[Selenium]计算坐标进行拖拽，重写dragAndDropO

      //@author jzhang6

	public void dragAndDropOffset(WebDriver driver,WebElement dragableEl, WebElement dropableEl, int offsetX, int offsetY){

		Actions action = new Actions(driver);

		action.clickAndHold(dragableEl).build().perform();

		action.moveByOffset(offsetX, offsetY);

		action.release(dropableEl);

		action.build().perform();

	}


    

      //@author jzhang6

	public void dragWidget(String widgetName){

		WebElement widgetIconEl=page.getWidgetIconInDockMenu(widgetName);

		((JavascriptExecutor) driver).executeScript("arguments[0].scrollIntoView();", widgetIconEl);

		

		WebElement workspaceEl=page.getWorkSpace();

		Point initialPositon = widgetIconEl.getLocation();

		Point targetPositon = workspaceEl.getLocation();

		int offsetX = (targetPositon.getX() - initialPositon.getX())/2;

		int offsetY = (targetPositon.getY() - initialPositon.getY())/2;

		System.out.println("Drag widget to : ("+offsetX+","+offsetY+")");

		

		WebElement dropableEl=page.getDropableIconInWorkspace();

		

		this.dragAndDropOffset(driver,widgetIconEl,dropableEl,offsetX, offsetY);

		

		SeleniumUtil.waitUntilAllAjaxRequestCompletes(driver);

		this.waitForLoadingDoneInNewWebPage(driver);

	}