[OpenLayers-Dev] OpenLayers for Mobile devices

Tue Dec 21 11:40:44 EST 2010

Benoit, 

I couldn't get the zooming to work at all on the N900.  But I don't
count that as a fault. 

I understand the complexities here, especially with regard to the
multi-touch aspects vs single touch enabled devices.  I think that in
the near term the gesture aspects are going to NEED to be targeted at
vendor specifics in order to take full advantage of each of them. 
Hopefully this will flesh out to a standard from the best available,
but, in the near term, I'm interested in seeing a process that works for
single touch (Could be all phone/mobile devices??) as a foundational
chunk of coding.  Hopefully this approach would get as many functional
mobile devices accounted for as possible.  Then it makes sense to attack
the vendor specific (extra) capabilities.  It seems to be easier to
design for the masses where possible (from my experience), and then to
enhance for the specialties, don't you think? 

I think there are options available for addressing these ideas, if
anyone else is interested. 

bobb 

>>> Benoit Quartier <benoit.quartier at camptocamp.com> wrote:

Hello Jimmy,

Thank you for your feedback.

In the current demonstration, zooming is done by double taping while
zooming out is done by a single two fingers tap... on iPhone (and likely
iPad).

Gestures are very interesting and we also did some work in this
direction. However, the issue we have with gestures is that they are
very vendor (read Apple) specific. Current Android phone cannot detect
two fingers event in the browser (see (and vote!)
http://code.google.com/p/android/issues/detail?id=11909 ). The primary
targets of our current work are iOS _and_ Android mobile phones (@Bob:
we didn't even test it on Nokia device, so we are happy to hear that it
works). Of course, we would like it to run on as many devices as
possible. This is why we didn't focus on Apple specific gesture for the
moment. One of the goal was to answer those questions you had in your
last e-mail about OpenLayers architecture and its ability to be used on
mobile devices.

The demo shows the working part of our job. We publish it mainly to
(re-)start the discussion about mobile OpenLayers development. Hence we
are happy to see interest from others!

Things are moving on and we will definitely continue working on this
topic next year. Let's see how we could collaborate.

Benoît

On Mon, Dec 20, 2010 at 9:18 PM, Duchesne, Jimmy <JDuchesne at korem.com>
wrote:

Thanks for your interesting answer Benoit.

We really appreciate you posting a demo of you work.

Here's what I have to say about it though. First off, your panning
behaviour is really good, as good as it can get actually.

But what about gesture zoom in, out and gesture panning (panning while
two fingers touch the screen)?
Those are the truly difficult features to implement, especially when
your users are experienced with native apps, and they expect to be
allowed to pan/zoom non-stop without any glitch.

I'll give you a few more information about our work so far.

- First of all, we developed this project for a specific client, who
only required an iPAD version.
That being said, we'll definitely adapt for other platforms in the
future, otherwise, we wouldn't
have done it with Web technologies.
- We have more than one layer overlaid above the base layer.
- By the way, that allowed us to discover a huge memory leak in Safari
iPAD. Basically, it looks like it never flushes loaded images.
The consequence is that if the user zooms in and out really often for 5
to 10 minutes, Safari will crash, or tiles will stop loading.

Finally, on our side, we'll definitely push our implementation to the
limit until we have something reusable that we can use in all our
projects.

We may publish a demo of our work soon, even though our implementation
is far from complete.

Thanks.

_____________________________
Jimmy Duchesne
Programmeur Analyste
jduchesne at korem.com

KOREM inc.
www.korem.com
_________________
____________

680, boul. Charest Est, bureau 120
Québec, QC G1K 3J4 Canada
Tél. : (418) 647-1555
Téléc. : (418) 647-1666
Sans frais : 1 888 440-1MAP

From: Benoit Quartier [mailto:benoit.quartier at camptocamp.com]
Sent: December 20, 2010 11:18 AM
To: Duchesne, Jimmy; openlayers-dev at lists.osgeo.org
Subject: Re: [OpenLayers-Dev] OpenLayers for Mobile devices

Hello,

At Camptocamp, we are also working on an adaptation of OpenLayers for
the mobile devices (phone and table, under iOS or Android for the
moment). You can check
http://www.camptocamp.com/fr/blog/2010/12/mobile-web-gis/ for more
information (and a demonstration) about our work in this field.

