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will eventually be deprecated according to |
Flutter’s deprecation policy.For most Flutter widgets, upgrading to Material 3 |
is seamless. But some widgets couldn’t be |
updated—entirely new implementations were needed, |
such as NavigationBar. |
You must make these changes to your code manually. |
Until your app is entirely updated, |
the UI might look or act a bit strange. |
You can find the entirely new Material components by |
visiting the Affected widgets page.Explore the updated components, typography, color system, |
and elevation support with the |
interactive Material 3 demo:<topic_end> |
<topic_start>More information |
To learn more about Material Design and Flutter, |
check out: |
<topic_end> |
<topic_start>Migrate to Material 3 |
<topic_end> |
<topic_start> |
Summary |
The Material library has been updated to match the Material 3 Design spec. |
Changes include new components and component themes, updated component visuals, |
and much more. Many of these updates are seamless. You’ll see the new version |
of an affected widget when recompiling your app against the 3.16 (or later) |
release. But some manual work is also required to complete the migration.<topic_end> |
<topic_start> |
Migration guide |
Prior to the 3.16 release, you could opt in to the Material 3 changes by |
setting the useMaterial3 flag to true. As of the Flutter 3.16 release |
(November 2023), useMaterial3 is true by default.By the way, you can revert to Material 2 behavior in your app by setting the |
useMaterial3 to false. However, this is just a temporary solution. The |
useMaterial3 flag and the Material 2 implementation will eventually be |
removed as part of Flutter’s deprecation policy.<topic_end> |
<topic_start> |
Colors |
The default values for ThemeData.colorScheme are updated to match |
the Material 3 Design spec.The ColorScheme.fromSeed constructor generates a ColorScheme |
derived from the given seedColor. The colors generated by this |
constructor are designed to work well together and meet contrast |
requirements for accessibility in the Material 3 Design system.When updating to the 3.16 release, your UI might look a little strange |
without the correct ColorScheme. To fix this, migrate to the |
ColorScheme generated from the ColorScheme.fromSeed constructor.Code before migration:Code after migration:To generate a content-based dynamic color scheme, use the |
ColorScheme.fromImageProvider static method. For an example of generating a |
color scheme, check out the ColorScheme from a network image sample.Changes to Flutter Material 3 include a new background color. |
ColorScheme.surfaceTint indicates an elevated widget. |
Some widgets use different colors.To return your app’s UI to its previous behavior (which we don’t recommend):Code before migration:Code after migration:The ColorScheme.surfaceTint value indicates a component’s elevation in |
Material 3. Some widgets might use both surfaceTint and shadowColor to |
indicate elevation (for example, Card and ElevatedButton) and others might |
only use surfaceTint to indicate elevation (such as AppBar).To return to the widget’s previous behavior, set, set Colors.transparent |
to ColorScheme.surfaceTint in the theme. To differentiate a widget’s shadow |
from the content (when it has no shadow), set the ColorScheme.shadow color to |
the shadowColor property in the widget theme without a default shadow color.Code before migration:Code after migration:The ElevatedButton now styles itself with a new combination of colors. |
Previously, when the useMaterial3 flag was set to false, ElevatedButton |
styled itself with ColorScheme.primary for the background and |
ColorScheme.onPrimary for the foreground. To achieve the same visuals, switch |
to the new FilledButton widget without the elevation changes or drop shadow.Code before migration:Code after migration:<topic_end> |
<topic_start> |
Typography |
The default values for ThemeData.textTheme are updated to match the |
Material 3 defaults. Changes include updated font size, font weight, letter |
spacing, and line height. For more details, check out the TextTheme |
documentation.As shown in the following example, prior to the 3.16 release, when a Text |
widget with a long string using TextTheme.bodyLarge in a constrained layout |
wrapped the text into two lines. However, the 3.16 release wraps the text into |
three lines. If you must achieve the previous behavior, adjust the text style |
and, if necessary, the letter spacing.Code before migration:Code after migration:<topic_end> |
<topic_start> |
Components |
Some components couldn’t merely be updated to match the Material 3 Design spec |
but needed a whole new implementation. Such components require manual migration |
since the Flutter SDK doesn’t know what, exactly, you want.Replace the Material 2 style BottomNavigationBar widget with the new |
NavigationBar widget. It’s slightly taller, contains pill-shaped |
navigation indicators, and uses new color mappings.Code before migration:Code after migration:Check out the complete sample on |
migrating from BottomNavigationBar to NavigationBar.Replace the Drawer widget with NavigationDrawer, which provides |
pill-shaped navigation indicators, rounded corners, and new color mappings.Code before migration:Code after migration:Check out the complete sample on migrating from Drawer to NavigationDrawer.Material 3 introduces medium and large app bars that display a larger headline |
before scrolling. Instead of a drop shadow, ColorScheme.surfaceTint color |
is used create a separation from the content when scrolling.The following code demonstrates how to implement the medium app bar:There are now two types of TabBar widgets: primary and secondary. |
Secondary tabs are used within a content area to further separate |
related content and establish hierarchy. Check out the TabBar.secondary |
example.The new TabBar.tabAlignment property specifies the horizontal alignment |
of the tabs.The following sample shows how to modify tab alignment in a scrollable TabBar:SegmentedButton, an updated version of ToggleButtons, |
uses fully rounded corners, differs in layout height and |
size, and uses a Dart Set to determine selected items.Code before migration:Code after migration:Check out the complete sample on |
migrating from ToggleButtons to SegmentedButton.<topic_end> |
<topic_start>New components |
<topic_end> |
<topic_start> |
Timeline |
In stable release: 3.16<topic_end> |
<topic_start> |
References |
Documentation:API documentation:Relevant issues:Relevant PRs: |
<topic_end> |
<topic_start>Text |
<topic_end> |
<topic_start> |
Topics |
<topic_end> |
<topic_start>Flutter's fonts and typography |
Typography covers the style and appearance of |
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