基于SurfaceView的可拖动视频控件

视频播放控件（一） 可拖动，变换SurfaceView

 public class DragSurfaceView extends SurfaceView implements View.OnTouchListener {
     protected int screenWidth;
     protected int screenHeight;
     protected int lastX;
     protected int lastY;
     private int oriLeft;
     private int oriRight;
     private int oriTop;
     private int oriBottom;
     private int dragDirection;
     private static final int TOP = 0x15;
     private static final int LEFT = 0x16;
     private static final int BOTTOM = 0x17;
     private static final int RIGHT = 0x18;
     private static final int LEFT_TOP = 0x11;
     private static final int RIGHT_TOP = 0x12;
     private static final int LEFT_BOTTOM = 0x13;
     private static final int RIGHT_BOTTOM = 0x14;
     private static final int CENTER = 0x19;
     private int offset = 20;

     /**
      * 初始化获取屏幕宽高
      */
     protected void initScreenW_H() {
         screenHeight = getResources().getDisplayMetrics().heightPixels - 40;
         screenWidth = getResources().getDisplayMetrics().widthPixels;
         Log.i("DragViewTAG", "DragSurfaceView.initScreenW_H: screenWidth="+screenWidth+", screenHeight="+screenHeight);
     }
     public DragSurfaceView(Context context) {
         super(context);
         setOnTouchListener(this);
         initScreenW_H();
     }

     public DragSurfaceView(Context context, AttributeSet attrs) {
         super(context, attrs);
         setOnTouchListener(this);
         initScreenW_H();
     }

     public DragSurfaceView(Context context, AttributeSet attrs, int defStyleAttr) {
         super(context, attrs, defStyleAttr);
         setOnTouchListener(this);
         initScreenW_H();
     }

     @Override
     public boolean onTouch(View v, MotionEvent event) {
         int action = event.getAction();
         if (action == MotionEvent.ACTION_DOWN) {
             oriLeft = v.getLeft();
             oriRight = v.getRight();
             oriTop = v.getTop();
             oriBottom = v.getBottom();
             lastY = (int) event.getRawY();
             lastX = (int) event.getRawX();
             dragDirection = getDirection(v, (int) event.getX(),
                     (int) event.getY());
         }
         // 处理拖动事件
         delDrag(v, event, action);
         if(action==MotionEvent.ACTION_UP){
             dragDirection=0;
         }
         invalidate();
         return true;
     }

     /**
      * 获取触摸点flag
      *
      * @param v
      * @param x
      * @param y
      * @return
      */
     protected int getDirection(View v, int x, int y) {
         int left = v.getLeft();
         int right = v.getRight();
         int bottom = v.getBottom();
         int top = v.getTop();
         if (x < 40 && y < 40) {
             return LEFT_TOP;
         }
         if (y < 40 && right - left - x < 40) {
             return RIGHT_TOP;
         }
         if (x < 40 && bottom - top - y < 40) {
             return LEFT_BOTTOM;
         }
         if (right - left - x < 40 && bottom - top - y < 40) {
             return RIGHT_BOTTOM;
         }
         if (x < 40) {
             return LEFT;
         }
         if (y < 40) {
             return TOP;
         }
         if (right - left - x < 40) {
             return RIGHT;
         }
         if (bottom - top - y < 40) {
             return BOTTOM;
         }
         return CENTER;
     }

     /**
      * 处理拖动事件
      *
      * @param v
      * @param event
      * @param action
      */
     protected void delDrag(View v, MotionEvent event, int action) {
         switch (action) {
             case MotionEvent.ACTION_MOVE:
                 int dx = (int) event.getRawX() - lastX;
                 int dy = (int) event.getRawY() - lastY;
                 switch (dragDirection) {
                     case LEFT: // 左边缘
                         left(v, dx);
                         break;
                     case RIGHT: // 右边缘
                         right(v, dx);
                         break;
                     case BOTTOM: // 下边缘
                         bottom(v, dy);
                         break;
                     case TOP: // 上边缘
                         top(v, dy);
                         break;
                     case CENTER: // 点击中心-->>移动
                         center(v, dx, dy);
                         break;
                     case LEFT_BOTTOM: // 左下
                         left(v, dx);
                         bottom(v, dy);
                         break;
                     case LEFT_TOP: // 左上
                         left(v, dx);
                         top(v, dy);
                         break;
                     case RIGHT_BOTTOM: // 右下
                         right(v, dx);
                         bottom(v, dy);
                         break;
                     case RIGHT_TOP: // 右上
                         right(v, dx);
                         top(v, dy);
                         break;
                     default:
                         break;
                 }
                 v.layout(oriLeft, oriTop, oriRight, oriBottom);
 //                if (dragDirection != CENTER) {
 //                    v.layout(oriLeft, oriTop, oriRight, oriBottom);
 //                }
                 lastX = (int) event.getRawX();
                 lastY = (int) event.getRawY();
                 Log.i("DragViewTAG", "DragSurfaceView.delDrag:ACTION_MOVE direction="+dragDirection+", left="+oriLeft+", top="+oriTop+", right="+oriRight+", bottom="+oriBottom);
                 break;
             case MotionEvent.ACTION_UP:
                 ViewGroup.LayoutParams newLayoutParams = getNewLayoutParams();
                 if(newLayoutParams!=null){
                     Log.i("DragViewTAG", "DragSurfaceView.delDrag:ACTION_UP width="+newLayoutParams.width+", height="+newLayoutParams.height);
                     setLayoutParams(newLayoutParams);
                 }else {
                     Log.e("DragViewTAG", "DragSurfaceView.delDrag: 父组件类型？");
                     v.layout(oriLeft, oriTop, oriRight, oriBottom);
                 }
                 break;
             default:
                 break;
         }
     }

