Move your object creation code into a separate Timer with a small interval, and rather than creating all of the objects at once, create them maybe 50 at a time every 25 MS or something.
This will allow for the main event loop to process other things like the animations for busy indicator while its loading.
Here's one way to go about implementing this
import QtQuick 2.12
import QtQuick.Window 2.12
import QtQuick.Controls 2.3
Window {
property int pbValue: 0
visible: true
width: 500
height: 400
title: qsTr("Hello World")
Rectangle {
id: mySplashScreen
anchors.fill: parent
ProgressBar {
// changed handling of progress bar
id: pBar
height: 20
width: parent.width
anchors.bottom: parent.bottom
from: 0
value: compList.length // bind this value
to: 15000
}
BusyIndicator {
anchors.right: parent.right
running: (pbValue < pBar.to + 1)
}
Button {
text: "click me"
onClicked: {
timer.running = true
}
}
}
property var compList: [] // created property to store all created components to track what has been done
Timer {
id: timer
interval: 25
running: false
repeat: true
onTriggered: {
for (var i = 0; i < 50; i++) {
var comp = mycomp.createObject(mySplashScreen) // moved component into timer
compList.push(comp) // added component to huge list of components for tracking
}
pbValue = compList.length
if ((pbValue >= 15000)) {
timer.running = false
console.log("All components completed")
}
}
}
Component {
id: mycomp
Rectangle {
width: 200
height: 200
color: "green"
}
}
}
As for me I guess its bad idea to overwrite system behavior of controls.
Anyway, you can play with animated gradient. For example:
<!-- language: lang-js -->
ProgressBar {
id: control
anchors.centerIn: parent
value: 0
height: 20
clip: true
background: Rectangle {
implicitWidth: 200
implicitHeight: 6
border.color: "#999999"
radius: 5
}
contentItem: Item {
implicitWidth: 200
implicitHeight: 4
Rectangle {
id: bar
width: control.visualPosition * parent.width
height: parent.height
radius: 5
}
LinearGradient {
anchors.fill: bar
start: Qt.point(0, 0)
end: Qt.point(bar.width, 0)
source: bar
gradient: Gradient {
GradientStop { position: 0.0; color: "#17a81a" }
GradientStop { id: grad; position: 0.5; color: Qt.lighter("#17a81a", 2) }
GradientStop { position: 1.0; color: "#17a81a" }
}
PropertyAnimation {
target: grad
property: "position"
from: 0.1
to: 0.9
duration: 1000
running: true
loops: Animation.Infinite
}
}
LinearGradient {
anchors.fill: bar
start: Qt.point(0, 0)
end: Qt.point(0, bar.height)
source: bar
gradient: Gradient {
GradientStop { position: 0.0; color: Qt.rgba(0,0,0,0) }
GradientStop { position: 0.5; color: Qt.rgba(1,1,1,0.3) }
GradientStop { position: 1.0; color: Qt.rgba(0,0,0,0.05) }
}
}
}
PropertyAnimation {
target: control
property: "value"
from: 0
to: 1
duration: 5000
running: true
loops: Animation.Infinite
}
}