创建边距以不从屏幕图像视图中拖出

Question

我已经创建了一个ImageView，我可以将它拖动到屏幕上。我使用画布将coordonates转换为2个整数的向量，我已经成功编程为immage而不是在上下都得到太多coordonates（y）但我无法在x上做（左和右）我不知道为什么不工作因为是相同的。

我的代码是：

private int offset_x = 0;
private int offset_y = 0;
RelativeLayout canvas;
boolean isselected = false;
View selected_item = null;
Button save,newdoor,newwindow;
static final int SNAP_GRID_INTERVAL = 43;
static final int SNAP_GRID_INTERVAL2 = 25;
@SuppressWarnings("deprecation")
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    canvas = (RelativeLayout) findViewById(R.id.container2);
    ViewGroup vg = (ViewGroup)findViewById(R.id.container3);

    save = (Button) findViewById(R.id.savebtn);
    newdoor = (Button) findViewById(R.id.btnnewdoor);
    newwindow = (Button) findViewById(R.id.btnnewwindow);

    save.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            final View canvas = ((View) v.getParent());
            final int []coord = new int[3];
            final int lungime = 66;
            final int inaltime = 20;

            final int canvasWidth = canvas.getWidth();
            final int canvasHeight = canvas.getHeight();
            ImageView image = new ImageView(getBaseContext());
            RelativeLayout mylayout = (RelativeLayout) findViewById(R.id.container2);
            image.setBackgroundResource(R.drawable.element_wall);
            mylayout.addView(image);
            image.setOnTouchListener(new View.OnTouchListener() {

                @Override
                public boolean onTouch(View v, MotionEvent event) {
                    // TODO Auto-generated method stub
                     switch(event.getAction())
                        {
                                case MotionEvent.ACTION_DOWN:
                                        selected_item = v;
                                        break;        
                                default:
                                        break;
                        }

                        return false;
                }
            });


            mylayout.setOnTouchListener(new View.OnTouchListener() {

                @Override
                public boolean onTouch(View v, MotionEvent event) {
                    // TODO Auto-generated method stub
                    MarginLayoutParams marginParams = new MarginLayoutParams(v.getLayoutParams());
                    canvas.getLocationOnScreen(coord);
                    switch(event.getAction())
                    {
                    case MotionEvent.ACTION_MOVE:
                        View canvas = ((View) v.getParent());
                        final int width = v.getWidth() / 2, height = v.getHeight() / 2;
                        canvas.getLocationOnScreen(coord);


                        int x = (int)event.getX() - offset_x;
                        int y = (int)event.getY() - offset_y;

                        int w = getWindowManager().getDefaultDisplay().getWidth() - 100;
                        int h = getWindowManager().getDefaultDisplay().getHeight() - 100;
                        int rawX = (int) event.getRawX(), rawY = (int) event.getRawY();
                        int x_coord = (int) event.getRawX() - coord[0] - width;
                        int y_coord = (int) event.getRawY() - coord[1] - height;
                           Log.i("arry", "x=" + coord[0] + ", y=" + coord[1]);

                        RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(
                                    new ViewGroup.MarginLayoutParams(
                                                    RelativeLayout.LayoutParams.WRAP_CONTENT,
                                                    RelativeLayout.LayoutParams.WRAP_CONTENT));

                        if (rawY < coord[1] + inaltime / 2)
                              lp.topMargin = 0;
                        else
                            if (rawY >= coord[1] + canvasHeight - inaltime / 2)
                                lp.topMargin = canvasHeight - inaltime;
                            else
                                lp.topMargin = y   / SNAP_GRID_INTERVAL  * SNAP_GRID_INTERVAL;

                                lp.leftMargin = x  / SNAP_GRID_INTERVAL  * SNAP_GRID_INTERVAL;



                         lp.setMargins(lp.leftMargin, lp.topMargin, 0, 0);


                                                selected_item.setLayoutParams(lp);

                                            break;

                                    default:
                                            break;
                    }
                    return true;
            }
            });

        }


    });

在SAVE上点击监听器我以编程方式创建imageView。

我在这里设置Y的限制：

                if (rawY < coord[1] + inaltime / 2)
                      lp.topMargin = 0;
                else
                    if (rawY >= coord[1] + canvasHeight - inaltime / 2)
                        lp.topMargin = canvasHeight - inaltime;
                    else
                        lp.topMargin = y   / SNAP_GRID_INTERVAL  * SNAP_GRID_INTERVAL;

我使用了LogCat上的日志，我得到的coord [0]为0，coord [1]为某个值（162）。 我的问题是，coord [0]每次都应为0？或0是正确的coordonate？