How to refresh a UIWebView by a "pull down and release" gesture?

Question

I know that this is possible in the Tweetie for iPhone or the xkcd iPhone app, but they are using a table. Any idea if this can be done for a simple UIWebView as well? I'm aware of the Javascript suggestions in this SO question, but what about making that natively?

Spannew

Answer 1

FYI, iOS 5 has officially introduced the property scrollView in UIWebView. I tested it. It worked perfectly with EGO's pull and refresh code. So the problem is no longer a problem for any iOS 5 devices.

For downward compatibility, you still need @CedricSoubrie's code though.

Unfriended

Answer 2

To retrieve scroll events on UIWebView I personnaly use this code to get the scrollview that is inside the UIWebView :

- (void) addScrollViewListener
{
    UIScrollView* currentScrollView;
    for (UIView* subView in self.myWebView.subviews) {
         if ([subView isKindOfClass:[UIScrollView class]]) {
            currentScrollView = (UIScrollView*)subView;
            currentScrollView.delegate = self;
        }
    }
}

It's working. You can also use it to call [(UIScrollView*)subView setContentOffset:offSet animated:YES]; The only problem may be not to pass Apple code checking. I don't know yet since I'm still in coding phase.

Anyone tried that yet ?

Buckwheat

I know from a certain developer that she has passed the approval process whilst having something like this in the code, for removing the UIWebView shadows (you'd have to get the UIScrollView for that as well) – Approval

Works like charm! (Though I didn't submit my app to App Store yet) – Unfriended

Beware, this code doesn't work in iOS 5 because the scrollView of the webView class changed. Use this code instead : if ([subView isKindOfClass:[UIScrollView class]]) I changed my original post so the code is compatible with iOS 5 – Buckwheat

Answer 3

To get a reference for the UIScrollView in UIWebView, simply search it by iterating trough subviews.

for(id eachSubview in [webView subviews]){
        if ([eachSubview isKindOfClass:[UIScrollView class]]){
            scrollView = eachSubview;
            break;
        }
}

After that you can easily wire up things to your EGORefreshTableHeaderView interface with the UIWebView and the UIScrollView delegate callbacks.

Laurettelauri

Answer 4

To tell the truth, UIWebVIew class has an undocumented getter method called _scrollView; So the code goes:

scrollView = [webView _scrollView];

Laurettelauri

Doing things this way is using a "private API". If you use CedricSoubrie's method above, you are using only public methods. – Perry