I am new to JavaFX and wanted to try to perform drag and drop on my app. I am bale to drag , however, i am getting problem of making a certain element the target, i plan to put all my cards onto the center of the border box, so it will be like in normal game. However, whenever i try it, it get stuck.
Here is the link to let you guys have a look and test it out : https://drive.google.com/drive/folders/1YILWdnXS3J2KmdQuOJ1VHOPrVMheFKcm?usp=sharing
PS : Maybe the image view wont be available but i should show what cards means to me

I tried to use library but still failed. im afraid that my fxml structured is wrong from the beginning and not suitable for this, which is why im asking for help.