On orientation changed view button textview not visible Android

Download file from Android device using Android Studio

stackoverflow.com/questions/34603355/android-device-monitor-data-folder-is-empty

• android.com/studio Start Android Studio
• Root device by Your Android model. This example is for 4.4 kingoapp.com/root-tutorials/how-to-root-android-4.4.htm
• Open command prompt console: Start -> Command prompt
• Write path to ADB plus command, and set chmod for every folder on path to apliccations database, for example: (user is Your name|nick!!!! shell@Kraft-A6000:/ is Your device, this is Lenovo A6000, may be different!!!!)
• Every dot is one line in Command prompt console!!!!! Dont write (press Enter) or (Enter). Dont brake line between root@Kraft-A6000:/ # and (Enter)!

C:\Users\user>c:\Users\user\AppData\Local\Android\sdk\platform-tools\adb shell (press Enter)
shell@Kraft-A6000:/ $ 
shell@Kraft-A6000:/ $ su (Enter)
root@Kraft-A6000:/ #
root@Kraft-A6000:/ # su -c "chmod 777 /data" (Enter)
root@Kraft-A6000:/ # su -c "chmod 777 /data/data" (Enter)
root@Kraft-A6000:/ # su -c "chmod 777 /data/data/com.your_package" (Enter)
root@Kraft-A6000:/ # su -c "chmod 777 /data/data/com.your_package/databases" (Enter)
root@Kraft-A6000:/ # su -c "chmod 777 /data/data/com.your_package/databases/database_name.db" (Enter)

• Open Android Studio -> Tools -> Android -> Android Device Monitor (meybe some message box, minimalize all windows to find message box - close message box )
• Pull data from Explorer

Date: 13.07.2020 - 08:23

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

If You have old PC (Android in emulator with high screen resolution uses a lot of memory) or your testing phone have small screen, You can try this trick.
Rename layout folder for small device screen f.g. from layout into layout-swXXXdp and a large layout-sw600dp into layout.
Your phone with small screnn will do select xml file from renamed layout folder (for small screen).
You can to testing rotation with device en stability of fragments if an application changed orientation.
If you have old pc, you can try to make a new virtual device running on older version of Android, which uses less memory of computer.
For testing of rotation stability - application orientation changed - use on emulator Ctrl+F11, Ctrl+F12 key (Windows).

Important
Before the release of application, you have to rename layout folder to older name layout-sw600dp and layout-swXXXdp to layout.

Problem in Android application:

E/AndroidRuntime(416): FATAL EXCEPTION: main
E/AndroidRuntime(416): java.lang.IndexOutOfBoundsException
E/AndroidRuntime(416): 	at java.util.Arrays$ArrayList.get(Arrays.java:75)
E/AndroidRuntime(416): 	at android.widget.ArrayAdapter.getItem(ArrayAdapter.java:298)
E/AndroidRuntime(416): 	at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:351)
E/AndroidRuntime(416): 	at android.widget.ArrayAdapter.getView(ArrayAdapter.java:323)
E/AndroidRuntime(416): 	at android.widget.Spinner.makeAndAddView(Spinner.java:192)
E/AndroidRuntime(416): 	at android.widget.Spinner.layout(Spinner.java:151)
E/AndroidRuntime(416): 	at android.widget.Spinner.onLayout(Spinner.java:115)

Solution: check code for set and get selection

// Spinner _spin1 contain only  49 items 
// you can set max 48 ( range 0 - 48)
// 50 is IndexOutOfBoundsException
_spin1.setSelection(50);

public class ApokusActivity 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);

		}
		
		@Override
		protected void onDraw(Canvas canvas) {
			Paint paint = new Paint();
			
			canvas.drawColor(Color.YELLOW);
            
	         
	         paint.setFilterBitmap(true);
	         Bitmap bitmapOrg = BitmapFactory.decodeResource(getResources(),R.drawable.flower_blue);
	         int targetWidth  = bitmapOrg.getWidth() * 2;
	         int targetHeight = bitmapOrg.getHeight() * 2;
	         Bitmap bmp = Bitmap.createBitmap(targetWidth, targetHeight,Bitmap.Config.ARGB_8888);
	         RectF rectf = new RectF(0, 0, targetWidth, targetHeight);
	         Canvas c = new Canvas(bmp);
	         Path path = new Path();
	         path.addRect(rectf, Path.Direction.CW);
	         c.clipPath(path);
	         c.drawBitmap( bitmapOrg, new Rect(0, 0, bitmapOrg.getWidth(), bitmapOrg.getHeight()),
	                         new Rect(0, 0, targetWidth, targetHeight), paint);
	         Matrix matrix = new Matrix();
	         matrix.postScale(1f, 1f);
	         Bitmap resizedBitmap = Bitmap.createBitmap(bmp, 0, 0, targetWidth, targetHeight, matrix, true);
	         int h = bitmapOrg.getHeight();
           canvas.drawBitmap(bitmapOrg, 10,10, paint);
           canvas.drawBitmap(resizedBitmap, 10,10 + h + 10, paint);
           
		}

	}
}