1 files changed, 173 insertions, 19 deletions

diff --git a/src/quicktemplates/qquickscrollview.cpp b/src/quicktemplates/qquickscrollview.cpp
index 8a352b7f61..5f7c7bf2fd 100644
--- a/src/quicktemplates/qquickscrollview.cpp
+++ b/src/quicktemplates/qquickscrollview.cpp
@@ -98,11 +98,17 @@ public:
     QQmlListProperty<QObject> contentData() override;
     QQmlListProperty<QQuickItem> contentChildren() override;
     QList<QQuickItem *> contentChildItems() const override;
+    QQuickItem* getFirstChild() const override;
 
     QQuickItem *getContentItem() override;
 
-    QQuickFlickable *ensureFlickable(bool content);
-    bool setFlickable(QQuickFlickable *flickable, bool content);
+    enum class ContentItemFlag {
+        DoNotSet,
+        Set
+    };
+
+    QQuickFlickable *ensureFlickable(ContentItemFlag contentItemFlag);
+    bool setFlickable(QQuickFlickable *flickable, ContentItemFlag contentItemFlag);
 
     void flickableContentWidthChanged();
     void flickableContentHeightChanged();
@@ -127,10 +133,17 @@ public:
 
     void itemImplicitWidthChanged(QQuickItem *item) override;
 
+    void updateScrollBarWidth();
+    void updateScrollBarHeight();
+
+    void disconnectScrollBarSignals(QQuickScrollBarAttachedPrivate *scrollBar);
     bool wasTouched = false;
     QQuickFlickable *flickable = nullptr;
     bool flickableHasExplicitContentWidth = true;
     bool flickableHasExplicitContentHeight = true;
+    bool isUpdatingScrollBar = false;
+    qreal effectiveScrollBarWidth = 0;
+    qreal effectiveScrollBarHeight = 0;
 };
 
 QList<QQuickItem *> QQuickScrollViewPrivate::contentChildItems() const
@@ -145,15 +158,23 @@ QQuickItem *QQuickScrollViewPrivate::getContentItem()
 {
     if (!contentItem)
         executeContentItem();
-    return ensureFlickable(false);
+    // This function is called by QQuickControl::contentItem() to lazily create
+    // a contentItem, so we don't need to try to set it again.
+    return ensureFlickable(ContentItemFlag::DoNotSet);
 }
 
-QQuickFlickable *QQuickScrollViewPrivate::ensureFlickable(bool content)
+QQuickItem* QQuickScrollViewPrivate::getFirstChild() const
+{
+    return contentChildItems().value(0);
+}
+
+QQuickFlickable *QQuickScrollViewPrivate::ensureFlickable(ContentItemFlag contentItemFlag)
 {
     Q_Q(QQuickScrollView);
     if (!flickable) {
         flickableHasExplicitContentWidth = false;
         flickableHasExplicitContentHeight = false;
+        // Pass ourselves as the Flickable's parent item.
         auto flickable = new QQuickFlickable(q);
         // We almost always want to clip the flickable so that flickable
         // contents doesn't show up outside the scrollview. The only time
@@ -163,12 +184,64 @@ QQuickFlickable *QQuickScrollViewPrivate::ensureFlickable(bool content)
         // child inside the scrollview, and control clipping on it explicit.
         flickable->setClip(true);
         flickable->setPixelAligned(true);
-        setFlickable(flickable, content);
+        setFlickable(flickable, contentItemFlag);
     }
     return flickable;
 }
 
