Android之GridView的Item移动

调用:

public class AniGridViewActivity extends Activity {
    /** GridView. */
    private DragGrid gridView;
    TranslateAnimation left, right;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        com.cn.theodore.util.Configure.init(this);
        gridView = (DragGrid) findViewById(R.id.gridview);
        ArrayList<String> l = new ArrayList<String>();
        for (int i = 0; i < 8; i++) {
            l.add("" + i);
        }
        DateAdapter adapter = new DateAdapter(AniGridViewActivity.this, l);
        gridView.setAdapter(adapter);
    }
}

重写的GridView：

public class DragGrid extends GridView {

    private int dragPosition;
    private int dropPosition;
    private int holdPosition;
    private int startPosition;
    private int specialPosition = -1;
    private int leftBottomPosition = -1;
    
    private int nColumns = 3;
    private int nRows;
    private int Remainder;
    
    private int itemTotalCount;    
    private int halfItemWidth;    

    private ImageView dragImageView = null;
    private ViewGroup dragItemView = null;

    private WindowManager windowManager = null;
    private WindowManager.LayoutParams windowParams = null;
    
    private int mLastX,xtox;
    private int mLastY,ytoy;
    private int specialItemY;
    private int leftBtmItemY;
    
    private String LastAnimationID;
    
    private boolean isCountXY = false;    
    private boolean isMoving = false;
    
    public DragGrid(Context context, AttributeSet attrs) {
        super(context, attrs);        
    }

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

    boolean flag = false;

    public void setLongFlag(boolean temp) {
        flag = temp;
    }
    
    public boolean setOnItemLongClickListener(final MotionEvent ev) {
        this.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
            @Override
            public boolean onItemLongClick(AdapterView<?> arg0, View arg1,
                    int arg2, long arg3) {

                int x = (int) ev.getX();
                int y = (int) ev.getY();
                mLastX=x;
                mLastY=y;
                startPosition = dragPosition = dropPosition = arg2;
                if (dragPosition == AdapterView.INVALID_POSITION) {

                }                
                ViewGroup itemView = (ViewGroup) getChildAt(dragPosition
                        - getFirstVisiblePosition());
                if(!isCountXY){
                    halfItemWidth = itemView.getWidth()/2;
                    int rows;
                    itemTotalCount = getCount();
                    rows = itemTotalCount/nColumns;
                    Remainder = itemTotalCount%nColumns;
                    nRows =  Remainder == 0 ?  rows : rows + 1;
                    specialPosition = itemTotalCount - 1 - Remainder;
                    if(Remainder!=1)
                        leftBottomPosition = nColumns*(nRows-1);
                    if(Remainder == 0 || nRows == 1)
                        specialPosition = -1;                
                    isCountXY = true;
                }
                if(specialPosition != dragPosition && dragPosition != -1){
                    specialItemY = getChildAt(specialPosition).getTop();
                }else{
                    specialItemY = -1;
                }
                if(leftBottomPosition != dragPosition && dragPosition != -1){
                    leftBtmItemY = getChildAt(leftBottomPosition).getTop();
                }else{
                    leftBtmItemY = -1;
                }
                dragItemView = itemView;
                itemView.destroyDrawingCache();
                itemView.setDrawingCacheEnabled(true);
                itemView.setDrawingCacheBackgroundColor(0x000000);
                Bitmap bm = Bitmap.createBitmap(itemView.getDrawingCache(true));
                Bitmap bitmap = Bitmap.createBitmap(bm, 8, 8, bm.getWidth()-8, bm.getHeight()-8);
                startDrag(bitmap, x, y);
                hideDropItem();
                itemView.setVisibility(View.INVISIBLE);                
                isMoving = false;
                return false;
            };
        });
        return super.onInterceptTouchEvent(ev);
    }
    
