Fix Andoid samples: black screen after resume problem

samples/android/15-puzzle/src/org/opencv/samples/puzzle15/SampleCvViewBase.java

@@ -14,7 +14,7 @@ import android.view.SurfaceHolder;
 import android.view.SurfaceView;
 
 public abstract class SampleCvViewBase extends SurfaceView implements SurfaceHolder.Callback, Runnable {
-    private static final String TAG = "Sample::SurfaceView";
+    private static final String TAG = "Sample-15puzzle::SurfaceView";
 
     private SurfaceHolder       mHolder;
     private VideoCapture        mCamera;
@@ -32,8 +32,7 @@ public abstract class SampleCvViewBase extends SurfaceView implements SurfaceHol
             releaseCamera();
             mCamera = new VideoCapture(Highgui.CV_CAP_ANDROID);
             if (!mCamera.isOpened()) {
-	            mCamera.release();
-	            mCamera = null;
+                releaseCamera();
                 Log.e(TAG, "Failed to open native camera");
                 return false;
             }

samples/android/15-puzzle/src/org/opencv/samples/puzzle15/puzzle15Activity.java

@@ -12,6 +12,7 @@ import android.util.Log;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.Window;
+import android.view.WindowManager;
 
 /** Activity class implements LoaderCallbackInterface to handle OpenCV initialization status **/
 public class puzzle15Activity extends Activity
@@ -21,6 +22,7 @@ public class puzzle15Activity extends Activity
     private MenuItem            mItemNewGame;
     private MenuItem            mItemToggleNumbers;
     private puzzle15View        mView = null;
+
     private BaseLoaderCallback  mOpenCVCallBack = new BaseLoaderCallback(this) {
         @Override
         public void onManagerConnected(int status) {
@@ -68,51 +70,38 @@ public class puzzle15Activity extends Activity
         }
     };
 
-    public puzzle15Activity()
-    {
+    public puzzle15Activity() {
         Log.i(TAG, "Instantiated new " + this.getClass());
     }
 
     @Override
     protected void onPause() {
         Log.i(TAG, "onPause");
-		super.onPause();
         if (null != mView)
             mView.releaseCamera();
+        super.onPause();
     }
 
     @Override
     protected void onResume() {
         Log.i(TAG, "onResume");
         super.onResume();
-		if( mView!=null && !mView.openCamera() ) {
-			AlertDialog ad = new AlertDialog.Builder(this).create();
-			ad.setCancelable(false); // This blocks the 'BACK' button
-			ad.setMessage("Fatal error: can't open camera!");
-			ad.setButton(AlertDialog.BUTTON_POSITIVE, "OK", new DialogInterface.OnClickListener() {
-			    public void onClick(DialogInterface dialog, int which) {
-				dialog.dismiss();
-				finish();
-			    }
-			});
-			ad.show();
+
+        Log.i(TAG, "Trying to load OpenCV library");
+        if (!OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_2, this, mOpenCVCallBack))
+        {
+            Log.e(TAG, "Cannot connect to OpenCV Manager");
         }
     }
 
     /** Called when the activity is first created. */
     @Override
-    public void onCreate(Bundle savedInstanceState)
-    {
+    public void onCreate(Bundle savedInstanceState) {
         Log.i(TAG, "onCreate");
         super.onCreate(savedInstanceState);
 
         requestWindowFeature(Window.FEATURE_NO_TITLE);
-
-        Log.i(TAG, "Trying to load OpenCV library");
-        if (!OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_2, this, mOpenCVCallBack))
-        {
-        	Log.e(TAG, "Cannot connect to OpenCV Manager");
-        }
+        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
     }
 
     @Override

samples/android/15-puzzle/src/org/opencv/samples/puzzle15/puzzle15View.java

@@ -83,11 +83,11 @@ public class puzzle15View extends SampleCvViewBase implements OnTouchListener {
         return sum % 2 == 0;
     }
 
-    private void createPuzzle(int cols, int rows) {
+    private void createPuzzle(int cols, int rows, int type) {
         mCells = new Mat[gridArea];
         mCells15 = new Mat[gridArea];
 
-        mRgba15 = new Mat(rows, cols, mRgba.type());
+        mRgba15 = new Mat(rows, cols, type);
         mIndexses = new int[gridArea];
 
         for (int i = 0; i < gridSize; i++) {
@@ -122,7 +122,11 @@ public class puzzle15View extends SampleCvViewBase implements OnTouchListener {
         cols = cols - cols%4;
 
         if (mCells == null)
-            createPuzzle(cols, rows);
+            createPuzzle(cols, rows, mRgba.type());
+        else if(mRgba15.cols() != cols || mRgba15.rows() != rows) {
+            releaseMats();
+            createPuzzle(cols, rows, mRgba.type());
+        }
 
