fix(focus)!: corrected outward/inward animations

BREAKING CHANGE: inward focus rings must be specified with `inward` rather than a negative offset.

PiperOrigin-RevId: 534552625

checkbox/lib/_checkbox.scss

@@ -86,7 +86,7 @@ $_checkmark-bottom-left: 7px, -14px;
 
     @include focus-ring.theme(
       (
-        'offset': -2px,
+        'outward-offset': -2px,
       )
     );
   }

chips/lib/_trailing-icon.scss

@@ -21,7 +21,7 @@
         'shape-end-start': var(--_container-shape-end-end),
         'shape-end-end': var(--_container-shape-end-end),
         'shape-start-end': var(--_container-shape-start-end),
-        'offset': -2px,
+        'outward-offset': -2px,
       )
     );
   }

fab/lib/forced-colors-styles.scss

@@ -12,7 +12,7 @@
     // Adjust the focus ring padding to account for the 1px border in HCM.
     @include focus-ring.theme(
       (
-        'offset': 3px,
+        'outward-offset': 3px,
       )
     );
     border: 1px solid ButtonText;

focus/demo/demo.ts

@@ -8,21 +8,25 @@ import './index.js';
 import './material-collection.js';
 
 import {KnobTypesToKnobs, MaterialCollection, materialInitsToStoryInits, setUpDemo} from './material-collection.js';
-import {cssCustomProperty, Knob, textInput} from './index.js';
+import {boolInput, cssCustomProperty, Knob, textInput} from './index.js';
 
 import {stories, StoryKnobs} from './stories.js';
 
 const collection =
     new MaterialCollection<KnobTypesToKnobs<StoryKnobs>>('Focus', [
+      new Knob('inward', {ui: boolInput(), defaultValue: false}),
       new Knob(
           '--md-focus-ring-width',
           {ui: textInput(), wiring: cssCustomProperty, defaultValue: '3px'}),
-      new Knob(
-          '--md-focus-ring-offset',
-          {ui: textInput(), wiring: cssCustomProperty, defaultValue: '2px'}),
       new Knob(
           '--md-focus-ring-active-width',
           {ui: textInput(), wiring: cssCustomProperty, defaultValue: '8px'}),
+      new Knob(
+          '--md-focus-ring-outward-offset',
+          {ui: textInput(), wiring: cssCustomProperty, defaultValue: '2px'}),
+      new Knob(
+          '--md-focus-ring-inward-offset',
+          {ui: textInput(), wiring: cssCustomProperty, defaultValue: '0px'}),
     ]);
 
 collection.addStories(...materialInitsToStoryInits(stories));

focus/demo/stories.ts

@@ -11,9 +11,11 @@ import {css, html} from 'lit';
 
 /** Knob types for focus ring stories. */
 export interface StoryKnobs {
+  inward: boolean;
   '--md-focus-ring-width': string;
-  '--md-focus-ring-offset': string;
   '--md-focus-ring-active-width': string;
+  '--md-focus-ring-outward-offset': string;
+  '--md-focus-ring-inward-offset': string;
 }
 
 const standard: MaterialStoryInit<StoryKnobs> = {
@@ -22,7 +24,7 @@ const standard: MaterialStoryInit<StoryKnobs> = {
     button {
       appearance: none;
       background: var(--md-sys-color-surface);
-      border: 1px solid var(--md-sys-color-outline);
+      border: none;
       border-radius: 16px;
       --md-focus-ring-shape: 16px;
       height: 64px;
@@ -33,20 +35,28 @@ const standard: MaterialStoryInit<StoryKnobs> = {
       width: 64px;
     }
 
+    button::before {
+      border: 1px solid var(--md-sys-color-outline);
+      border-radius: inherit;
+      content: '';
+      inset: 0;
+      position: absolute;
+    }
+
     button:focus {
       background: var(--md-sys-color-surface-variant);
     }
   `,
-  render() {
+  render({inward}) {
     return html`
       <button aria-label="A button with a focus ring">
-        <md-focus-ring></md-focus-ring>
+        <md-focus-ring ?inward=${inward}></md-focus-ring>
       </button>
       <button aria-label="A button with a focus ring">
-        <md-focus-ring></md-focus-ring>
+        <md-focus-ring ?inward=${inward}></md-focus-ring>
       </button>
       <button aria-label="A button with a focus ring">
-        <md-focus-ring></md-focus-ring>
+        <md-focus-ring ?inward=${inward}></md-focus-ring>
       </button>
     `;
   }
@@ -59,7 +69,6 @@ const multiAction: MaterialStoryInit<StoryKnobs> = {
       align-items: center;
       appearance: none;
       background: var(--md-sys-color-surface);
-      border: 1px solid var(--md-sys-color-outline);
       border-radius: 16px;
       --md-focus-ring-shape: 16px;
       display: flex;
@@ -94,17 +103,25 @@ const multiAction: MaterialStoryInit<StoryKnobs> = {
     }
 
