ThemeData's accent properties have been deprecated
Summary
#The ThemeData accentColor, accentColorBrightness, accentIconTheme and accentTextTheme properties have been deprecated.
The Material Design spec no longer specifies or uses an "accent"
color for the Material components. The default values for component
colors are derived from the overall theme's color scheme.
The ColorScheme
's secondary color is now typically used instead of
accentColor
and the onSecondary color is used when a contrasting
color is needed.
Context
#This was a small part of the Material Theme System Updates project.
As of Flutter 1.17, the ThemeData accent properties - accentColor,
accentColorBrightness, accentIconTheme, and accentTextTheme - were no
longer used by the Material library. They had been replaced by
dependencies on the theme's colorScheme
and
textTheme
properties as part of the long-term goal of
making the default configurations of the material components depend
almost exclusively on these two properties.
The motivation for these changes is to make the theme system easier to
understand and use. The default colors for all components are to be
defined by the components themselves and based on the color
scheme. The defaults for specific component types can be overridden
with component-specific themes like FloatingActionButtonThemeData
or
CheckBoxTheme
. Previously, properties like accentColor were used by a
handful of component types and only in some situations, which made it
difficult to understand the implications of overriding them.
Description of change
#The ThemeData accentColor, accentColorBrightness, accentIconTheme and accentTextTheme properties have been deprecated because the Material library no longer uses them.
Migration guide
#Application theme
#ThemeData
values no longer need to specify accentColor,
accentColorBrightness, accentIconTheme, or accentTextTheme.
To configure the appearance of the material components in about the same way as before, specify the color scheme's secondary color instead of accentColor.
Code before migration:
MaterialApp(
theme: ThemeData(accentColor: myColor),
// ...
);
Code after migration:
final ThemeData theme = ThemeData();
MaterialApp(
theme: theme.copyWith(
colorScheme: theme.colorScheme.copyWith(secondary: myColor),
),
//...
)
accentColor
#The closest backwards compatible ColorScheme
color is
ColorScheme.secondary
. To hew most closely to the latest Material
Design guidelines one can substitute ColorScheme.primary
instead.
If a contrasting color is needed then use ColorScheme.onSecondary
.
Custom components that used to look up the theme's accentColor, can look up
the ColorScheme.secondary
instead.
Code before migration:
Color myColor = Theme.of(context).accentColor;
Code after migration:
Color myColor = Theme.of(context).colorScheme.secondary;
accentColorBrightness
#The static ThemeData.estimateBrightnessForColor()
method can be used
to compute the brightness of any color.
accentTextTheme
#This was white TextStyle
s for dark themes, black
TextStyles for light themes. In most cases textTheme can be used
instead. A common idiom was to refer to one TextStyle from
accentTextTheme, since the text style's color was guaranteed to contrast
well with the accent color (now ColorScheme.secondaryColor
).
To get the same result now, specify the text style's color as
ColorScheme.onSecondary
:
Code before migration:
TextStyle style = Theme.of(context).accentTextTheme.headline1;
Code after migration:
final ThemeData theme = Theme.of(context);
TextStyle style = theme.textTheme.headline1.copyWith(
color: theme.colorScheme.onSecondary,
)
accentIconTheme
#This property had only been used to configure the color of icons
within a FloatingActionButton
. It's now possible to configure the icon
color directly or with the FloatingActionButtonThemeData
. See
FloatingActionButton and ThemeData's accent properties.
Timeline
#Landed in version: 2.3.0-0.1.pre
In stable release: 2.5
References
#API documentation:
Relevant issues:
Relevant PRs:
Other:
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