Communication between QML files

QGroundControl
1

I am working on qgroundcontrol and I want a tab to open when my button is hovered over. I created my view in flyview.qml. The operations to be performed are in flyviewtoolbar.qml. When I run the application, my view does not appear. Why?
//flyviewtoolbar.qml
Rectangle {
id: button
property color baseColor: “purple”
anchors.right: parent.right
width: textItem.implicitWidth+10
height:parent.height
color:if (buttonMouseArea.containsPress){
return Qt.darker(baseColor)
}else if(buttonMouseArea.containsMouse)
{
return Qt.lighter(baseColor)
}else
{
return baseColor}

            Text{
            id:textItem
            text:"RTSP Url change"
            color: "white"

            anchors.centerIn: parent}


            MouseArea {
                property bool isActive:false
                property string oldAltitude:rtspUrl +"554/"+"screen=1"
                property string newAltitude:rtspUrl + "555/"+"screen=2"

                id: buttonMouseArea
                anchors.fill: parent
                hoverEnabled: true
                onClicked:{
                    isActive = !isActive;
                    buttonClicked()
                    console.log("Button clicked!")
                    if(isActive){
                      _videoSettings.rtspUrl.rawValue = newAltitude;
                    }else{
                         _videoSettings.rtspUrl.rawValue = oldAltitude;
                    }
                }
                onEntered: {
                    rstpWidget.visible=true;
                    console.log("rstpWidget visible: ", rstpWidget.visible);
                }
                onExited: {
                    rstpWidget.visible=false;
                    console.log("rstpWidget visible: ", rstpWidget.visible);
                 }
            }
        }
}
signal buttonClicked()

//flyview.qml
Rectangle{
id:rstpWidget
width: 200
height: 100
color:“gray”
visible:false
anchors.top:toolbar.bottom
anchors.left:parent.left

    Text {
               anchors.centerIn: parent
               text: "RTSP Info"
               color: "white"
           }
}