android 能夠自動換行的 layout

public class InviteFrientView extends RelativeLayout {
        int mLeft, mRight, mTop, mBottom, currentBottom;
        Hashtable<View, Position> map = new Hashtable<View, InviteFrientView.Position>();
        
        public InviteFrientView(Context context, AttributeSet attrs, int defStyle) {
                super(context, attrs, defStyle);
        }
        public InviteFrientView(Context context, AttributeSet attrs) {
                super(context, attrs);
        }
        public InviteFrientView(Context context) {
                super(context);
        }
        @Override
        protected void onLayout(boolean changed, int l, int t, int r, int b) {
                // TODO Auto-generated method stub
                int count = getChildCount();
                for (int i = 0; i < count; i++) {
                        View child = getChildAt(i);
                        Position pos = map.get(child);
                        if (pos != null) {
                                child.layout(pos.left, pos.top, pos.right, pos.bottom);
                        } else {
                                Log.i("MyLayout", "error");
                        }
                }
        }
        public int getPosition(int IndexInRow, int childIndex) {
                if (IndexInRow > 0) {
                        return getPosition(IndexInRow - 1, childIndex - 1)
                                        + getChildAt(childIndex - 1).getMeasuredWidth()+10;
                }
                return 0;
        }
        @Override
        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
                // TODO Auto-generated method stub
                super.onMeasure(widthMeasureSpec, heightMeasureSpec);
                int width = MeasureSpec.getSize(widthMeasureSpec);
                mLeft = 0;
                mRight = 0;
                mTop = 0;
                mBottom = 0;
                int j = 0;
                int count = getChildCount();
                for (int i = 0; i < count; i++) {
                        Position position = new Position();
                        View view = getChildAt(i);
                        mLeft = getPosition(i - j, i);
                        mRight = mLeft + view.getMeasuredWidth();
                        if (mRight >= width) {
                                j = i;
                                mLeft = getPosition(i - j, i);
                                mRight = mLeft + view.getMeasuredWidth();
                                mTop += getChildAt(i).getMeasuredHeight()+15;
                        }
                        mBottom = mTop + view.getMeasuredHeight();
                        position.left = mLeft;
                        position.top = mTop;
                        position.right = mRight;
                        position.bottom = mBottom;
                        map.put(view, position);
                }
                setMeasuredDimension(width, mBottom);
        }
        private class Position {
                int left, top, right, bottom;
        }
}