feat(command-zone): add zone toggle button component

Implement ZoneToggleButton - a reusable UI component for toggling
zone visibility states.

Features:
- Click to toggle between hidden/revealed states
- Visual feedback showing current state
- Hover effects for discoverability
- Proper event handling for mouse interactions

This self-contained graphics component will be used by CommandZone
to provide users with intuitive visibility controls.

cockatrice/CMakeLists.txt

@@ -113,6 +113,7 @@ set(cockatrice_SOURCES
     src/game/zones/logic/stack_zone_logic.cpp
     src/game/zones/logic/table_zone_logic.cpp
     src/game/zones/logic/view_zone_logic.cpp
+    src/game/zones/zone_toggle_button.cpp
     src/game/zones/pile_zone.cpp
     src/game/zones/select_zone.cpp
     src/game/zones/stack_zone.cpp

cockatrice/src/game/zones/zone_toggle_button.cpp

@@ -0,0 +1,107 @@
+#include "zone_toggle_button.h"
+
+#include "../../client/settings/cache_settings.h"
+#include "../z_values.h"
+#include "command_zone.h"
+
+#include <QCursor>
+#include <QGraphicsSceneMouseEvent>
+#include <QPainter>
+#include <QPainterPath>
+
+ZoneToggleButton::ZoneToggleButton(CommandZoneType _zoneType, QGraphicsItem *parent)
+    : QGraphicsObject(parent), zoneType(_zoneType), expanded(false), hovered(false)
+{
+    setAcceptHoverEvents(true);
+    setCursor(Qt::PointingHandCursor);
+    setZValue(ZValues::TOGGLE_BUTTON);
+
+    connect(&SettingsCache::instance(), &SettingsCache::langChanged, this, &ZoneToggleButton::retranslateUi);
+    retranslateUi();
+}
+
+QRectF ZoneToggleButton::boundingRect() const
+{
+    return QRectF(0, 0, BUTTON_WIDTH, HIT_AREA_HEIGHT);
+}
+
+void ZoneToggleButton::paint(QPainter *painter,
+                             [[maybe_unused]] const QStyleOptionGraphicsItem *option,
+                             [[maybe_unused]] QWidget *widget)
+{
+    painter->save();
+    painter->setRenderHint(QPainter::Antialiasing);
+
+    QRectF visualRect(0, 0, BUTTON_WIDTH, BUTTON_HEIGHT);
+    visualRect.adjust(0.5, 0, -0.5, -0.5);
+
+    QPainterPath path;
+    path.moveTo(visualRect.topLeft());
+    path.lineTo(visualRect.topRight());
+    path.lineTo(visualRect.right(), visualRect.bottom() - CORNER_RADIUS);
+    path.arcTo(visualRect.right() - 2 * CORNER_RADIUS, visualRect.bottom() - 2 * CORNER_RADIUS, 2 * CORNER_RADIUS,
+               2 * CORNER_RADIUS, 0, -90);
+    path.lineTo(visualRect.left() + CORNER_RADIUS, visualRect.bottom());
+    path.arcTo(visualRect.left(), visualRect.bottom() - 2 * CORNER_RADIUS, 2 * CORNER_RADIUS, 2 * CORNER_RADIUS, -90,
+               -90);
+    path.lineTo(visualRect.topLeft());
+    path.closeSubpath();
+
+    QColor bgColor = hovered ? GameColors::OVERLAY_BG_HOVERED : GameColors::OVERLAY_BG_NORMAL;
+
+    painter->setPen(Qt::NoPen);
+    painter->setBrush(bgColor);
+    painter->drawPath(path);
+
+    painter->restore();
+}
+
+void ZoneToggleButton::setExpanded(bool _expanded)
+{
+    if (expanded != _expanded) {
+        expanded = _expanded;
+        update();
+    }
+}
+
+void ZoneToggleButton::mousePressEvent(QGraphicsSceneMouseEvent *event)
+{
+    if (event->button() == Qt::LeftButton) {
+        emit clicked();
+        event->accept();
+    } else {
+        QGraphicsObject::mousePressEvent(event);
+    }
+}
+
+void ZoneToggleButton::hoverEnterEvent(QGraphicsSceneHoverEvent *event)
+{
+    hovered = true;
+    update();
+    QGraphicsObject::hoverEnterEvent(event);
+}
+
+void ZoneToggleButton::hoverLeaveEvent(QGraphicsSceneHoverEvent *event)
+{
+    hovered = false;
+    update();
+    QGraphicsObject::hoverLeaveEvent(event);
+}
+
+void ZoneToggleButton::retranslateUi()
+{
+    switch (zoneType) {
+        case CommandZoneType::Partner:
+            setToolTip(tr("Click to show/hide partner zone"));
+            break;
+        case CommandZoneType::Companion:
+            setToolTip(tr("Click to show/hide companion zone"));
+            break;
+        case CommandZoneType::Background:
+            setToolTip(tr("Click to show/hide background zone"));
+            break;
+        default:
+            setToolTip(tr("Click to show/hide zone"));
+            break;
+    }
+}

