android - 在 imageview 范围内移动 textview

Question

我想在 imageview 内移动一个 textview，这样它就不会超出 imageview 的范围。如果我触摸并移动 textview，它应该跟随我的手指。但是如果我把它移到图像视图之外，我的文本视图不应该移到图像视图之外。

public boolean onTouch(View view, MotionEvent event) 
{
    final int X = (int) event.getRawX();
    final int Y = (int) event.getRawY();
    RelativeLayout.LayoutParams lParams = (RelativeLayout.LayoutParams)view.getLayoutParams();
    imgrect=new Rect(parent.getLeft(), parent.getTop(), parent.getRight(), parent.getBottom());

    switch (event.getAction()) 
    {
        case MotionEvent.ACTION_DOWN:
            x = X - lParams.leftMargin;
            y = Y - lParams.topMargin;
            break;
        case MotionEvent.ACTION_UP:
            break;
        case MotionEvent.ACTION_MOVE:
            int w=parent.getWidth() - imgrect.left-view.getWidth();
            int h=parent.getHeight() - imgrect.top;//-view.getHeight();

            if(lParams.leftMargin<1)
            {
                lParams.leftMargin = 1;
                    view.setLayoutParams(lParams);
            }
            else if(lParams.topMargin<1)
            {
                lParams.topMargin = 1;
                    view.setLayoutParams(lParams);
            }
            else if(lParams.leftMargin>w)
            {
                lParams.leftMargin = w-1;
                    view.setLayoutParams(lParams);
            }
            else if(lParams.topMargin>h)
            {
                lParams.topMargin = h-1;
                    view.setLayoutParams(lParams);
            }
            else
            {
                lParams.leftMargin = X - x;
                lParams.topMargin = Y - y;
                    view.setLayoutParams(lParams);
            }
            break;
    }
parent.invalidate();
    return false;
}