feat(aio): display code-tabs in a Material Design "card" (#24027)

This helps to connect the "content" of the tab to its label.

Closes #23985

PR Close #24027

aio/src/app/custom-elements/code/code-tabs.component.ts

@@ -25,20 +25,22 @@ export interface TabInfo {
     <!-- Use content projection so that the provided HTML's code-panes can be split into tabs -->
     <div #content style="display: none"><ng-content></ng-content></div>
 
-    <mat-tab-group class="code-tab-group" disableRipple>
-      <mat-tab style="overflow-y: hidden;" *ngFor="let tab of tabs">
-        <ng-template mat-tab-label>
-          <span class="{{ tab.class }}">{{ tab.title }}</span>
-        </ng-template>
-        <aio-code class="{{ tab.class }}"
-                  [language]="tab.language"
-                  [linenums]="tab.linenums"
-                  [path]="tab.path"
-                  [region]="tab.region"
-                  [title]="tab.title">
-        </aio-code>
-      </mat-tab>
-    </mat-tab-group>
+    <mat-card>
+      <mat-tab-group class="code-tab-group" disableRipple>
+        <mat-tab style="overflow-y: hidden;" *ngFor="let tab of tabs">
+          <ng-template mat-tab-label>
+            <span class="{{ tab.class }}">{{ tab.title }}</span>
+          </ng-template>
+          <aio-code class="{{ tab.class }}"
+                    [language]="tab.language"
+                    [linenums]="tab.linenums"
+                    [path]="tab.path"
+                    [region]="tab.region"
+                    [title]="tab.title">
+          </aio-code>
+        </mat-tab>
+      </mat-tab-group>
+    </mat-card>
   `,
 })
 export class CodeTabsComponent implements OnInit, AfterViewInit {

aio/src/app/custom-elements/code/code-tabs.module.ts

@@ -1,12 +1,12 @@
 import { NgModule, Type } from '@angular/core';
 import { CommonModule } from '@angular/common';
 import { CodeTabsComponent } from './code-tabs.component';
-import { MatTabsModule } from '@angular/material';
+import { MatCardModule, MatTabsModule } from '@angular/material';
 import { CodeModule } from './code.module';
 import { WithCustomElementComponent } from '../element-registry';
 
 @NgModule({
-  imports: [ CommonModule, MatTabsModule, CodeModule ],
+  imports: [ CommonModule, MatCardModule, MatTabsModule, CodeModule ],
   declarations: [ CodeTabsComponent ],
   exports: [ CodeTabsComponent ],
   entryComponents: [ CodeTabsComponent ]

aio/src/styles/2-modules/_code.scss

@@ -3,8 +3,9 @@ code-example, code-tabs {
     display: block;
 }
 
-code-example,
-code-tabs mat-tab-body {
+code-example {
+
+
   &:not(.no-box) {
     background-color: rgba($backgroundgray, 0.2);
     border: 0.5px solid $lightgray;
@@ -27,6 +28,16 @@ code-tabs mat-tab-body {
   }
 }
 
+code-example, code-tabs {
+  .mat-card {
+    padding: 0;
+    border-radius: 5px;
+  }
+  code {
+    overflow: auto;
+  }
+}
+
 // TERMINAL / SHELL TEXT STYLES
 
 code-example.code-shell, code-example[language=sh], code-example[language=bash] {