main.qml

import QtQuick 2.3
import "Classes" as Class

Item {
	width: 600
	height: 800

	Class.Pcd {
		id: personalDesktop
	}

	MouseArea {
		anchors.fill: parent
		onClicked: personalDesktop.startPcdCall()
	}
}

Pcd.qml

// Classes/Pcd.qml
import QtQuick 2.3

Rectangle {
	color: "red"
	implicitWidth: 200
	implicitHeight: 200

	function startPcdCall() {
		console.log("startPcdCall function called...");
	}
}