Android Studio reduce memory usage of PC

Set focus on a View in Android application example source code for Button, EditText, View, TextView, isFocused(), requestFocus() .

// set focus on Button Android example
 private Button mRightButton;
 mRightButton = (Button) a.findViewById(R.id.rightButton);
 mRightButton.requestFocus();
// boolean isFocused() 
boolean b = mRightButton.isFocused(); // true or false

// set focus on TextView directly Android example
((TextView) findViewById(R.id.myText)).requestFocus();

// set focus on View Android example
private View mView;
mView = findViewById(R.id.showAll);
mView.requestFocus();

// set focus on EditText Android example
private EditText mEdit;
mEdit = (EditText)findViewById(R.id.myEdit);
mEdit.requestFocus();

Try this code:

final String ERROR = "my error message....";

 private class DownloadWebPageTask extends AsyncTask<String, Void, String> {
// some code and method ..... see AsyncTask

       @Override
        protected String doInBackground(String... urls) {

              URL urlL = null;
                try {
                    urlL = new URL(url);//"//chmi.cz..../"
                    HttpURLConnection urlConnection = null;
                    try {
                         urlConnection = (HttpURLConnection) urlL.openConnection();
                        InputStream in = new BufferedInputStream(urlConnection.getInputStream());
                      response =  readStream(in);
                        return response;
                    } catch (IOException e) {
                        //throw new RuntimeException(e);

                    } finally {
                        if(urlConnection != null)
                            urlConnection.disconnect();
                        return ERROR;
                    }
                } catch (MalformedURLException e) {
                    e.printStackTrace();
                    return ERROR;
                }
           }
            return response;
        }

        private String readStream(InputStream is) {
            try {
                ByteArrayOutputStream bo = new ByteArrayOutputStream();
                int i = is.read();
                while(i != -1) {
                    bo.write(i);
                    i = is.read();
                }
                return bo.toString();
            } catch (IOException e) {
                return "";
            }
        }

Check your xml files in Eclipse Graphical Editor and fix problems.



Check project setup, right click on project, select properties, Java build path and
select correct Android version etc.


Right click on project, Android Tools, Fix Project Properties

Menu Eclipse select Project ->Clean.

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();
	            
	            
	        }
	    }
	}

Why the app selects data from basic layout folder if smallest width is higher then the number in folder name?
Example 1
layout-sw600dp values-sw600dp (smallest width sw for data usage from this folder is 600dp density independent pixel!!!!!)
Device screen resolution is 1200 x 900 px (pixel) Wow, app to be select data from sw600dp folder! Realy?
DPI of device screen - dot per inch (pixel per inch) is 480 pixel it is wery important number!

1. App selects smallest dimension of screen. In our case 900 px
   Medium screen have 160 dpi (The density-independent pixel is equivalent to one physical pixel on a 160 dpi screen, which is the baseline density assumed by the system for a "medium" density screen.).



2. App calculate ratio 480 / 160 = 3 (The conversion of dp units to screen pixels: px = dp * (dpi / 160))



3. App calculate smallest dimesnion of screen in dp 900 / 3 = 300 dip or dp (density independed pixel).



4. App selects data from basic values and layout folder because sw600dp is greater than 300dp.

In our case smallest dimension of screen must be at least 1800 real - physical pixels (1800 px / 3 ratio(dpi/160) = 600 dp (dip density independend pixels) to be used data from folders values-sw600dp and layout-sw600dp.


Example 2 see Example 1 abouve
Device: Nexus 7 (2012) selected from Android Studio tool layout editor
Resolution: 800x1280 px
DPI: tvdpi (approximately 213dpi)
Ratio: 1.33 (213 / 160)
Smallest width in px: 800
Convert px to dp: 601.5 (800 / 1.33)
Result:Smallest width is 601.5dp The App to be used data from folders values-sw600dp and layout-sw600dp.