         // copy shuffled tiles
         for (int i = 0; i < gridArea; i++) {
@@ -162,6 +166,15 @@ public class puzzle15View extends SampleCvViewBase implements OnTouchListener {
         super.run();
 
         synchronized (this) {
+            releaseMats();
+
+            if (mRgba != null)
+                mRgba.release();
+            mRgba = null;
+        }
+    }
+
+    private void releaseMats() {
         // Explicitly deallocate Mats
         if (mCells != null) {
             for (Mat m : mCells)
@@ -171,18 +184,15 @@ public class puzzle15View extends SampleCvViewBase implements OnTouchListener {
             for (Mat m : mCells15)
                 m.release();
         }
-            if (mRgba != null)
-                mRgba.release();
+
         if (mRgba15 != null)
             mRgba15.release();
 
-            mRgba = null;
         mRgba15 = null;
         mCells = null;
         mCells15 = null;
         mIndexses = null;
     }
-    }
 
     public boolean onTouch(View v, MotionEvent event) {
         if(mRgba==null) return false;

samples/android/color-blob-detection/src/org/opencv/samples/colorblobdetect/ColorBlobDetectionActivity.java

@@ -10,10 +10,11 @@ import android.content.DialogInterface;
 import android.os.Bundle;
 import android.util.Log;
 import android.view.Window;
+import android.view.WindowManager;
 
 public class ColorBlobDetectionActivity extends Activity {
 
-	private static final String TAG = "Example/ColorBlobDetection";
+    private static final String TAG = "Sample-ColorBlobDetection::Activity";
     private ColorBlobDetectionView mView;
 
     private BaseLoaderCallback  mOpenCVCallBack = new BaseLoaderCallback(this) {
@@ -63,34 +64,27 @@ public class ColorBlobDetectionActivity extends Activity {
         }
     };
 
-	public ColorBlobDetectionActivity()
-	{
+    public ColorBlobDetectionActivity() {
         Log.i(TAG, "Instantiated new " + this.getClass());
     }
 
     @Override
     protected void onPause() {
         Log.i(TAG, "onPause");
-		super.onPause();
         if (null != mView)
             mView.releaseCamera();
+        super.onPause();
     }
 
     @Override
     protected void onResume() {
         Log.i(TAG, "onResume");
         super.onResume();
-		if( (null != mView) && !mView.openCamera() ) {
-			AlertDialog ad = new AlertDialog.Builder(this).create();
-			ad.setCancelable(false); // This blocks the 'BACK' button
-			ad.setMessage("Fatal error: can't open camera!");
-			ad.setButton(AlertDialog.BUTTON_POSITIVE, "OK", new DialogInterface.OnClickListener() {
-			    public void onClick(DialogInterface dialog, int which) {
-				dialog.dismiss();
-				finish();
-			    }
-			});
-			ad.show();
+
+        Log.i(TAG, "Trying to load OpenCV library");
+        if (!OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_2, this, mOpenCVCallBack))
+        {
+            Log.e(TAG, "Cannot connect to OpenCV Manager");
         }
     }
 
@@ -99,12 +93,7 @@ public class ColorBlobDetectionActivity extends Activity {
     public void onCreate(Bundle savedInstanceState) {
         Log.i(TAG, "onCreate");
         super.onCreate(savedInstanceState);
-
         requestWindowFeature(Window.FEATURE_NO_TITLE);
-        Log.i(TAG, "Trying to load OpenCV library");
-        if (!OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_2, this, mOpenCVCallBack))
-        {
-        	Log.e(TAG, "Cannot connect to OpenCV Manager");
-        }
+        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
     }
 }
\ No newline at end of file

samples/android/color-blob-detection/src/org/opencv/samples/colorblobdetect/ColorBlobDetectionView.java

@@ -33,13 +33,12 @@ public class ColorBlobDetectionView extends SampleCvViewBase implements OnTouchL
     private static Size SPECTRUM_SIZE = new Size(200, 32);
 
     // Logcat tag
-	private static final String TAG = "Example/ColorBlobDetection";
+    private static final String TAG = "Sample-ColorBlobDetection::View";
 
     private static final Scalar CONTOUR_COLOR = new Scalar(255,0,0,255);
 