-bool QQuickScrollViewPrivate::setFlickable(QQuickFlickable *item, bool content)
+void QQuickScrollViewPrivate::updateScrollBarWidth()
+{
+    Q_Q(QQuickScrollView);
+    qreal oldEffectiveScrollBarWidth = effectiveScrollBarWidth;
+    if (auto *vBar = verticalScrollBar()) {
+        if (vBar->policy() == QQuickScrollBar::AlwaysOff || !vBar->isVisible())
+            effectiveScrollBarWidth = 0;
+        else
+            effectiveScrollBarWidth = vBar->width();
+    }
+    if (effectiveScrollBarWidth != oldEffectiveScrollBarWidth) {
+        if (!isUpdatingScrollBar) {
+            QScopedValueRollback<bool> rollback(isUpdatingScrollBar, true);
+            emit q->effectiveScrollBarWidthChanged();
+        }
+    }
+}
+
+void QQuickScrollViewPrivate::updateScrollBarHeight()
+{
+    Q_Q(QQuickScrollView);
+    qreal oldEffectiveScrollBarHeight = effectiveScrollBarHeight;
+    if (auto *hBar = horizontalScrollBar()) {
+        if (hBar->policy() == QQuickScrollBar::AlwaysOff || !hBar->isVisible())
+            effectiveScrollBarHeight = 0;
+        else
+            effectiveScrollBarHeight = hBar->height();
+    }
+    if (effectiveScrollBarHeight != oldEffectiveScrollBarHeight) {
+        if (!isUpdatingScrollBar) {
+            QScopedValueRollback<bool> rollback(isUpdatingScrollBar, true);
+            emit q->effectiveScrollBarHeightChanged();
+        }
+
+    }
+}
+
+void QQuickScrollViewPrivate::disconnectScrollBarSignals(QQuickScrollBarAttachedPrivate *scrollBar)
+{
+    if (!scrollBar)
+        return;
+
+    if (scrollBar->vertical) {
+        QObjectPrivate::disconnect(scrollBar->vertical, &QQuickScrollBar::policyChanged, this, &QQuickScrollViewPrivate::updateScrollBarWidth);
+        QObjectPrivate::disconnect(scrollBar->vertical, &QQuickScrollBar::visibleChanged, this, &QQuickScrollViewPrivate::updateScrollBarWidth);
+    }
+    if (scrollBar->horizontal) {
+        QObjectPrivate::disconnect(scrollBar->horizontal, &QQuickScrollBar::policyChanged, this, &QQuickScrollViewPrivate::updateScrollBarHeight);
+        QObjectPrivate::disconnect(scrollBar->horizontal, &QQuickScrollBar::visibleChanged, this, &QQuickScrollViewPrivate::updateScrollBarHeight);
+    }
+}
+
+bool QQuickScrollViewPrivate::setFlickable(QQuickFlickable *item, ContentItemFlag contentItemFlag)
 {
     Q_Q(QQuickScrollView);
     if (item == flickable)
@@ -179,8 +252,11 @@ bool QQuickScrollViewPrivate::setFlickable(QQuickFlickable *item, bool content)
     if (flickable) {
         flickable->removeEventFilter(q);
 
-        if (attached)
-            QQuickScrollBarAttachedPrivate::get(attached)->setFlickable(nullptr);
+        if (attached) {
+            auto *scrollBar = QQuickScrollBarAttachedPrivate::get(attached);
+            scrollBar->setFlickable(nullptr);
+            disconnectScrollBarSignals(scrollBar);
+        }
 
         QObjectPrivate::disconnect(flickable->contentItem(), &QQuickItem::childrenChanged, this, &QQuickPanePrivate::contentChildrenChange);
         QObjectPrivate::disconnect(flickable, &QQuickFlickable::contentWidthChanged, this, &QQuickScrollViewPrivate::flickableContentWidthChanged);
@@ -188,7 +264,7 @@ bool QQuickScrollViewPrivate::setFlickable(QQuickFlickable *item, bool content)
     }
 
     flickable = item;
-    if (content)
+    if (contentItemFlag == ContentItemFlag::Set)
         q->setContentItem(flickable);
 
     if (flickable) {
@@ -202,8 +278,18 @@ bool QQuickScrollViewPrivate::setFlickable(QQuickFlickable *item, bool content)
         else
             flickableContentHeightChanged();
 
