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
Drag and drop colors
- Python
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
.
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 of type DragTargetEvent
.
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).