Android - JavaScript : touchstart event not fired until zoom or scroll the page

Ahmed Al Khashab picture Ahmed Al Khashab · Jan 23, 2013 · Viewed 8.3k times · Source

In my Android application, The user can browse some HTML pages using ViewPager, and the user can touch an element to highlight.

the problem is when trying to get the touch event using javascript using the following code, elementFromPoint returns null when navigate to new page, but after the user zoom the page or scroll on it, it works right.

I found that register of the touchstart event happens after zoom or scroll the page. so it works right after that although it is registered on $(document).ready()

        $(document).ready(function(){
            document.addEventListener("touchstart", touchstart, false);     
        });     

        function touchstart(e) {                              
            var x = e.targetTouches[0].clientX; 
            var y = e.targetTouches[0].clientY;                             
             el = document.elementFromPoint(x, y);  
            }

Thank you

Answer

Mohamed Abdel Latif picture Mohamed Abdel Latif · Jan 29, 2013

write next code in your java code after calling javascript :

    myWebview.scrollTo(1, 0);
    myWebview.scrollTo(0, 0);

or use zoom in then zoom out

    myWebview.zoomIn();
    myWebview.zoomOut();