Fix visualSize calculation when width is changing

Position of the ScrollBar handle is fixed when it's being resized except
when it's on the extreme side (position + size = 1). In this case, when
the width is growing, the handle size should grow and the position
should decrease as a result.

Fixes: QTBUG-98387
Change-Id: Ibb18c03a741bb4e5a19425a57f14a68d27d68d12
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>

4 files changed, 68 insertions, 7 deletions

diff --git a/src/quicktemplates2/qquickscrollbar.cpp b/src/quicktemplates2/qquickscrollbar.cpp
index 9858ad1f38..9397f098d2 100644
--- a/src/quicktemplates2/qquickscrollbar.cpp
+++ b/src/quicktemplates2/qquickscrollbar.cpp
@@ -169,10 +169,12 @@ QQuickScrollBarPrivate::VisualArea QQuickScrollBarPrivate::visualArea() const
     if (minimumSize > size && size != 1.0)
         visualPos = position / (1.0 - size) * (1.0 - minimumSize);
 
-    qreal visualSize = qBound<qreal>(0, qMax(size, minimumSize) + qMin<qreal>(0, visualPos),
-                                     qMax(0.0, 1.0 - visualPos));
+    qreal maximumSize = qMax<qreal>(0.0, 1.0 - visualPos);
+    qreal visualSize =  qMax<qreal>(minimumSize,
+                                    qMin<qreal>(qMax(size, minimumSize) + qMin<qreal>(0, visualPos),
+                                                maximumSize));
 
-    visualPos = qBound<qreal>(0, visualPos, qMax<qreal>(0, 1.0 - visualSize));
+    visualPos = qMax<qreal>(0,qMin<qreal>(visualPos,qMax<qreal>(0, 1.0 - visualSize)));
 
     return VisualArea(visualPos, visualSize);
 }
@@ -333,7 +335,7 @@ bool QQuickScrollBarPrivate::handleMove(const QPointF &point, ulong timestamp)
     if (!pressed)
         return true;
 
-    qreal pos = qBound<qreal>(0.0, positionAt(point) - offset, 1.0 - size);
+    qreal pos = qMax<qreal>(0.0, qMin<qreal>(positionAt(point) - offset, 1.0 - size));
     if (snapMode == QQuickScrollBar::SnapAlways)
         pos = snapPosition(pos);
     q->setPosition(pos);
@@ -353,7 +355,7 @@ bool QQuickScrollBarPrivate::handleRelease(const QPointF &point, ulong timestamp
             return true;
     }
 
-    qreal pos = qBound<qreal>(0.0, positionAt(point) - offset, 1.0 - size);
+    qreal pos = qMax<qreal>(0.0, qMin<qreal>(positionAt(point) - offset, 1.0 - size));
     if (snapMode != QQuickScrollBar::NoSnap)
         pos = snapPosition(pos);
     q->setPosition(pos);
@@ -446,6 +448,12 @@ void QQuickScrollBar::setSize(qreal size)
     d->size = size;
 
     auto oldVisualArea = d->visualArea();
+    d->size = qBound(0.0, size, 1.0);
+    if (d->size + d->position > 1.0) {
+        setPosition(1.0 - d->size);
+        oldVisualArea = d->visualArea();
+    }
+
     if (isComponentComplete())
         d->resizeContent();
     emit sizeChanged();
diff --git a/src/quicktemplates2/qquickscrollindicator.cpp b/src/quicktemplates2/qquickscrollindicator.cpp
index 7f83f36813..918f7db86d 100644
--- a/src/quicktemplates2/qquickscrollindicator.cpp
+++ b/src/quicktemplates2/qquickscrollindicator.cpp
@@ -163,9 +163,12 @@ QQuickScrollIndicatorPrivate::VisualArea QQuickScrollIndicatorPrivate::visualAre
     if (minimumSize > size)
         visualPos = position / (1.0 - size) * (1.0 - minimumSize);
 
-    qreal visualSize = qBound<qreal>(0, qMax(size, minimumSize) + qMin<qreal>(0, visualPos), 1.0 - visualPos);
+    qreal maximumSize = qMax<qreal>(0.0, 1.0 - visualPos);
+    qreal visualSize =  qMax<qreal>(minimumSize,
+                                    qMin<qreal>(qMax(size, minimumSize) + qMin<qreal>(0, visualPos),
+                                                maximumSize));
 
