Column Layout Height and Implicit Height

code_guri

I trying to build a small window using column layout. It has rectangles with conditional visibility.

ColumnLayout{
        id : mainLayout
        anchors.margins: 5
        anchors.fill: parent        
		
        Rectangle{
            Layout.preferredHeight: 160
            Layout.preferredWidth: 230
            visible: (imageListView.count == 0)           
        }
        Rectangle{
            Layout.preferredHeight: 160
            Layout.preferredWidth: 230
            visible: (docListView.count != 0)
        }
		
        Rectangle{
            Layout.preferredHeight: 160
            Layout.preferredWidth: 230
			visible: (urlListView.count != 0)
        }
     
    }

I am loading it using qml Loader. The first time a load it, its height and implicit height are different and position of this window on screen is not what I intend. When I close the window and load it again, All seems perfect. It's Position on window is right and implicit height and height are same.

There is no such issue if i don't use layout. Am I missing something ? Height and implicit height are not coming same.