Flutter Extend ThemeData, add colours etc - flutter

I am trying to extend the color scheme used by my first app. I created a separate file that contains the following:
import 'package:flutter/cupertino.dart';
class Testy extends CupertinoThemeData {
final Color bgws = Color.fromRGBO(120, 120, 120, 1);
}
I then imported it into Main.Dart but cannot see how to use my new color. I thought Testy.bgws would do it but clearly I am missing something.


You can use default textTheme without Cupertino
like
final ThemeData appThemeLight = ThemeData(
/// theme
brightness: Brightness.light,
/// screen
primaryColor: Colors.blue,
/// brightness color
accentColor: Colors.white,
/// opacity color
hintColor: Colors.grey,
/// here you can add cupertino
cupertinoOverrideTheme: CupertinoThemeData(
primaryColor: Colors.black,
),
....
and use it Theme.of(context)...
also don't forget add appThemeLight to MaterialApp like theme: appThemeLight

Related

Theme responsible for CircularProgressIndicator

I want to give every CircularProgressIndicator a color in my app but what attribute is responsible for it in MaterialApp widget:
MaterialApp(
theme: ThemeData(
// what is the attribute for this widget.
)
)
I used both accentColor and colorScheme.secondary but still not change.

You can use accentColor to change the color of CircularProgressIndicator. It will look like this:
theme: ThemeData(
accentColor: Colors.red,
EDIT:
In the newest version of Flutter, you should use colorScheme instead of accentColor.
colorScheme: ColorScheme.fromSwatch().copyWith(
secondary: Colors.red,
),

In ThemeData there is progressIndicatorTheme attribute which you can assign ProgressIndicatorThemeData constructor to it, and there you can change the default color of ProgressIndicator.

Primary color declared in colorScheme and ThemeData in Flutter

I was following the Material Design components and at the bottom, there was a Theming section for every component.
Here's the ThemeData code,
final ThemeData base = ThemeData.light();
return base.copyWith(
colorScheme: _shrineColorScheme,
toggleableActiveColor: shrinePink400,
accentColor: shrineBrown900,
primaryColor: shrinePink100, //defines primary
buttonColor: shrinePink100,
scaffoldBackgroundColor: shrineBackgroundWhite,
cardColor: shrineBackgroundWhite,
textSelectionColor: shrinePink100,
errorColor: shrineErrorRed,
primaryIconTheme: _customIconTheme(base.iconTheme),
textTheme: _buildShrineTextTheme(base.textTheme),
primaryTextTheme: _buildShrineTextTheme(base.primaryTextTheme),
accentTextTheme: _buildShrineTextTheme(base.accentTextTheme),
iconTheme: _customIconTheme(base.iconTheme),
);
}
Here's the definition of the ColorScheme,
const ColorScheme _shrineColorScheme = ColorScheme(
primary: shrinePink400, //defines primary
primaryVariant: shrineBrown900,
secondary: shrinePink50,
secondaryVariant: shrineBrown900,
surface: shrineSurfaceWhite,
background: shrineBackgroundWhite,
error: shrineErrorRed,
onPrimary: shrineBrown900,
onSecondary: shrineBrown900,
onSurface: shrineBrown900,
onBackground: shrineBrown900,
onError: shrineSurfaceWhite,
brightness: Brightness.light,
);
Here the value of the primary color is set twice. Why is that? We already defined primary in the ColorScheme so why bother doing it in ThemeData.

Although they have the exact same name, but they are in two different classes, basically there are two classes, ThemeData and ColorScheme. ThemeData is one holding all of your theme settings, and the one controlling how the app will look, but ColorScheme is just a set of colors that you create to easily maintain the app's colors. Notice that ThemeData class has a parameter colorScheme,
so you can create your own colorScheme and add it to the ThemeData object.
the primaryColor in ThemeData is the primary color for all your application, and you can access it through this line:
Theme.of(context).primaryColor
the primary in ColorScheme, is just the primaryColor for that colorScheme object, and you can also access it by using that line:
Theme.of(context).colorScheme.primary
Note
all of widgets styling inherits from colors or themes from ThemeData (defined in MaterialApp) not ColorScheme, colorScheme is just extra colors that you define to use whether in ThemeData or anywhere across the app.
so colorScheme will only affect widgets colors only if you use these colors in ThemeData, like this:
final ThemeData base = ThemeData.light();
return base.copyWith(
colorScheme: _shrineColorScheme,
accentColor: _shrineColorScheme.secondary,
primaryColor: _shrineColorScheme.primary,
scaffoldBackgroundColor: _shrineColorScheme.background,
);
}

A comment in the ThemeData object provides some clarity:
[colorScheme] is the preferred way to configure colors. The other
color properties (as well as primaryColorBrightness, and
primarySwatch) will gradually be phased out, see
https://github.com/flutter/flutter/issues/91772.
So for now, I'd recommend setting the colorScheme property using your ColorScheme object and then referencing the values in that object in the ThemeData properties, like primaryColor, focusColor, etc.

How to set the overscroll from ThemeData

I have tried to change accentColor, colorScheme, primaryColor, secondaryColor, but none could change the overscroll color it still blue.

In a MaterialApp, the edge glow color is the overall theme's ColorScheme.secondary color.
GlowingOverscrollIndicator Docs
ThemeData Docs

Update theme in MaterialApp in main.dart like this:
theme: ThemeData(
primarySwatch: Colors.purple,
buttonTheme: ButtonThemeData(
buttonColor: Colors.purple,
textTheme: ButtonTextTheme.primary,
)
),

Can't set different colors for text in AppBar and text in Scaffold using ThemeData

In my MaterialApp widget, I'm using the theme property to set the universal theme for my app. I want to set a blue color for the text in the AppBar, and red color for text in the Scaffold body. But using textTheme in ThemeData, only the Scaffold's text has the intended color, not the AppBar text.
This is the code for the theme I'm using in MaterialApp:
theme: ThemeData(
primaryColor: Color(0xFF0A0E21), //a navy bluish color
scaffoldBackgroundColor: Color(0xFF0A0E21),
accentColor: Colors.purple,
textTheme: TextTheme(
headline6: TextStyle(
color: Colors.blue
),
bodyText2: TextStyle(
color: Colors.red
)
)
The AppBar text remains white, but text in the body of the app (in the Scaffold I'm using) changes to red. I'm not setting different colors anywhere else.

you have to use appBarTheme on themeData
ThemeData(
scaffoldBackgroundColor: Color(0xFF0A0E21),,
appBarTheme: AppBarTheme(
color: Colors.blue,
),

Single color for all background pages in flutter

Is there an option where we can give a single color to the background of every pages in flutter. I couldn't find one in flutter.

MaterialApp has a theme property which you can adjust the ScaffoldBackgroundColor with:
MaterialApp(
theme: ThemeData(
scaffoldBackgroundColor: Colors.white, //your preferred color
),
);