Angular Material 主题 Theming Angular Material

Theming Angular Material

Angular Material's theming system lets you customize color and typography styles for components in your application. The theming system is based on Google's Material Design specification.

This document describes the concepts and APIs for customizing colors. For typography customization, see Angular Material Typography. For guidance on building components to be customizable with this system, see Theming your own components.

Angular Material's theming APIs are built with Sass. This document assumes familiarity with CSS and Sass basics, including variables, functions, and mixins.

You can use Angular Material without Sass by using a pre-built theme, described in Using a pre-built theme below. However, using the library's Sass API directly gives you the most control over the styles in your application.

A palette is a collection of colors representing a portion of color space. Each value in this collection is called a hue. In Material Design, each hues in a palette has an identifier number. These identifier numbers include 50, and then each 100 value between 100 and 900. The numbers order hues within a palette from lightest to darkest.

Angular Material represents a palette as a Sass map. This map contains the palette's hues and another nested map of contrast colors for each of the hues. The contrast colors serve as text color when using a hue as a background color. The example below demonstrates the structure of a palette. See the Material Design color system for more background.

$indigo-palette: (
 50: #e8eaf6,
 100: #c5cae9,
 200: #9fa8da,
 300: #7986cb,
 // ... continues to 900
 contrast: (
   50: rgba(black, 0.87),
   100: rgba(black, 0.87),
   200: rgba(black, 0.87),
   300: white,
   // ... continues to 900
 )
);

You can create your own palette by defining a Sass map that matches the structure described in the Palettes section above. The map must define hues for 50 and each hundred between 100 and 900. The map must also define a contrast map with contrast colors for each hue.

You can use the Material Design palette tool to help choose the hues in your palette.

Angular Material offers predefined palettes based on the 2014 version of the Material Design spec. See the Material Design 2014 color palettes for a full list.

In addition to hues numbered from zero to 900, the 2014 Material Design palettes each include distinct accent hues numbered as A100, A200, A400, and A700. Angular Material does not require these hues, but you can use these hues when defining a theme as described in Defining a theme below.

@use '[email protected]/material' as mat;

$my-palette: mat.$indigo-palette;

A theme is a collection of color and typography options. Each theme includes three palettes that determine component colors:

  • A primary palette for the color that appears most frequently throughout your application
  • An accent, or secondary, palette used to selectively highlight key parts of your UI
  • A warn, or error, palette used for warnings and error states

You can include the CSS styles for a theme in your application in one of two ways: by defining a custom theme with Sass, or by importing a pre-built theme CSS file.

A theme file is a Sass file that calls Angular Material Sass mixins to output color and typography CSS styles.

Angular Material defines a mixin named core that includes prerequisite styles for common features used by multiple components, such as ripples. The core mixin must be included exactly once for your application, even if you define multiple themes. Including the core mixin multiple times will result in duplicate CSS in your application.

@use '[email protected]/material' as mat;

@include mat.core();

Angular Material represents a theme as a Sass map that contains your color and typography choices. For more about typography customization, see Angular Material Typography.

Constructing the theme first requires defining your primary and accent palettes, with an optional warn palette. The define-palette Sass function accepts a color palette, described in the Palettes section above, as well as four optional hue numbers. These four hues represent, in order: the "default" hue, a "lighter" hue, a "darker" hue, and a "text" hue. Components use these hues to choose the most appropriate color for different parts of themselves.

@use '[email protected]/material' as mat;

$my-primary: mat.define-palette(mat.$indigo-palette, 500);
$my-accent: mat.define-palette(mat.$pink-palette, A200, A100, A400);

// The "warn" palette is optional and defaults to red if not specified.
$my-warn: mat.define-palette(mat.$red-palette);

You can construct a theme by calling either define-light-theme or define-dark-theme with the result from define-palette. The choice of a light versus a dark theme determines the background and foreground colors used throughout the components.

@use '[email protected]/material' as mat;

$my-primary: mat.define-palette(mat.$indigo-palette, 500);
$my-accent: mat.define-palette(mat.$pink-palette, A200, A100, A400);

// The "warn" palette is optional and defaults to red if not specified.
$my-warn: mat.define-palette(mat.$red-palette);

$my-theme: mat.define-light-theme((
 color: (
   primary: $my-primary,
   accent: $my-accent,
   warn: $my-warn,
 )
));

The core-theme Sass mixin emits prerequisite styles for common features used by multiple components, such as ripples. This mixin must be included once per theme.

