public class DayDreamService extends DreamService {

	private final static String TAG = "DayDreamService";
	private ViewPager viewPager;
	private List<ImageView> imageViews;

	private int currentItem = 0;
	private MyAdapter pageAdapter;
	boolean nowAction = false;// 當前使用者正在滑動檢視
	String[] fileName = new String[0];
	AssetManager manager;
	private String[] imageUrls=null;
	private ScheduledExecutorService scheduledExecutorService;
	ImageLoader imageLoader;

	@Override
	public void onAttachedToWindow() {
		super.onAttachedToWindow();
		setInteractive(false);
		setFullscreen(true);
		setContentView(R.layout.mydream);
		configImageLoader();
		init();
	}
	
	//退出的時候幹掉自己哈哈哈哈
	@Override
	public void onDetachedFromWindow(){
		super.onDetachedFromWindow();
		
		viewPager = null;
		manager = null;
		imageLoader = null;
		imageViews = null;
		scheduledExecutorService=null;
		imageUrls=null;
		fileName=null;
		pageAdapter=null;
		
		System.exit(0);
		android.os.Process.killProcess(android.os.Process.myPid());
		Log.d(TAG, "onDetachedFromWindow");
	}

	@SuppressLint("HandlerLeak")
	private Handler handler = new Handler() {
		public void handleMessage(android.os.Message msg) {
			viewPager.setCurrentItem(currentItem);
		};
	};

	//獲取目錄下的圖片的絕對路徑
	@SuppressWarnings("finally")
	public String[] getImageName(Context context, String loc) {
		String prefix = "";
		try {
			
			if (loc.equalsIgnoreCase("screen")) {
				manager = context.getAssets();
				fileName = manager.list(loc);
				prefix = "assets://screen/";
			} else {
				File f = new File(loc);
				fileName = f.list();
				prefix = "file:///data/local/tmp/image/";
			}
		}  catch (IOException e) {
			e.printStackTrace();
		} finally {
			if(fileName!=null){
			for (int i = 0; i < fileName.length; i++) {
				fileName[i] = prefix + fileName[i];
			}
			}
			return fileName;
		}
	}

	@Override
	public void onDreamingStarted() {
		scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();
		//20秒換一圖
		scheduledExecutorService.scheduleAtFixedRate(new ScrollTask(), 20, 20, TimeUnit.SECONDS);
		super.onDreamingStarted();
	}

	private class ScrollTask implements Runnable {

		public void run() {
			synchronized (viewPager) {
				if (!nowAction) {
					System.out.println("currentItem: " + currentItem);
					currentItem = currentItem + 1;
					handler.obtainMessage().sendToTarget();
				}
			}
		}
	}

	private class MyPageChangeListener implements OnPageChangeListener {

		public void onPageSelected(int position) {
			currentItem = position;

		}

		public void onPageScrollStateChanged(int arg0) {
			if (arg0 == 0) {
				nowAction = false;
			}
			if (arg0 == 1) {
				nowAction = true;
			}
			if (arg0 == 2) {
			}
		}

		public void onPageScrolled(int arg0, float arg1, int arg2) {

		}

	}

	public void init() {
		//首先獲取/data/local/tmp/image/目錄下的圖片，如果沒有就獲取screen裡的預設圖片
		imageUrls = getImageName(this, "/data/local/tmp/image/");
		if (imageUrls==null||imageUrls.length==0) {
			imageUrls = getImageName(this, "screen");
		}

		imageViews = new ArrayList<ImageView>();

		for (int i = 0; i < imageUrls.length; i++) {
			// ImageView imageView = new ImageView(this);

			ImageView imageView = (ImageView) LayoutInflater.from(this).inflate(R.layout.view_banner, null);
			ImageLoader.getInstance().displayImage(imageUrls[i], imageView);

			// imageView.setImageResource(imageResId[i]);
			imageView.setScaleType(ScaleType.CENTER_CROP);
			imageViews.add(imageView);
		}

		viewPager = (ViewPager) findViewById(R.id.vp);
		pageAdapter = new MyAdapter();
		viewPager.setCurrentItem(Integer.MAX_VALUE / 4);
		viewPager.setAdapter(pageAdapter);

		// 切換動畫實現淡入淡出效果
		viewPager.setPageTransformer(true, new DepthPageTransformer());

		// 設定滑動切換時間
		try {
			Field mScroller = null;
			mScroller = ViewPager.class.getDeclaredField("mScroller");
			mScroller.setAccessible(true);
			FixedSpeedScroller scroller = new FixedSpeedScroller(viewPager.getContext());
			scroller.setScrollDuration(1500);
			mScroller.set(viewPager, scroller);
		} catch (NoSuchFieldException e) {

		} catch (IllegalArgumentException e) {

		} catch (IllegalAccessException e) {

		}

		viewPager.setOnPageChangeListener(new MyPageChangeListener());

	}

	//ViewPager的Adapter
	private class MyAdapter extends PagerAdapter {

		@Override
		public int getCount() {
			//定義一個極大的數，實現偽無線迴圈
			return Integer.MAX_VALUE / 2;
		}

		@Override
		public Object instantiateItem(View arg0, int position) {
			View view = null;
			if (position % imageViews.size() < 0) {
				view = imageViews.get(imageViews.size() + position);
			} else {
				view = imageViews.get(position % imageViews.size());
			}
			ViewParent vp = view.getParent();
			if (vp != null) {
				ViewGroup parent = (ViewGroup) vp;
				parent.removeView(view);
			}
			((ViewPager) arg0).addView(view);

			return view;
		}

		@Override
		public void destroyItem(View arg0, int arg1, Object arg2) {
		}

		@Override
		public boolean isViewFromObject(View arg0, Object arg1) {
			return arg0 == arg1;
		}
	}

	//configImageLoader框架，用來管理和處理圖片
	private void configImageLoader() {
		// 初始化ImageLoader
		@SuppressWarnings("deprecation")
		DisplayImageOptions options = new DisplayImageOptions.Builder().showStubImage(R.drawable.ic_launcher) // 設定圖片下載期間顯示的圖片
				// .showImageForEmptyUri(R.drawable.ic_launcher) //
				// 設定圖片Uri為空或是錯誤的時候顯示的圖片
				.showImageOnFail(R.drawable.icon) // 設定圖片載入或解碼過程中發生錯誤顯示的圖片
				.bitmapConfig(Bitmap.Config.RGB_565) // 圖片太多的時候設定 ，避免記憶體溢位和解碼失敗
				//.cacheInMemory(true) // 設定下載的圖片是否快取在記憶體中
				//.cacheOnDisc(true) // 設定下載的圖片是否快取在SD卡中
				// .displayer(new RoundedBitmapDisplayer(20)) // 設定成圓角圖片
				.build(); // 建立配置過得DisplayImageOption物件

		ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(getApplicationContext())
				.defaultDisplayImageOptions(options).threadPriority(Thread.NORM_PRIORITY - 2)
				.denyCacheImageMultipleSizesInMemory().discCacheFileNameGenerator(new Md5FileNameGenerator())
				.tasksProcessingOrder(QueueProcessingType.LIFO).build();
		ImageLoader.getInstance().init(config);
	}

}
 

/**
 * 自定義高度的viewpapger
 */
public class BaseViewPager extends ViewPager {
	private boolean scrollable = true;

	public BaseViewPager(Context context) {
		super(context);
	}

	public BaseViewPager(Context context, AttributeSet attrs) {
		super(context, attrs);
	}

	/**
	 * 設定viewpager是否可以滾動
	 * 
	 * @param enable
	 */
	public void setScrollable(boolean enable) {
		scrollable = enable;
	}

	@Override
	public boolean onInterceptTouchEvent(MotionEvent event) {
		if (scrollable) {
			return super.onInterceptTouchEvent(event);
		} else {
			return false;
		}
	}
}
 

/**
 * 自定義的淡入淡出效果
 */
public class DepthPageTransformer implements BaseViewPager.PageTransformer {  

	
	 private static final float MIN_ALPHA = 0.0f;    //最小透明度  
	  
	    @SuppressLint("NewApi")
		public void transformPage(View view, float position) {  
	        int pageWidth = view.getWidth();    //得到view寬  
	  
	        if (position < -1) { // [-Infinity,-1)  
	            // This page is way off-screen to the left. 出了左邊螢幕  
	            view.setAlpha(0);  
	  
	        } else if (position <= 1) { // [-1,1]  
	            if (position < 0) {  
	                //消失的頁面  
	                view.setTranslationX(-pageWidth * position);  //阻止消失頁面的滑動  
	            } else {  
	                //出現的頁面  
	                view.setTranslationX(pageWidth);        //直接設定出現的頁面到底  
	                view.setTranslationX(-pageWidth * position);  //阻止出現頁面的滑動  
	            }  
	            // Fade the page relative to its size.  
	            float alphaFactor = Math.max(MIN_ALPHA, 1 - Math.abs(position));  
	            //透明度改變Log  
	            view.setAlpha(alphaFactor);  
	        } else { // (1,+Infinity]  
	            // This page is way off-screen to the right.    出了右邊螢幕  
	            view.setAlpha(0);  
	        }  
	    }  	  
	
}  
 

/**
 * 自定義的Scroller
 */

public class FixedSpeedScroller extends Scroller {
	private int mDuration = 1000;

	public void setScrollDuration(int duration){  
        this.mDuration = duration;  
    } 
	
	public FixedSpeedScroller(Context context) {
		super(context);
		// TODO Auto-generated constructor stub
	}

	public FixedSpeedScroller(Context context, Interpolator interpolator) {
		super(context, interpolator);
	}

	@Override
	public void startScroll(int startX, int startY, int dx, int dy, int duration) {
		// Ignore received duration, use fixed one instead
		super.startScroll(startX, startY, dx, dy, mDuration);
	}

	@Override
	public void startScroll(int startX, int startY, int dx, int dy) {
		// Ignore received duration, use fixed one instead
		super.startScroll(startX, startY, dx, dy, mDuration);
	}

	public void setmDuration(int time) {
		mDuration = time;
	}

	public int getmDuration() {
		return mDuration;
	}

}