Re: Qt embedded, touchscreens, and cursors

["Eric Bénard" <eric@eukrea.com>]

Hi Steve,

Le Tue, 25 Jun 2013 09:34:05 -0700,
Steve Sakoman <sakoman@gmail.com> a écrit :

> I'm new to the Qt world, so perhaps this is a stupid question . . .
> 
> I'm helping a client create a custom layer for their touchscreen based
> hardware and Qt applications.
> 
> They've decided to use Qt4e and we are including the stock danny qt4e
> binaries in the image.
> 
> All works as desired with one exception:  the Qt cursor appears at app
> launch time with a green 16x16 background, converts to the app
> background shortly thereafter, and then stays on the screen until the
> first time you touch the screen, then disappears and stays gone.
> 
> Some quick googling indicates this is a common problem with touchsceen
> Qt implementations and that there are no satisfactory runtime
> solutions.  The most often recommended solution is to disable the
> cursor at build time with -no-feature-CURSOR added to the Qt config
> options.  This option is also claimed to give a significant
> performance boost.
> 
> I tried adding a bbappend to add this option, but as some of the above
> mentioned sources indicated the Qt build will fail unless you disable
> demos, examples, and a couple of other build features.  I started
> going down this path but I suspect it will require changes to the base
> Qte recipe.
> 
> Have others run into this issue?  I suspect that most target hardware
> for Yocto builds are touchscreen based, so this will likely come up
> over and over again.
> 
> Any suggestions?

IIRC you can hack this in 
qwscursor_qws.cpp
around "// default cursor"
you change ArrowCursor to BlankCursor
(sorry no clean patch for that ATM).

Eric