How to threading data in app?

[tanthinh1510]

Hi all!
I created simple app as picture below
threading.png
code in file main.qml

import QtQuick 2.3
import QtQuick.Controls 1.2
 
ApplicationWindow {
    visible: true
    width: 640
    height: 480
Rectangle{
    color: "red"
    width: 100
    height: 100
    anchors.centerIn: parent
    Timer{
       interval: 30
       running: true
       repeat: true
       onTriggered: {
            _processdata.calculator()
       }
    }
}
}

import QtQuick 2.3
import QtQuick.Controls 1.2

ApplicationWindow {
    visible: true
    width: 640
    height: 480
Rectangle{
    color: "red"
    width: 100
    height: 100
    anchors.centerIn: parent
    Timer{
       interval: 30
       running: true
       repeat: true
       onTriggered: {
            _processdata.calculator()
       }
    }
}
}

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I have one component is a rectangle. In rectangle have timer and 30ms it Triggered to call function _processdata.calculator() from class C++
It's works fine if I put less rectangle(1- 100 rectangle). But I put about 500 - 1000 rectangle in my app, It became slow and when I move app, it is shaking shock
Cause is all rectangle call function _processdata.calculator() time.
How to it works fine when I put 500 - 1000 rectangle in my app? Please help me!