-        if (attached)
-            QQuickScrollBarAttachedPrivate::get(attached)->setFlickable(flickable);
+        if (attached) {
+            auto *scrollBar = QQuickScrollBarAttachedPrivate::get(attached);
+            scrollBar->setFlickable(flickable);
+            if (scrollBar->vertical) {
+                QObjectPrivate::connect(scrollBar->vertical, &QQuickScrollBar::policyChanged, this, &QQuickScrollViewPrivate::updateScrollBarWidth);
+                QObjectPrivate::connect(scrollBar->vertical, &QQuickScrollBar::visibleChanged, this, &QQuickScrollViewPrivate::updateScrollBarWidth);
+            }
+            if (scrollBar->horizontal) {
+                QObjectPrivate::connect(scrollBar->horizontal, &QQuickScrollBar::policyChanged, this, &QQuickScrollViewPrivate::updateScrollBarHeight);
+                QObjectPrivate::connect(scrollBar->horizontal, &QQuickScrollBar::visibleChanged, this, &QQuickScrollViewPrivate::updateScrollBarHeight);
+            }
+        }
 
         QObjectPrivate::connect(flickable->contentItem(), &QQuickItem::childrenChanged, this, &QQuickPanePrivate::contentChildrenChange);
         QObjectPrivate::connect(flickable, &QQuickFlickable::contentWidthChanged, this, &QQuickScrollViewPrivate::flickableContentWidthChanged);
@@ -305,11 +391,14 @@ void QQuickScrollViewPrivate::setScrollBarsInteractive(bool interactive)
 void QQuickScrollViewPrivate::contentData_append(QQmlListProperty<QObject> *prop, QObject *obj)
 {
     QQuickScrollViewPrivate *p = static_cast<QQuickScrollViewPrivate *>(prop->data);
-    if (!p->flickable && p->setFlickable(qobject_cast<QQuickFlickable *>(obj), true))
+    // If we don't yet have a flickable assigned, and this object is a Flickable,
+    // make it our contentItem.
+    if (!p->flickable && p->setFlickable(qobject_cast<QQuickFlickable *>(obj), ContentItemFlag::Set))
         return;
 
-    QQuickFlickable *flickable = p->ensureFlickable(true);
+    QQuickFlickable *flickable = p->ensureFlickable(ContentItemFlag::Set);
     Q_ASSERT(flickable);
+    // Add the object that was declared as a child of us as a child object of the Flickable.
     QQmlListProperty<QObject> data = flickable->flickableData();
     data.append(&data, obj);
 }
@@ -348,10 +437,11 @@ void QQuickScrollViewPrivate::contentChildren_append(QQmlListProperty<QQuickItem
 {
     QQuickScrollViewPrivate *p = static_cast<QQuickScrollViewPrivate *>(prop->data);
     if (!p->flickable)
-        p->setFlickable(qobject_cast<QQuickFlickable *>(item), true);
+        p->setFlickable(qobject_cast<QQuickFlickable *>(item), ContentItemFlag::Set);
 
-    QQuickFlickable *flickable = p->ensureFlickable(true);
+    QQuickFlickable *flickable = p->ensureFlickable(ContentItemFlag::Set);
     Q_ASSERT(flickable);
+    // Add the item that was declared as a child of us as a child item of the Flickable's contentItem.
     QQmlListProperty<QQuickItem> children = flickable->flickableChildren();
     children.append(&children, item);
 }
@@ -406,6 +496,48 @@ QQuickScrollView::QQuickScrollView(QQuickItem *parent)
     setWheelEnabled(true);
 }
 
