opacity

opacity : real
This property holds the opacity of the item. Opacity is specified as a number between 0.0 (fully transparent) and 1.0 (fully opaque). The default value is 1.0.

When this property is set, the specified opacity is also applied individually to child items. This may have an unintended effect in some circumstances. For example in the second set of rectangles below, the red rectangle has specified an opacity of 0.5, which affects the opacity of its blue child rectangle even though the child has not specified an opacity.

Item {
Rectangle {
color: "red"
width: 100; height: 100
Rectangle {
color: "blue"
x: 50; y: 50; width: 100; height: 100
}
}
}

Item {
Rectangle {
opacity: 0.5
color: "red"
width: 100; height: 100
Rectangle {
color: "blue"
x: 50; y: 50; width: 100; height: 100
}
}
}