Intercepting mouse events on an iPad

In the last post we saw how we could easily work with mouse events on an iPad. Touchscreen devices like the iPad do not have a cursor, so the user cannot exactly move the mouse over an HTML element triggering a ‘mouseover’ event. One of the readers requested on how we could use a different interaction pattern on an iPad for a ‘mouseover’ event than on a desktop browser. For example in the following web page code the image-container class is attached to images div which displays a preview link overlay on mouseover.

$('.image-container').live('mouseover', function(){
     $(this).children('div').attr('class', 'image-info-active');
});

Obviously this will not work exactly on an iPad like it would on a desktop browser. The overlay will be displayed on a single tap, but will not disappear till we tap another clickable element. One different interaction pattern for the above example is to trigger the overlay on a touchstart event and remove the overlay after some delay. The first step however is to detect if the site is being viewed on an iPad using the browser user-agent string.

var isiPad = navigator.userAgent.match(/iPad/i) != null;

Later we can run the appropriate code depending the viewing device.

if(isiPad) 
{
    $('.image-container').live('touchstart', function(){
        $(this).children('div').delay(100).fadeIn();
        $(this).children('div').attr('class', 'image-info-active');
        $(this).children('div').delay(2000).fadeOut();
    });
}
else
{
    $('.image-container').live('mouseover', function(){
        $(this).children('div').attr('class', 'image-info-active');
    });
}

Now on an iPad the above code will ‘fadeIn’ the preview overlay once the image is touched and then ‘fadeOut’ after a delay. Of course you could try some different interaction pattern to make better use of the touch capabilities of a tablet.