Getting the Axis aligned Bound Box of an item is has transformations (rotation, scaling,...)

Flamaros

I need to find a way to retrieve the AABB of an item that works even if it has transformations applied.
I thought anchors was always AA, but left can look to bottom with a rotation of -45 degrees.

I need something precise to be able to place other elements correctly.

I tried with a component but it's not really easy to implement and there is a lot of hacks without success.

Flamaros

I got the solution, I just miss Rect are Axis Aligned so we can simply apply the item transformation to get the AABB :

AABB.qml
@
import QtQuick 2.1

Rectangle {
id: aabb
color: "#AAAAFF"

property real   childrenRotation: {
    if (children.length)
        return children[0].rotation
    else
        return false
}

property real   childrenScaling: {
    if (children.length)
        return children[0].scale
    else
        return false
}

onChildrenRotationChanged: update()
onChildrenScalingChanged: update()

function    update()
{
    var rect = mapFromItem(children[0], children[0].x, children[0].y, children[0].width, children[0].height)
    width = rect.width
    height = rect.height
}

}
@

main.qml (Center the child in the AABB component) :
@
import QtQuick 2.0

Rectangle {
width: 360
height: 360
AABB {
anchors.centerIn: parent

    Text {
        text: qsTr("Hello World")
        anchors.centerIn: parent
        transformOrigin: Item.Center

        SequentialAnimation on rotation {
            // Animations on properties start running by default
            running: true
            loops: Animation.Infinite // The animation is set to loop indefinitely
            NumberAnimation { from: 0; to: 359; duration: 50000 }
        }
        SequentialAnimation on scale {
            // Animations on properties start running by default
            running: true
            loops: Animation.Infinite // The animation is set to loop indefinitely
            NumberAnimation { from: 0.25; to: 4; duration: 50000 }
        }
    }
}
MouseArea {
    anchors.fill: parent
    onClicked: {
        Qt.quit();
    }
}

}
@