 
-	public ColorBlobDetectionView(Context context)
-	{
+    public ColorBlobDetectionView(Context context) {
         super(context);
         setOnTouchListener(this);
     }
@@ -54,8 +53,7 @@ public class ColorBlobDetectionView extends SampleCvViewBase implements OnTouchL
         super.surfaceCreated(holder);
     }
 
-	public boolean onTouch(View v, MotionEvent event)
-	{
+    public boolean onTouch(View v, MotionEvent event) {
         int cols = mRgba.cols();
         int rows = mRgba.rows();
 
@@ -86,9 +84,7 @@ public class ColorBlobDetectionView extends SampleCvViewBase implements OnTouchL
         mBlobColorHsv = Core.sumElems(touchedRegionHsv);
         int pointCount = touchedRect.width*touchedRect.height;
         for (int i = 0; i < mBlobColorHsv.val.length; i++)
-        {
             mBlobColorHsv.val[i] /= pointCount;
-        }
 
         mBlobColorRgba = converScalarHsv2Rgba(mBlobColorHsv);
 
@@ -110,8 +106,7 @@ public class ColorBlobDetectionView extends SampleCvViewBase implements OnTouchL
 
         Bitmap bmp = Bitmap.createBitmap(mRgba.cols(), mRgba.rows(), Bitmap.Config.ARGB_8888);
 
-        if (mIsColorSelected)
-        {            
+        if (mIsColorSelected) {
             mDetector.process(mRgba);
             List<MatOfPoint> contours = mDetector.getContours();
             Log.e(TAG, "Contours count: " + contours.size());
@@ -135,8 +130,7 @@ public class ColorBlobDetectionView extends SampleCvViewBase implements OnTouchL
         return bmp;
     }
 
-	private Scalar converScalarHsv2Rgba(Scalar hsvColor)
-	{	
+    private Scalar converScalarHsv2Rgba(Scalar hsvColor) {
         Mat pointMatRgba = new Mat();
         Mat pointMatHsv = new Mat(1, 1, CvType.CV_8UC3, hsvColor);
         Imgproc.cvtColor(pointMatHsv, pointMatRgba, Imgproc.COLOR_HSV2RGB_FULL, 4);

samples/android/color-blob-detection/src/org/opencv/samples/colorblobdetect/ColorBlobDetector.java

@@ -11,15 +11,12 @@ import org.opencv.core.MatOfPoint;
 import org.opencv.core.Scalar;
 import org.opencv.imgproc.Imgproc;
 
-public class ColorBlobDetector
-{
-	public void setColorRadius(Scalar radius)
-	{
+public class ColorBlobDetector {
+    public void setColorRadius(Scalar radius) {
         mColorRadius = radius;
     }
 
-	public void setHsvColor(Scalar hsvColor)
-	{
+    public void setHsvColor(Scalar hsvColor) {
         double minH = (hsvColor.val[0] >= mColorRadius.val[0]) ? hsvColor.val[0]-mColorRadius.val[0] : 0;
         double maxH = (hsvColor.val[0]+mColorRadius.val[0] <= 255) ? hsvColor.val[0]+mColorRadius.val[0] : 255;
 
@@ -37,28 +34,23 @@ public class ColorBlobDetector
 
         Mat spectrumHsv = new Mat(1, (int)(maxH-minH), CvType.CV_8UC3);
 
- 		for (int j = 0; j < maxH-minH; j++)
-   		{
+        for (int j = 0; j < maxH-minH; j++) {
             byte[] tmp = {(byte)(minH+j), (byte)255, (byte)255};
             spectrumHsv.put(0, j, tmp);
         }
 
         Imgproc.cvtColor(spectrumHsv, mSpectrum, Imgproc.COLOR_HSV2RGB_FULL, 4);
-
     }
 
-	public Mat getSpectrum()
-	{
+    public Mat getSpectrum() {
         return mSpectrum;
     }
 
-	public void setMinContourArea(double area)
-	{
+    public void setMinContourArea(double area) {
         mMinContourArea = area;
     }
 
-	public void process(Mat rgbaImage)
-	{
+    public void process(Mat rgbaImage) {
         Mat pyrDownMat = new Mat();
 