Each Angular Material component has a "color" mixin that emits the component's color styles and a "typography" mixin that emits the component's typography styles.

Additionally, each component has a "theme" mixin that emits styles for both color and typography. This theme mixin will only emit color or typography styles if you provided a corresponding configuration to define-light-theme or define-dark-theme.

Apply the styles for each of the components used in your application by including each of their theme Sass mixins.

@use '[email protected]/material' as mat;

@include mat.core();

$my-primary: mat.define-palette(mat.$indigo-palette, 500);
$my-accent: mat.define-palette(mat.$pink-palette, A200, A100, A400);

$my-theme: mat.define-light-theme((
 color: (
   primary: $my-primary,
   accent: $my-accent,
 )
));

// Emit theme-dependent styles for common features used across multiple components. 
@include mat.core-theme($my-theme);

// Emit styles for MatButton based on `$my-theme`. Because the configuration
// passed to `define-light-theme` omits typography, `button-theme` will not
// emit any typography styles.
@include mat.button-theme($my-theme);

// Include the theme mixins for other components you use here.

As an alternative to listing every component that your application uses, Angular Material offers Sass mixins that includes styles for all components in the library: all-component-colors, all-component-typographies, and all-component-themes. These mixins behave the same as individual component mixins, except they emit styles for core-theme and all 35+ components in Angular Material. Unless your application uses every single component, this will produce unecessary CSS.

@use '[email protected]/material' as mat;

@include mat.core();

$my-primary: mat.define-palette(mat.$indigo-palette, 500);
$my-accent: mat.define-palette(mat.$pink-palette, A200, A100, A400);

$my-theme: mat.define-light-theme((
 color: (
   primary: $my-primary,
   accent: $my-accent,
 )
));

@include mat.all-component-themes($my-theme);

To include the emitted styles in your application, add your theme file to the styles array of your project's angular.json file.

Angular Material includes four pre-built theme CSS files, each with different palettes selected. You can use one of these pre-built themes if you don't want to define a custom theme with Sass.

Theme Light or dark? Palettes (primary, accent, warn)
deeppurple-amber.css Dark deep-purple, amber, red
indigo-pink.css Light indigo, pink, red
pink-bluegray.css Dark pink, bluegray, red
purple-green.css Light purple, green, red

These files include the CSS for every component in the library. To include only the CSS for a subset of components, you must use the Sass API detailed in Defining a theme above. You can reference the source code for these pre-built themes to see examples of complete theme definitions.

You can find the pre-built theme files in the "prebuilt-themes" directory of Angular Material's npm package (@angular/material/prebuilt-themes). To include the pre-built theme in your application, add your chosen CSS file to the styles array of your project's angular.json file.

Using the Sass API described in Defining a theme, you can also define multiple themes by repeating the API calls multiple times. You can do this either in the same theme file or in separate theme files.

Defining multiple themes in a single file allows you to support multiple themes without having to manage loading of multiple CSS assets. The downside, however, is that your CSS will include more styles than necessary.

To control which theme applies when, @include the mixins only within a context specified via CSS rule declaration. See the documentation for Sass mixins for further background.

@use '[email protected]/material' as mat;

@include mat.core();

// Define a light theme
$light-primary: mat.define-palette(mat.$indigo-palette);
$light-accent: mat.define-palette(mat.$pink-palette);
$light-theme: mat.define-light-theme((
 color: (
   primary: $light-primary,
   accent: $light-accent,
 )
));

// Define a dark theme
$dark-primary: mat.define-palette(mat.$pink-palette);
$dark-accent: mat.define-palette(mat.$bluegray-palette);
$dark-theme: mat.define-dark-theme((
 color: (
   primary: $dark-primary,
   accent: $dark-accent,
 )
));

// Apply the dark theme by default
@include mat.core-theme($dark-theme);
@include mat.button-theme($dark-theme);

// Apply the light theme only when the `.my-light-theme` CSS class is applied
// to an ancestor element of the components (such as `body`).
.my-light-theme {
 @include mat.core-color($light-theme);
 @include mat.button-color($light-theme);
}

You can define multiple themes in seprate files by creating multiple theme files per Defining a theme, adding each of the files to the styles of your angular.json. However, you must additionally set the inject option for each of these files to false in order to prevent all the theme files from being loaded at the same time. When setting this property to false, your application becomes responsible for manually loading the desired file. The approach for this loading depends on your application.