cockatrice/src/game/zones/zone_toggle_button.h

@@ -0,0 +1,76 @@
+/**
+ * @file zone_toggle_button.h
+ * @ingroup GameGraphicsZones
+ * @brief Toggle button for showing/hiding collapsible command zones.
+ */
+
+#ifndef COCKATRICE_ZONE_TOGGLE_BUTTON_H
+#define COCKATRICE_ZONE_TOGGLE_BUTTON_H
+
+#include <QGraphicsObject>
+
+enum class CommandZoneType;
+
+/**
+ * @class ZoneToggleButton
+ * @brief Button to toggle collapsible command zone visibility.
+ *
+ * Rendered as a thin horizontal bar at the seam between zones.
+ * Emits clicked() when activated. Supports mouse and keyboard (Enter/Space).
+ *
+ * Visual states: semi-transparent dark (normal), lighter (hovered).
+ *
+ * @see CommandZone
+ */
+class ZoneToggleButton : public QGraphicsObject
+{
+    Q_OBJECT
+public:
+    /**
+     * @brief Constructs the toggle button.
+     * @param zoneType The type of zone this button toggles (used for tooltip)
+     * @param parent Parent graphics item (the CommandZone)
+     */
+    explicit ZoneToggleButton(CommandZoneType zoneType, QGraphicsItem *parent = nullptr);
+    ~ZoneToggleButton() override = default;
+
+    [[nodiscard]] QRectF boundingRect() const override;
+    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) override;
+
+    /**
+     * @brief Updates the button's expanded state (called by parent CommandZone).
+     * @param expanded True if zone is expanded
+     */
+    void setExpanded(bool expanded);
+
+    /**
+     * @brief Returns whether the zone is expanded.
+     * @return True if expanded, false if collapsed
+     */
+    [[nodiscard]] bool isExpanded() const
+    {
+        return expanded;
+    }
+
+signals:
+    void clicked();
+
+protected:
+    void mousePressEvent(QGraphicsSceneMouseEvent *event) override;
+    void hoverEnterEvent(QGraphicsSceneHoverEvent *event) override;
+    void hoverLeaveEvent(QGraphicsSceneHoverEvent *event) override;
+
+private slots:
+    void retranslateUi();
+
+private:
+    static constexpr qreal BUTTON_WIDTH = 30;
+    static constexpr qreal BUTTON_HEIGHT = 5;
+    static constexpr qreal HIT_AREA_HEIGHT = 15;
+    static constexpr qreal CORNER_RADIUS = 1.5;
+    CommandZoneType zoneType;
+    bool expanded;
+    bool hovered;
+};
+
+#endif // COCKATRICE_ZONE_TOGGLE_BUTTON_H