         Imgproc.pyrDown(rgbaImage, pyrDownMat);
@@ -80,8 +72,7 @@ public class ColorBlobDetector
         // Find max contour area
         double maxArea = 0;
         Iterator<MatOfPoint> each = contours.iterator();
-        while (each.hasNext())
-        {
+        while (each.hasNext()) {
             MatOfPoint wrapper = each.next();
             double area = Imgproc.contourArea(wrapper);
             if (area > maxArea)
@@ -91,19 +82,16 @@ public class ColorBlobDetector
         // Filter contours by area and resize to fit the original image size
         mContours.clear();
         each = contours.iterator();
-        while (each.hasNext())
-        {
+        while (each.hasNext()) {
             MatOfPoint contour = each.next();
-        	if (Imgproc.contourArea(contour) > mMinContourArea*maxArea)
-        	{
+            if (Imgproc.contourArea(contour) > mMinContourArea*maxArea) {
                 Core.multiply(contour, new Scalar(4,4), contour);
                 mContours.add(contour);
             }
         }
     }
 
-	public List<MatOfPoint> getContours()
-	{
+    public List<MatOfPoint> getContours() {
         return mContours;
     }
 

samples/android/color-blob-detection/src/org/opencv/samples/colorblobdetect/SampleCvViewBase.java

@@ -32,8 +32,7 @@ public abstract class SampleCvViewBase extends SurfaceView implements SurfaceHol
             releaseCamera();
             mCamera = new VideoCapture(Highgui.CV_CAP_ANDROID);
             if (!mCamera.isOpened()) {
-	            mCamera.release();
-	            mCamera = null;
+                releaseCamera();
                 Log.e(TAG, "Failed to open native camera");
                 return false;
             }

samples/android/face-detection/jni/DetectionBasedTracker_jni.cpp

@@ -133,7 +133,6 @@ JNIEXPORT void JNICALL Java_org_opencv_samples_fd_DetectionBasedTracker_nativeSe
             DetectorParams.minObjectSize = faceSize;
             ((DetectionBasedTracker*)thiz)->setParameters(DetectorParams);
         }
-
     }
     catch(cv::Exception e)
     {

samples/android/face-detection/src/org/opencv/samples/fd/DetectionBasedTracker.java

@@ -5,33 +5,27 @@ import org.opencv.core.MatOfRect;
 
 public class DetectionBasedTracker
 {
-	public DetectionBasedTracker(String cascadeName, int minFaceSize)
-	{
+    public DetectionBasedTracker(String cascadeName, int minFaceSize) {
         mNativeObj = nativeCreateObject(cascadeName, minFaceSize);
     }
 
-	public void start()
-	{
+    public void start() {
         nativeStart(mNativeObj);
     }
 
-	public void stop()
-	{
+    public void stop() {
         nativeStop(mNativeObj);
     }
 
-	public void setMinFaceSize(int size)
-	{
+    public void setMinFaceSize(int size) {
         nativeSetFaceSize(mNativeObj, size);
     }
 
-	public void detect(Mat imageGray, MatOfRect faces)
-	{
+    public void detect(Mat imageGray, MatOfRect faces) {
         nativeDetect(mNativeObj, imageGray.getNativeObjAddr(), faces.getNativeObjAddr());
     }
 
-	public void release()
-	{
+    public void release() {
         nativeDestroyObject(mNativeObj);
         mNativeObj = 0;
     }
@@ -45,8 +39,7 @@ public class DetectionBasedTracker
     private static native void nativeSetFaceSize(long thiz, int size);
     private static native void nativeDetect(long thiz, long inputImage, long faces);
 
-	static
-	{
+    static {
         System.loadLibrary("detection_based_tracker");
     }
 }

samples/android/face-detection/src/org/opencv/samples/fd/FdActivity.java

@@ -12,16 +12,18 @@ import android.util.Log;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.Window;
+import android.view.WindowManager;
 
 public class FdActivity extends Activity {
-    private static final String TAG         = "Sample::Activity";
+    private static final String TAG         = "Sample-FD::Activity";
 
     private MenuItem            mItemFace50;
     private MenuItem            mItemFace40;
     private MenuItem            mItemFace30;
     private MenuItem            mItemFace20;
     private MenuItem            mItemType;
-    
+    private int                 mDetectorType = 0;
+    private String[]            mDetectorName;
     private FdView              mView;
 
     private BaseLoaderCallback  mOpenCVCallBack = new BaseLoaderCallback(this) {
@@ -77,10 +79,6 @@ public class FdActivity extends Activity {
         }
     };
 
-
-    private int                 mDetectorType = 0;
-    private String[]            mDetectorName; 
-
     public FdActivity() {
         Log.i(TAG, "Instantiated new " + this.getClass());
         mDetectorName = new String[2];
@@ -91,26 +89,20 @@ public class FdActivity extends Activity {
     @Override
     protected void onPause() {
         Log.i(TAG, "onPause");
-		super.onPause();
         if (mView != null)
             mView.releaseCamera();
+        super.onPause();
     }
 
