app/node_modules/@angular/material/form-field/_form-field-focus-overlay.scss

@use '../core/tokens/m2/mat/form-field' as tokens-mat-form-field;
@use '../core/tokens/token-utils';
@use '../core/style/layout-common';

// MDC text-field used to use their ripple in order to show a focus and hover effect for
// text-fields. This is unnecessary because the ripples bring in a lot of unnecessary
// styles and runtime code while the actual goal for the text-field is simply showing a
// focus and hover effect. The ripples will unnecessarily provide CSS selectors and JS
// runtime code for launching interaction ripples at pointer location. This is not needed
// for the text-field, so we create our own minimal focus overlay styles. Our focus overlay
// uses the exact same logic to compute the colors as in the default MDC text-field ripples.
@mixin private-form-field-focus-overlay() {
  .mat-mdc-form-field-focus-overlay {
    @include layout-common.fill;
    opacity: 0;
    pointer-events: none; // Make sure we don't block click on the prefix/suffix.

    @include token-utils.use-tokens(
      tokens-mat-form-field.$prefix, tokens-mat-form-field.get-token-slots()) {
      @include token-utils.create-token-slot(background-color, state-layer-color);

      .mat-mdc-text-field-wrapper:hover & {
        @include token-utils.create-token-slot(opacity, hover-state-layer-opacity);
      }

      .mat-mdc-form-field.mat-focused & {
        @include token-utils.create-token-slot(opacity, focus-state-layer-opacity);
      }
    }
  }
}