How to make a quick start the android emulator

Screen Android example source code for developers.
Get orientation of screen.

 public int getScreenOrientation() {
  if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT)                {
       return 1; // Portrait Mode
   
  }else if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) {
       return 2;   // Landscape mode
  }
  return 0;
 }

Select file in project explorer
Menu:
File - Make File Read-only - to lock
File - Make File Writable - to unlock

Solution:

public void alertMy(String sTitle, String sMessage){
	AlertDialog.Builder builder = new AlertDialog.Builder(Test.this); // activity
  builder.setTitle(sTitle)
  .setMessage(sMessage)
  .setCancelable(false)
  .setNegativeButton("Close",new DialogInterface.OnClickListener() {
      public void onClick(DialogInterface dialog, int id) {
          dialog.cancel();
      }
  });
  AlertDialog alert = builder.create();
  alert.show();

}

Get assets folder files to array of strings.
Its show files in assets folder and sub folders:

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        final AssetManager assetManager = getAssets();
        try {
			// for assets folder add empty string
                        String[] filelist = assetManager.list("");
                        // for assets/subFolderInAssets add only subfolder name
                        String[] filelistInSubfolder = assetManager.list("subFolderInAssets");
			if (filelist == null) {
			    // dir does not exist or is not a directory
			} else {
			    for (int i=0; i<filelist.length; i++) {
			        // Get filename of file or directory
			        String filename = filelist[i];
			    }
			}
                     
                        // if(filelistInSubfolder == null) ............  

		} catch (IOException e) {
			e.printStackTrace();
		}
     }

Bitmap size calculation:
bmpHeight * bmpWidth
For example:
Resolution of image 1024x860 = 880 640 pixels
If every pixel get 4 byte of memory:
880 640x4= 3 522 560 (3.5MB)

Get bitmap size without allocation of memory:

   	BitmapFactory.Options options = new BitmapFactory.Options();
        // If set to true, the decoder will return null (no bitmap), but the out... fields will still
        // be set, allowing the caller to query the bitmap without having to allocate the memory for its pixels. 
    	options.inJustDecodeBounds = true; 
    	BitmapFactory.decodeResource(getResources(), R.drawable.my_image, options);
    	int imageHeight = options.outHeight; // 1024
    	int imageWidth = options.outWidth; // 860
    	String imageType = options.outMimeType; // .jpg .png .gif
 

Get Memory size:
Make your bitmap not bigger as maxMemory size
final int maxMemory = (int) (Runtime.getRuntime().maxMemory() / 1024);

    float density = getResources().getDisplayMetrics().density;

    Debug.MemoryInfo memoryInfo = new Debug.MemoryInfo();
    Debug.getMemoryInfo(memoryInfo);
    final int maxMemory = (int) (Runtime.getRuntime().maxMemory() / 1024);
    final int freeMemory = (int) (Runtime.getRuntime().freeMemory() / 1024);
    String memMessage = String.format(
        "Free=%d kB,

MaxMem=%d kB,

 Memory: Pss=%.2f MB, Private=%.2f MB, Shared=%.2f MB",
        freeMemory,
        maxMemory,
        memoryInfo.getTotalPss() / 1024.0,
        memoryInfo.getTotalPrivateDirty() / 1024.0,
        memoryInfo.getTotalSharedDirty() / 1024.0);
    ((TextView)findViewById(R.id.textViewInfo)).setText(memMessage );