Dual Display with Android

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Arpit

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Nov 11, 2010, 3:27:58 AM11/11/10
to android-porting
I had attended the Mobile Developer Summit in Bangalore yesterday and
missed out on one of the important session about how to achieve dual
display on Android (http://goo.gl/4y4ax) . Teleca in partnership with
TI has somehow achieve this.

Has any one been able to do this? Is there some official doc from
Android on how to achieve this?

Thanks & Regards,
Arpit

Deva R

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Nov 11, 2010, 12:08:28 PM11/11/10
to robin...@gmail.com, android-porting

>Has any one been able to do this? Is there some official doc from
>Android on how to achieve this?

me too curious to know more about 'dual drift' => have seen TAT UI on xserver, but such demo on android (really?) is impressive..

TI OMAP4 chip can support 3 displays at a time (1 graphics pipeline, 3 video video pipelines => to lcd/hdmi-tv/pico-projector etc. more info - www.omappedia.com/images/b/b1/OMAP4_planned_features.ppt  )

Graphics UI can be switched to any desired panel (lcd/tv..)
But Split UI support across panels like the 'dual drift' below, requires multiple frame buffer support and extensive changes to surfaceflinger design and apps.

Apart from GUI,
In eclair =>  player/framework is modified to support video playback on any panel on the go.. 

In froyo => framework is changed to support lcd/hdmi 

-- 
Regards,
Deva


Deva R

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Nov 22, 2010, 6:25:02 AM11/22/10
to robin...@gmail.com, android-porting


>Has any one been able to do this? Is there some official doc from
Android on how to achieve this?

Just came across this.
If you are more interested => Teleca is presenting dual display feature, next bangalore-android meetup. http://www.meetup.com/blrdroid/calendar/15523904/

[snip]

 12.15 PM to 1:00 PM – Bhavya Siddappa, Technology Evangelist at Teleca will talk on Dual Display for Android Applications.

From mobile to tablet, Android has gone a long way to emerge as a generic operating system. Dual Drift is a next generation, dual display mobile UI. Dual screens create exiting opportunities for great user experiences and more dynamic UIs with fast actions, adaptive content focus and dual multi-touch. The workshop will explore how to enable dual display on Android platform. Learn how internally Android renders on screen.

About Speaker: Bhavya is responsible for Technology trend evaluation and Analysis within Teleca. A Gold Medalist from Pune University, and has always been passionate about upcoming technology. Her current profile involves doing market research and analysis in the mobile space and providing leading edge technology solutions.

--
Regards,
Deva

Mikkel Christensen

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Nov 30, 2010, 3:51:36 AM11/30/10
to android-porting
Hi,

On Nov 22, 12:25 pm, Deva R <r.deva...@gmail.com> wrote:
> >Has any one been able to do this? Is there some official doc from
> Android on how to achieve this?

In the company that I work for, we have been working on an Android 2.2
dual display solution.

The basic idea is:
- Applications will via a framework extension indicate the display ID
where the application should run
- The WindowManagerService will at application start time get the
requested display ID from the starting application
- WindowManagerService provides the display ID to the SurfaceFlinger
which will create a new surface on the requested display
- The SurfaceFlinger has been modified to handle compositions using
OpenGL on multiple displays
- The ActivityManager has been modified to allow the top applications
to run simultaneously on two displays
- The event system has been extended to handle a secondary touch
device operating in parallel. This has been integrated with the
WindowManagerService which takes care of dispatching events to the
proper applications

We have uploaded a video to YouTube showing our prototype:
http://www.youtube.com/watch?v=5CWl4bTRKuw

Hope this will help you.

Best regards,
Mikkel Christensen
Ixonos Plc.

Al Sutton

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Nov 30, 2010, 7:39:29 AM11/30/10
to mikkel.ch...@ixonos.com, android-porting
Something I'd suggest is a method for one app to address both displays.

This could be as a vendor specific library as opposed to modifications to the existing framework, but I can see a number of apps being able to make use of two screens in a nintendo-DS style manner (e.g. city guides with a map on one display and details of a selected attraction on the other).

Al.

======
Funky Android Limited is registered in England & Wales with the company number 6741909.

The views expressed in this email are those of the author and not necessarily those of Funky Android Limited, it's associates, or it's subsidiaries.

Subramani Venkatesh

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Dec 13, 2010, 3:17:37 PM12/13/10
to r.de...@gmail.com, robin...@gmail.com, android-porting
Hi,
What manifest I can try to download the branch p-froyo, I am curious
to try dual-drift on my omap platform...

Regards,
Subbu

Dianne Hackborn

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Dec 13, 2010, 5:54:55 PM12/13/10
to mikkel.ch...@ixonos.com, android-porting
It looks like in your demo you have multiple resumed activities running at the same time.  I would very strongly recommend against this, if you want your device to be considered compatible with Market.  This has very deep repercussions for the activity lifecycle, which is likely to cause subtle application incompatibility.  Especially if multiple people are doing their own slightly different implementations.

If you don't care about Market, of course, have at it.


--



--
Dianne Hackborn
Android framework engineer
hac...@android.com

Note: please don't send private questions to me, as I don't have time to provide private support, and so won't reply to such e-mails.  All such questions should be posted on public forums, where I and others can see and answer them.

Mikkel Christensen

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Dec 15, 2010, 9:31:16 AM12/15/10
to Dianne Hackborn, android...@googlegroups.com
Hi,

We are aware of the Market implications altering the application
lifecycle to have multiple activities resumed. We do know that the
current Android CDD does not allow this.
As this is our early prototype we took some degrees of freedom and
implemented it this way to be able to utilize both displays.

There are many ways of using a secondary display. It could e.g. be a
smaller “info” display like those on clamshell phones that would be
rendered natively. But we wanted to integrate the display into the
system in order for full Android applications to run there. With the
standard Android activity lifecycle, an activity will be paused
whenever another activity comes in front, hence starting a new
activity on the secondary display will pause the activity on the
primary display. This makes the dual-display concept a little less
useful.

We see a lot of really useful use-cases that can be implemented on
Android devices by having multiple activities running on dual
displays. So is there any way of allowing applications to run on both
displays without breaking the CDD requirements?

Best regards
Mikkel Christensen
Ixonos Plc

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>
> --
> Dianne Hackborn
> Android framework engineer

> hack...@android.com

Dianne Hackborn

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Dec 15, 2010, 12:33:25 PM12/15/10
to Mikkel Christensen, android...@googlegroups.com
On Wed, Dec 15, 2010 at 6:31 AM, Mikkel Christensen <mikkel.ch...@ixonos.com> wrote:
We see a lot of really useful use-cases that can be implemented on
Android devices by having multiple activities running on dual
displays. So is there any way of allowing applications to run on both
displays without breaking the CDD requirements?

Not today.

--
Dianne Hackborn
Android framework engineer
hac...@android.com
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