[webkit-dev] Touch operation corrupts screen when specifying other than overflow:visible in css

Thu Nov 1 04:54:15 PDT 2012

Hi, I filed this problem to https://bugs.webkit.org with 
test case as an HTML file after I was suggested to do so.

Bug id 99842.

I am trying to find a workaround to resolve this problem.
If someone has it, post it, please.

> Hi,
> 
> On a windows 7 tablet, PAN operation(=scroll) causes
> corruption of screen.
> 
> Does anybody know how to resolve this or have the fix?
> 
> How to reproduce.
> 1. Prepare a HTML contents which have an element specifying
>    other than "visible" to the property overflow in css.
> 2. Load the contents with webkit
> 3. Operate the touch operaion, PAN on the element.
> 
> Problem
> The content in the element protrudes outside the placeholder 
> for it and can disappear.
> 
> The build version
> Webkit.exe on r131112 for Nightly builds
> 
> We guess Source\WebKit\win\WebView.cpp has some bugs on this 
> issue.
> 
> Here is the sample contents to reproduce problem. You will see the
> problem if you PAN on the field for "overflow:auto".
> 
> ----------
> <HTML>
> <HEAD><TITLE>pan with css:overflow</TITLE></HEAD>
> <BODY>
> <font size="+2">
> <div style="border: 2px solid blue; padding: 5px 5px 5px 5px; overflow:visible;">
> overflow:visible
> </div>
> <br>
> <div style="border: 2px solid red; padding: 5px 5px 5px 5px; overflow:auto;">
> overflow:auto
> </div>
> </font>
> </BODY>
> </HTML>
> ----------
> 
>                                                         Hideki
> 
> ***************************************************************************
>   Hideki Yoshida
>   Embedded Software Division
>   NEC System Technologies, Ltd.
>     E-MAIL:yoshida-hxa at necst.nec.co.jp
> ***************************************************************************