You can use Angular Material's Sass mixins to customize component styles within a specific scope in your application. The CSS rule declaration in which you include a Sass mixin determines its scope. The example below shows how to customize the color of all buttons inside elements marked with the .my-special-section CSS class.

@use '[email protected]/material' as mat;

.my-special-section {
 $special-primary: mat.define-palette(mat.$orange-palette);
 $special-accent: mat.define-palette(mat.$brown-palette);
 $special-theme: mat.define-dark-theme((
   color: (primary: $special-primary, accent: $special-accent),
 ));

 @include mat.button-color($special-theme);
}

You can use the get-color-from-palette function to get specific hues from a palette by their number identifier. You can also access the contrast color for a particular hue by suffixing the hue's number idenfier with -contrast.

@use '[email protected]/material' as mat;

$my-palette: mat.define-palette(mat.$indigo-palette);

.my-custom-style {
 background: mat.get-color-from-palette($my-palette, '500');
 color: mat.get-color-from-palette($my-palette, '500-contrast');
}

You can also reference colors using the "default", "lighter", "darker", and "text" colors passed to define-palette.

@use '[email protected]/material' as mat;

$my-palette: mat.define-palette(mat.$indigo-palette);

.my-custom-darker-style {
 background: mat.get-color-from-palette($my-palette, 'darker');
 color: mat.get-color-from-palette($my-palette, 'darker-contrast');
}

By default, most components indicate browser focus by changing their background color as described by the Material Design specification. This behavior, however, can fall short of accessibility requirements, such as WCAG, which require a stronger indication of browser focus.

Angular Material supports rendering highly visible outlines on focused elements. Applications can enable these strong focus indicators via two Sass mixins: strong-focus-indicators and strong-focus-indicators-theme.

The strong-focus-indicators mixin emits structal indicator styles for all components. This mixin should be included exactly once in an application, similar to the core mixin described above.

The strong-focus-indicators-theme mixin emits only the indicator's color styles. This mixin should be included once per theme, similar to the theme mixins described above. Additionally, you can use this mixin to change the color of the focus indicators in situations in which the default color would not contrast sufficiently with the background color.

The following example includes strong focus indicator styles in an application alongside the rest of the custom theme API.

@use '[email protected]/material' as mat;

@include mat.core();
@include mat.strong-focus-indicators();

$my-primary: mat.define-palette(mat.$indigo-palette, 500);
$my-accent: mat.define-palette(mat.$pink-palette, A200, A100, A400);

$my-theme: mat.define-light-theme((
 color: (
   primary: $my-primary,
   accent: $my-accent,
 )
));

@include mat.all-component-themes($my-theme);
@include mat.strong-focus-indicators-theme($my-theme);

You can pass a configuration map to strong-focus-indicators to customize the appearance of the indicators. This configuration includes border-style, border-width, and border-radius.

You also can customize the color of indicators with strong-focus-indicators-theme. This mixin accepts either a theme, as described earlier in this guide, or a CSS color value. When providing a theme, the indicators will use the default hue of the primary palette.

The following example includes strong focus indicator styles with custom settings alongside the rest of the custom theme API.

@use '[email protected]/material' as mat;

@include mat.core();
@include mat.strong-focus-indicators((
  border-style: dotted,
  border-width: 4px,
  border-radius: 2px,
));

$my-primary: mat.define-palette(mat.$indigo-palette, 500);
$my-accent: mat.define-palette(mat.$pink-palette, A200, A100, A400);

$my-theme: mat.define-light-theme((
 color: (
   primary: $my-primary,
   accent: $my-accent,
 )
));

@include mat.all-component-themes($my-theme);
@include mat.strong-focus-indicators-theme(purple);

Angular Material assumes that, by default, all theme styles are loaded as global CSS. If you want to use Shadow DOM in your application, you must load the theme styles within each shadow root that contains an Angular Material component. You can accomplish this by manually loading the CSS in each shadow root, or by using Constructable Stylesheets.

Angular Material supports customizing color and typography as outlined in this document. Angular strongly discourages, and does not directly support, overriding component CSS outside the theming APIs described above. Component DOM structure and CSS classes are considered private implementation details that may change at any time.