String Array of Array Java Example

Sensor, getSystemService(), getSensorList(), getDefaultDisplay(), WindowManager,
Surface.ROTATION_0, onAccuracyChanged() Android sample.

public class _MotionActivity extends Activity implements SensorEventListener {
    private float mSensorX;
    private float mSensorY;
    private Display mDisplay;
    private SensorManager sm;
    private PowerManager mPowerManager;
    private WindowManager mWindowManager;
   
    TextView textview;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // Get an instance of the SensorManager
        sm = (SensorManager) getSystemService(SENSOR_SERVICE);
        if(sm.getSensorList(Sensor.TYPE_ACCELEROMETER).size()!=0){
        	Sensor s = sm.getSensorList(Sensor.TYPE_ACCELEROMETER).get(0);
        	sm.registerListener(this,s, SensorManager.SENSOR_DELAY_NORMAL);
        }

        // Get an instance of the PowerManager
        mPowerManager = (PowerManager) getSystemService(POWER_SERVICE);

        // Get an instance of the WindowManager
        mWindowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
        mDisplay = mWindowManager.getDefaultDisplay();

 
        
        setContentView(R.layout.main);
        textview = (TextView)findViewById(R.id.textView1);
    }
    
    @Override
    public void onSensorChanged(SensorEvent event) {

    	
        if (event.sensor.getType() != Sensor.TYPE_ACCELEROMETER)
            return;

        switch (mDisplay.getRotation()) {
            case Surface.ROTATION_0:
                mSensorX = event.values[0];
                mSensorY = event.values[1];
                textview.setText(String.valueOf( mSensorX));
                break;
            case Surface.ROTATION_90:
                mSensorX = -event.values[1];
                mSensorY = event.values[0];
                textview.setText(String.valueOf( mSensorX));
                break;
            case Surface.ROTATION_180:
                mSensorX = -event.values[0];
                mSensorY = -event.values[1];
                textview.setText(String.valueOf( mSensorX));
                break;
            case Surface.ROTATION_270:
                mSensorX = event.values[1];
                mSensorY = -event.values[0];
                textview.setText(String.valueOf( mSensorX));
                break;
        }

    }

	@Override
	public void onAccuracyChanged(Sensor sensor, int accuracy) {
		// TODO Auto-generated method stub
		
	}
	@Override
	protected void onResume() {
		super.onResume();

             if(sm.getSensorList(Sensor.TYPE_ACCELEROMETER).size()!=0){
        	Sensor s = sm.getSensorList(Sensor.TYPE_ACCELEROMETER).get(0);
        	sm.registerListener(this,s, SensorManager.SENSOR_DELAY_NORMAL);
             }
	}

	@Override
	protected void onPause() {
		
		sm.unregisterListener(this);
		super.onStop();
	}       
    
}

Terms Screen size, density, density independent pixel, resolution as a picture - pictogram.


Test your knowledge
Q: How to find out the phone screen size?
A: (By length of display diagonale in inch -  Not to measure a diagonal of device!!!)

Q: What resolution has 720 x 1280 display?
A: (921600 pixels)

Q: What does it mean "240 dpi" screen density?
A: (Display have density 240 x 240  dots - "Tri-color LED etc." - per every physical (real) square inch. If you have icon 240x240 pixels, this will just occupy an area of one square inch on the display.)

Q: Phone have screen density 240 dpi. Image for 160 dpi screen density have size 128x 128 pixels. What will be the size of the image for 240 dpi screen density?
A: (Calculate the virtual pixels size.   128 * (240/160)  =  192.  You have to resize image to new size 192 x 192 physical pixels and put into folder drawable-hdpi (high) ~240dpi  for phone with screen density 240 dpi. ) or use density independend pixels 128dp x 128dp.

 

 

The Android WebView changing the height according to text size.
If you need to change the height to a minimum try this source:

//public void loadDataWithBaseURL (String baseUrl, String data, String mimeType, String encoding, String historyUrl) 
WebView _webView; // findById(.....
String entryContent = "";
 _webView.loadDataWithBaseURL(
	"blabol",//  javascript i styly
	entryContent, null,
	"utf-8", null
);

Log.e println needs a message error.
E/AndroidRuntime(330): FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{b.paint/b.paint.MainActivity}: java.lang.NullPointerException: println needs a message

Try this code:

		// Error
                String s = null;
		Log.e("bla", s); // !!! error Log.e println needs a message error.
                // OK
		String s = null;
		Log.e("bla", s+""); // OK 

How get Android SDK location - PATH on PC from Eclipse tutorial.

1. Open dialog from menu Window -> AVD and SDK manager


2. In dialog select Available packages


3. On top of dialog will displayed similar path: SKD Location: C:\PROGRA~1\Android\android-sdk-windows\