Utils: Introduce QtcTabBarHEADmaster

This adds a designed QTabBar to the list of QtcWidgets. A QtcTabBar
instance can be assigned to a derived QTabWidget via
QTabWidget::setTabBar.

Change-Id: I9676fcf790d3696c6ce2078cb7cb6f492b9ad00d
Reviewed-by: hjk <[email protected]>

3 files changed, 83 insertions, 0 deletions

diff --git a/src/libs/utils/qtcwidgets.cpp b/src/libs/utils/qtcwidgets.cpp
index aba8c258c7a..fcf47f1f064 100644
--- a/src/libs/utils/qtcwidgets.cpp
+++ b/src/libs/utils/qtcwidgets.cpp
@@ -828,6 +828,67 @@ void QtcImage::setPixmap(const QPixmap &px)
     update();
 }
 
+constexpr TextFormat TabBarTf
+    {Theme::Token_Text_Muted, StyleHelper::UiElementLabelMedium};
+constexpr TextFormat TabBarTfActive
+    {Theme::Token_Text_Default, TabBarTf.uiElement};
+
+QtcTabBar::QtcTabBar(QWidget *parent)
+    : QTabBar(parent)
+{
+    setExpanding(false);
+    setMouseTracking(true);
+}
+
+void QtcTabBar::paintEvent([[maybe_unused]] QPaintEvent *event)
+{
+    // +------------+------------+------------+
+    // |            |(VPaddingXs)|            |
+    // |            +------------+            |
+    // |(HPaddingXs)|   <text>   |(HPaddingXs)|
+    // |            +------------+            |
+    // |            |(VPaddingXs)|            |
+    // +------------+------------+------------+
+
+    QPainter p(this);
+    p.setFont(TabBarTf.font());
+    for (int tabIndex = 0; tabIndex < count(); tabIndex++) {
+        QStyleOptionTab opt;
+        initStyleOption(&opt, tabIndex);
+        const bool selected = opt.state & QStyle::State_Selected;
+        if (selected) {
+            QRect rect = opt.rect;
+            rect.moveTop(rect.height() - 2); // Same height as the active mode highlight marker
+            const QColor color = creatorColor(isEnabled() ? Theme::Token_Accent_Default
+                                                          : Theme::Token_Foreground_Subtle);
+            p.fillRect(rect, color);
+        } else if (opt.rect.contains(mapFromGlobal(QCursor::pos()))) {
+            p.fillRect(opt.rect, creatorColor(Theme::Token_Foreground_Muted));
+        }
+        const QColor textColor = isEnabled() ? (selected ? TabBarTfActive : TabBarTf).color()
+                                             : creatorColor(Theme::Token_Text_Subtle);
+        p.setPen(textColor);
+        p.drawText(opt.rect, Qt::AlignCenter, opt.text);
+    }
+}
+
+bool QtcTabBar::event(QEvent *event)
+{
+    if (event->type() == QEvent::MouseMove || event->type() == QEvent::Leave)
+        repaint();
+    return QTabBar::event(event);
+}
+
+QSize QtcTabBar::minimumTabSizeHint(int index) const
+{
+    const QString text = tabText(index);
+    const QFontMetrics fm(TabBarTf.font());
+    const int textWidth = fm.boundingRect(text).width();
+
+    return {ExPaddingGapL + textWidth + textWidth,
+            VPaddingXxs + TabBarTf.lineHeight() + VPaddingXxs};
+}
+
 namespace QtcWidgets {
 
 Button::Button()
diff --git a/src/libs/utils/qtcwidgets.h b/src/libs/utils/qtcwidgets.h
index 75e3d655211..26fe3ef0d85 100644
--- a/src/libs/utils/qtcwidgets.h
+++ b/src/libs/utils/qtcwidgets.h
@@ -185,6 +185,17 @@ private:
     int m_radius = 0;
 };
 
+class QTCREATOR_UTILS_EXPORT QtcTabBar : public QTabBar
+{
+public:
+    QtcTabBar(QWidget *parent = nullptr);
+
+protected:
+    void paintEvent(QPaintEvent *event) override;
+    bool event(QEvent *event) override;
+    QSize minimumTabSizeHint(int index) const override;
+};
+
 
 namespace QtcWidgets {
 
diff --git a/tests/manual/widgets/components/tst_manual_widgets_components.cpp b/tests/manual/widgets/components/tst_manual_widgets_components.cpp
index 2c0ec9dd250..00e665b6e6e 100644
--- a/tests/manual/widgets/components/tst_manual_widgets_components.cpp
+++ b/tests/manual/widgets/components/tst_manual_widgets_components.cpp
@@ -23,6 +23,11 @@ QWidget *widgets()
     auto switchOff = new QtcSwitch("Qt::LeftToRight");
     switchOff->setLayoutDirection(Qt::LeftToRight);
 
+    auto tabBar = new QtcTabBar;
+    tabBar->addTab("Tab number 1");
+    tabBar->addTab("2");
+    tabBar->addTab("3");
+
     using namespace Layouting;
     Column {
         Group {
@@ -65,6 +70,12 @@ QWidget *widgets()
                 switchOff,
             },
         },
+        Group {
+            title("TabBar"),
+            Row {
+                tabBar,
+            },
+        },
     }.attachTo(widget);
 
     return widget;