Stetch support for Android View classes added (Feature #2840)

modules/java/generator/src/java/android+CameraBridgeViewBase.java

@@ -15,6 +15,7 @@ import android.content.DialogInterface;
 import android.content.res.TypedArray;
 import android.graphics.Bitmap;
 import android.graphics.Canvas;
+import android.graphics.Rect;
 import android.util.AttributeSet;
 import android.util.Log;
 import android.view.SurfaceHolder;
@@ -44,6 +45,7 @@ public abstract class CameraBridgeViewBase extends SurfaceView implements Surfac
     protected int mFrameHeight;
     protected int mMaxHeight;
     protected int mMaxWidth;
+    protected float mScale = 0;
     protected int mPreviewFormat = Highgui.CV_CAP_ANDROID_COLOR_FRAME_RGBA;
     protected int mCameraIndex = -1;
     protected boolean mEnabled;
@@ -389,7 +391,22 @@ public abstract class CameraBridgeViewBase extends SurfaceView implements Surfac
             Canvas canvas = getHolder().lockCanvas();
             if (canvas != null) {
                 canvas.drawColor(0, android.graphics.PorterDuff.Mode.CLEAR);
-                canvas.drawBitmap(mCacheBitmap, (canvas.getWidth() - mCacheBitmap.getWidth()) / 2, (canvas.getHeight() - mCacheBitmap.getHeight()) / 2, null);
+                Log.d(TAG, "mStretch value: " + mScale);
+
+                if (mScale != 0) {
+                    canvas.drawBitmap(mCacheBitmap, new Rect(0,0,mCacheBitmap.getWidth(), mCacheBitmap.getHeight()),
+                         new Rect((int)((canvas.getWidth() - mScale*mCacheBitmap.getWidth()) / 2),
+                         (int)((canvas.getHeight() - mScale*mCacheBitmap.getHeight()) / 2),
+                         (int)((canvas.getWidth() - mScale*mCacheBitmap.getWidth()) / 2 + mScale*mCacheBitmap.getWidth()),
+                         (int)((canvas.getHeight() - mScale*mCacheBitmap.getHeight()) / 2 + mScale*mCacheBitmap.getHeight())), null);
+                } else {
+                     canvas.drawBitmap(mCacheBitmap, new Rect(0,0,mCacheBitmap.getWidth(), mCacheBitmap.getHeight()),
+                         new Rect((canvas.getWidth() - mCacheBitmap.getWidth()) / 2,
+                         (canvas.getHeight() - mCacheBitmap.getHeight()) / 2,
+                         (canvas.getWidth() - mCacheBitmap.getWidth()) / 2 + mCacheBitmap.getWidth(),
+                         (canvas.getHeight() - mCacheBitmap.getHeight()) / 2 + mCacheBitmap.getHeight()), null);
+                }
+
                 if (mFpsMeter != null) {
                     mFpsMeter.measure();
                     mFpsMeter.draw(canvas, 20, 30);

modules/java/generator/src/java/android+JavaCameraView.java

@@ -10,6 +10,7 @@ import android.hardware.Camera.PreviewCallback;
 import android.os.Build;
 import android.util.AttributeSet;
 import android.util.Log;
+import android.view.ViewGroup.LayoutParams;
 
 import org.opencv.core.CvType;
 import org.opencv.core.Mat;
@@ -130,6 +131,11 @@ public class JavaCameraView extends CameraBridgeViewBase implements PreviewCallb
                     mFrameWidth = params.getPreviewSize().width;
                     mFrameHeight = params.getPreviewSize().height;
 
+                    if ((getLayoutParams().width == LayoutParams.MATCH_PARENT) && (getLayoutParams().height == LayoutParams.MATCH_PARENT))
+                        mScale = Math.min(((float)height)/mFrameHeight, ((float)width)/mFrameWidth);
+                    else
+                        mScale = 0;
+
                     if (mFpsMeter != null) {
                         mFpsMeter.setResolution(mFrameWidth, mFrameHeight);
                     }

modules/java/generator/src/java/android+NativeCameraView.java

@@ -8,6 +8,7 @@ import org.opencv.highgui.VideoCapture;
 import android.content.Context;
 import android.util.AttributeSet;
 import android.util.Log;
+import android.view.ViewGroup.LayoutParams;
 
 /**
  * This class is an implementation of a bridge between SurfaceView and native OpenCV camera.
@@ -102,6 +103,11 @@ public class NativeCameraView extends CameraBridgeViewBase {
             mFrameWidth = (int)frameSize.width;
             mFrameHeight = (int)frameSize.height;
 
+            if ((getLayoutParams().width == LayoutParams.MATCH_PARENT) && (getLayoutParams().height == LayoutParams.MATCH_PARENT))
+                mScale = Math.min(((float)height)/mFrameHeight, ((float)width)/mFrameWidth);
+            else
+                mScale = 0;
+
             if (mFpsMeter != null) {
                 mFpsMeter.setResolution(mFrameWidth, mFrameHeight);
             }

samples/android/tutorial-3-cameracontrol/res/layout/tutorial3_surface_view.xml

@@ -4,8 +4,8 @@
     android:layout_height="match_parent" >
 
     <org.opencv.samples.tutorial3.Tutorial3View
-        android:layout_width="fill_parent"
-        android:layout_height="fill_parent"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
         android:visibility="gone"
         android:id="@+id/tutorial3_activity_java_surface_view" />