    public void GetItemShadow(int x,int y){
        
        
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        if (ev.getAction() == MotionEvent.ACTION_DOWN) {
            return setOnItemLongClickListener(ev);
        }
        return super.onInterceptTouchEvent(ev);
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        if (dragImageView != null
                && dragPosition != AdapterView.INVALID_POSITION) {
            int x = (int) ev.getX();
            int y = (int) ev.getY();
            switch (ev.getAction()) {
            case MotionEvent.ACTION_MOVE:
                if(!isCountXY) {
                    xtox = x-mLastX;
                    ytoy = y-mLastY;
                    isCountXY= true;
                }
                onDrag(x, y);
                if(!isMoving )
                    OnMove(x,y);            
                break;
            case MotionEvent.ACTION_UP:
                stopDrag();
                onDrop(x, y);
                break;
            }
        }
        return super.onTouchEvent(ev);
    }

    private void startDrag(Bitmap bm, int x, int y) {
        stopDrag();
        windowParams = new WindowManager.LayoutParams();
        windowParams.gravity = Gravity.TOP | Gravity.LEFT;
        windowParams.x = dragItemView.getLeft() + 8;
        windowParams.y = dragItemView.getTop()+(int)(45*Configure.screenDensity);
        windowParams.height = WindowManager.LayoutParams.WRAP_CONTENT;
        windowParams.width = WindowManager.LayoutParams.WRAP_CONTENT;
        windowParams.alpha = 0.8f;

        ImageView iv = new ImageView(getContext());
        iv.setImageBitmap(bm);
        windowManager = (WindowManager) getContext().getSystemService(
                Context.WINDOW_SERVICE);
        windowManager.addView(iv, windowParams);
        
        dragImageView = iv;
    }
    
    public  void OnMove(int x, int y){
        int TempPosition = pointToPosition(x,y);
        int sOffsetY = specialItemY == -1 ? y - mLastY : y - specialItemY - halfItemWidth;
        int lOffsetY = leftBtmItemY == -1 ? y - mLastY : y - leftBtmItemY - halfItemWidth;
        if(TempPosition != AdapterView.INVALID_POSITION && TempPosition != dragPosition){
            dropPosition = TempPosition;
        }else if(specialPosition != -1 && dragPosition == specialPosition && sOffsetY >= halfItemWidth){
            dropPosition = (itemTotalCount - 1);
        }else if(leftBottomPosition != -1 && dragPosition == leftBottomPosition && lOffsetY >= halfItemWidth){
            dropPosition = (itemTotalCount - 1);
        }    
        if(dragPosition != startPosition)
            dragPosition = startPosition;
        int MoveNum = dropPosition - dragPosition;
        if(dragPosition != startPosition && dragPosition == dropPosition)
            MoveNum = 0;
        if(MoveNum != 0){
            int itemMoveNum = Math.abs(MoveNum);
            float Xoffset,Yoffset;
            for (int i = 0;i < itemMoveNum;i++){
            if(MoveNum > 0){
                holdPosition = dragPosition + 1;
                Xoffset = (dragPosition/nColumns == holdPosition/nColumns) ? (-1) : (nColumns -1);
                Yoffset = (dragPosition/nColumns == holdPosition/nColumns) ? 0 : (-1);
            }else{
                holdPosition = dragPosition - 1;
                Xoffset = (dragPosition/nColumns == holdPosition/nColumns) ? 1 : (-(nColumns-1));
                Yoffset = (dragPosition/nColumns == holdPosition/nColumns) ? 0 : 1;
            }
            ViewGroup moveView = (ViewGroup)getChildAt(holdPosition);                
            Animation animation = getMoveAnimation(Xoffset,Yoffset);
            moveView.startAnimation(animation);
            dragPosition = holdPosition;
            if(dragPosition == dropPosition)
                LastAnimationID = animation.toString();
            final DateAdapter adapter = (DateAdapter)this.getAdapter();
            animation.setAnimationListener(new Animation.AnimationListener() {
                    
                @Override
                public void onAnimationStart(Animation animation) {
                        // TODO Auto-generated method stub
                    isMoving = true;
                }
                    
                @Override
                public void onAnimationRepeat(Animation animation) {
                        // TODO Auto-generated method stub
                        