     @Override
     protected void onResume() {
         Log.i(TAG, "onResume");
         super.onResume();
-		if( mView != null && !mView.openCamera() ) {
-			AlertDialog ad = new AlertDialog.Builder(this).create();  
-			ad.setCancelable(false); // This blocks the 'BACK' button  
-			ad.setMessage("Fatal error: can't open camera!");  
-			ad.setButton(AlertDialog.BUTTON_POSITIVE, "OK", new DialogInterface.OnClickListener() {  
-			    public void onClick(DialogInterface dialog, int which) {  
-			        dialog.dismiss();                      
-					finish();
-			    }  
-			});  
-			ad.show();
+
+        Log.i(TAG, "Trying to load OpenCV library");
+        if (!OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_2, this, mOpenCVCallBack))
+        {
+            Log.e(TAG, "Cannot connect to OpenCV Manager");
         }
     }
 
@@ -120,12 +112,7 @@ public class FdActivity extends Activity {
         Log.i(TAG, "onCreate");
         super.onCreate(savedInstanceState);
         requestWindowFeature(Window.FEATURE_NO_TITLE);
-
-        Log.i(TAG, "Trying to load OpenCV library");
-        if (!OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_2, this, mOpenCVCallBack))
-        {
-        	Log.e(TAG, "Cannot connect to OpenCV Manager");
-        }
+        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
     }
 
     @Override
@@ -136,7 +123,6 @@ public class FdActivity extends Activity {
         mItemFace30 = menu.add("Face size 30%");
         mItemFace20 = menu.add("Face size 20%");
         mItemType   = menu.add(mDetectorName[mDetectorType]);
-        		
         return true;
     }
 

samples/android/face-detection/src/org/opencv/samples/fd/FdView.java

@@ -22,7 +22,7 @@ import android.util.Log;
 import android.view.SurfaceHolder;
 
 class FdView extends SampleCvViewBase {
-    private static final String   TAG = "Sample::FdView";
+    private static final String   TAG = "Sample-FD::View";
     private Mat                   mRgba;
     private Mat                   mGray;
     private File                  mCascadeFile;
@@ -39,25 +39,19 @@ class FdView extends SampleCvViewBase {
     private float                 mRelativeFaceSize = 0;
     private int                   mAbsoluteFaceSize = 0;
 
-    public void setMinFaceSize(float faceSize)
-    {
+    public void setMinFaceSize(float faceSize) {
         mRelativeFaceSize = faceSize;
         mAbsoluteFaceSize = 0;
     }
 
-    public void setDetectorType(int type)
-    {
-    	if (mDetectorType != type)
-    	{
+    public void setDetectorType(int type) {
+        if (mDetectorType != type) {
             mDetectorType = type;
 
-    		if (type == NATIVE_DETECTOR)
-    		{
+            if (type == NATIVE_DETECTOR) {
                 Log.i(TAG, "Detection Based Tracker enabled");
                 mNativeDetector.start();
-    		}
-    		else
-    		{
+            } else {
                 Log.i(TAG, "Cascade detector enabled");
                 mNativeDetector.stop();
             }
@@ -114,11 +108,9 @@ class FdView extends SampleCvViewBase {
         capture.retrieve(mRgba, Highgui.CV_CAP_ANDROID_COLOR_FRAME_RGBA);
         capture.retrieve(mGray, Highgui.CV_CAP_ANDROID_GREY_FRAME);
 
-        if (mAbsoluteFaceSize == 0)
-        {
+        if (mAbsoluteFaceSize == 0) {
             int height = mGray.rows();
-        	if (Math.round(height * mRelativeFaceSize) > 0);
-        	{
+            if (Math.round(height * mRelativeFaceSize) > 0) {
                 mAbsoluteFaceSize = Math.round(height * mRelativeFaceSize);
             }
             mNativeDetector.setMinFaceSize(mAbsoluteFaceSize);
@@ -126,19 +118,16 @@ class FdView extends SampleCvViewBase {
 
         MatOfRect faces = new MatOfRect();
 
