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DragTarget

A control that completes drag operation when a Draggable widget is dropped.

When a draggable is dragged on top of a drag target, the drag target is asked whether it will accept the data the draggable is carrying. The drag target will accept incoming drag if it belongs to the same group as draggable. If the user does drop the draggable on top of the drag target (and the drag target has indicated that it will accept the draggable's data), then the drag target is asked to accept the draggable's data.

Examples​

Live example

Drag and drop colors​

import flet as ft

def main(page: ft.Page):
    page.title = "Drag and Drop example"

    def drag_will_accept(e):
        e.control.content.border = ft.border.all(
            2, ft.colors.BLACK45 if e.data == "true" else ft.colors.RED
        )
        e.control.update()

    def drag_accept(e: ft.DragTargetEvent):
        src = page.get_control(e.src_id)
        e.control.content.bgcolor = src.content.bgcolor
        e.control.content.border = None
        e.control.update()

    def drag_leave(e):
        e.control.content.border = None
        e.control.update()

    page.add(
        ft.Row(
            [
                ft.Column(
                    [
                        ft.Draggable(
                            group="color",
                            content=ft.Container(
                                width=50,
                                height=50,
                                bgcolor=ft.colors.CYAN,
                                border_radius=5,
                            ),
                            content_feedback=ft.Container(
                                width=20,
                                height=20,
                                bgcolor=ft.colors.CYAN,
                                border_radius=3,
                            ),
                        ),
                        ft.Draggable(
                            group="color",
                            content=ft.Container(
                                width=50,
                                height=50,
                                bgcolor=ft.colors.YELLOW,
                                border_radius=5,
                            ),
                        ),
                        ft.Draggable(
                            group="color1",
                            content=ft.Container(
                                width=50,
                                height=50,
                                bgcolor=ft.colors.GREEN,
                                border_radius=5,
                            ),
                        ),
                    ]
                ),
                ft.Container(width=100),
                ft.DragTarget(
                    group="color",
                    content=ft.Container(
                        width=50,
                        height=50,
                        bgcolor=ft.colors.BLUE_GREY_100,
                        border_radius=5,
                    ),
                    on_will_accept=drag_will_accept,
                    on_accept=drag_accept,
                    on_leave=drag_leave,
                ),
            ]
        )
    )

ft.app(target=main)

Properties​

content​

The Control that is a visual representation of the drag target.

group​

The group this target belongs to. Note that for this target to accept an incoming drop from a Draggable, they must both be in thesame group.

Events​

on_accept​

Fires when the user does drop an acceptable(same group) draggable on this target. Event handler argument is an instance of DragTargetEvent class with the following fields:

  • src_id - unique control ID of draggable.
  • x - x component of the global position when the specific pointer event occurred on the draggable.
  • y - y component of the global position when the specific pointer event occurred on the draggable.

Use page.get_control(e.src_id) to retrieve Control reference by its ID.

on_leave​

Fires when a draggable leaves this target.

on_move​

Fires when a draggable moves within this target. Event handler argument is also an instance of DragTargetEvent class.

on_will_accept​

Fires when a draggable is dragged on this target. data field of event details contains true (String) if both the draggable and this target are in the same group; otherwise false (String).