MouseDown プロパティ (TabClientEvents)

// The client event MouseDown takes two parameters sender and e
// sender  is the object which is raising the event
// e is the TabMouseEventArgs

function WebTab1_MouseDown(sender, e) {

    var tab = sender;

    //Gets the index of the tab involved in the MouseDown event
    var tabIndex = e.get_tabIndex();

    //Gets index of scroll button involved in mouse event. 
    //Possible values: 0 - right or top scroll button, 1 - left or bottom scroll button,
    // -1 - it is event over tab item or add-new-tab button
    var scrollButtonIndex = e.get_scrollButtonIndex();

    //Assuming you have a label called labelOutput on the form
    var label = $get('labelOutput');


    if (e.isAddNewTabButton()) {

        label.innerHTML = "Mouse down on add new tab button";
    }
    else if (e.isCloseButton()) {
        label.innerHTML = "Mouse down on close button with tab index" + tabIndex;
    }
    else
        if (tabIndex != -1) {

        label.innerHTML = "Mouse down on the tab with index '" + tabIndex + "'";
    }
    else {

        if (scrollButtonIndex == 0) {
            label.innerHTML = "Mouse down on the right scroll button";
        }
        else
            label.innerHTML = "Mouse down on the left scroll button";
    }  

}