-        if (mDetectorType == JAVA_DETECTOR)
-        {
+        if (mDetectorType == JAVA_DETECTOR) {
             if (mJavaDetector != null)
-                mJavaDetector.detectMultiScale(mGray, faces, 1.1, 2, 2 // TODO: objdetect.CV_HAAR_SCALE_IMAGE
-                        , new Size(mAbsoluteFaceSize, mAbsoluteFaceSize), new Size());
+                mJavaDetector.detectMultiScale(mGray, faces, 1.1, 2, 2, // TODO: objdetect.CV_HAAR_SCALE_IMAGE
+                        new Size(mAbsoluteFaceSize, mAbsoluteFaceSize), new Size());
         }
-        else if (mDetectorType == NATIVE_DETECTOR)
-        {
+        else if (mDetectorType == NATIVE_DETECTOR) {
             if (mNativeDetector != null)
                 mNativeDetector.detect(mGray, faces);
         }
-        else
-        {
+        else {
             Log.e(TAG, "Detection method is not selected!");
         }
 

samples/android/face-detection/src/org/opencv/samples/fd/SampleCvViewBase.java

@@ -34,8 +34,7 @@ public abstract class SampleCvViewBase extends SurfaceView implements SurfaceHol
             releaseCamera();
             mCamera = new VideoCapture(Highgui.CV_CAP_ANDROID);
             if (!mCamera.isOpened()) {
-	            mCamera.release();
-	            mCamera = null;
+                releaseCamera();
                 Log.e(TAG, "Failed to open native camera");
                 return false;
             }

samples/android/image-manipulations/src/org/opencv/samples/imagemanipulations/ImageManipulationsActivity.java

@@ -12,6 +12,7 @@ import android.util.Log;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.Window;
+import android.view.WindowManager;
 
 public class ImageManipulationsActivity extends Activity {
 
@@ -93,26 +94,20 @@ public class ImageManipulationsActivity extends Activity {
     @Override
     protected void onPause() {
         Log.i(TAG, "onPause");
-		super.onPause();
         if (null != mView)
             mView.releaseCamera();
+        super.onPause();
     }
 
     @Override
     protected void onResume() {
         Log.i(TAG, "onResume");
         super.onResume();
-		if( (null != mView) && !mView.openCamera() ) {
-			AlertDialog ad = new AlertDialog.Builder(this).create();  
-			ad.setCancelable(false); // This blocks the 'BACK' button  
-			ad.setMessage("Fatal error: can't open camera!");  
-			ad.setButton(AlertDialog.BUTTON_POSITIVE, "OK", new DialogInterface.OnClickListener() {  
-			    public void onClick(DialogInterface dialog, int which) {  
-			        dialog.dismiss();                      
-					finish();
-			    }  
-			});  
-			ad.show();
+
+        Log.i(TAG, "Trying to load OpenCV library");
+        if (!OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_2, this, mOpenCVCallBack))
+        {
+            Log.e(TAG, "Cannot connect to OpenCV Manager");
         }
     }
 
@@ -122,12 +117,7 @@ public class ImageManipulationsActivity extends Activity {
         Log.i(TAG, "onCreate");
         super.onCreate(savedInstanceState);
         requestWindowFeature(Window.FEATURE_NO_TITLE);
-
-        Log.i(TAG, "Trying to load OpenCV library");
-        if (!OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_2, this, mOpenCVCallBack))
-        {
-        	Log.e(TAG, "Cannot connect to OpenCV Manager");
-        }
+        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
     }
 
     @Override

samples/android/image-manipulations/src/org/opencv/samples/imagemanipulations/SampleCvViewBase.java

@@ -34,8 +34,7 @@ public abstract class SampleCvViewBase extends SurfaceView implements SurfaceHol
             releaseCamera();
             mCamera = new VideoCapture(Highgui.CV_CAP_ANDROID);
             if (!mCamera.isOpened()) {
-	            mCamera.release();
-	            mCamera = null;
+                releaseCamera();
                 Log.e(TAG, "Failed to open native camera");
                 return false;
             }

samples/android/tutorial-0-androidcamera/src/org/opencv/samples/tutorial0/Sample0View.java

@@ -35,7 +35,7 @@ class Sample0View extends SampleViewBase {
                 rgba[i] = 0xff000000 + (y << 16) + (y << 8) + y;
             }
         } else if (view_mode == VIEW_MODE_RGBA) {
-            for (int i = 0; i < getFrameHeight(); i++)
+            for (int i = 0; i < getFrameHeight(); i++) {
                 for (int j = 0; j < getFrameWidth(); j++) {
                     int index = i * getFrameWidth() + j;
                     int supply_index = frameSize + (i >> 1) * getFrameWidth() + (j & ~1);
@@ -56,6 +56,7 @@ class Sample0View extends SampleViewBase {
                     rgba[i * getFrameWidth() + j] = 0xff000000 + (b << 16) + (g << 8) + r;
                 }
             }
+        }
 
         mBitmap.setPixels(rgba, 0/* offset */, getFrameWidth() /* stride */, 0, 0, getFrameWidth(), getFrameHeight());
         return mBitmap;

samples/android/tutorial-1-addopencv/src/org/opencv/samples/tutorial1/Sample1Java.java