-    visualPos = qBound<qreal>(0, visualPos, 1.0 - visualSize);
+    visualPos = qMax<qreal>(0,qMin<qreal>(visualPos,qMax<qreal>(0, 1.0 - visualSize)));
 
     return VisualArea(visualPos, visualSize);
 }
@@ -234,6 +237,10 @@ void QQuickScrollIndicator::setSize(qreal size)
 
     auto oldVisualArea = d->visualArea();
     d->size = size;
+    if (d->size + d->position > 1.0) {
+        setPosition(1.0 - d->size);
+        oldVisualArea = d->visualArea();
+    }
     if (isComponentComplete())
         d->resizeContent();
     emit sizeChanged();
diff --git a/tests/auto/quickcontrols2/controls/data/tst_scrollbar.qml b/tests/auto/quickcontrols2/controls/data/tst_scrollbar.qml
index d453f017e7..9e3f8e31d9 100644
--- a/tests/auto/quickcontrols2/controls/data/tst_scrollbar.qml
+++ b/tests/auto/quickcontrols2/controls/data/tst_scrollbar.qml
@@ -965,6 +965,29 @@ TestCase {
         compare(vertical.contentItem.y, vertical.topPadding + 0.2 * vertical.availableHeight)
     }
 
+    function test_resize() {
+        var vertical = createTemporaryObject(scrollBar, testCase, { height:200, orientation: Qt.Vertical, size: 0.5, position: 0.5 })
+        verify(vertical)
+
+        vertical.size = 0.8
+        compare(vertical.position, 0.2)
+        compare(vertical.visualPosition, 0.2)
+        vertical.size = 0.5
+        compare(vertical.position, 0.2)
+        compare(vertical.visualPosition, 0.2)
+
+
+        var horizontal = createTemporaryObject(scrollBar, testCase, { width:200, orientation: Qt.Horizontal, size: 0.5, position: 0.5 })
+        verify(horizontal)
+
+        horizontal.size = 0.8
+        compare(horizontal.position, 0.2)
+        compare(horizontal.visualPosition, 0.2)
+        horizontal.size = 0.5
+        compare(horizontal.position, 0.2)
+        compare(horizontal.visualPosition, 0.2)
+    }
+
     function test_setting_invalid_property_values() {
         var control = createTemporaryObject(scrollBar, testCase, {size: 2.0, minimumSize: -1.0})
         verify(control)
diff --git a/tests/auto/quickcontrols2/controls/data/tst_scrollindicator.qml b/tests/auto/quickcontrols2/controls/data/tst_scrollindicator.qml
index 363048c0bd..672b349719 100644
--- a/tests/auto/quickcontrols2/controls/data/tst_scrollindicator.qml
+++ b/tests/auto/quickcontrols2/controls/data/tst_scrollindicator.qml
@@ -306,4 +306,27 @@ TestCase {
         compare(vertical.visualPosition, 0.2)
         compare(vertical.contentItem.y, vertical.topPadding + 0.2 * vertical.availableHeight)
     }
+
+    function test_resize() {
+        var vertical = createTemporaryObject(scrollIndicator, testCase, { height:200, orientation: Qt.Vertical, size: 0.5, position: 0.5 })
+        verify(vertical)
+
+        vertical.size = 0.8
+        compare(vertical.position, 0.2)
+        compare(vertical.visualPosition, 0.2)
+        vertical.size = 0.5
+        compare(vertical.position, 0.2)
+        compare(vertical.visualPosition, 0.2)
+
+
+        var horizontal = createTemporaryObject(scrollIndicator, testCase, { width:200, orientation: Qt.Horizontal, size: 0.5, position: 0.5 })
+        verify(horizontal)
+
+        horizontal.size = 0.8
+        compare(horizontal.position, 0.2)
+        compare(horizontal.visualPosition, 0.2)
+        horizontal.size = 0.5
+        compare(horizontal.position, 0.2)
+        compare(horizontal.visualPosition, 0.2)
+    }
 }