Images with Coverflow like animation in ANDROID

AIM:  To show an array of images in CoverFlow like animation in ANDROID Gallery.
Solution:
We need to create one custom gallery extends Gallery.


File 1: 
import android.content.Context;
import android.graphics.Camera;
import android.graphics.Matrix;
import android.util.AttributeSet;
import android.view.View;
import android.view.animation.Transformation;
import android.widget.Gallery;
import android.widget.ImageView;

public class CoverFlow extends Gallery {

    /**
     * Graphics Camera used for transforming the matrix of ImageViews
     */
    private Camera mCamera = new Camera();

    /**
     * The maximum angle the Child ImageView will be rotated by
     */  
    private int mMaxRotationAngle = 60;
  
    /**
     * The maximum zoom on the centre Child
     */
    private int mMaxZoom = -120;
  
    /**
     * The Centre of the Coverflow
     */  
    private int mCoveflowCenter;
  
 public CoverFlow(Context context) {
  super(context);
  this.setStaticTransformationsEnabled(true);
 }

 public CoverFlow(Context context, AttributeSet attrs) {
  super(context, attrs);
        this.setStaticTransformationsEnabled(true);
 }

  public CoverFlow(Context context, AttributeSet attrs, int defStyle) {
   super(context, attrs, defStyle);
   this.setStaticTransformationsEnabled(true);  
  }
 
    /**
     * Get the max rotational angle of the image
  * @return the mMaxRotationAngle
  */
 public int getMaxRotationAngle() {
  return mMaxRotationAngle;
 }

 /**
  * Set the max rotational angle of each image
  * @param maxRotationAngle the mMaxRotationAngle to set
  */
 public void setMaxRotationAngle(int maxRotationAngle) {
  mMaxRotationAngle = maxRotationAngle;
 }

 /**
  * Get the Max zoom of the centre image
  * @return the mMaxZoom
  */
 public int getMaxZoom() {
  return mMaxZoom;
 }

 /**
  * Set the max zoom of the centre image
  * @param maxZoom the mMaxZoom to set
  */
 public void setMaxZoom(int maxZoom) {
  mMaxZoom = maxZoom;
 }

 /**
     * Get the Centre of the Coverflow
     * @return The centre of this Coverflow.
     */
    private int getCenterOfCoverflow() {
        return (getWidth() - getPaddingLeft() - getPaddingRight()) / 2 + getPaddingLeft();
    }
  
    /**
     * Get the Centre of the View
     * @return The centre of the given view.
     */
    private static int getCenterOfView(View view) {
        return view.getLeft() + view.getWidth() / 2;
    }
    /**
  * {@inheritDoc}
  *
  * @see #setStaticTransformationsEnabled(boolean)
  */
    protected boolean getChildStaticTransformation(View child, Transformation t) {
 
  final int childCenter = getCenterOfView(child);
  final int childWidth = child.getWidth() ;
  int rotationAngle = 0;
 
  t.clear();
  t.setTransformationType(Transformation.TYPE_MATRIX);
 
        if (childCenter == mCoveflowCenter) {
            transformImageBitmap((ImageView) child, t, 0);
        } else {    
            rotationAngle = (int) (((float) (mCoveflowCenter - childCenter)/ childWidth) *  mMaxRotationAngle);
            if (Math.abs(rotationAngle) > mMaxRotationAngle) {
             rotationAngle = (rotationAngle < 0) ? -mMaxRotationAngle : mMaxRotationAngle;  
            }
            transformImageBitmap((ImageView) child, t, rotationAngle);        
        }  
            
  return true;
 }

 /**
  * This is called during layout when the size of this view has changed. If
  * you were just added to the view hierarchy, you're called with the old
  * values of 0.
  *
  * @param w Current width of this view.
  * @param h Current height of this view.
  * @param oldw Old width of this view.
  * @param oldh Old height of this view.
     */
     protected void onSizeChanged(int w, int h, int oldw, int oldh) {
      mCoveflowCenter = getCenterOfCoverflow();
      super.onSizeChanged(w, h, oldw, oldh);
     }
 
     /**
      * Transform the Image Bitmap by the Angle passed
      *
      * @param imageView ImageView the ImageView whose bitmap we want to rotate
      * @param t transformation
      * @param rotationAngle the Angle by which to rotate the Bitmap
      */
     private void transformImageBitmap(ImageView child, Transformation t, int rotationAngle) {          
      mCamera.save();
      final Matrix imageMatrix = t.getMatrix();;
      final int imageHeight = child.getLayoutParams().height;;
      final int imageWidth = child.getLayoutParams().width;
      final int rotation = Math.abs(rotationAngle);
                    
      mCamera.translate(0.0f, 0.0f, 100.0f);
        
      //As the angle of the view gets less, zoom in    
      if ( rotation < mMaxRotationAngle ) {
       float zoomAmount = (float) (mMaxZoom +  (rotation * 1.5));
       mCamera.translate(0.0f, 0.0f, zoomAmount);        
      }
    
      mCamera.rotateY(rotationAngle);
      mCamera.getMatrix(imageMatrix);              
      imageMatrix.preTranslate(-(imageWidth/2), -(imageHeight/2));
      imageMatrix.postTranslate((imageWidth/2), (imageHeight/2));
      mCamera.restore();
 }
}