     #secondary {
-      border: 1px solid var(--md-sys-color-outline);
       height: 32px;
       width: 32px;
       border-radius: 32px;
       --md-focus-ring-shape: 32px;
     }
+
+    [role="list"]::before,
+    #secondary::before {
+      border: 1px solid var(--md-sys-color-outline);
+      border-radius: inherit;
+      content: '';
+      inset: 0;
+      position: absolute;
+    }
   `,
-  render() {
+  render({inward}) {
     return html`
       <div role="list">
-        <md-focus-ring for="primary"></md-focus-ring>
+        <md-focus-ring for="primary" ?inward=${inward}></md-focus-ring>
 
         <div role="listitem">
           <button id="primary" aria-label="The primary action for a multi-action component">
@@ -115,7 +132,7 @@ const multiAction: MaterialStoryInit<StoryKnobs> = {
         <div role="listitem">
           <button id="secondary" aria-label="The secondary action for a multi-action component">
             X
-            <md-focus-ring></md-focus-ring>
+            <md-focus-ring ?inward=${inward}></md-focus-ring>
           </button>
         </div>
       </div>

focus/lib/_focus-ring.scss

@@ -44,37 +44,80 @@ $_md-sys-motion: tokens.md-sys-motion-values();
     --_shape-end-end: var(--md-focus-ring-shape-end-end, var(--_shape));
     --_shape-end-start: var(--md-focus-ring-shape-end-start, var(--_shape));
 
-    animation-duration: var(--_duration);
+    animation-delay: 0s, calc(var(--_duration) * 0.25);
+    animation-duration: calc(var(--_duration) * 0.25),
+      calc(var(--_duration) * 0.75);
     animation-timing-function: map.get($_md-sys-motion, 'easing-emphasized');
-    border-end-end-radius: calc(var(--_offset) + var(--_shape-end-end));
-    border-end-start-radius: calc(var(--_offset) + var(--_shape-end-start));
-    border-start-end-radius: calc(var(--_offset) + var(--_shape-start-end));
-    border-start-start-radius: calc(var(--_offset) + var(--_shape-start-start));
-    box-shadow: inset 0 0 0 0 currentColor;
     box-sizing: border-box;
     color: var(--_color);
     display: none;
-    inset: calc(-1 * (var(--_offset) + 1px));
-    // NOTE: this 1px offset hides a transparent ring between the outline and
-    // offset when border-radius is large
-    outline-offset: -1px;
-    outline: var(--_width) solid currentColor;
     pointer-events: none;
     position: absolute;
   }
 
   :host([visible]) {
     display: flex;
-    animation-name: focus-ring;
   }
 
-  @keyframes focus-ring {
+  :host(:not([inward])) {
+    animation-name: outward-grow, outward-shrink;
+    border-end-end-radius: calc(var(--_shape-end-end) + var(--_outward-offset));
+    border-end-start-radius: calc(
+      var(--_shape-end-start) + var(--_outward-offset)
+    );
+    border-start-end-radius: calc(
+      var(--_shape-start-end) + var(--_outward-offset)
+    );
+    border-start-start-radius: calc(
+      var(--_shape-start-start) + var(--_outward-offset)
+    );
+    inset: calc(-1 * (var(--_outward-offset)));
+    outline: var(--_width) solid currentColor;
+  }
+
+  :host([inward]) {
+    animation-name: inward-grow, inward-shrink;
+    border-end-end-radius: calc(var(--_shape-end-end) - var(--_inward-offset));
+    border-end-start-radius: calc(
+      var(--_shape-end-start) - var(--_inward-offset)
+    );
+    border-start-end-radius: calc(
+      var(--_shape-start-end) - var(--_inward-offset)
+    );
+    border-start-start-radius: calc(
+      var(--_shape-start-start) - var(--_inward-offset)
+    );
+    border: var(--_width) solid currentColor;
+    inset: var(--_inward-offset);
+  }
+
+  @keyframes outward-grow {
     from {
-      outline-width: 0px;
+      outline-width: 0;
     }
-    25% {
-      box-shadow: inset 0 0 0 calc(var(--_active-width) / 2) currentColor;
-      outline-width: calc(var(--_active-width) / 2);
+    to {
+      outline-width: var(--_active-width);
+    }
+  }
+
+  @keyframes outward-shrink {
+    from {
+      outline-width: var(--_active-width);
+    }
+  }
+
+  @keyframes inward-grow {
+    from {
+      border-width: 0;
+    }
+    to {
+      border-width: var(--_active-width);
+    }
+  }
+
+  @keyframes inward-shrink {
+    from {
+      border-width: var(--_active-width);
     }
   }
 

focus/lib/focus-ring.ts

@@ -15,6 +15,7 @@ export class FocusRing extends LitElement {
    * Makes the focus ring visible.
    */
   @property({type: Boolean, reflect: true}) visible = false;
+  @property({type: Boolean, reflect: true}) inward = false;
 
