android coverflow widget example

gistfile1.java

/*
 * Copyright (C) 2010 Neil Davies
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 * This code is base on the Android Gallery widget and was Created 
 * by Neil Davies neild001 'at' gmail dot com to be a Coverflow widget
 * 
 * @author Neil Davies
 */
package com.example.coverflow;

import java.io.FileInputStream;

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.LinearGradient;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PorterDuffXfermode;
import android.graphics.Bitmap.Config;
import android.graphics.PorterDuff.Mode;
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;
import android.widget.ImageView.ScaleType;

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);
     
     //coverImageAdapter.createReflectedImages();
     
     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.kasabian_kasabian,
             R.drawable.starssailor_silence_is_easy,
             R.drawable.killers_day_and_age,
             R.drawable.garbage_bleed_like_me,
             R.drawable.death_cub_for_cutie_the_photo_album,
             R.drawable.kasabian_kasabian,
             R.drawable.massive_attack_collected,
             R.drawable.muse_the_resistance,
             R.drawable.starssailor_silence_is_easy
     };

     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);
          imageView.setLayoutParams(new CoverFlow.LayoutParams(120, 180));
          imageView.setScaleType(ScaleType.MATRIX);
          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(130, 130));
         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))); 
      } 

 }
}

Taken from http://www.inter-fuser.com/2010/02/android-coverflow-widget-v2.html