EffectComposer: Show scrollbar on show more error view

Fixes: QDS-14238
Change-Id: I5f352b224ead4745100180c724b5e6270a68cea7
Reviewed-by: Mahmoud Badri <mahmoud.badri@qt.io>

share/qtcreator/qmldesigner/effectComposerQmlSources/PreviewError.qml

@@ -37,26 +37,21 @@ Rectangle {
         }
     }
 
-    MouseArea {
-        id: errorMouseArea
-
-        hoverEnabled: true
-        acceptedButtons: Qt.NoButton
-        anchors.fill: parent
-
     HelperWidgets.Button {
+        id: showLessButton
+
         width: 100
         height: 30
         text: qsTr("Show Less")
         visible: root.showErrorDetails
-            opacity: errorMouseArea.containsMouse ? 1 : 0.3
+        opacity: scrollView.hovered || showLessButton.hovered ? 1 : 0.3
         anchors.right: parent.right
         anchors.bottom: parent.bottom
-            anchors.margins: 4
+        anchors.bottomMargin: 8
+        anchors.rightMargin: 8 + StudioTheme.Values.scrollBarThicknessHover
 
         onClicked: root.showErrorDetails = false
     }
-    }
 
     Column {
         anchors.centerIn: parent

share/qtcreator/qmldesigner/propertyEditorQmlSources/imports/HelperWidgets/ScrollView.qml

@@ -15,7 +15,6 @@ Flickable {
     readonly property bool horizontalScrollBarVisible: horizontalScrollBar.scrollBarVisible
     readonly property bool bothVisible: flickable.verticalScrollBarVisible
                                         && flickable.horizontalScrollBarVisible
-
     property bool hideVerticalScrollBar: false
     property bool hideHorizontalScrollBar: false
 
@@ -24,6 +23,8 @@ Flickable {
     default property alias content: areaItem.children
 
     property bool adsFocus: false
+    property alias hovered: hoverHandler.hovered
+
     // objectName is used by the dock widget to find this particular ScrollView
     // and set the ads focus on it.
     objectName: "__mainSrollView"