Sunday, August 11, 2013

mice, scrollbars and lazy loading don't mix

If you're designing for a platform that allows user input in multiple forms you must account for all the forms of user input at each time.

Let's consider what happens if you've got a list that the app will add more to it when the user gets near to the end.
For example, imagine a list that starts with 20 items and when the user gets 5 from the end it loads 10 more. If the app can always load more this will go on forever or maybe it only does this until it can load no more.
Now consider a non-touch screen device--there are still a lot of them around.  To scroll the list the user uses their mouse and drags the scrollbar.
Considering the above, if the user drags the scrollbar 75% of the way down we reach the magic trigger value. Let's say the user hovers at this point to view the items at that position in the list. But then all of a sudden, without the user doing anything, the items on display have changed.

What happened?
  • The user was confused.
  • The user lost confidence in their ability to use the app.
  • The user lost confidence in the app.

Not feelings or reactions you should want to create in your users. Well, not if you want them to come back and use your app again, leave positive reviews or recommend it to others.

What happened technically?
After the additional items had been added to the list, it changed from showing the items 75% of the way through 20 items to be showing the items at 75% through 30 items. Depending on how many items are visible at once this might mean that the items that were on display are now completely gone.

If you have an app that incorporates lazy loading, I'd recommend implementing an alternative way of allowing a user to interact with the list than just dragging the scrollbar if using a mouse.


  1. Anonymous5:49 am

    Every Omega Seamaster 300m in addition to Rolex Submariner are usually magnificent replica watches uk timepieces which have the particular seal of approval related to beauty, professional in addition to position. When you would like the actual budget-friendly inexpensive rolex replica look out for casual placed on, these kinds of are not to suit your needs. Nevertheless when you would like something which might enhance your personal cultural standing in addition to provide you with a trendy page, they're the most effective recommendations. Regarding accumulating more info concerning 2 superb guys timepieces for example Omega Seamaster 300m in addition to Rolex Submariner, be sure you check out these kinds of back links. omega replica uk Look at Business setup inside 1918, are actually generating top quality timepieces for nearly a hundred years at this time. rolex replica uk timepieces have supplied most of us wonderful timepieces over the last millennium. Resident timepieces have always been related to outstanding designs in addition to best. Their very own tag heuer replica timepieces are actually connected together with durability in addition to design. Few of the amazing operates related to Resident Timepieces are actually analyzed under.

  2. This comment has been removed by the author.