>From this point, we are discussing internally how we can move on with
this development. If other people are showing an interest, it may be a
good time to start talking together about how we can get an efficient
OpenLayers mobile.

By the way, have you a demo available? Are you specifically targeting
Apple devices?

Regards,
Benoît
On Mon, Dec 20, 2010 at 4:29 PM, Duchesne, Jimmy <JDuchesne at korem.com>
wrote:
Hi to everyone,
(If you think that I should address this email to someone in
particular, or another mailing list, I'd be glad to know)

For over a year now, my team and I have been using OpenLayers
thoroughly. We used it as much for internal projects as we did for our
clients' projects.
Overall, we're pretty much satisfied with what you guys created. It's
an extensive framework that dramatically improves the speed at which we
can develop our applications.

That being said, for some months now, a new need has been brought to us
by both our clients and our users. We need a framework for the different
mobile platforms.

So far, we've seen some patches posted on the OpenLayers' Issue tracker
that added limited support for the new events that come with mobile
devices: touches and gestures.
Those patches were obviously just a start. They did show us that it was
possible to use those new browser events, but as they were, they weren't
much use.

Actually, we could have used them, but when you compared the behaviour
they had with the one mobile device's users are used to, Google Maps App
or http://maps.google.com,
it wasn't going to satisfy our clients.

>From that perspective, our goal was this one: To achieve map behaviour
comparable to what users get with Google Maps App on iPAD, but with
OpenLayers as the base framework,
and Google Maps as the base layer. At some point, the base layer
shouldn't actually matter though.

Considering the lack of time that we had for this development, and the
fact that we could not find any similar existing implementation, we
finally went for some key features:
- Pan the map with one finger.
- Double touching the map zooms around where you touched the map.
- Double tapping the map zooms out one zoom level.
- Pinching the map stretches the map in real time, with a minimal
amount of lag.
- Had to use HTML5/CSS3 there.
- While pinching, you can also pan.
- If you pan or zooms the map, and your fingers leave the screen and
touch it again quickly enough, you continue the current map
manipulation.
- Map panning or stretching, while your fingers touch the screen acts
on all visible layers, whatever their type may be.

It was very important to us that while the fingers move the map or
stretch it, the expected result had to be visible in real-time, like it
does with the Google Maps App on iPAD.

In the end, we actually could achieve all these goals. It means that we
could get map behaviour comparable, or even better, to what one gets on
http://maps.google.com.
We couldn't reach all Google Maps App behaviour because of our lack of
time though.

As you may imagine, achieving these features in the amount of time that
we had, we actually hacked quite a lot of OpenLayers code. We'll
probably take some time
in the next few weeks to make it more portable so we can use it in all
our mobile device projects, but doing all this hacking made us curious.

What ar
e the current plans for OpenLayers regarding the support for
most mobile devices? In our case, all those tablets coming on looks like
a really promising market.
Do you guys plan on actually putting any effort in supporting mobile
devices? Do you think that the current OpenLayers architecture can
support such changes, or a new dedicated framework should be developed?
When are you planning on using HTML5/CSS3, since it makes the overall
experience more pleasing to the user?

We're really curious to hear about what you guys think about all this.

_______________________________________________
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--
Benoît Quartier

Camptocamp SA
PSE-A, Parc Scientifique EPFL
CH-1015 Lausanne

Tel: +41 21 619 10 40
Fax: +41 21 619 10 00

--
Benoît Quartier

Camptocamp SA
PSE-A, Parc Scientifique EPFL
CH-1015 Lausanne

Tel: +41 21 619 10 40
Fax: +41 21 619 10 00

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