_button-base.scss

@use '@material/touch-target' as mdc-touch-target;
@use '../mdc-helpers/mdc-helpers';
@use '../../material/core/style/layout-common';

// Adds styles necessary to provide stateful interactions with the button. This includes providing
// content for the state container's ::before and ::after so that they can be given a background
// color and opacity for states like hover, active, and focus. Additionally, adds styles to the
// ripple and state container so that they fill the button, match the border radius, and avoid
// pointer events.
@mixin mat-private-button-interactive() {
  .mdc-button__ripple::before, .mdc-button__ripple::after,
  .mdc-fab__ripple::before, .mdc-fab__ripple::after {
    content: '';
    pointer-events: none;
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    opacity: 0;
    border-radius: inherit;
    @content;
  }

  // The ripple container should match the bounds of the entire button.
  .mat-mdc-button-ripple, .mdc-button__ripple, .mdc-fab__ripple {
    @include layout-common.fill;

    // Disable pointer events for the ripple container and state overlay because the container
    // will overlay the user content and we don't want to disable mouse events on the user content.
    // Pointer events can be safely disabled because the ripple trigger element is the host element.
    pointer-events: none;

    // Inherit the border radius from the parent so that state overlay and ripples don't exceed the
    // parent button boundaries. Note that an inherited border radius does not work properly if
    // the actual button element does have a border because it causes the inner content to be
    // smaller. We have special logic for stroked buttons to handle this scenario.
    border-radius: inherit;
  }

  // The content should appear over the state and ripple layers, otherwise they may adversely affect
  // the accessibility of the text content.
  .mdc-button__label {
    z-index: 1;
  }

  // The focus indicator should match the bounds of the entire button.
  .mat-mdc-focus-indicator {
    @include layout-common.fill();
  }
}

// MDC's disabled buttons define a default cursor with pointer-events none. However, they select
// :disabled for this, which does not affect anchor tags.
// TODO(andrewseguin): Discuss with the MDC team about a mixin we can call for applying this style,
// and note that having pointer-events may have unintended side-effects, e.g. allowing the user
// to click the target underneath the button.
@mixin mat-private-button-disabled() {
  &[disabled] {
    cursor: default;
    pointer-events: none;
  }
}

@mixin mat-private-button-touch-target($is-square) {
  // Element used to ensure that the button has a touch target that meets the required minimum.
  // Note that we use this, instead of MDC's built-in `mdc-button--touch` class, because the MDC
  // class is implemented as `margin-top: 6px; margin-bottom: 6px` on the host element which
  // goes against our rule of not having margins on the host node. Furthermore, having the margin on
  // the button itself would require us to wrap it in another div. See:
  // https://github.com/material-components/material-components-web/tree/master/packages/mdc-button#making-buttons-accessible
  .mat-mdc-button-touch-target {
    @include mdc-touch-target.touch-target(
      $set-width: $is-square,
      $query: mdc-helpers.$mat-base-styles-query);

      @if ($is-square) {
        [dir='rtl'] & {
          left: auto;
          right: 50%;
          transform: translate(50%, -50%);
        }
      }
  }
}