Cover Flow Animation in Android.

Hello, Friend today i am going to post Coverflow animation sample code.

CoverFlow.java

import android.content.Context;

import android.graphics.Camera;

import android.graphics.Color;

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;

@SuppressWarnings("deprecation")

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);

this.setBackgroundColor(Color.BLACK);

}

public CoverFlow(Context context, AttributeSet attrs) {

super(context, attrs);

this.setStaticTransformationsEnabled(true);

this.setBackgroundColor(Color.BLACK);

}

public CoverFlow(Context context, AttributeSet attrs, int defStyle) {

super(context, attrs, defStyle);

this.setStaticTransformationsEnabled(true);

this.setBackgroundColor(Color.BLACK);

}

/**

* 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();

}

}

CoverFlowDemo.java

import android.app.Activity;

import android.content.Context;

import android.graphics.Bitmap;

import android.graphics.Bitmap.Config;

import android.graphics.BitmapFactory;

import android.graphics.Canvas;

import android.graphics.LinearGradient;

import android.graphics.Matrix;

import android.graphics.Paint;

import android.graphics.PorterDuff.Mode;

import android.graphics.PorterDuffXfermode;

import android.graphics.Shader.TileMode;

import android.graphics.drawable.BitmapDrawable;

import android.os.Bundle;

import android.view.View;

import android.view.ViewGroup;

import android.widget.BaseAdapter;

import android.widget.ImageView;

public class CoverFlowDemo extends Activity 

{

@SuppressWarnings("deprecation")

@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);

coverFlow.setOnItemClickListener(new OnItemClickListener() {

@Override
public void onItemClick(AdapterView arg0, View arg1, int position,
long arg3) {
Toast.makeText(CoverFlowDemo.this, "" + position,
Toast.LENGTH_LONG).show();
}
});

setContentView(coverFlow);

}

public class ImageAdapter extends BaseAdapter 

{

int mGalleryItemBackground;

private Context mContext;

private Integer[] mImageIds = { R.drawable.android,

R.drawable.img1, R.drawable.img2,

R.drawable.img3, R.drawable.img4,

R.drawable.img1, R.drawable.img2,

R.drawable.img3, R.drawable.img4

};

private ImageView[] mImages;

public ImageAdapter(Context c) {

mContext = c;

mImages = new ImageView[mImageIds.length];

}

@SuppressWarnings("deprecation")

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;

}

@SuppressWarnings("deprecation")

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)));

}

}

}