如何检测用户何时将手指放在UIWebView中的图像上？

Question

In Mobile Safari, if you hold your finger over an image for a second or two, a little popup appears giving you the option of saving or copying the image.

Is there any way to do this in a UIWebView in an app? Gesture recognizers seem to be ignored and I don't see any way to hook into that behavior.

Answer 1

I am not very strong in web dev, but i am pretty shure you should use custom java script code which will detect the click on image and call the popup to appear.

Here is just an example how simple js injection works in iOS UiWebView.

Answer 2

There are javascript events you can hook into to get the effect you want

- (void)webViewDidFinishLoad:(UIWebView *)webView {
  [webView stringByEvaluatingJavaScriptFromString:@"window.ontouchstart=function(/* ... */);"];
}

Put your custom code in ontouchstart. I'd imagine what you want is a timer that checks if the user releases the touch before x milliseconds, and if that doesn't happen, you can call an obj-c function from javascript to activate the popup. Get the coords of the touch event and compare them to the coords of all the images in your page.

I'm hoping someone will know of a native way to do this though; this is a really hackish workaround.