[Qt-interest] How can I write Qt apps for my everyday cell phone?

[K. Frank]

Hello All!

Thanks to all who replied.

On Tue, Aug 23, 2011 at 2:15 PM, Paul Miller <paul at fxtech.com> wrote:
> On 8/23/2011 11:51 AM, Yuvraaj Kelkar wrote:
>> Assuming you get an Android phone and root it:
> ...

Some follow-up questions, if I may.

It sound like android is the (semi-) consensus.  So my first step would
be to buy a Verizon (CDMA) compatible android phone.  Any particular
recommendation?  I would want 1) a good-quality "conventional" smart
phone, and 2) the ability to build / deploy my own Qt apps to it.

Asked another way, are there any android phones that might look good
but that I should stay away from?

Are most / all android phones arm based?

So if "platform" means os + processor, then I would be targeting the
android / arm platform.  True?  So my second step would be to
download the version of the necessitas sdk that is hosted on windows
and targets android / arm.

I've been poking around the necessitas wiki, but there are still some
things I'm a little vague on.  How would I deploy an app to an android
phone?  On a pc I can simply copy an executable (or an executable
plus some libraries) to the target machine and then run it.  I may
also have to add something to my path.  Can I simply copy an
executable to an android over a usb cable?  Do I have to build some
kind of official android "deployment package?"

Is the development cycle basically: build on host, deploy to target,
run on target, observe bugs on target, fix bugs on host, rebuild,
re-deploy, etc.?  Or is there some way to run / debug on the host?
Paul mentioned "USB debugging."  What is that?  It sounds like I
could run the debugger on the host, run (a debug version of) the app
on the target, and that the debugger hooks into the running app over
a usb cable.  That would be cool.  Is that what "USB debugging" means?

Atlant mentioned some ways an app can misbehave, mainly by using
too much of some resource.  That I understand, and am not really worried
about it.  I can  always just exit / kill off the misbehaving app.  (I
can, can't
I?)  I'm more worried about the possibility of a rogue app  messing up
the phone in a way that persists after the app is shut down so that I
would have to reboot the phone, or worse, re-load the phone's os.
How much of a worry is that?  On modern pc's you have to try pretty
hard to write a user app that screws up the system (to be contrasted,
for example, with programming in the old dos days).  Is programming
for an android as safe as programming for a modern pc?  Or is it more
like programming for an old dos pc?

Last question:  I realize that a well-designed cell-phone Qt app will look
rather different than a desktop app.  But, for simple apps, can I run the
same app on both platforms, or are they inherently different?  Let's say
I write a simple "hello world" app -- maybe it has a couple of buttons or
other widgets that do something simple -- and I get it working on the
desktop.  Can I simply rebuild it for the cell phone and have it run
correctly (even if it's design is not really appropriate for a cell phone)?

Any other things I should know?

As you can see, I'm trying to get an overview of what writing Qt apps
for a cell phone would actually entail before I decide to jump into it.

Since it seems like the way to go is to get an android and use necessitas
to build Qt apps for it, I would especially like to hear from folks who have
built Qt apps for android and run them, presumably using necessitas.
Is this something that works "in principle," or have people actually done
this and found it to be satisfactory?

Thanks again for all of your advice.


K. Frank