     private ViewGroup.LayoutParams getNewLayoutParams(){
         if(getLayoutParams() instanceof RelativeLayout.LayoutParams){
             RelativeLayout.LayoutParams lp = (RelativeLayout.LayoutParams)getLayoutParams( );
             lp.leftMargin = oriLeft;
             lp.topMargin = oriTop;
             lp.width = oriRight-oriLeft;
             lp.height = oriBottom-oriTop;
             return lp;
         }else if(getLayoutParams() instanceof FrameLayout.LayoutParams) {
             FrameLayout.LayoutParams lp = (FrameLayout.LayoutParams) getLayoutParams();
             lp.leftMargin = oriLeft;
             lp.topMargin = oriTop;
             lp.width = oriRight - oriLeft;
             lp.height = oriBottom - oriTop;
             return lp;
         }
         return null;
     }

     /**
      * 触摸点为中心->>移动
      *
      * @param v
      * @param dx
      * @param dy
      */
     private void center(View v, int dx, int dy) {
         oriLeft += dx;
         oriTop += dy;
         oriRight += dx;
         oriBottom += dy;
         Log.i("DragViewTAG", "DragSurfaceView.center: v.left="+v.getLeft()+", v.top="+v.getTop());
         if (oriLeft < -offset) {
             Log.e("DragViewTAG", "DragSurfaceView.center: 左侧越界, left="+oriLeft+", offset="+offset);
             oriLeft = -offset;
             oriRight = oriLeft + v.getWidth();
         }
         if (oriRight > screenWidth + offset) {
             Log.e("DragViewTAG", "DragSurfaceView.center: 右侧越界, right="+oriRight+", screenWidth="+screenWidth+", offset="+offset);
             oriRight = screenWidth + offset;
             oriLeft = oriRight - v.getWidth();
         }
         if (oriTop < -offset) {
             Log.e("DragViewTAG", "DragSurfaceView.center: 顶部越界, top="+oriTop+", offset="+offset);
             oriTop = -offset;
             oriBottom = oriTop + v.getHeight();
         }
         if (oriBottom > screenHeight + offset) {
             Log.e("DragViewTAG", "DragSurfaceView.center: 底部越界, bottom="+oriBottom+", screenHeight="+screenHeight+", offset="+offset);
             oriBottom = screenHeight + offset;
             oriTop = oriBottom - v.getHeight();
         }
 //        v.layout(left, top, right, bottom);

     }

     /**
      * 触摸点为上边缘
      *
      * @param v
      * @param dy
      */
     private void top(View v, int dy) {
         oriTop += dy;
         if (oriTop < -offset) {
             oriTop = -offset;
         }
         if (oriBottom - oriTop - 2 * offset < 200) {
             oriTop = oriBottom - 2 * offset - 200;
         }
     }

     /**
      * 触摸点为下边缘
      *
      * @param v
      * @param dy
      */
     private void bottom(View v, int dy) {
         oriBottom += dy;
         if (oriBottom > screenHeight + offset) {
             oriBottom = screenHeight + offset;
         }
         if (oriBottom - oriTop - 2 * offset < 200) {
             oriBottom = 200 + oriTop + 2 * offset;
         }
     }

     /**
      * 触摸点为右边缘
      *
      * @param v
      * @param dx
      */
     private void right(View v, int dx) {
         oriRight += dx;
         if (oriRight > screenWidth + offset) {
             oriRight = screenWidth + offset;
         }
         if (oriRight - oriLeft - 2 * offset < 200) {
             oriRight = oriLeft + 2 * offset + 200;
         }
     }

     /**
      * 触摸点为左边缘
      *
      * @param v
      * @param dx
      */
     private void left(View v, int dx) {
         oriLeft += dx;
         if (oriLeft < -offset) {
             oriLeft = -offset;
         }
         if (oriRight - oriLeft - 2 * offset < 200) {
             oriLeft = oriRight - 2 * offset - 200;
         }
     }

     /**
      * 获取截取宽度
      *
      * @return
      */
     public int getCutWidth() {
         return getWidth() - 2 * offset;
     }

     /**
      * 获取截取高度
      *
      * @return
      */
     public int getCutHeight() {
         return getHeight() - 2 * offset;
     }
 }