Sharing data across QML files (properties) - qt

Question

I am writing an App and I already managed to resolve some issues, with the latest one being the Screen.Width/Height for adjusting the window size dynamically on different monitors (I use laptop, phone, PC, it's simply convenient).
To write the code efficiently and nicely, I want to obtain that specific information and put it into a single set of 2 "variables", that would then hold this information.
I tried assigning the ApplicationWindow object an id: mainWindow, in order to call upon it from a different QML file, to obtain the property value as:
mainWindow.height, mainWindow.width
I then was told to use another approach, custom QML properties, that are declared like:
property (type) (name): (value)
I then followed the advice and declared those properties in Main.qml (with AppWindow) and it does work. The properties of AppWindow (ApplicationWindow) contain the width and height of the Screen multiplied by a specific coefficient.
Then those variables are accessed by the object itself, drawing the App Window as I want it to be.
The problem is that this approach was meant to solve the issue of sharing code across .QML files, and it doesn't
[go down]
ApplicationWindow {
id: mainWindow
//Wide screen support
//Screen.desktopAvailableWidth / 4
//Screen.desktopAvailableHeight / 6
//The below is monitor cross-compatible (phone, PC, laptop)
property int globalWidth: Screen.width / 2
property int globalHeight: Screen.height / 3
width: globalWidth
height: globalHeight
visible: true
title: qsTr("Redacted")
//setWindowIcon(QIcon(":/path/to/icon.png"));
The piece of code below resides in main.qml. It is called upon from that file. Just ignoring the IDs (IDs supposedly [as stated by users/docs] can't be accessed outside of local scope...), the properties (especially custom properties) should be accessible inside Page1, Page2, Page3 etc.
SwipeView {
id: swipeView
anchors.fill: parent
currentIndex: tabBar.currentIndex
Page1Form {
}
Page2Form {
}
Page3Form {
}
}
The below is the Page2Form.qml file that is called upon (as class definition) in main.qml.
The properties declared in parent objects in main.qml (imo) should be inherited by child objects (imo).
Page {
id: localPage2
width: globalWidth
height: globalHeight
Rectangle {
id: rectangle
x: (localPage2.width / 2) - (width / 2)
y: (localPage2.height / 4) - (height / 2)
width: localPage2.width / 3
height: localPage2.height / 6
color: "#ffffff"
border.color: "#a45c5c"
border.width: 2
TextInput {
id: textInput
x: 0
y: 0
width: localPage2.width / 3
height: localPage2.height / 6
text: qsTr("Redacted")
font.pixelSize: 12
horizontalAlignment: Text.AlignHCenter
verticalAlignment: Text.AlignVCenter
font.weight: Font.Normal
focus: true
}
}
Ok, so what is the problem?
I can try calling those properties as:
mainWindow.globalHeight
globalHeight
mainWindow.height
etc.
They won't be accessed. The form editor will provide me preview of Page object that has 0 size.
The page does render eventually (when compiled and ran), but there is an issue in passing (accessing) the value of that property.
As you can notice, both IDs and custom properties seem to work just fine locally.
Update:
I haven't fixed that issue, I also tried using aliases (references) and the "foreign" QML file will still fail to be assigned proper size (Page width and height).
I then put another custom property of string type with some text in it, I then managed to access that property in Page2.qml and the property is originally in main.qml.
It's bugged, or I have no idea what it is.
I tried 3 approaches:
ID (it's not global as it turns out)
Custom property (kind of works, just not with Screen size...)
Aliases on object's default properties
(property alias globalWidth: mainWindow.width
property alias globalHeight: mainWindow.height)