Change implementation according to different platform

[stereomatching]

ex :

Rectangle{

android{
width: 320
height: 240
}

win32{
width: 640
height: 480
}

}

I remember I saw something like this before, but can't find it now(what keyword?).

[Vincent007]

"Overview of the new features in Qt Quick":http://blog.qt.digia.com/blog/2013/06/21/overview-of-the-new-features-in-qt-quick/

bq. Jens Bache-Wiig says:
June 21, 2013 at 22:26
Sure for instance:
anchors.margins: Qt.platform.os === "mac" ? 12 : 4
Alternatively you can use this in a loader to load different files based on platform.