@@ -12,6 +12,7 @@ import android.util.Log;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.Window;
+import android.view.WindowManager;
 
 public class Sample1Java extends Activity {
     private static final String TAG = "Sample::Activity";
@@ -45,6 +46,7 @@ public class Sample1Java extends Activity {
                         ad.show();
                     }
                 } break;
+
                 /** OpenCV loader cannot start Google Play **/
                 case LoaderCallbackInterface.MARKET_ERROR:
                 {
@@ -75,26 +77,20 @@ public class Sample1Java extends Activity {
     @Override
     protected void onPause() {
         Log.i(TAG, "onPause");
-		super.onPause();
         if (null != mView)
             mView.releaseCamera();
+        super.onPause();
     }
 
     @Override
     protected void onResume() {
         Log.i(TAG, "onResume");
         super.onResume();
-		if( (null != mView) && !mView.openCamera() ) {
-			AlertDialog ad = new AlertDialog.Builder(this).create();  
-			ad.setCancelable(false); // This blocks the 'BACK' button  
-			ad.setMessage("Fatal error: can't open camera!");  
-			ad.setButton(AlertDialog.BUTTON_POSITIVE, "OK", new DialogInterface.OnClickListener() {  
-			    public void onClick(DialogInterface dialog, int which) {  
-				dialog.dismiss();
-				finish();
-			    }  
-			});  
-			ad.show();
+
+        Log.i(TAG, "Trying to load OpenCV library");
+        if (!OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_2, this, mOpenCVCallBack))
+        {
+            Log.e(TAG, "Cannot connect to OpenCV Manager");
         }
     }
 
@@ -104,12 +100,7 @@ public class Sample1Java extends Activity {
         Log.i(TAG, "onCreate");
         super.onCreate(savedInstanceState);
         requestWindowFeature(Window.FEATURE_NO_TITLE);
-
-        Log.i(TAG, "Trying to load OpenCV library");
-        if (!OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_2, this, mOpenCVCallBack))
-        {
-        	Log.e(TAG, "Cannot connect to OpenCV Manager");
-        }
+        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
     }
 
     @Override

samples/android/tutorial-2-opencvcamera/src/org/opencv/samples/tutorial2/Sample2NativeCamera.java

@@ -12,6 +12,7 @@ import android.util.Log;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.Window;
+import android.view.WindowManager;
 
 public class Sample2NativeCamera extends Activity {
     private static final String TAG             = "Sample::Activity";
@@ -82,26 +83,20 @@ public class Sample2NativeCamera extends Activity {
     @Override
     protected void onPause() {
         Log.i(TAG, "onPause");
-		super.onPause();
         if (null != mView)
             mView.releaseCamera();
+        super.onPause();
     }
 
     @Override
     protected void onResume() {
         Log.i(TAG, "onResume");
         super.onResume();
-		if((null != mView) && !mView.openCamera() ) {
-			AlertDialog ad = new AlertDialog.Builder(this).create();  
-			ad.setCancelable(false); // This blocks the 'BACK' button  
-			ad.setMessage("Fatal error: can't open camera!");  
-			ad.setButton(AlertDialog.BUTTON_POSITIVE, "OK", new DialogInterface.OnClickListener() {  
-			    public void onClick(DialogInterface dialog, int which) {  
-			        dialog.dismiss();
-					finish();
-			    }  
-			});  
-			ad.show();
+
+        Log.i(TAG, "Trying to load OpenCV library");
+        if (!OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_2, this, mOpenCVCallBack))
+        {
+            Log.e(TAG, "Cannot connect to OpenCV Manager");
         }
     }
 
@@ -111,11 +106,7 @@ public class Sample2NativeCamera extends Activity {
         Log.i(TAG, "onCreate");
         super.onCreate(savedInstanceState);
         requestWindowFeature(Window.FEATURE_NO_TITLE);
-        Log.i(TAG, "Trying to load OpenCV library");
-        if (!OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_2, this, mOpenCVCallBack))
-        {
-        	Log.e(TAG, "Cannot connect to OpenCV Manager");
-        }
+        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
     }
 
