1 files changed, 157 insertions, 0 deletions
diff --git a/src/libs/utils/qtdesignsystemstyle.cpp b/src/libs/utils/qtdesignsystemstyle.cpp
new file mode 100644
index 00000000000..1eebe93a297
--- /dev/null
+++ b/src/libs/utils/qtdesignsystemstyle.cpp
@@ -0,0 +1,157 @@
+// Copyright (C) 2025 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+#include "qtdesignsystemstyle.h"
+
+#include "stylehelper.h"
+#include "utilsicons.h"
+
+#include <QGuiApplication>
+#include <QPaintEvent>
+#include <QPainter>
+#include <QPainterPath>
+#include <QPixmapCache>
+#include <QWidget>
+#include <QStyleOption>
+#include <QTabBar>
+
+namespace Utils {
+
+using namespace StyleHelper;
+using namespace StyleHelper::SpacingTokens;
+
+constexpr TextFormat TabBarTf
+    {Theme::Token_Text_Muted, StyleHelper::UiElementH5};
+constexpr TextFormat TabBarTfActive
+    {Theme::Token_Text_Default, TabBarTf.uiElement};
+constexpr TextFormat TabBarTfDisabled
+    {Theme::Token_Text_Subtle, TabBarTf.uiElement};
+
+QtDesignSystemStyle::QtDesignSystemStyle()
+{
+}
+
+QtDesignSystemStyle::~QtDesignSystemStyle() = default;
+
+void QtDesignSystemStyle::drawControl(ControlElement element, const QStyleOption *opt,
+                                      QPainter *painter, const QWidget *widget) const
+{
+    switch (element) {
+    case CE_TabBarTabLabel: {
+        auto tabOpt = qstyleoption_cast<const QStyleOptionTab*>(opt);
+        QStyleOptionTab myTabOpt = *tabOpt;
+        const QColor c = ((myTabOpt.state & QStyle::State_Enabled) ?
+                              (myTabOpt.state & QStyle::State_Selected) ? TabBarTfActive
+                                                                        : TabBarTf
+                                                                   : TabBarTfDisabled).color();
+        myTabOpt.palette.setColor(widget->foregroundRole(), c);
+        myTabOpt.state = myTabOpt.state & ~QStyle::State_HasFocus; // Avoid extra focus rect
+        QCommonStyle::drawControl(element, &myTabOpt, painter, widget);
+        break;
+    }
+    case CE_TabBarTabShape: {
+        const bool selected = opt->state & QStyle::State_Selected;
+        const bool enabled = opt->state & QStyle::State_Enabled;
+        const bool hovered = !selected && opt->rect.contains(widget->mapFromGlobal(QCursor::pos()));
+        auto tabOpt = qstyleoption_cast<const QStyleOptionTab*>(opt);
+        const int paddingL = tabOpt->position == QStyleOptionTab::Beginning ? 0 : PaddingHXxs;
+        const int paddingR = tabOpt->position == QStyleOptionTab::End ? 0 : PaddingHXxs;
+        const QRect shapeR = opt->rect.adjusted(paddingL, 0, -paddingR, 0);
+        if (selected || (hovered && enabled)) {
+            if (hovered || tabOpt->position == QStyleOptionTab::Moving) {
+                StyleHelper::drawCardBg(painter, shapeR.adjusted(0, 0, 0, +SpacingTokens::RadiusS),
+                                        creatorColor(Theme::Token_Foreground_Subtle));
+            }
+            QRect highLightRect = shapeR;
+            highLightRect.moveTop(highLightRect.height() - StyleHelper::HighlightThickness);
+            const QColor color = creatorColor(enabled ? hovered ? Theme::Token_Text_Subtle
+                                                                : Theme::Token_Accent_Default
+                                                      : Theme::Token_Foreground_Subtle);
+            painter->fillRect(highLightRect, color);
+        }
+        break;
+    }
+    default:
+        QCommonStyle::drawControl(element, opt, painter, widget);
+        break;
+    }
+}
+
+void QtDesignSystemStyle::drawPrimitive(PrimitiveElement element, const QStyleOption *opt,
+                                        QPainter *painter, const QWidget *widget) const
+{
+    switch (element) {
+    case PE_FrameTabBarBase: {
+        QRectF borderR = opt->rect.toRectF();
+        const int lineWidth = 1;
+        borderR.setTop(borderR.bottom() - lineWidth);
+        const bool enabled = opt->state & QStyle::State_Enabled;
+        const QColor color = creatorColor(enabled ? Theme::Token_Stroke_Subtle
+                                                  : Theme::Token_Foreground_Subtle);
+        painter->fillRect(borderR, color);
+        break;
+    }
+    default:
+        QCommonStyle::drawPrimitive(element, opt, painter, widget);
+        break;
+    }
+}
+
+int QtDesignSystemStyle::pixelMetric(PixelMetric m, const QStyleOption *opt,
+                                     const QWidget *widget) const
+{
+    switch (m) {
+    case PM_TabBarTabShiftVertical:
+    case PM_TabBarTabShiftHorizontal:
+        return 0;
+    case PM_TabBarTabHSpace:
+        return PaddingHL + PaddingHL;
+    case PM_TabBarTabVSpace: {
+        const int textHeight = opt->fontMetrics.height();
+        return PaddingVM + TabBarTf.lineHeight() + PaddingVM - textHeight;
+    }
+    default:
+        return QCommonStyle::pixelMetric(m, opt, widget);
+    }
+}
+
+QIcon QtDesignSystemStyle::standardIcon(StandardPixmap sp, const QStyleOption *opt,
+                                        const QWidget *widget) const
+{
+    QIcon icon;
+
+    switch (sp) {
+    case SP_TabCloseButton: {
+        static const QIcon tabClose = Icons::CLOSE_FOREGROUND.icon();
+        icon = tabClose;
+        break;
+    }
+    default:
+        icon = QCommonStyle::standardIcon(sp, opt, widget);
+        break;
+    }
+
+    return icon;
+}
+void QtDesignSystemStyle::polish(QWidget *widget)
+{
+    QCommonStyle::polish(widget);
+
+    if (auto tabBar = qobject_cast<QTabBar*>(widget)) {
+        tabBar->setFont(TabBarTf.font());
+        for (int count = tabBar->count(), i = 0; i < count; ++i ) {
+            for (const QTabBar::ButtonPosition pos : {QTabBar::LeftSide, QTabBar::RightSide}) {
+                if (QWidget *tabButton = tabBar->tabButton(i, pos))
+                    tabButton->setStyle(this);
+            }
+        }
+    }
+}
+
+QStyle *QtDesignSystemStyle::instance()
+{
+    static QtDesignSystemStyle style;
+    return &style;
+}
+
+} // namespace Utils