Abs Abs - 8 days ago 5
Objective-C Question

HTML Content fit in UIWebview without zooming out

I am making use of the

UIWebView
to render some HTML. However, although the width of my webview is 320 my HTML is still shown full width and can be scrolled horizontally.

I want to achieve the same thing the native mail application achieves which is it fits all content within that width without zooming out - how does the native mail application render HTML like this?

Update



I thought making use of the viewport meta tag will help, but I couldn't get this to work.

This is what is happening:

enter image description here

As you can see the content does not fit the device width. I've tried so many combinations of
viewport
meta tag. The below is an example of what happens when I try Martins suggestion.

Original HTML is can be found here.

The way this HTML is rendered by the native mail application is like so.

Answer

Here's what you do:

In your UI controller that owns the web view, make it a UIWebViewDelegate. Then where you set the URL to load, set the delegate as the controller:

NSString *urlAddress = @"http://dl.dropbox.com/u/50941418/2-build.html";
NSURL *url = [NSURL URLWithString:urlAddress];
NSURLRequest *requestObj = [NSURLRequest requestWithURL:url];
[webView loadRequest:requestObj];  
webView.delegate = self;

And finally implement the webViewDidFinishLoad: to correctly set the zoom level:

This option will applicable from iOS 5.0 and >

- (void)webViewDidFinishLoad:(UIWebView *)theWebView
{
  CGSize contentSize = theWebView.scrollView.contentSize;
  CGSize viewSize = theWebView.bounds.size;

  float rw = viewSize.width / contentSize.width;

  theWebView.scrollView.minimumZoomScale = rw;
  theWebView.scrollView.maximumZoomScale = rw;
  theWebView.scrollView.zoomScale = rw;  
}

I hope this helps...

Option B, you can try to alter the HTML (this example does the job but is less than perfect from an HTML parsing standpoint. I just wanted to illustrate my point. It does work for your example, and probably most cases. The inset of 40 can probably be detected programmatically, I didn't try to research that.

NSString *urlAddress = @"http://dl.dropbox.com/u/50941418/2-build.html";
NSURL *url = [NSURL URLWithString:urlAddress];

NSString *html = [NSString stringWithContentsOfURL:url encoding:[NSString defaultCStringEncoding] error:nil];
NSRange range = [html rangeOfString:@"<body"];

if(range.location != NSNotFound) {
  // Adjust style for mobile
  float inset = 40;
  NSString *style = [NSString stringWithFormat:@"<style>div {max-width: %fpx;}</style>", self.view.bounds.size.width - inset];
  html = [NSString stringWithFormat:@"%@%@%@", [html substringToIndex:range.location], style, [html substringFromIndex:range.location]];
}

[webView loadHTMLString:html baseURL:url];