                }
                    
                @Override
                public void onAnimationEnd(Animation animation) {
                        // TODO Auto-generated method stub
                    String animaionID = animation.toString();
                    if(animaionID.equalsIgnoreCase(LastAnimationID)){
                        adapter.exchange(startPosition, dropPosition);
                        startPosition = dropPosition;
                        isMoving = false;
                    }                    
                }
            });    
          }
       }
    }
    
    private void onDrop(int x,int y){
        final DateAdapter adapter = (DateAdapter) this.getAdapter();
        adapter.showDropItem(true);
        adapter.notifyDataSetChanged();    
    }

    private void onDrag(int x, int y) {
        if (dragImageView != null) {
            windowParams.alpha = 0.8f;
            windowParams.x = (x-mLastX-xtox)+dragItemView.getLeft()+8;
//            windowParams.y = (y-mLastY-ytoy)+dragItemView.getTop()+(int)(45*Configure.screenDensity);
            windowParams.y = y;
            windowManager.updateViewLayout(dragImageView, windowParams);
        }
    }
    
    private void stopDrag() {
        if (dragImageView != null) {
            windowManager.removeView(dragImageView);
            dragImageView = null;
        }
    }
    
    private void hideDropItem(){
        final DateAdapter adapter = (DateAdapter)this.getAdapter();
        adapter.showDropItem(false);
    }
    
    public Animation getMoveAnimation(float x,float y){
        TranslateAnimation go = new TranslateAnimation(Animation.RELATIVE_TO_SELF, 0, Animation.RELATIVE_TO_SELF, x, 
                Animation.RELATIVE_TO_SELF, 0, Animation.RELATIVE_TO_SELF, y);
        go.setFillAfter(true);
        go.setDuration(300);    
        return go;
    }
}

GridView使用的Adapter：

public class DateAdapter extends BaseAdapter {

    private Context context;
    private List<String> lstDate;
    private TextView txtAge;
    private int holdPosition;
    private boolean isChanged = false;
    private boolean ShowItem = false;

    public DateAdapter(Context mContext, List<String> list) {
        this.context = mContext;
        lstDate = list;
    }

    @Override
    public int getCount() {
        return lstDate.size();
    }

    @Override
    public Object getItem(int position) {
        return lstDate.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    public void exchange(int startPosition, int endPosition) {
        System.out.println(startPosition + "--" + endPosition);
        holdPosition = endPosition;
        Object startObject = getItem(startPosition);
        System.out.println(startPosition + "========" + endPosition);
        Log.d("ON","startPostion ==== " + startPosition );
        Log.d("ON","endPosition ==== " + endPosition );
        if(startPosition < endPosition){
            lstDate.add(endPosition + 1, (String) startObject);
            lstDate.remove(startPosition);
        }else{
            lstDate.add(endPosition,(String)startObject);
            lstDate.remove(startPosition + 1);
        }
        isChanged = true;
        notifyDataSetChanged();
    }
    
    public void showDropItem(boolean showItem){
        this.ShowItem = showItem;        
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        convertView = LayoutInflater.from(context).inflate(R.layout.item, null);
        txtAge = (TextView) convertView.findViewById(R.id.txt_userAge);
        txtAge.setText("Item" + lstDate.get(position));
        if (isChanged){
            if (position == holdPosition){
                if(!ShowItem){
                    convertView.setVisibility(View.INVISIBLE);
                }
            }
        }
        return convertView;
    }

}

Configure：

public class Configure {
    public static int screenHeight=0;
    public static int screenWidth=0;
    public static float screenDensity=0;
    
    public static void init(Activity context) {
        if(screenDensity==0||screenWidth==0||screenHeight==0){
            DisplayMetrics dm = new DisplayMetrics();
            context.getWindowManager().getDefaultDisplay().getMetrics(dm);
            Configure.screenDensity = dm.density;
            Configure.screenHeight = dm.heightPixels;
            Configure.screenWidth = dm.widthPixels;
        }
    }

}

main.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:gravity="center"
    android:background="@drawable/notesbackground" >
    <com.cn.theodore.util.DragGrid
        android:id="@+id/gridview"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:numColumns="3"
        android:scrollbars="vertical"
        android:stretchMode="columnWidth"
        android:verticalSpacing="25dp" >
    </com.cn.theodore.util.DragGrid>
         <!--   android:listSelector="@android:color/transparent"-->
</RelativeLayout>