NavigationBar
Examples#
Basic Example#
import flet as ft
def main(page: ft.Page):
page.title = "NavigationBar Example"
page.navigation_bar = ft.NavigationBar(
destinations=[
ft.NavigationBarDestination(icon=ft.Icons.EXPLORE, label="Explore"),
ft.NavigationBarDestination(icon=ft.Icons.COMMUTE, label="Commute"),
ft.NavigationBarDestination(
icon=ft.Icons.BOOKMARK_BORDER,
selected_icon=ft.Icons.BOOKMARK,
label="Favorites",
),
]
)
page.add(ft.Text("Body!"))
ft.run(main)
NavigationBar
#
Bases: ConstrainedControl
, AdaptiveControl
Material 3 Navigation Bar component.
Navigation bars offer a persistent and convenient way to switch between primary destinations in an app.
adaptive
#
adaptive: bool | None = None
Enables platform-specific rendering or inheritance of adaptiveness from parent controls.
animate_offset
#
animate_offset: AnimationValue | None = None
animate_opacity
#
animate_opacity: AnimationValue | None = None
animate_position
#
animate_position: AnimationValue | None = None
animate_rotation
#
animate_rotation: AnimationValue | None = None
animate_scale
#
animate_scale: AnimationValue | None = None
animation_duration
#
animation_duration: DurationValue | None = None
The transition time for each destination as it goes between selected and unselected.
bottom
#
bottom: Number | None = None
The distance that the child's bottom edge is inset from the bottom of the stack.
Note
Effective only if this control is a descendant of one of the following:
Stack
control, Page.overlay
list.
col
#
col: ResponsiveNumber = 12
If a parent of this control is a ResponsiveRow
,
this property is used to determine
how many virtual columns of a screen this control will span.
Can be a number or a dictionary configured to have a different value for specific
breakpoints, for example col={"sm": 6}
.
This control spans the 12 virtual columns by default.
Dimensions
Breakpoint | Dimension |
---|---|
xs | <576px |
sm | ≥576px |
md | ≥768px |
lg | ≥992px |
xl | ≥1200px |
xxl | ≥1400px |
destinations
#
destinations: list[NavigationBarDestination] = field(
default_factory=list
)
Defines the appearance of the button items that are arrayed within the navigation bar.
The value must be a list of two or more NavigationBarDestination
instances.
disabled
#
disabled: bool = False
Every control has disabled
property which is False
by default - control and all
its children are enabled.
Note
The value of this property will be propagated down to all children controls recursively.
expand
#
expand_loose
#
expand_loose: bool = False
Allows the control to expand along the main axis if space is available, but does not require it to fill all available space.
More information here.
indicator_color
#
indicator_color: ColorValue | None = None
The color of the selected destination indicator.
indicator_shape
#
indicator_shape: OutlinedBorder | None = None
The shape of the selected destination indicator.
label_behavior
#
label_behavior: NavigationBarLabelBehavior | None = None
Defines how the destinations' labels will be laid out and when they'll be displayed.
Can be used to show all labels, show only the selected label, or hide all labels.
Defaults to NavigationBarLabelBehavior.ALWAYS_SHOW
.
left
#
left: Number | None = None
The distance that the child's left edge is inset from the left of the stack.
Note
Effective only if this control is a descendant of one of the following:
Stack
control, Page.overlay
list.
offset
#
offset: OffsetValue | None = None
Applies a translation transformation before painting the control.
The translation is expressed as an Offset
scaled to the control's size.
So, Offset(x=0.25, y=0)
, for example, will result in a horizontal translation
of one quarter the width of this control.
Example
The following example displays container at 0, 0
top left corner of a stack as
transform applies -1 * 100, -1 * 100
(offset * control's size
) horizontal and
vertical translations to the control:
on_animation_end
#
on_animation_end: (
ControlEventHandler[ConstrainedControl] | None
) = None
Called when animation completes.
Can be used to chain multiple animations.
The data
property of the event handler argument contains the name of the animation.
More information here.
on_change
#
on_change: ControlEventHandler[NavigationBar] | None = None
Called when selected destination changed.
opacity
#
opacity: Number = 1.0
Defines the transparency of the control.
Value ranges from 0.0
(completely transparent) to 1.0
(completely opaque
without any transparency).
overlay_color
#
overlay_color: ControlStateValue[ColorValue] | None = None
The highlight color of the
NavigationDestination
in various
ControlState
states.
The following ControlState
values are supported: PRESSED
, HOVERED
and FOCUSED
.
page
#
The page (of type Page
or PageView
) to which this control belongs to.
parent
#
parent: BaseControl | None
The direct ancestor(parent) of this control.
It defaults to None
and will only have a value when this control is mounted (added to the page tree).
The Page
control (which is the root of the tree) is an exception - it always has parent=None
.
right
#
right: Number | None = None
The distance that the child's right edge is inset from the right of the stack.
Note
Effective only if this control is a descendant of one of the following:
Stack
control, Page.overlay
list.
rotate
#
rotate: RotateValue | None = None
Transforms this control using a rotation around its center.
The value of rotate
property could be one of the following types:
number
- a rotation in clockwise radians. Full circle360°
ismath.pi * 2
radians,90°
ispi / 2
,45°
ispi / 4
, etc.Rotate
- allows to specify rotationangle
as well asalignment
- the location of rotation center.
scale
#
scale: ScaleValue | None = None
Scales this control along the 2D plane. Default scale factor is 1.0
, meaning no-scale.
Setting this property to 0.5
, for example, makes this control twice smaller, while 2.0
makes it twice larger.
Different scale multipliers can be specified for x
and y
axis, by setting
Control.scale
property to an instance of Scale
class.
Either scale
or scale_x
and scale_y
could be specified, but not all of them.
selected_index
#
selected_index: int = 0
The index into destinations
for the current selected NavigationBarDestination
or
None
if no destination is selected.
shadow_color
#
shadow_color: ColorValue | None = None
The color used for the drop shadow to
indicate elevation
.
surface_tint_color
#
surface_tint_color: ColorValue | None = None
The surface tint of the Material that holds the NavigationDrawer's contents.
tooltip
#
tooltip: TooltipValue | None = None
The tooltip ot show when this control is hovered over.
top
#
top: Number | None = None
The distance that the child's top edge is inset from the top of the stack.
Note
Effective only if this control is a descendant of one of the following:
Stack
control, Page.overlay
list.
visible
#
visible: bool = True
Every control has visible
property which is True
by default - control is
rendered on the page. Setting visible
to False
completely prevents control (and
all its children if any) from rendering on a page canvas. Hidden controls cannot be
focused or selected with a keyboard or mouse and they do not emit any events.