     @Override

samples/android/tutorial-2-opencvcamera/src/org/opencv/samples/tutorial2/SampleCvViewBase.java

@@ -32,8 +32,7 @@ public abstract class SampleCvViewBase extends SurfaceView implements SurfaceHol
             releaseCamera();
             mCamera = new VideoCapture(Highgui.CV_CAP_ANDROID);
             if (!mCamera.isOpened()) {
-	            mCamera.release();
-	            mCamera = null;
+                releaseCamera();
                 Log.e(TAG, "Failed to open native camera");
                 return false;
             }

samples/android/tutorial-3-native/src/org/opencv/samples/tutorial3/Sample3Native.java

@@ -10,6 +10,7 @@ import android.content.DialogInterface;
 import android.os.Bundle;
 import android.util.Log;
 import android.view.Window;
+import android.view.WindowManager;
 
 public class Sample3Native extends Activity {
     private static final String TAG = "Sample::Activity";
@@ -73,26 +74,20 @@ public class Sample3Native extends Activity {
     @Override
     protected void onPause() {
         Log.i(TAG, "onPause");
-		super.onPause();
         if (null != mView)
             mView.releaseCamera();
+        super.onPause();
     }
 
     @Override
     protected void onResume() {
         Log.i(TAG, "onResume");
         super.onResume();
-		if((null != mView) && !mView.openCamera() ) {
-			AlertDialog ad = new AlertDialog.Builder(this).create();  
-			ad.setCancelable(false); // This blocks the 'BACK' button  
-			ad.setMessage("Fatal error: can't open camera!");  
-			ad.setButton(AlertDialog.BUTTON_POSITIVE, "OK", new DialogInterface.OnClickListener() {  
-			    public void onClick(DialogInterface dialog, int which) {  
-				dialog.dismiss();
-				finish();
-			    }  
-			});  
-			ad.show();
+
+        Log.i(TAG, "Trying to load OpenCV library");
+        if (!OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_2, this, mOpenCVCallBack))
+        {
+            Log.e(TAG, "Cannot connect to OpenCV Manager");
         }
     }
 
@@ -102,10 +97,6 @@ public class Sample3Native extends Activity {
         Log.i(TAG, "onCreate");
         super.onCreate(savedInstanceState);
         requestWindowFeature(Window.FEATURE_NO_TITLE);
-
-        if (!OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_2, this, mOpenCVCallBack))
-        {
-        	Log.e(TAG, "Cannot connect to OpenCV Manager");
-        }
+        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
     }
 }

samples/android/tutorial-4-mixed/src/org/opencv/samples/tutorial4/Sample4Mixed.java

@@ -12,6 +12,7 @@ import android.util.Log;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.Window;
+import android.view.WindowManager;
 
 public class Sample4Mixed extends Activity {
     private static final String TAG = "Sample::Activity";
@@ -81,26 +82,20 @@ public class Sample4Mixed extends Activity {
     @Override
     protected void onPause() {
         Log.i(TAG, "onPause");
-		super.onPause();
         if (null != mView)
             mView.releaseCamera();
+        super.onPause();
     }
 
     @Override
     protected void onResume() {
         Log.i(TAG, "onResume");
         super.onResume();
-		if((null != mView) && !mView.openCamera() ) {
-			AlertDialog ad = new AlertDialog.Builder(this).create();  
-			ad.setCancelable(false); // This blocks the 'BACK' button  
-			ad.setMessage("Fatal error: can't open camera!");  
-			ad.setButton(AlertDialog.BUTTON_POSITIVE, "OK", new DialogInterface.OnClickListener() {  
-			    public void onClick(DialogInterface dialog, int which) {  
-			        dialog.dismiss();                      
-					finish();
-			    }  
-			});  
-			ad.show();
+
+        Log.i(TAG, "Trying to load OpenCV library");
+        if (!OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_2, this, mOpenCVCallBack))
+        {
+            Log.e(TAG, "Cannot connect to OpenCV Manager");
         }
     }
 
@@ -109,14 +104,8 @@ public class Sample4Mixed extends Activity {
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         Log.i(TAG, "onCreate");
-        
         requestWindowFeature(Window.FEATURE_NO_TITLE);
-        
-        Log.i(TAG, "Trying to load OpenCV library");
-        if (!OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_2, this, mOpenCVCallBack))
-        {
-        	Log.e(TAG, "Cannot connect to OpenCV Manager");
-        }
+        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
     }
 
     public boolean onCreateOptionsMenu(Menu menu) {