feat(material/card): support filled variant

this commit add `filled` variant for material card which provides subtle seperation from background and has less emphasis than elevated or outlined cards

fixes #29840

Author: naaajii

goldens/material/card/index.api.md

@@ -32,7 +32,7 @@ export class MatCardActions {
 }
 
 // @public (undocumented)
-export type MatCardAppearance = 'outlined' | 'raised';
+export type MatCardAppearance = 'outlined' | 'raised' | 'filled';
 
 // @public
 export class MatCardAvatar {

src/material/card/_card-theme.scss

@@ -8,6 +8,7 @@
 @use '../core/tokens/m2/mat/card' as tokens-mat-card;
 @use '../core/tokens/m2/mat/elevated-card' as tokens-mat-elevated-card;
 @use '../core/tokens/m2/mat/outlined-card' as tokens-mat-outlined-card;
+@use '../core/tokens/m2/mat/filled-card' as tokens-mat-filled-card;
 
 @mixin base($theme) {
   @if inspection.get-theme-version($theme) == 1 {
@@ -110,6 +111,11 @@
       tokens: tokens-mat-outlined-card.get-token-slots(),
       prefix: 'outlined-',
     ),
+    (
+      namespace: tokens-mat-filled-card.$prefix,
+      tokens: tokens-mat-filled-card.get-token-slots(),
+      prefix: 'outlined-',
+    )
   );
 }
 
@@ -149,6 +155,10 @@
       tokens-mat-outlined-card.$prefix,
       map.get($tokens, tokens-mat-outlined-card.$prefix)
     );
+    @include token-utils.create-token-values(
+      tokens-mdc-filled-card.$prefix,
+      map.get($tokens, tokens-mdc-filled-card.$prefix)
+    );
     @include token-utils.create-token-values(
       tokens-mat-card.$prefix,
       map.get($tokens, tokens-mat-card.$prefix)

src/material/card/card.scss

@@ -2,6 +2,7 @@
 @use '../core/tokens/m2/mat/card' as tokens-mat-card;
 @use '../core/tokens/m2/mat/elevated-card' as tokens-mat-elevated-card;
 @use '../core/tokens/m2/mat/outlined-card' as tokens-mat-outlined-card;
+@use '../core/tokens/m2/mdc/filled-card' as tokens-mat-filled-card;
 
 // Size of the `mat-card-header` region custom to Angular Material.
 $mat-card-header-size: 40px !default;
@@ -68,6 +69,17 @@ $mat-card-default-padding: 16px !default;
   }
 }
 
+.mat-mdc-card-filled {
+  @include token-utils.use-tokens(
+    tokens-mdc-filled-card.$prefix,
+    tokens-mdc-filled-card.get-token-slots()
+  ) {
+    @include token-utils.create-token-slot(background-color, container-color);
+    @include token-utils.create-token-slot(border-radius, container-shape);
+    @include token-utils.create-token-slot(box-shadow, container-elevation);
+  }
+}
+
 .mdc-card__media {
   position: relative;
   box-sizing: border-box;

src/material/card/card.ts

@@ -16,7 +16,7 @@ import {
   inject,
 } from '@angular/core';
 
-export type MatCardAppearance = 'outlined' | 'raised';
+export type MatCardAppearance = 'outlined' | 'raised' | 'filled';
 
 /** Object that can be used to configure the default options for the card module. */
 export interface MatCardConfig {
@@ -41,6 +41,8 @@ export const MAT_CARD_CONFIG = new InjectionToken<MatCardConfig>('MAT_CARD_CONFI
     'class': 'mat-mdc-card mdc-card',
     '[class.mat-mdc-card-outlined]': 'appearance === "outlined"',
     '[class.mdc-card--outlined]': 'appearance === "outlined"',
+    '[class.mat-mdc-card-filled]': 'appearance === "filled"',
+    '[class.mdc-card--filled]': 'appearance === "filled"',
   },
   exportAs: 'matCard',
   encapsulation: ViewEncapsulation.None,

