Force an android activity to always use landscape mode

Question

Hi,

I am using android vnc viewer on my G1. But for some reason, that application always in landscape mode despite my G1 is in portrait mode. Since android vnc viewer is open source, I would like know how is it possible hard code an activity to be 'landscape'. I would like to change it to respect the phone orientation.

Thank you.

Answer 1

You can specify the orientation of an activity in the manifest. See here.

<activity android:allowTaskReparenting=["true" | "false"]
...
          android:screenOrientation=["unspecified" | "user" | "behind" |
                                     "landscape" | "portrait" |
                                     "sensor" | "nosensor"]
...
                                       "adjustResize", "adjustPan"] >  

Answer 2

You can set the same data in your java code as well.

myActivity.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);

Other values on ActivityInfo will let you set it back to sensor driven or locked portrait. Personally, I like to set it to something in the Manifest as suggested in another answer to this question and then change it later using the above call in the Android SDK if there's a need.

Answer 3

Looking at the AndroidManifest.xml (link), on line 9:

<activity android:screenOrientation="landscape" android:configChanges="orientation|keyboardHidden" android:name="VncCanvasActivity">

This line specifies the screenOrientation as landscape, but author goes further in overriding any screen orientation changes with configChanges="orientation|keyboardHidden". This points to a overridden function in VncCanvasActivity.java.

If you look at VncCanvasActivity, on line 109 is the overrided function:

@Override
public void onConfigurationChanged(Configuration newConfig) {
  // ignore orientation/keyboard change
  super.onConfigurationChanged(newConfig);
}

The author specifically put a comment to ignore any keyboard or orientation changes.

---

If you want to change this, you can go back to the AndroidManifest.xml file shown above, and change the line to:

<activity android:screenOrientation="sensor" android:name="VncCanvasActivity">

This should change the program to switch from portrait to landscape when the user rotates the device.

This may work, but might mess up how the GUI looks, depending on how the layout were created. You will have to account for that. Also, depending on how the activities are coded, you may notice that when screen orientation is changed, the values that were filled into any input boxes disappear. This also may have to be handled.