   /**
    * Reflects the value of the `for` attribute, which is the ID of the focus

list/lib/listitem/_list-item.scss

@@ -47,8 +47,7 @@
 
     @include focus-ring.theme(
       (
-        'offset': -3px,
-        'shape': map.get(tokens.md-sys-shape-values(), 'corner-extra-small'),
+        'shape': 8px,
       )
     );
     @include ripple.theme(

list/lib/listitem/list-item.ts

@@ -159,7 +159,7 @@ export class ListItemEl extends LitElement implements ListItem {
    * Handles rendering of the focus ring.
    */
   protected renderFocusRing() {
-    return html`<md-focus-ring class="focus-ring" for="item"></md-focus-ring>`;
+    return html`<md-focus-ring class="focus-ring" for="item" inward></md-focus-ring>`;
   }
 
   /**

navigationtab/lib/_navigation-tab.scss

@@ -43,8 +43,8 @@ $_custom-property-prefix: 'navigation-bar';
 
     @include focus-ring.theme(
       (
-        'offset': -2px,
         'shape': map.get(tokens.md-sys-shape-values(), 'corner-small'),
+        'inward-offset': -1px,
       )
     );
 

navigationtab/lib/navigation-tab.ts

@@ -52,8 +52,9 @@ export class NavigationTab extends LitElement implements NavigationTabState {
         aria-label=${ariaLabel || nothing}
         tabindex="${this.active ? 0 : -1}"
         @click="${this.handleClick}"
-      ${ripple(this.getRipple)}>
-        <md-focus-ring></md-focus-ring>
+        ${ripple(this.getRipple)}
+      >
+        <md-focus-ring inward></md-focus-ring>
         ${when(this.showRipple, this.renderRipple)}
         <span aria-hidden="true" class="md3-navigation-tab__icon-content"
           ><span class="md3-navigation-tab__active-indicator"

radio/lib/_radio.scss

@@ -45,7 +45,7 @@ $_md-sys-motion: tokens.md-sys-motion-values();
 
     @include focus-ring.theme(
       (
-        'offset': -2px,
+        'outward-offset': -2px,
       )
     );
 

slider/lib/_slider.scss

@@ -450,7 +450,7 @@ $_md-sys-shape: tokens.md-sys-shape-values();
   md-focus-ring {
     @include focus-ring.theme(
       (
-        'offset': -2px,
+        'outward-offset': -2px,
       )
     );
   }

tabs/lib/_tab.scss

@@ -54,14 +54,15 @@
 
     @include focus-ring.theme(
       (
-        // desired border-radius is 8px and it's internally calc'd as sum
-        // of shape + offset (-7 + 15)
-        shape: 15px,
-        offset: -7px
+        'shape': 8px,
       )
     );
   }
 
+  :host([selected]) md-focus-ring {
+    margin-bottom: calc(var(--_active-indicator-height) + 1px);
+  }
+
   .button {
     display: inline-flex;
     align-items: center;

tabs/lib/tab.ts

@@ -115,7 +115,7 @@ export class Tab extends LitElement {
         aria-label=${this.ariaLabel || nothing}
         ${ripple(this.getRipple)}
       >
-        <md-focus-ring></md-focus-ring>
+        <md-focus-ring inward></md-focus-ring>
         <md-elevation></md-elevation>
         ${when(this.showRipple, this.renderRipple)}
         <span class="touch"></span>

tokens/_md-comp-focus-ring.scss

@@ -19,7 +19,8 @@ $supported-tokens: (
   'active-width',
   'color',
   'duration',
-  'offset',
+  'inward-offset',
+  'outward-offset',
   'shape',
   'width',
   // go/keep-sorted end
@@ -36,7 +37,8 @@ $_default: (
     'active-width': if($exclude-hardcoded-values, null, 8px),
     'color': map.get($deps, 'md-sys-color', 'secondary'),
     'duration': map.get($deps, 'md-sys-motion', 'duration-long4'),
-    'offset': if($exclude-hardcoded-values, null, 2px),
+    'inward-offset': if($exclude-hardcoded-values, null, 0px),
+    'outward-offset': if($exclude-hardcoded-values, null, 2px),
     'shape': map.get($deps, 'md-sys-shape', 'corner-full'),
     'width': if($exclude-hardcoded-values, null, 3px),
   );