src/material/core/tokens/m2/mat/_filled-card.scss

@@ -0,0 +1,81 @@
+@use '../../../style/elevation';
+@use '../../../theming/inspection';
+@use '../../../style/sass-utils';
+@use '../../token-definition';
+
+// The prefix used to generate the fully qualified name for tokens in this file.
+$prefix: (mdc, filled-card);
+
+// Tokens that can't be configured through Angular Material's current theming API,
+// but may be in a future version of the theming API.
+//
+// Tokens that are available in MDC, but not used in Angular Material should be mapped to `null`.
+// `null` indicates that we are intentionally choosing not to emit a slot or value for the token in
+// our CSS.
+@function get-unthemable-tokens() {
+  @return (
+    // The border-radius of the card.
+    container-shape: 4px,
+    // =============================================================================================
+    // = TOKENS NOT USED IN ANGULAR MATERIAL                                                       =
+    // =============================================================================================
+    // Angular Material's card is not an interactive element, and therefore does not support states.
+    disabled-container-elevation: null,
+    disabled-outline-color: null,
+    disabled-outline-opacity: null,
+    dragged-container-elevation: null,
+    dragged-outline-color: null,
+    dragged-state-layer-color: null,
+    dragged-state-layer-opacity: null,
+    focus-container-elevation: null,
+    focus-outline-color: null,
+    focus-state-layer-color: null,
+    focus-state-layer-opacity: null,
+    hover-container-elevation: null,
+    hover-outline-color: null,
+    hover-state-layer-color: null,
+    hover-state-layer-opacity: null,
+    pressed-container-elevation: null,
+    pressed-outline-color: null,
+    pressed-state-layer-color: null,
+    pressed-state-layer-opacity: null,
+    container-shadow-color: null,
+    // Angular Material does not currently support surface tint.
+    container-surface-tint-layer-color: null,
+    // MDC does not seem to use these tokens.
+    icon-color: null,
+    icon-size: null,
+  );
+}
+
+// Tokens that can be configured through Angular Material's color theming API.
+@function get-color-tokens($theme) {
+  $elevation: inspection.get-theme-color($theme, foreground, elevation);
+
+  @return (
+    // The background color of the card.
+    container-color: inspection.get-theme-color($theme, background, card),
+    container-elevation: elevation.get-box-shadow(0),
+  );
+}
+
+// Tokens that can be configured through Angular Material's typography theming API.
+@function get-typography-tokens($theme) {
+  @return ();
+}
+
+// Tokens that can be configured through Angular Material's density theming API.
+@function get-density-tokens($theme) {
+  @return ();
+}
+
+// Combines the tokens generated by the above functions into a single map with placeholder values.
+// This is used to create token slots.
+@function get-token-slots() {
+  @return sass-utils.deep-merge-all(
+      get-unthemable-tokens(),
+      get-color-tokens(token-definition.$placeholder-color-config),
+      get-typography-tokens(token-definition.$placeholder-typography-config),
+      get-density-tokens(token-definition.$placeholder-density-config)
+  );
+}

src/material/core/tokens/m3/mat/_filled-card.scss

@@ -0,0 +1,22 @@
+@use 'sass:map';
+@use '../../../style/elevation';
+@use '../../token-definition';
+
+// The prefix used to generate the fully qualified name for tokens in this file.
+$prefix: (mdc, filled-card);
+
+/// Generates the tokens for MDC filled-card
+/// @param {Map} $systems The MDC system tokens
+/// @param {Boolean} $exclude-hardcoded Whether to exclude hardcoded token values
+/// @param {Map} $token-slots Possible token slots
+/// @return {Map} A set of tokens for the MDC filled-card
+@function get-tokens($systems, $exclude-hardcoded, $token-slots) {
+  $tokens: token-definition.get-mdc-tokens('filled-card', $systems, $exclude-hardcoded);
+  $elevation: map.get($tokens, container-elevation);
+
+  @if ($elevation != null) {
+    $tokens: map.set($tokens, container-elevation, elevation.get-box-shadow($elevation));
+  }
+
+  @return token-definition.namespace-tokens($prefix, $tokens, $token-slots);
+}