Develop Reference

When would one justify overriding orientation handling

When would one justify adding this to manifest.xml?
android:configChanges="orientation|keyboardHidden|screenSize"
Thankyou

Yes its required based on your requirement. I had an app in which we had to show videos on orientation change the video would restart hence i had to overide the onConfigureation() method and handle it, As i said it depends on your requirement

Adding this to the manifest means that you will control what happens when orientation changes, keyboard is minimized, screen size changes. If you do not add this then the onCreate gets called again on these events.
But say you have a different layout for landscape and portrait. Then you would like to call onCreate again to render the landscape layout.

Device orientation lock causes problems

I got an app that is locked in landscape orientation. Now, when I change the devices settings to set its orientation locked to portrait, some problems occur.
After a bit of testing, it seems that for each Activity that is started, the onCreate is called twice.
First time for portrait orientation, second time as an orientationChange with orientation set to landscape. The first orientation is wrong, and probably has something to do with the device being locked to portrait.
In the app, the orientation is forced to landscape programmatically (using setRequestedOrientation), and I prefer to keep it that way, if possible, for various reasons.
Any ideas about how to avoid this behavior?
Thanks in advance!

Ok, I found a solution myself.
After a lot of searching and digging in the code, the solution was fairly simple.
All I had to do was add:
android:configChanges="orientation|screenSize"
... to all my Activities in the manifest file.
This tells the app that I will handle configuration changes myself in the code. Instead of doing this, I didn't add any handlers for these config changes. This way, my Activities aren't recreated when the orientation change happens at the creation of those Activities. I can do it this way, because my app is locked in a certain orientation.
This post came closest to my problem, but it's solution didn't work for me:
Android: set activity orientation BEFORE onCreate, but not in manifest (HDMI plugged in issue)
This post gave me the answer:
http://www.acnenomor.com/1053172p1/oncreate-were-called-twice-after-implementing-setrequestedorientation

Try setting up the orientation directly in the manifest instead of programmatically. Under your activity tag in AndroidManifest.xml add android:screenOrientation="landscape".
This should force the activity to be directly created in the correct orientation.

Android onConfigurationChanged() only in certain cases

I have stumbled on a problem, that, when the screen turns off while being in LANDSCAPE orientation, certain devices "rotate" the app back to PORTRAIT position (because the lockscreen is PORTRAIT only or something like that). I did a little research before posting this, and most popular work-around is to modify app's configuration change process to prevent activity being recreated after the configuration has changed.
But disabling activity recreation is not a solution for me, because my app supports both orientations with sepparate layout's etc.
So i would like to find out, is it possible to disable the configuration change only in special cases (Screen turned off and orientation is landscape)? Or is the right way to override onConfigurationChanged() then manually manage activity recreation inside that function (i guess simply setting different layout resources when orientation is changed simply wont cut it)?

Or is the right way to override onConfigurationChanged() then manually manage activity recreation inside that function?
Yes to an extent.
You cannot set the configChanges attribute programmatically. I guess it's to do with the way an Activity is created. They're created from the XML first and then the overridden methods in your activity implementation are invoked. There's nothing in the API that lets you change the configChanges attribute.
Now in your case it doesn't sound like you need to. If you support both orientations, then if the user locks the device and it rotates back why does it matter? From a UX perspective we know it's in portrait mode again. So should your app when it opens back up.

Android - Handle Screen Orientation

I'm currently working on an Android application that have different behaviors according to the screen orientation.
I'm using getWindowManager().getDefaultDisplay().getRotation() to get the screen orientation in the onCreate() method and manage from there.
Basically, my problem is that I need a control over the orientation. In landscape mode, when the user decides it, the application must switch to portrait mode, and stays like that, but only until the use goes to portrait mode, and then again to landscape.
I'm using setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT) to change the orientation when in Landscape. The problem is, using this, I can not go back to landscape.
If I use setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED) in onCreate(), the problem is that is switches back to landscape mode after a few seconds (since the screen is still in landscape).
Is there any other way to manage this? Basically, is there a way to catch the screen orientation change with a listner (or anywhere else than in onCreate, since it's not called when the views is locked in portrait mode)? I can't find anything about that...
Any idea is welcome!
Thanks!

Why not try creating two layouts, one in layout-land and one in layout-port. These will automatically be applied when the device orientation changes.
Inside each of these, create two distinct child layouts one for a portrait view, and one for a landscape view and change the visibility of these to reflect the user's preference.
So, you don't need to handle the rotation change at all, let Android manage that for you, and you just manage the user override.

Android screen orientation bug

I am using android HTC HERO 2.1 version.
The activity I write :
<activity android:name=".gogogo"
android:label="#string/app_name"
android:theme="#style/Theme.mine"
android:screenOrientation="landscape"
android:configChanges="orientation">
let my orientation change to landscape.
However, I figured out that every time I pressed "power" button and then come back to my activity, it always start at portrait.
I tried the game : TEETER , which was written not by me. Has the same problem too, any one know how to fix it??
Edit: it always start at portrait. --> I mean, if you come back from power, you have to scroll down to do everything, there is something like screen lock.
You can see that there is a "status bar" at the top of the screen and at this time, the orientation is "portrait". So after You scroll the "screen lock" a little bit down, you can see the activity (such as TEETER) is at "portrait" state. When you scroll all the way down, the activity's orientation will suddenly change to the state "landscape".
So the conclusion is : My activity is forced to orient once. And I really want to know how to fix it!

Hai Steven Shih:
Pls go through this page of developer guide.
http://developer.android.com/guide/topics/manifest/activity-element.html
and try this line
android:windowSoftInputMode="stateUnspecified|adjustPan"

Not sure if it's the same problem, but here is the problem I had :
I force the orientation as landscape in the manifest
My activity has a two surfaceviews ( a camera preview and a layer on top of it )
After pressing the power button and coming back, my views were suddenly in the wrong orientation
It seems to be the same problem as another question : Disable orientation but detect orientation
I think the problem is that once you press the power button, the lock screen forces the orientation as portrait. In the onConfigurationChanged I get an orientation change right when I press the power button, which was unexpected because I told to explicitly lock the orientation. The fact is that when another activity which comes in front forces the orientation, the other activities get notified of the orientation change, even if they asked for an explicit orientation.
Here's my workaround :
in onPause, detach the views with removeView ( my application has programmatically created views, not an xml layout )
in onResume , first check if the orientation is the one you requested ( getResources().getConfiguration().orientation ). If it's the case, reattach the views ( addContentView or whatever ).
if the orientation is not the one you expect, call setRequestedOrientation
onConfigurationChanged will be called to tell the orientation has been changed to the one you requested. At this point you can reattach the views with setContentView.
Seems a bit complicated, but that's what I had to go through in my particular case, since my views are created dynamically and directly attach to the default FrameLayout of the activity. Maybe I then missed some default behaviors because of that, but this way I could achieve the reactivity I was looking for.

Not sure whether this can be called a fix, but it's kind of a work-around.
#Override
public void onWindowFocusChanged(boolean hasFocus) {
if (hasFocus)
setContentView(mGameView);
else
setContentView(mEmptyView);
}
Where mGameView is your ordinary content and mEmptyView is just a simple View object. The activity will still be drawn in portrait for a frame or two, but it will not be visible to the user.
I've tested this with HTC Hero and Nexus S.