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and enhanced accessibility, to foundations for
large screen layouts, and design tokens.
warning warning
as of the flutter 3.16 release, material 3 is
enabled by default. for now, you can opt out
of material 3 by setting the useMaterial3 property
to false. but be aware that the useMaterial3
property and support for material 2
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.