CODEWITHSUNDEEP
javajavafxcollision-detectionshapescollision
J.Doe
J.Doe

Reputation: 1

JavaFX: prevent shape from dragging over another shape

I am doing a JavaFX application and I have a board with multiple shape (circles and rectangle) added to a Pane. I don't want circle to be moved accross rectangle.

Circle are allowed to be dragged using Mouse Event (OnMousePressed,Dragged,Released) while rectangle are not allowed to move.

I am using this code to detect when my circle are colliding with the rectangles. 

private void checkIntersection(Shape block) {
    boolean collisionDetected = false;
    for (Shape static_bloc : nodes) {
      if (static_bloc != block) {
        Shape intersect = Shape.intersect(block, static_bloc);

        if (intersect.getBoundsInLocal().getWidth() != -1) {
          collisionDetected = true;
        }
      }
    }

    if (collisionDetected) {
      System.out.println("Collision detected");
    } else {
        System.out.println("Collision non deteted");
    }
}

What I need to do is make my rectangle impossible to drag over while dragging circles. I don't want to send the shape back to his initial location. Is there a way to do this using intersect or am I missing something?

Upvotes: 0

Views: 1275

Answers (2)

Carrol
Carrol

Reputation: 1285

Just wanted to share my solution.

I wanted to check the node before the movement was done. So I modified the previous solution, to create the following.

Node Class: I am working with a custom Node class that extends Label. The methods used here are those inherited from Label.

   private boolean hasNoCollision(Node dragged, double x, double y) {
        // For each node
        for (Node n : nodes) {
            // If it is not the same, and future position overlaps
            if (!n.equals(dragged) &&
                    n.getBoundsInParent().intersects(x, y, dragged.getWidth(), dragged.getHeight())) {
                // Then prevent collission
                return false;
            }
        }
        // Otherwise all is good!
        return true;
   }

Upvotes: 0

Petr
Petr

Reputation: 1219

It's not so easy to answer. You can have a class for instance GameObject. This class contains your Shape. In this GameObject class you have your drag&drop logic. Then u will have a class GameObjectManager which contains list of all GameObjects. And every instance of GameObject will have a reference to this GameObjectManager so knows about all GameObjects as well. So in your move logic you can check if there is some collision between specific GameObject types and if, u can stop moving.

For collision assessment class GameObject contains method like:

protected boolean isInCollision() {
    for (GameObject gameObject : gameObjectManager.getAllGameObjects()) {
        if (!gameObject.equals(this)) {
            if (getView().getBoundsInParent().intersects(gameObject.getView().getBoundsInParent())) {
                return true;
            }
        }
    }
    return false;
}

In your case you need to loop just some types of objects in this isInCollision method.

Upvotes: 1

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