From 7996c5afac0dd7d14f931baf9886268e8029a973 Mon Sep 17 00:00:00 2001
From: Eike Ziller <eike.ziller@qt.io>
Date: Wed, 15 May 2024 14:45:17 +0200
Subject: [PATCH] Editors: Improve the highlight of the current view

Make the overlay widget as small as possible, paint it opaque, and paint
only on the editor tool bar.

Change-Id: If48f8f7c4dd221cb605548449f5bbb1a30c25a76
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>
---
 src/libs/utils/overlaywidget.cpp              | 27 ++++++++++++++++---
 src/libs/utils/overlaywidget.h                | 10 ++++++-
 .../coreplugin/editormanager/editorview.cpp   | 14 +++++-----
 3 files changed, 39 insertions(+), 12 deletions(-)

diff --git a/src/libs/utils/overlaywidget.cpp b/src/libs/utils/overlaywidget.cpp
index 720c5a90e18..950dc4b5dc3 100644
--- a/src/libs/utils/overlaywidget.cpp
+++ b/src/libs/utils/overlaywidget.cpp
@@ -8,16 +8,34 @@
 #include <QEvent>
 #include <QPainter>
 
+namespace Utils::Internal {
+class OverlayWidgetPrivate
+{
+public:
+    OverlayWidget::PaintFunction m_paint;
+    OverlayWidget::ResizeFunction m_resize;
+};
+} // namespace Utils::Internal
+
 Utils::OverlayWidget::OverlayWidget(QWidget *parent)
+    : d(new Internal::OverlayWidgetPrivate)
 {
     setAttribute(Qt::WA_TransparentForMouseEvents);
     if (parent)
         attachToWidget(parent);
+    d->m_resize = [](QWidget *w, const QSize &size) { w->setGeometry(QRect(QPoint(0, 0), size)); };
 }
 
+Utils::OverlayWidget::~OverlayWidget() = default;
+
 void Utils::OverlayWidget::setPaintFunction(const Utils::OverlayWidget::PaintFunction &paint)
 {
-    m_paint = paint;
+    d->m_paint = paint;
+}
+
+void Utils::OverlayWidget::setResizeFunction(const ResizeFunction &resize)
+{
+    d->m_resize = resize;
 }
 
 bool Utils::OverlayWidget::eventFilter(QObject *obj, QEvent *ev)
@@ -29,9 +47,9 @@ bool Utils::OverlayWidget::eventFilter(QObject *obj, QEvent *ev)
 
 void Utils::OverlayWidget::paintEvent(QPaintEvent *ev)
 {
-    if (m_paint) {
+    if (d->m_paint) {
         QPainter p(this);
-        m_paint(this, p, ev);
+        d->m_paint(this, p, ev);
     }
 }
 
@@ -50,5 +68,6 @@ void Utils::OverlayWidget::attachToWidget(QWidget *parent)
 void Utils::OverlayWidget::resizeToParent()
 {
     QTC_ASSERT(parentWidget(), return );
-    setGeometry(QRect(QPoint(0, 0), parentWidget()->size()));
+    if (d->m_resize)
+        d->m_resize(this, parentWidget()->size());
 }
diff --git a/src/libs/utils/overlaywidget.h b/src/libs/utils/overlaywidget.h
index 8bc5b7d1eb5..c5686ad171c 100644
--- a/src/libs/utils/overlaywidget.h
+++ b/src/libs/utils/overlaywidget.h
@@ -8,18 +8,26 @@
 #include <QWidget>
 
 #include <functional>
+#include <memory>
 
 namespace Utils {
 
+namespace Internal {
+class OverlayWidgetPrivate;
+}
+
 class QTCREATOR_UTILS_EXPORT OverlayWidget : public QWidget
 {
 public:
     using PaintFunction = std::function<void(QWidget *, QPainter &, QPaintEvent *)>;
+    using ResizeFunction = std::function<void(QWidget *, QSize)>;
 
     explicit OverlayWidget(QWidget *parent = nullptr);
+    ~OverlayWidget();
 
     void attachToWidget(QWidget *parent);
     void setPaintFunction(const PaintFunction &paint);
+    void setResizeFunction(const ResizeFunction &resize);
 
 protected:
     bool eventFilter(QObject *obj, QEvent *ev) override;
@@ -28,7 +36,7 @@ protected:
 private:
     void resizeToParent();
 
-    PaintFunction m_paint;
+    std::unique_ptr<Internal::OverlayWidgetPrivate> d;
 };
 
 } // namespace Utils
diff --git a/src/plugins/coreplugin/editormanager/editorview.cpp b/src/plugins/coreplugin/editormanager/editorview.cpp
index fd9d375d81d..42ad07d2498 100644
--- a/src/plugins/coreplugin/editormanager/editorview.cpp
+++ b/src/plugins/coreplugin/editormanager/editorview.cpp
@@ -133,13 +133,13 @@ EditorView::EditorView(SplitterOrView *parentSplitterOrView, QWidget *parent)
 
     auto currentViewOverlay = new OverlayWidget;
     currentViewOverlay->attachToWidget(this);
-    currentViewOverlay->setPaintFunction([this](QWidget *w, QPainter &p, QPaintEvent *) {
-        const int width = 2;
-        const QPoint margin{0, width};
-        p.setPen({w->palette().color(QPalette::Highlight), width});
-        p.drawLine(
-            m_toolBar->geometry().bottomLeft() + margin,
-            m_toolBar->geometry().bottomRight() + margin);
+    currentViewOverlay->setAttribute(Qt::WA_OpaquePaintEvent);
+    currentViewOverlay->setResizeFunction([this](QWidget *w, const QSize &) {
+        const QRect toolbarRect = m_toolBar->geometry();
+        w->setGeometry(toolbarRect.x(), toolbarRect.bottom() - 1, toolbarRect.width(), 2);
+    });
+    currentViewOverlay->setPaintFunction([](QWidget *w, QPainter &p, QPaintEvent *) {
+        p.fillRect(w->rect(), w->palette().color(QPalette::Highlight));
     });
     currentViewOverlay->setVisible(false);
     const auto updateCurrentViewOverlay = [this, currentViewOverlay] {