I have a really long UIWebView, and I need to add a way for the user to tap the UINavigationBar to scroll to top (something like the Facebook app, where it's little glow when you tap).
How can I do this?
A:
First, you could create a custom view for the titleView of your UINavigationItem that handles the touch events.
Second, I'm a little more hazy on, but it would appear that getting a UIWebView to scroll to the top of its contents is a bit harder than with a UITableView (UIWebView does not inherit from UIScrollView). There has been some discussion about it in this question http://stackoverflow.com/questions/1361614/iphone-os-tap-status-bar-to-scroll-to-top-doesnt-work-after-remove-add-back. However, the proposed solution:
((UIScrollView *)[[webView valueForKey:@"_internal"] valueForKey:@"scroller"]).scrollsToTop = NO;
may violate the new static checking that Apple is doing on apps.
lyonanderson
2009-12-06 18:50:34
Highly possibility that the could reject your app for using the private API's
nduplessis
2009-12-06 20:04:11
Agreed. You almost certainly would. However, I think the first part of my answer is ok.
lyonanderson
2009-12-06 20:42:05
A:
You could use javascript to scroll the web view to the top. You could execute the javascript from the Objective-C side using
- (NSString *)stringByEvaluatingJavaScriptFromString:(NSString *)script
nduplessis
2009-12-06 20:03:31
Actually that I knew, what I'm mainly struggling with is how I can make it do that when I tap the UINavigationBar?
mofle
2009-12-06 20:38:35
As lyonanderson said, you could create a custom titleView for your navigation bar to handle the touch events and execute the javascript in your webView
nduplessis
2009-12-06 21:51:27
Alternatively you could add a UINavigationBar category which overrides the touches methods to integrate your custom code to talk to the webView
nduplessis
2009-12-06 21:54:30