Android Emulator switching landscape to portrait problem.

[RageMatrix]

I am half-following along with the "Hello, Android" book (3rd edition) by Ed Burnette. I have added a portrait GUI layout main.xml under "res/layout/main.xml" and a landscape GUI layout under "res/layout-land/main.xml" as described in the book. When using my app under the SDK emulator, I can switch my GUI from portrait to landscape by pressing CTRL-F11. However, if I press this again, the GUI is stuck in landscape mode. I have no other code other than: -

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package com.thenode.mobile.podgrab;

import android.app.Activity;
import android.os.Bundle;

public class PodGrabActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }
}

What do I have to do to make my GUI switch back to portrait mode from landscape? Am I missing something or is this a bug in the emulator? The book makes no mention of this problem. Any advice?

I use LinuxQuestions.org a lot for Linux stuff and they've recently opened AndroidQuestions.org too - but my posts never seem to show up there, so I'm posting here

[Darkflame]

Dont you have a phone to test stuff on? I find its quicker and easier debugging on the real hardware. (any android phone would do and a normal usb connection)

[RageMatrix]

Tried it out on my Nexus S, it ignored the landscape layout completely which was a slightly different result than I was expecting since the emulator will change to landscape but not change back Anyway, it turns out this entry in the Android manifest file is the culprit: -

android:configChanges="orientation"

This ignores the /res/layout-land directory completely and only uses the one in /res/layout only.
If you create a different XML for landscape orientation, don't use the

Code: Select all

android:configChanges="orientation" 

tag for that Activity or add a new overridden event method. It's there to stop the Activity from restarting apparently, so also from reloading the XML layout which you usually do in onCreate(). Instead, onConfigurationChanged(newConfig) is called. So you can do:

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@Override
public void onConfigurationChanged(Configuration newConfig){
super.onConfigurationChanged(newConfig);
setContentView(R.layout.main);
}

This wil reload the layout from the layout-land directory if available. Thanks for mentioning that in the "Hello, Android" book, Ed! :-/

[sack]

Speaking of Android...

does anybody know of a way of using the orientation stuff to figure out which way is down in Android (2.1)? I managed to get some code together to listen to the various sensors and spit them out onto the screen, but I haven't managed to connect the dots and figure out which way is down (although it was getting a bit late when I was playing with this).

Ideally what I'm after is having a GL context that is locked in orientation, so turning the device has no effect on the screen layout, and to be able to generate a unit vector pointing downwards that I can use to set gravity in a game.

Any pointers where to look for this kind of stuff?

[BillyT]

To lock to a particular view you would add this to your manifest file:

android:screenOrientation="landscape" or android:screenOrientation="portrait" depending on what you want.

As for which way is up, there is a problem with all that because it depends on what the real default orientation of the device is. Some devices can think landscape and the sensors are configured around that.

I cannot remember where the article is (Android dev site) but it goes in depth on how to detect which way the sensor is.