QML ERROR :invalid property name minX (M16)

Question

i Am using Qt 5.12.8 , i have imported

import QtQml.Models 2.2 
import QtQuick 2.7 
import QtQuick.Controls 2.2 
import QtQuick.Layouts 1.3 

but i get this error :invalid property name minX (M16) . Can some one guide me what is my mistake!!

NewWindow {
    id: newWindow
    visible: !privateVars.isLoading && !privateVars.isEditing
    x: (maxX-minX)/2
    y: (maxY-minY)/2
    minX: -parent.x        //ERROR invalid property name minX (M16)
    maxX: monitor.width - width - parent.x - additionalToolbarRightMargin -25 //ERROR invalid property name maxX (M16)
    minY: -parent.y    //ERROR invalid property name minY (M16)
    maxY: monitor.height - height -parent.y  //ERROR invalid property name maxY (M16)
    onLoadClicked: privateVars.isLoading = true
    //selectedMissionInstance: loadMissionWindow.selectedMissionInstance
    onNewClicked:
    {
        //Create new mission in missionmodel and go to edit view
        missionPlanningModel.newMissionClicked()
        privateVars.isEditing = true
    }
}

Answer 1

I guess you want to make a variables minX/minY/etc for NewWindow, not to set a value for existing ones. If that's so you should declare it. Like that:

NewWindow {
    id: newWindow
    visible: !privateVars.isLoading && !privateVars.isEditing
    x: (maxX-minX)/2
    y: (maxY-minY)/2
    property int minX: -parent.x     //Now it's not firing an error
    property int maxX: monitor.width - width - parent.x - additionalToolbarRightMargin -25 
    property int minY: -parent.y   
    property int maxY: monitor.height - height -parent.y maxY (M16)
    onLoadClicked: privateVars.isLoading = true
    //selectedMissionInstance: loadMissionWindow.selectedMissionInstance
    onNewClicked:
    {
        //Create new mission in missionmodel and go to edit view
        missionPlanningModel.newMissionClicked()
        privateVars.isEditing = true
    }
}