AppBar
A material design app bar.
Examples
AppBar
loading...
Properties
actions
A list of Controls to display in a row after the title control.
Typically these controls are IconButtons representing common operations. For less common operations, consider using a PopupMenuButton as the last action.
Note that, if AppBar.adaptive=True and the app is opened on an iOS or macOS device, only the first element of this list will be used. This is because the CupertinoAppBar(which will be used on those two platforms) only accepts one - trailing - action control.
adaptive
If the value is True, an adaptive AppBar is created based on whether the target platform is iOS/macOS.
On iOS and macOS, a CupertinoAppBar is created, which has matching functionality and presentation as AppBar, and the graphics as expected on iOS. On other platforms, a Material AppBar is created.
Value is of type bool and defaults to False.
automatically_imply_leading
Controls whether we should try to imply the leading widget if null.
If True and leading is null, automatically try to deduce what the leading widget should be. If False and leading is null, leading space is given to title. If leading widget is not null, this parameter has no effect.
Value is of type bool.
bgcolor
The fill color to use for an AppBar. Default color is defined by current theme.
center_title
Whether the title should be centered.
Value is of type bool and defaults to False.
clip_behavior
The content will be clipped (or not) according to this option.
Value is of type ClipBehavior.
color
The default color for Text and Icon controls within the app bar. Default color is defined by current theme.
elevation
The app bar's elevation.
Note: This effect is only visible when using the Material 2 design (Theme.use_material3=False).
Value is of type OptionalNumber and defaults to 4.
elevation_on_scroll
The elevation to be used if this app bar has something scrolled underneath it.
Value is of type OptionalNumber.
exclude_header_semantics
Whether the title should be wrapped with header Semantics.
Value is of type bool and defaults to False.
force_material_transparency
Forces the app bar to be transparent (instead of Material's default type).
This will also remove the visual display of bgcolor and elevation, and affect other characteristics of this app bar.
Value is of type bool.
is_secondary
Whether this app bar is not being displayed at the top of the screen.
Value is of type bool and defaults to False.
leading
A Control to display before the toolbar's title.
Typically the leading control is an Icon or an IconButton.
Value is of type Control.
leading_width
Defines the width of leading control.
Value is of type OptionalNumber and defaults to 56.0.
shadow_color
The color of the shadow below the app bar.
A shadow is only visible and displayed if the elevation is greater than zero.
shape
The shape of the app bar's Material as well as its shadow.
Value is of type OutlinedBorder.
surface_tint_color
The color of the surface tint overlay applied to the app bar's bgcolor to indicate elevation.
By default, no overlay will be applied.
title
The primary Control displayed in the app bar. Typically a Text control that contains a description of the current contents of the app.
Note that, if AppBar.adaptive=True and the app is opened on an iOS or macOS device, this control will be automatically centered.
Value is of type Control.
title_spacing
The spacing around title on the horizontal axis. It is applied even if there are no leading or actions controls.
If you want title to take all the space available, set this value to 0.0.
Value is of type OptionalNumber.
title_text_style
The style to be used for the Text controls in the title.
Value is of type TextStyle.
toolbar_height
Defines the height of the toolbar component of an AppBar.
Value is of tye OptionalNumber and defaults to 56.0.
toolbar_opacity
The opacity of the toolbar. Value ranges from 0.0 (transparent) to 1.0 (fully opaque).
Value is of type OptionalNumber and defaults to 1.0.
toolbar_text_style
The style to be used for the Text controls in the app bar's leading and actions (but not title).
Value is of type TextStyle.