Set theme of AdActivity to @android:style/Theme.Translucent

Very dark picture, in photo editor black remains black


Very bright picture, in photo editor white will white


Dark picture but the chart is not in black color area - dark shades can be lighten in graphics editor

Try this:
- check names of drawables (file name must contain only abc...xyz 012...789 _ . in Resources folder ,
names have to start with lower case
MyImage.jpg == problem ,
names with space
my image.jpg == problem,
names with -
my-image.png == problem)
- check duplicate names with other extension ( my_image.jpg - my_image.png makes the problem)
- restart Android Studio
- if problem persist:
- check c:\Users\me\AndroidStudioProjects\myProject\myModule\build\intermediates\res\merged\debug\ drawable folder for corupted names or delete ALL drawable folders
- synk projekt, rebuild projekt
- if problem persist:
- restart Android Studio, wait for complete closure of the Android Studio!

public class MainActivity extends Activity {
//  //www.apache.org/licenses/LICENSE-2.0
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(new SampleView(this));
	}

	   private static class SampleView extends View {
	        private Rect    mRect;
	        private GradientDrawable mDrawable;

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

	            mRect = new Rect(0, 0, 220, 120);
	      
/*	            GradientDrawable.Orientation  BL_TR  draw the gradient from the bottom-left to the top-right   
	              BOTTOM_TOP  draw the gradient from the bottom to the top   
	              BR_TL  draw the gradient from the bottom-right to the top-left   
	              LEFT_RIGHT  draw the gradient from the left to the right   
	              RIGHT_LEFT  draw the gradient from the right to the left   
	              TL_BR  draw the gradient from the top-left to the bottom-right   
	              TOP_BOTTOM  draw the gradient from the top to the bottom   
	              TR_BL  draw the gradient from the top-right to the bottom-left   
*/
	            
	            mDrawable = new GradientDrawable(GradientDrawable.Orientation.LEFT_RIGHT,
	                                             new int[] { 0xFFFF0000, 0xFF00FF00,
	                                                 0xFF0000FF });
	            mDrawable.setShape(GradientDrawable.RECTANGLE);
	            mDrawable.setGradientRadius((float)(Math.sqrt(2) * 60));
	        }
	        
	        static void setCornerRadius(GradientDrawable drawable, float r0,
	                                   float r1, float r2, float r3) {
/*	        	setCornerRadii
	        	Specify radii for each of the 4 corners. For each corner, 
	        	the array contains 2 values, [X_radius, Y_radius]. 
	        	The corners are ordered top-left, top-right, bottom-right, 
	        	bottom-left 
*/
	            drawable.setCornerRadii(new float[] { r0, r0, r1, r1,
	                                                  r2, r2, r3, r3 });
	        }
	        
	        @Override protected void onDraw(Canvas canvas) {
	            
	            mDrawable.setBounds(mRect);

	            float r = 35;
	            
	            canvas.save();
	            canvas.translate(10, 10);
	            mDrawable.setGradientType(GradientDrawable.LINEAR_GRADIENT);
	            setCornerRadius(mDrawable, r, r, 0, 0);
	            mDrawable.draw(canvas);
	            canvas.restore();
	            
	            canvas.translate(0, mRect.height() + 10);
	            canvas.save();
	            canvas.translate(10, 10);
	            mDrawable.setGradientType(GradientDrawable.RADIAL_GRADIENT);
	            setCornerRadius(mDrawable, 0, 0, r, r);
	            mDrawable.draw(canvas);
	            canvas.restore();
	            
	            canvas.translate(0, mRect.height() + 10);
	            canvas.save();
	            canvas.translate(10, 10);
	            mDrawable.setGradientType(GradientDrawable.SWEEP_GRADIENT);
	            setCornerRadius(mDrawable, 0, r, r, 0);
	            mDrawable.draw(canvas);
	            canvas.restore();
	            
	            
	        }
	    }
	}

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);

Eclipse: failed to create the java virtual machine - message box

1. Open folder with Eclipse.exe and find eclipse.ini file


2. Replace -vmargs
   by your current real path of javaw.exe:
   -vm "c:\Program Files\Java\jdk1.7.0_07\bin\javaw.exe"
   
   

-startup
plugins/org.eclipse.equinox.launcher_1.3.0.v20120522-1813.jar
--launcher.library
plugins/org.eclipse.equinox.launcher.win32.win32.x86_1.1.200.v20120522-1813
-product
com.android.ide.eclipse.adt.package.product
--launcher.XXMaxPermSize
256M
-showsplash
com.android.ide.eclipse.adt.package.product
--launcher.XXMaxPermSize
256m
--launcher.defaultAction
openFile
-vm "c:\Program Files\Java\jdk1.7.0_07\bin\javaw.exe” 
-Dosgi.requiredJavaVersion=1.6
-Xms40m
-Xmx768m
-Declipse.buildId=v21.1.0-569685