Create array of strings in xml file Android example

Draw the trajectory of shot.

public class MainActivity extends Activity {
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(new SampleView(this));
	}

	private static class SampleView extends View {

		// CONSTRUCTOR
		public SampleView(Context context) {
			super(context);
			setFocusable(true);

		}
	       private static void makePath(Path p) {
	            p.moveTo(10, 0);
	            p.cubicTo(100, -50, 200, 150, 300, 0);
	        }
		@Override
		protected void onDraw(Canvas canvas) {

			canvas.drawColor(Color.CYAN);
			Paint p = new Paint();
			// smooths
			p.setAntiAlias(true);
			p.setColor(Color.RED);
			p.setStyle(Paint.Style.STROKE); 
			p.setStrokeWidth(5);
			// opacity
			//p.setAlpha(0x80);
 
			p.setColor(Color.BLACK);
			Path mPath = new Path();
            makePath(mPath);
			canvas.drawPath(mPath, p); //(rectF, 90, 45, true, p);
		}

	}
}

Invalid proguard configuration file path
C:\documents\my_android_projects\my_project\proguard.cfg does not exist or is not a regular file

Solution:
Check if exist file proguard.cfg in your project on the path C:\docum.........
If not exist, copy a file proguard.cfg from other project or create file proguard.cfg and insert
this source code to file and save this file.

-optimizationpasses 5
-dontusemixedcaseclassnames
-dontskipnonpubliclibraryclasses
-dontpreverify
-verbose
-optimizations !code/simplification/arithmetic,!field/*,!class/merging/*

-keep public class * extends android.app.Activity
-keep public class * extends android.app.Application
-keep public class * extends android.app.Service
-keep public class * extends android.content.BroadcastReceiver
-keep public class * extends android.content.ContentProvider
-keep public class * extends android.app.backup.BackupAgentHelper
-keep public class * extends android.preference.Preference
-keep public class com.android.vending.licensing.ILicensingService

-keepclasseswithmembernames class * {
    native <methods>;
}

-keepclasseswithmembers class * {
    public <init>(android.content.Context, android.util.AttributeSet);
}

-keepclasseswithmembers class * {
    public <init>(android.content.Context, android.util.AttributeSet, int);
}

-keepclassmembers class * extends android.app.Activity {
   public void *(android.view.View);
}

-keepclassmembers enum * {
    public static **[] values();
    public static ** valueOf(java.lang.String);
}

-keep class * implements android.os.Parcelable {
  public static final android.os.Parcelable$Creator *;
}

From more details see:
//developer.android.com/guide/developing/tools/proguard.html

Android development

long is 64 bit signed type and used when int is not large enough to hold the value.

long je celé číslo 64 bitů -9223372036854775808 +9223372036854775807 a používá se tam, kde typ int není schopen pojmout takovou hodnotu čísla.

		// declaration and assignment of value type long
		long n = 22337203685477580L;
		// print formated value
		System.out.printf("The value of x is %d%n", n); // 22337203685477580
		System.out.format("%+,8d%n%n", n); // +22 337 203 685 477 580

		// declaring more variables in single statement
		long lo1 = 12L, lo2 = 56, lo3 = 1455555555589L;

		// long range of value
		System.out.println(Long.MAX_VALUE); // 9223372036854775807
		System.out.println(Long.MIN_VALUE); // -9223372036854775808

		// check if a string is a valid number in Java example
		// convert string to long Java example
		String sLong = "1288888888888888";
		long longParse = Long.parseLong(sLong);

		// convert strings to numbers
		long longFromString = (Long.valueOf(sLong)).longValue();

		// long to string in Java example code
		Long longObj = new Long(229999999999L);
		String str = longObj.toString();
		// else
		Long longS = 888888888888L;
		String strLong = longS.toString();

		// compare two long variables
		Long longComp1 = 5555L;
		if (longComp1.equals(55555555L))
			System.out.print("true");

		// compares the two specified long values in Java example

		int i = longS.compareTo(444444L); // -1 first < second
		// 0 first == second
		// 1 first > second
		System.out.print(i);

Put extends PreferenceFragment API level 11 instead PreferenceActivity

public class SettingsActivity extends PreferenceFragment {
  @Override
  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      addPreferencesFromResource(R.xml.preferences);
  }
}

// or insert suppresswarning
public class SettingsActivity extends PreferenceActivity {
  @SuppressWarnings("deprecation")
	@Override
  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      addPreferencesFromResource(R.xml.preferences);
  }
}

InputStream, getResources(),openRawResource()

 java.io.InputStream is;
is = context.getResources().openRawResource(R.drawable.my_image);

Drawable mDrawable = context.getResources().getDrawable(R.drawable.button);
mDrawable.setBounds(150, 20, 300, 100);


Drawable[] mDrawables;
int[] resIDs = new int[] {
                R.drawable.btn_ok,
                R.drawable.btn_storno,
                R.drawable.btn_help
            };
            mDrawables = new Drawable[resIDs.length];
            Drawable prev = mDrawable;
            for (int i = 0; i < resIDs.length; i++) {
                mDrawables[i] = context.getResources().getDrawable(resIDs[i]);
                mDrawables[i].setDither(true);
                addToTheRight(mDrawables[i], prev);
                prev = mDrawables[i];
            }