Comments on: iPhone accelerometer and device orientation

By: mohit

mohit — Fri, 04 Nov 2011 05:56:43 +0000

Hi… i have sent you an email. Please reply to it soon. I need your help.

By: mohit

mohit — Thu, 03 Nov 2011 07:03:32 +0000

awesome tutorial….just priceless…

By: Is there a way to determine device orientation if view is loaded before [window makeKeyAndVisible] is called? | taking a bite into Apple

Fri, 01 Jul 2011 00:03:02 +0000

[...] EDIT: for whose who are interested on getting orientation info based on accelerometer reading: http://blog.sallarp.com/iphone-accelerometer-device-orientation/ [...]

By: Bob

Bob — Sun, 26 Sep 2010 01:05:11 +0000

You should definitely be adding M_PI_2 instead of 1.5 to the affine transformation angle, or the text isn’t level!

By: Suman

Suman — Mon, 29 Mar 2010 09:14:04 +0000

hi there, i am very much inspired by your “ScrollViewImageGallery” example. I would want to add 2 more functionalities – a tile based home page, where i have 16 buttons to press which will lead different groups. I want to create a scrap with lots of pictures.

Second is to add Tab bar to this gallery. Can you guide me how to do this? Thanks a ton.

By: Lars

Lars — Tue, 09 Feb 2010 13:51:11 +0000

Aha, now after having a closer look at your “ScrollViewImageGallery” example, I see how to add a view controller dynamically! Thank you very much for all the comments, very useful.

Kind regards, Lars

By: Lars

Lars — Tue, 09 Feb 2010 12:57:24 +0000

Hei Björn, Takk skal du ha! (15 months in Norway, but this is pretty much all I can say in Norwegian, sorry

Thank you very much indeed for your excellent sample code and all the great examples which are extremely useful for iPhone development beginners like myself.

As I can see from your sample code, the orientation determination always starts when the first view is already added to the window as a subview. Is there a way of starting earlier? Actually I do not like Apple’s approach to start all applications in Portrait Orientation first and only then switch to Landscape Orientation if necessary.

If I hold my iPhone already in Landscape Orientation and start an app or safari (yes, I know, I shouldn’t), it will show Portrait Orientation first and switch directly to Landscape Orientation afterwards. I would like to prevent this animated orientation switch entirely and start right away with the “correct” orientation of the app accordingly to the device’s physical orientation (yes, I saw your discussion on flipping the whole app’s or just the view orientation of the image view).

This is a minor issue with the iPhone since the UI of the springboard is not (yet) available in landscape orientation anyway, but rather soon it will be more important, because – even Apple admits – one cannot predict the “user preferred orientation” anymore when it comes to the iPad.

So, can I already start with this accelerometer determination at the point of “applicationDidFinishLaunching”? I would like to determine the necessary view orientation first (accordingly to the physical orientation of the device) and only then add the respective (portrait or landscape) view controller and view as a subview to the window.

How would I add a view controller dynamically then (sorry, I am still a beginner)?

Since I do not love too much this animated rotation of the views, I would rather like to use something which is shown in Apple’s AlternateViews example and to have this quick and neat cross-dissolve effect instead.

Thanks again for your helpful blog and those great insights.

Kind regards from Berlin, Lars

By: Shawn Brinkman

Shawn Brinkman — Fri, 05 Feb 2010 20:24:55 +0000

I get this build error when tring to run the project.
error: There is no SDK with the name or path ‘iphoneos2.0′

Can you please help me .

Thank you
Shawn

By: Bo Gehring

Bo Gehring — Fri, 02 Oct 2009 13:00:51 +0000

This is a great blog! A question… these solutions appear to be for yaw only. Is it possible to derive pitch and roll too? That would fully describe the device’s orientation.

By: Joel Morris

Joel Morris — Mon, 22 Jun 2009 06:05:31 +0000

Also, the file which defines atan2() also has a bunch of constants defined like M_PI M_PI_2 (pi/2) and M_PI_4 (pi/4) I think your code could be a tiny bit more accurate if you used these instead.