include <optional>
+
+#include <QColor>
+#include <QPixmap>
+#include <QString>
+#include <QWidget>
+
+#include "BuildingId.h"
+#include "BuildingType.h"
+#include "SelectionContext.h"
+
+struct Building;
+class QLabel;
+class QVBoxLayout;
+
+// One card of the selection panel: the content shown for a particular kind of selection
+// (REQ-UI-SELECTION-CARD). Every content is this base plus the parts its constructor
+// puts into the two groups; which content is shown for which selection is decided in
+// SelectionContentFactory (REQ-UI-SELECTION-CONTENT).
+//
+// The card has three parts, top to bottom:
+//   * the header  -- identity symbol, name, and one optional right slot (a status
+//     indicator, a ship's behavior, or an object count);
+//   * the configuration group -- controls that change how the object is set up;
+//   * the runtime group -- what the object is currently doing.
+//
+// A construction site keeps its configuration group and has its whole runtime group
+// replaced by the construction section (REQ-BLD-SITE-CONFIG). That rule lives here and
+// nowhere else: a subclass fills both groups unconditionally in its constructor and
+// never asks whether it is showing a site.
+class SelectionContent : public QWidget
+{
+    Q_OBJECT
+
+public:
+    ~SelectionContent() override;
+
+    // Re-reads the live values behind the card. It never changes the card's structure:
+    // a change that would (a site finishing, the selection changing) is a rebuild, and
+    // SelectionPanel owns that decision.
+    void refresh();
+
+protected:
+    // constructionSiteId is set only while the card shows a construction site, in which
+    // case this base builds and drives the construction section in place of whatever the
+    // subclass puts into the runtime group.
+    SelectionContent(const SelectionContext& context,
+                     std::optional<BuildingId> constructionSiteId,
+                     QWidget* parent);
+
+    // Live values of the runtime group. Not called while the card shows a construction
+    // site, which has neither buffers nor a production cycle (REQ-BLD-SITE-CONFIG).
+    virtual void refreshRuntime() = 0;
+
+    // Live values of the configuration group. Called for a site too, because a site is
+    // configured exactly like the building it will become (REQ-BLD-SITE-CONFIG).
+    virtual void refreshConfiguration() {}
+
+    const SelectionContext& getContext() const { return m_context; }
+
+    // The two group layouts a subclass adds its parts to, in its constructor.
+    QVBoxLayout* getConfigurationLayout();
+    QVBoxLayout* getRuntimeLayout();
+
+    void setIdentity(const QPixmap& symbol, const QString& name);
+    // Header symbol for a building type: its chip icon, or nothing when the icon file is
+    // missing -- which is not an error (REQ-UI-BUILD-ICON, REQ-UI-SELECTION-CARD).
+    void setBuildingIdentity(BuildingType type, const QString& name);
+
+    // Fills the header's right slot. A null dot color leaves the dot off, for the slots
+    // that are a plain caption (a construction site, a ship's behavior).
+    void setSlot(const QColor& dotColor, const QString& caption);
+    // "x<count>", for an aggregated multi-selection (REQ-UI-SELECTION-AGGREGATE).
+    void setCountSlot(int count);
+    void clearSlot();
+
+    // Fills the right slot from the building's production status, mapped to the same
+    // colors and states the world's status light uses (REQ-UI-SELECTION-STATUS). Leaves
+    // the slot empty for a type that has no status light.
+    void setProductionStatusSlot(const Building& building);
+
+private:
+    void refreshConstruction();
+
+    SelectionContext m_context;
+    // Set while this card shows a construction site rather than a finished object.
+    std::optional<BuildingId> m_siteId;
+
+    QLabel* m_symbolLabel;
+    QLabel* m_nameLabel;
+    QLabel* m_slotDot;
+    QLabel* m_slotLabel;
+
+    QWidget* m_configurationGroup;
+    QWidget* m_runtimeGroup;
+    // Replaces the runtime group while this card shows a construction site; null
+    // otherwise.
+    QLabel* m_constructionLabel;
+};