kivy-dragdrop

Kivy Drag and Drop

A lightweight and easy-to-use drag-and-drop behavior library for Kivy applications.

kivy-dragdrop allows you to add sophisticated drag-and-drop interactions to any Kivy widget effortlessly using pure Python. It brings an overarching Drag Manager that handles tracking widgets, hover states, dropping, and interaction zones.

Features

• Extremely Simple API: Just use DraggableBehavior and DropZoneBehavior alongside your UI widgets.
• Hover Detection: Visual feedback when a draggable widget enters or leaves a drop zone.
• Cross-Widget Drop Manager: The internal drag_manager singleton seamlessly tracks items globally across your float layouts or screens.
• Customizable Events: Override on_drag_enter, on_drag_leave, and on_drop to trigger visual or structural changes exactly when you want them.

Installation

You can install it directly or use it by copying the kivy_dnd package into your project's directory.

Quick Start

1. Make a Widget Draggable

Inherit from DraggableBehavior to make any widget movable.

from kivy_dnd.draggable import DraggableBehavior
from kivy.uix.button import Button

class DragButton(DraggableBehavior, Button):
    pass

2. Create a Drop Zone

Inherit from DropZoneBehavior to create a region that can receive draggables. You can override hover and drop methods to change behavior or UI!

from kivy_dnd.drop_zone import DropZoneBehavior
from kivy.uix.boxlayout import BoxLayout

class DropBox(DropZoneBehavior, BoxLayout):
    def on_drag_enter(self, draggable_widget):
        super().on_drag_enter(draggable_widget)
        # Change color to green when hovering!
        self.canvas.before.children[0].rgba = (0.2, 0.8, 0.4, 1) 

    def on_drag_leave(self, draggable_widget):
        super().on_drag_leave(draggable_widget)
        # Change color back to blue
        self.canvas.before.children[0].rgba = (0.2, 0.4, 0.8, 1)

    def on_drop(self, draggable_widget):
        super().on_drop(draggable_widget)
        self.canvas.before.children[0].rgba = (0.2, 0.4, 0.8, 1)
        
        # Remove from old parent and add to the drop box
        if draggable_widget.parent:
            draggable_widget.parent.remove_widget(draggable_widget)
        
        self.add_widget(draggable_widget)

Running the Demo

Find a fully working example inside the /demo directory. Run it with:

python demo/main.py