Is it a good idea to use tree-view UI structure in iPhone or other Mobile devices? (e.g. for file browsing etc.)
Tree navigations is a simple and effective solution to discover hierarchical structures. I would test two different solutions.
- Accordion: http://ui-patterns.com/patterns/AccordionMenu
- Drilldown lists: http://mobile-patterns.com/lists
Accordions work if you have flat hierarchies (e.g. one sub level). They keep the user in context and you don't have to remember the other category names since you stay in the screen. The handler for open/collapse the category shouldn't be a small button, but the whole list item instead.
Lists are pretty ease to use and fits perfectly if you have to use multiple sublevels. The following items you should provide for smooth content discovery within subs:
- header with title of the current category
- shortcut which takes you to the top level in the hierarchy
- backup which takes you one level up
From an interaction pov, the main challenge is that browsing trees requires a lot of scrolling up and down to re-find items. Also from an information architecture point of view it might be not the most efficient system to organize information. User has to know in which category the object-to-find is hiding. At least there should be a category specific search. To increase flexibility and improve findability I would also combine it with a tagging system.
The NestView method for representing a text hierarchy (specifically xml) came up as an answer on a programmers.stackexchange question. This is quite 'out there', but it does save a fair amount of horizontal space, compared to either a tree-view or indented text. It also has the benefit of having a larger 'touch area' than a tree-view, it could possibly also suit more general usage than just hierarchical text structures: