package com.roboo.like.netease.view;
import java.io.File;
import java.util.LinkedList;
import android.content.Context;
import android.graphics.Bitmap;
import android.os.Environment;
import android.os.Handler;
import android.os.Handler.Callback;
import android.os.Message;
import android.support.v4.util.LruCache;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.ImageView;
import android.widget.ImageView.ScaleType;
import android.widget.LinearLayout;
import android.widget.ScrollView;
import com.android.volley.Cache;
import com.android.volley.Network;
import com.android.volley.RequestQueue;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.BasicNetwork;
import com.android.volley.toolbox.DiskBasedCache;
import com.android.volley.toolbox.HurlStack;
import com.android.volley.toolbox.ImageLoader;
import com.android.volley.toolbox.ImageLoader.ImageCache;
import com.android.volley.toolbox.ImageLoader.ImageContainer;
import com.android.volley.toolbox.ImageLoader.ImageListener;
import com.roboo.like.netease.R;
public class MyScrollView extends ScrollView implements OnTouchListener
{
private static final int PAGE_SIZE = 20;
private int mPage;
private static String[] mImages = new String[] {
"http://img.my.csdn.net/uploads/201309/01/1378037235_3453.jpg",
"http://img.my.csdn.net/uploads/201309/01/1378037235_7476.jpg",
"http://img.my.csdn.net/uploads/201309/01/1378037235_9280.jpg",
"http://img.my.csdn.net/uploads/201309/01/1378037234_3539.jpg",
"http://img.my.csdn.net/uploads/201309/01/1378037234_6318.jpg",
"http://img.my.csdn.net/uploads/201309/01/1378037194_2965.jpg",
"http://img.my.csdn.net/uploads/201309/01/1378037193_1687.jpg",
"http://img.my.csdn.net/uploads/201309/01/1378037193_1286.jpg",
"http://img.my.csdn.net/uploads/201309/01/1378037192_8379.jpg",
"http://img.my.csdn.net/uploads/201309/01/1378037178_9374.jpg",
"http://img.my.csdn.net/uploads/201309/01/1378037177_1254.jpg",
"http://img.my.csdn.net/uploads/201309/01/1378037177_6203.jpg",
"http://img.my.csdn.net/uploads/201309/01/1378037152_6352.jpg",
"http://img.my.csdn.net/uploads/201309/01/1378037151_9565.jpg",
"http://img.my.csdn.net/uploads/201309/01/1378037151_7904.jpg",
"http://img.my.csdn.net/uploads/201309/01/1378037148_7104.jpg",
"http://img.my.csdn.net/uploads/201309/01/1378037129_8825.jpg",
"http://img.my.csdn.net/uploads/201309/01/1378037128_5291.jpg",
"http://img.my.csdn.net/uploads/201309/01/1378037128_3531.jpg",
"http://img.my.csdn.net/uploads/201309/01/1378037127_1085.jpg",
"http://img.my.csdn.net/uploads/201309/01/1378037095_7515.jpg",
"http://img.my.csdn.net/uploads/201309/01/1378037094_8001.jpg",
"http://img.my.csdn.net/uploads/201309/01/1378037093_7168.jpg",
"http://img.my.csdn.net/uploads/201309/01/1378037091_4950.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949643_6410.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949642_6939.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949630_4505.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949630_4593.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949629_7309.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949629_8247.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949615_1986.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949614_8482.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949614_3743.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949614_4199.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949599_3416.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949599_5269.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949598_7858.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949598_9982.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949578_2770.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949578_8744.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949577_5210.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949577_1998.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949482_8813.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949481_6577.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949480_4490.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949455_6792.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949455_6345.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949442_4553.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949441_8987.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949441_5454.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949454_6367.jpg",
"http://img.my.csdn.net/uploads/201308/31/1377949442_4562.jpg"
};
private LinkedList<ImageView> mImageViews = new LinkedList<ImageView>();
private LinearLayout mLinearContainer;
private LinearLayout mFirstLinearContainer;
private LinearLayout mSecondLinearContainer;
private LinearLayout mThirdLinearContainer;
private int mFirstColumnHeight, mSecondColumnHeight, mThirdColumnHeight;
private ImageLoader mImageLoader;
private RequestQueue mRequestQueue;
private Handler mHandler;
private int mFirstLinearContainerWidth ;
private int mLastScrollY = -1;
/**
* MyScrollView height
*/
private int mScrollViewHeight;
private boolean isFirstLoad = true;
private BitmapImageCache mImageCache;
public MyScrollView(Context context)
{
super(context);
init(context);
}
public MyScrollView(Context context, AttributeSet attrs, int defStyle)
{
super(context, attrs, defStyle);
init(context);
}
public MyScrollView(Context context, AttributeSet attrs)
{
super(context, attrs);
init(context);
}
private void init(Context context)
{
Cache cache = new DiskBasedCache(new File("/mnt/sdcard/android", "volley"));
Network network = new BasicNetwork(new HurlStack());
mRequestQueue = new RequestQueue(cache, network);
mRequestQueue.start();
mImageCache = new BitmapImageCache();
mImageLoader = new ImageLoader(mRequestQueue, mImageCache);
setOnTouchListener(this);
mHandler = new Handler(new Callback()
{
@Override
public boolean handleMessage(Message msg)
{
MyScrollView myScrollView = (MyScrollView) msg.obj;
int scrollY = myScrollView.getScrollY();
// 如果当前的滚动位置和上次相同，表示已停止滚动
if (scrollY == mLastScrollY)
{
// 当滚动的最底部，并且当前没有正在下载的任务时，开始加载下一页的图片
if (mScrollViewHeight + scrollY >= mLinearContainer.getHeight())
{
myScrollView.loadMoreImages();
}
myScrollView.checkVisibility();
}
else
{
mLastScrollY = scrollY;
Message message = new Message();
message.obj = myScrollView;
// 5毫秒后再次对滚动位置进行判断
mHandler.sendMessageDelayed(message, 5);
}
return false;
}
});
}
protected void checkVisibility()
{
for (int i = 0; i < mImageViews.size(); i++)
{
ImageView imageView = mImageViews.get(i);
int borderTop = (Integer) imageView.getTag(R.string.border_top);
int borderBottom = (Integer) imageView.getTag(R.string.border_bottom);
if (borderBottom > getScrollY() && borderTop < getScrollY() + mScrollViewHeight)
{
String imageUrl = (String) imageView.getTag(R.string.image_url);
Bitmap bitmap = mImageCache.getBitmap(imageUrl);
if (bitmap != null)
{
imageView.setImageBitmap(bitmap);
}
else
{
mImageLoader.get(imageUrl, ImageLoader.getImageListener(imageView, R.drawable.ic_empty_photo, R.drawable.ic_stub));
}
}
else
{
imageView.setImageResource(R.drawable.ic_stub);
}
}
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b)
{
super.onLayout(changed, l, t, r, b);
if (changed && isFirstLoad)
{
mScrollViewHeight = getHeight();
mLinearContainer = (LinearLayout) getChildAt(0);
mFirstLinearContainer = (LinearLayout) mLinearContainer.findViewById(R.id.first_linear_container);
mSecondLinearContainer = (LinearLayout) mLinearContainer.findViewById(R.id.second_linear_container);
mThirdLinearContainer = (LinearLayout) mLinearContainer.findViewById(R.id.third_linear_container);
mFirstLinearContainerWidth = mFirstLinearContainer.getWidth();
isFirstLoad = false;
loadMoreImages();
}
}
private void loadMoreImages()
{
if (isHasSDCard())
{
int startIndex = mPage * PAGE_SIZE;
int endIndex = (1 + mPage) * PAGE_SIZE;
if (startIndex < mImages.length)
{
if (endIndex > mImages.length)
{
endIndex = mImages.length;
}
for (int i = startIndex; i < endIndex; i++)
{
addImageViewToContainer(i);
}
}
}
}
private void addImageViewToContainer(final int i)
{
final ImageView imageView = new ImageView(getContext());
imageView.setLayoutParams(new LinearLayout.LayoutParams(mFirstLinearContainerWidth, 160));
imageView.setScaleType(ScaleType.FIT_XY);
imageView.setPadding(5, 5, 5, 5);
imageView.setTag(R.string.image_url, mImages[i]);
mImageLoader.get(mImages[i], new ImageListener()
{
@Override
public void onErrorResponse(VolleyError error)
{
imageView.setImageResource(R.drawable.ic_stub);
findImageToAddWhichColumnLinearLayout(imageView, 160).addView(imageView);
}
@Override
public void onResponse(ImageContainer response, boolean isImmediate)
{
if (null != response)
{
int height = 160;
if (null != response.getBitmap())
{
Bitmap bitmap = response.getBitmap();
mImageCache.mLruCache.put(mImages[i], bitmap);
imageView.setImageBitmap(bitmap);
height =(int) (bitmap.getHeight() *((float)mFirstLinearContainerWidth/bitmap.getWidth()));
imageView.setLayoutParams(new LinearLayout.LayoutParams(mFirstLinearContainerWidth,height));
findImageToAddWhichColumnLinearLayout(imageView, height).addView(imageView);
}
}
}
});
mImageViews.add(i, imageView);
}
private boolean isHasSDCard()
{
return Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState());
}
private LinearLayout findImageToAddWhichColumnLinearLayout(ImageView imageView, int imageHeight)
{
if (mFirstColumnHeight < mSecondColumnHeight)
{
if (mFirstColumnHeight < mThirdColumnHeight)
{
imageView.setTag(R.string.border_top, mFirstColumnHeight);
mFirstColumnHeight += imageHeight;
imageView.setTag(R.string.border_bottom, mFirstColumnHeight);
return mFirstLinearContainer;
}
else
{
imageView.setTag(R.string.border_top, mThirdColumnHeight);
mThirdColumnHeight += imageHeight;
imageView.setTag(R.string.border_bottom, mThirdColumnHeight);
return mThirdLinearContainer;
}
}
else
{
if (mSecondColumnHeight <= mThirdColumnHeight)
{
imageView.setTag(R.string.border_top, mSecondColumnHeight);
mSecondColumnHeight += imageHeight;
imageView.setTag(R.string.border_bottom, mSecondColumnHeight);
return mSecondLinearContainer;
}
else
{
imageView.setTag(R.string.border_top, mThirdColumnHeight);
mThirdColumnHeight += imageHeight;
imageView.setTag(R.string.border_bottom, mThirdColumnHeight);
return mThirdLinearContainer;
}
}
}
private class BitmapImageCache implements ImageCache
{
private static final int MAX_CACHE_SIZE = 10 * 1024 * 1024;
private LruCache<String, Bitmap> mLruCache = new LruCache<String, Bitmap>(MAX_CACHE_SIZE);
@Override
public Bitmap getBitmap(String url)
{
return mLruCache.get(url);
}
@Override
public void putBitmap(String url, Bitmap bitmap)
{
mLruCache.put(url, bitmap);
}
}
@Override
public boolean onTouch(View v, MotionEvent event)
{
if (event.getAction() == MotionEvent.ACTION_UP)
{
Message message = new Message();
message.obj = this;
mHandler.sendMessageDelayed(message, 5);
}
return false;
}
}