+QQuickScrollView::~QQuickScrollView()
+{
+    Q_D(QQuickScrollView);
+    QQuickScrollBarAttached *attached = qobject_cast<QQuickScrollBarAttached *>(qmlAttachedPropertiesObject<QQuickScrollBar>(this, false));
+    if (attached) {
+        auto *scrollBar = QQuickScrollBarAttachedPrivate::get(attached);
+        d->disconnectScrollBarSignals(scrollBar);
+    }
+}
+
+/*!
+    \qmlproperty real QtQuick.Controls::ScrollView::effectiveScrollBarWidth
+    \since 6.6
+
+    This property holds the effective width of the vertical scrollbar.
+    When the scrollbar policy is \c QQuickScrollBar::AlwaysOff or the scrollbar
+    is not visible, this property is \c 0.
+
+    \sa {ScrollBar::policy}
+*/
+qreal QQuickScrollView::effectiveScrollBarWidth()
+{
+    Q_D(QQuickScrollView);
+    return d->effectiveScrollBarWidth;
+}
+
+/*!
+    \qmlproperty real QtQuick.Controls::ScrollView::effectiveScrollBarHeight
+    \since 6.6
+
+    This property holds the effective height of the horizontal scrollbar.
+    When the scrollbar policy is \c QQuickScrollBar::AlwaysOff or the scrollbar
+    is not visible, this property is \c 0.
+
+    \sa {ScrollBar::policy}
+*/
+qreal QQuickScrollView::effectiveScrollBarHeight()
+{
+    Q_D(QQuickScrollView);
+    return d->effectiveScrollBarHeight;
+}
+
 /*!
     \qmlproperty list<QtObject> QtQuick.Controls::ScrollView::contentData
     \qmldefault
@@ -543,7 +675,7 @@ void QQuickScrollView::componentComplete()
     Q_D(QQuickScrollView);
     QQuickPane::componentComplete();
     if (!d->contentItem)
-        d->ensureFlickable(true);
+        d->ensureFlickable(QQuickScrollViewPrivate::ContentItemFlag::Set);
 }
 
 void QQuickScrollView::contentItemChange(QQuickItem *newItem, QQuickItem *oldItem)
@@ -557,7 +689,25 @@ void QQuickScrollView::contentItemChange(QQuickItem *newItem, QQuickItem *oldIte
         auto newItemAsFlickable = qobject_cast<QQuickFlickable *>(newItem);
         if (newItem && !newItemAsFlickable)
             qmlWarning(this) << "ScrollView only supports Flickable types as its contentItem";
-        d->setFlickable(newItemAsFlickable, false);
+        // This is called by QQuickControlPrivate::setContentItem_helper, so no need to
+        // try to set it as the contentItem.
+        d->setFlickable(newItemAsFlickable, QQuickScrollViewPrivate::ContentItemFlag::DoNotSet);
+        // We do, however, need to set us as its parent item, as setContentItem_helper will only
+        // do so if the item doesn't already have a parent. If newItem wasn't declared as our
+        // child and was instead imperatively assigned, it may already have a parent item,
+        // which we'll need to override.
+        if (newItem) {
+            newItem->setParentItem(this);
+
+            // Make sure that the scroll bars are stacked in front of the flickable,
+            // otherwise events won't get through to them.
+            QQuickScrollBar *verticalBar = d->verticalScrollBar();
+            if (verticalBar)
+                verticalBar->stackAfter(newItem);
+            QQuickScrollBar *horizontalBar = d->horizontalScrollBar();
+            if (horizontalBar)
+                horizontalBar->stackAfter(newItem);
+        }
     }
     QQuickPane::contentItemChange(newItem, oldItem);
 }
@@ -573,10 +723,14 @@ void QQuickScrollView::contentSizeChange(const QSizeF &newSize, const QSizeF &ol
         // exception is if the application has assigned a content size
         // directly to the scrollview, which will then win even if the
         // application has assigned something else to the flickable.
-        if (d->hasContentWidth || !d->flickableHasExplicitContentWidth)
+        if (d->hasContentWidth || !d->flickableHasExplicitContentWidth) {
             d->flickable->setContentWidth(newSize.width());
-        if (d->hasContentHeight || !d->flickableHasExplicitContentHeight)
+            d->updateScrollBarWidth();
+        }
+        if (d->hasContentHeight || !d->flickableHasExplicitContentHeight) {
             d->flickable->setContentHeight(newSize.height());
+            d->updateScrollBarHeight();
+        }
     }
 }