File 2:

Activity Class ,where you need to show the Coverflow of Images

public class CoverFlowExample extends Activity {

    /** Called when the activity is first created. */

    @Override

    public void onCreate(Bundle savedInstanceState) {

     super.onCreate(savedInstanceState);

     

     CoverFlow coverFlow;

     coverFlow = new CoverFlow(this);

     

     coverFlow.setAdapter(new ImageAdapter(this));

     ImageAdapter coverImageAdapter =  new ImageAdapter(this);

     

      coverFlow.setAdapter(coverImageAdapter);

     

     coverFlow.setSpacing(-25);

     coverFlow.setSelection(4, true);

     coverFlow.setAnimationDuration(1000);

         

     setContentView(coverFlow);

    }

 public class ImageAdapter extends BaseAdapter {

     int mGalleryItemBackground;

     private Context mContext;

     private FileInputStream fis;

        

     private Integer[] mImageIds = {

     R.drawable.yadi,

             R.drawable.yadi_1,

             R.drawable.yadi_2,

             R.drawable.yadi_3,

             R.drawable.yadi_4,

             R.drawable.yadi_5,

             R.drawable.yadi_6,

             R.drawable.yadi_7,

             R.drawable.yadi_8

             

     };

     private ImageView[] mImages;

     

     public ImageAdapter(Context c) {

      mContext = c;

      mImages = new ImageView[mImageIds.length];

     }

  public boolean createReflectedImages() {

          //The gap we want between the reflection and the original image

          final int reflectionGap = 4;

          

          

          int index = 0;

          for (int imageId : mImageIds) {

        Bitmap originalImage = BitmapFactory.decodeResource(getResources(), 

          imageId);

           int width = originalImage.getWidth();

           int height = originalImage.getHeight();

           

     

           //This will not scale but will flip on the Y axis

           Matrix matrix = new Matrix();

           matrix.preScale(1, -1);

           

           //Create a Bitmap with the flip matrix applied to it.

           //We only want the bottom half of the image

           Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0, height/2, width, height/2, matrix, false);

           

               

           //Create a new bitmap with same width but taller to fit reflection

           Bitmap bitmapWithReflection = Bitmap.createBitmap(width 

             , (height + height/2), Config.ARGB_8888);

         

          //Create a new Canvas with the bitmap that's big enough for

          //the image plus gap plus reflection

          Canvas canvas = new Canvas(bitmapWithReflection);

          //Draw in the original image

          canvas.drawBitmap(originalImage, 0, 0, null);

          //Draw in the gap

          Paint deafaultPaint = new Paint();

          canvas.drawRect(0, height, width, height + reflectionGap, deafaultPaint);

          //Draw in the reflection

          canvas.drawBitmap(reflectionImage,0, height + reflectionGap, null);

          

          //Create a shader that is a linear gradient that covers the reflection

          Paint paint = new Paint(); 

          LinearGradient shader = new LinearGradient(0, originalImage.getHeight(), 0, 

            bitmapWithReflection.getHeight() + reflectionGap, 0x70ffffff, 0x00ffffff, 

            TileMode.CLAMP); 

          //Set the paint to use this shader (linear gradient)

          paint.setShader(shader); 

          //Set the Transfer mode to be porter duff and destination in

          paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN)); 

          //Draw a rectangle using the paint with our linear gradient

          canvas.drawRect(0, height, width, 

            bitmapWithReflection.getHeight() + reflectionGap, paint); 

          

          ImageView imageView = new ImageView(mContext);

          imageView.setImageBitmap(bitmapWithReflection);

          android.widget.Gallery.LayoutParams imgLayout = new CoverFlow.LayoutParams(320, 480);

          imageView.setLayoutParams(imgLayout);

          imageView.setPadding(30, 100, 20, 20);

          mImages[index++] = imageView;

          

          }

       return true;

  }

     public int getCount() {

         return mImageIds.length;

     }

     public Object getItem(int position) {

         return position;

     }

     public long getItemId(int position) {

         return position;

     }

     public View getView(int position, View convertView, ViewGroup parent) {

      //Use this code if you want to load from resources

         ImageView i = new ImageView(mContext);

         i.setImageResource(mImageIds[position]);

         i.setLayoutParams(new CoverFlow.LayoutParams(380, 450));

         i.setScaleType(ImageView.ScaleType.CENTER_INSIDE); 

         

         //Make sure we set anti-aliasing otherwise we get jaggies

         BitmapDrawable drawable = (BitmapDrawable) i.getDrawable();

         drawable.setAntiAlias(true);

         return i;

      

      //return mImages[position];

     }

   /** Returns the size (0.0f to 1.0f) of the views 

      * depending on the 'offset' to the center. */ 

      public float getScale(boolean focused, int offset) { 

        /* Formula: 1 / (2 ^ offset) */ 

          return Math.max(0, 1.0f / (float)Math.pow(2, Math.abs(offset))); 

      } 

 }

}

The output will be as follows ( in GAlaXY TABlet) 

Please let me know if any.