DragDrop2D

DragDrop2D is a simple GDScript framework to allow the player to drag/drop CharacterBody2Ds around. It supports:

• Collision bodies for detecting mouse events.
• Compatibility with 2D physics for bounds checking and constraining where the player can drag to.
• Tracking drop regions using arbitrary Area2Ds.
• Validating/filtering drop areas via collision layers or per physics frame.

Usage

• Create instances of Draggable in your scene.
• Add at least one CollisionShape2D or CollisionPolygon2D, and set at least one layer (required for mouse detection).
• Assign collision layer/mask for bounds checking.
• Add other children to create the desired visuals.
• Optionally assign a drop mask to detect drop regions.
• Listen to the events (hovered, drag_started, drop_target_changed, drag_ended) to add logic and visual effects.

Caveats

Because these bodies are characters, they must be the the root of the collision objects. You could probably use RemoteTransform2D to sync the drag/drop with a sibling node, but I haven't tried that. You can also control Draggables in script, but do so in _physics_process via move_and_slide or other physics-compatible ways. Remember to call super() for overriden methods and use caution if attempting to do so while the player is dragging.

I have not tested this for mobile.

Credits

No AI was used when creating this code. While trying to create draggable physics objects, I was inspired by this video from Person Dude Games https://www.youtube.com/watch?v=JW_IyrcYNyQ