I write software for Windows, mobile phones and the web. All have different ways of organising a UI, this is some musings on them related to why (I think) the iPhone OS's UI is considered to be so "revolutionary".

 

First, a "standard" dialog for a Windows application (in this case, an RSS feed reader)...

 

 

This dialog follows the "usual" way of working on a PC - you select the item in question from the list and then choose an action from the ones available. Another way to have presented this would be to have the list the main body of the dialog and the buttons along the top in a toolbar. Either way there are some obvious "issues":

 

 

Here's the same dialog using a "context aware" approach:

 

 

Here we only have two buttons which apply to the task in hand - managing the feeds - we can close the dialog or add a new feed. Clicking a feed in the list will show a popup menu with the tasks that are only relevant to that action and are obviously related to it as the action resulted in them appearing. In this case it's obvious that the items in that menu relate only to that item.

 

This is, what I consider, to be the main "ease-of-use" feature of the iPhone's OS: the fact that everything you do is logically related to the action you took - there's no breaking of the context or disconnects - you don't click an email to select it then find the delete option - you either put it into the delete "state" then click a button on emails to delete them or show the email then click a "delete" item.

 

Now, people may complain that it takes longer, or takes more clicks to do something with this approach but with the improved logical flow of the task it makes things a) easier to use and b) allows more to be done in a smaller space (the reason on the iPhone). It also removes the need for so many buttons - you need a means to select an item and an "action" button - eg. up/down and fire or a touch screen and a means to go back (and possibly "home").

 

Another example. To edit this post I had to click the following buttons on the blog engine: "Posts" -> "Drafts" -> (this post's ID) -> "Edit Content". OK, that may have been 4 steps but then it's more logical than selecting a "drafts" folder from a list on the side, then selecting this post in the main list then clicking a toolbar button for "edit content". Each step had a "back" button taking me one step back up (eg. clicked the wrong post? click "Back" to go back to "Drafts" and click the right one) and a Home button for quickly returning to the start. And, importantly, this works on any internet connected device as all the actual work is done server side. Here's a picture of what it looks like (yes, I like the design...)

 

 

Things do seem to be going this way more often on the desktop these days - the removal of menu bars from IE and Firefox 4 and such.

 

Anyway, that's my comment. Put yours below - I'd be interested in hearing them...

 

 

The iPhone, Windows Phone 7 and other phones only present one application at a time - the screen is too small for much else. Much like the netbook I have - you can't do much without whatever you're doing being maximised.

 

In most cases when using an application it doesn't need to do anything when it's not being actively used - games, word processors etc - they only serve a purpose if you're doing something with them. These applications are obviously a perfect fit for the "one app at a time" system used - they save their state when told to shut down and restore it when started up again.

 

Some apps need to run in the background - music, email, im etc. But they don't need all the app to be running. When you're IM client is not being used it only needs to check for new IMs, it doesn't need the UI or processing to send messages or such.

 

There are two possible ways to overcome the problems. One only works for apps needing a periodic task, the other will work for all.