fix(material-experimental/mdc-form-field): fix outline notch width

This commit fixes a couple of issues that have been introduced
by accident over time:

1. The outline notch width is incorrectly calculated since
   #21676. This happens
   because we manually override the label's typography level to `body1`
   but didn't account for the `font-size` set by the `notched-outline`.
   This resulted in the computed label width being incorrect.

2. #22089 added `line-height:
   0` to fix textarea's accidentally expanding the infix vertically.
   This breaks custom controls and their alignment. Textarea's behave a
   little different compared to a native input, and the actual fix seems
   to be to fix the alignment from `top` to `middle` so that the infix
   does not try to add additional padding (due to the inherited `body1`
   line-height and to satisfy `min-height`). Example:
   https://jsfiddle.net/rpvm4bkL/6/.

3. Typography has been moved with
   #21676 to the
   input control (notice how `font: inherit` is removed too). This
   breaks custom form controls that rely on the typography provided
   by the form-field (these controls would just inherit typography)

4. Not an actual fix, but a cleanup since 21ab17f
  added a class to avoid styles from the form-field leaking into
  standalone inputs. The class has been updated to be more specific that
  it only matches form-control inputs, and not _any_ type of form
  control.

Author: devversion

src/dev-app/mdc-input/mdc-input-demo.html

@@ -731,6 +731,25 @@ <h3>&lt;textarea&gt; with bindable autosize </h3>
       <mat-label>Label</mat-label>
       <input matInput>
     </mat-form-field>
+
+    <p>
+      Textarea alignment
+    </p>
+
+    <mat-form-field appearance="outline">
+      <mat-label>Textarea</mat-label>
+      <textarea matInput rows="1"></textarea>
+    </mat-form-field>
+
+    <mat-form-field appearance="outline">
+      <mat-label>Input</mat-label>
+      <input matInput>
+    </mat-form-field>
+
+    <mat-form-field appearance="outline">
+      <mat-label>Input</mat-label>
+      <input matInput>
+    </mat-form-field>
   </mat-card-content>
 </mat-card>
 

src/material-experimental/mdc-chips/chip-input.spec.ts

@@ -130,7 +130,7 @@ describe('MDC-based MatChipInput', () => {
 
     it('should set input styling classes', () => {
       expect(inputNativeElement.classList).toContain('mat-mdc-input-element');
-      expect(inputNativeElement.classList).toContain('mat-mdc-form-field-control');
+      expect(inputNativeElement.classList).toContain('mat-mdc-form-field-input-control');
       expect(inputNativeElement.classList).toContain('mat-mdc-chip-input');
       expect(inputNativeElement.classList).toContain('mdc-text-field__input');
     });

src/material-experimental/mdc-chips/chip-input.ts

@@ -134,7 +134,7 @@ export class MatChipInput implements MatChipTextControl, AfterContentInit, OnCha
       this.inputElement = this._elementRef.nativeElement as HTMLInputElement;
 
       if (formField) {
-        this.inputElement.classList.add('mat-mdc-form-field-control');
+        this.inputElement.classList.add('mat-mdc-form-field-input-control');
       }
     }
 

src/material-experimental/mdc-form-field/_form-field-native-select.scss

@@ -18,7 +18,7 @@ $mat-form-field-select-horizontal-end-padding: $mat-form-field-select-arrow-widt
   // Remove the native select down arrow and ensure that the native appearance
   // does not conflict with the form-field. e.g. Focus indication of the native
   // select is undesired since we handle focus as part of the form-field.
-  select.mat-mdc-form-field-control {
+  select.mat-mdc-form-field-input-control {
     -moz-appearance: none;
     -webkit-appearance: none;
     background-color: transparent;
@@ -83,7 +83,7 @@ $mat-form-field-select-horizontal-end-padding: $mat-form-field-select-arrow-widt
 
     // Add padding on the end of the native select so that the content does not
     // overlap with the Material Design arrow.
-    .mat-mdc-form-field-control {
+    .mat-mdc-form-field-input-control {
       padding-right: $mat-form-field-select-horizontal-end-padding;
       [dir='rtl'] & {
         padding-right: 0;
@@ -105,7 +105,7 @@ $mat-form-field-select-horizontal-end-padding: $mat-form-field-select-arrow-widt
     $dropdown-icon-color: rgba(mdc-theme-color.prop-value(on-surface), 0.54);
     $disabled-dropdown-icon-color: rgba(mdc-theme-color.prop-value(on-surface), 0.38);
 
-    select.mat-mdc-form-field-control {
+    select.mat-mdc-form-field-input-control {
       // On dark themes we set the native `select` color to some shade of white,
       // however the color propagates to all of the `option` elements, which are
       // always on a white background inside the dropdown, causing them to blend in.

src/material-experimental/mdc-form-field/_form-field-sizing.scss

@@ -38,7 +38,3 @@ $mat-form-field-no-label-padding-top: 16px;
 // The amount of padding between the icon prefix/suffix and the infix.
 // This assumes that the icon will be a 24px square with 12px padding.
 $mat-form-field-icon-prefix-infix-padding: 4px;
-
-// The amount of padding between the end of the form-field and the infix for a form-field with no
-// icons.
-$mat-form-field-end-padding: 16px;

src/material-experimental/mdc-form-field/_form-field-subscript.scss

@@ -1,6 +1,7 @@
 @use '@material/textfield' as mdc-textfield;
 @use '@material/theme/theme' as mdc-theme;
 @use '@material/typography' as mdc-typography;
+@use '@material/textfield/variables' as mdc-textfield-variables;
 @use 'form-field-sizing';
 @use '../mdc-helpers/mdc-helpers';
 @use '../../material/core/theming/theming';
@@ -13,16 +14,13 @@
     position: relative;
   }
 
-  // The horizontal padding between the edge of the text box and the start of the subscript text.
-  $subscript-horizontal-padding: 16px;
-
   .mat-mdc-form-field-hint-wrapper,
   .mat-mdc-form-field-error-wrapper {
     position: absolute;
     top: 0;
     left: 0;
     right: 0;
-    padding: 0 $subscript-horizontal-padding;
+    padding: 0 mdc-textfield-variables.$padding-horizontal;
   }
 
   .mat-mdc-form-field-bottom-align::before {
@@ -31,14 +29,8 @@
     height: 16px;
   }
 
-  // Scale down icons in the subscript to be the same size as the text.
-  .mat-mdc-form-field-subscript-wrapper,
-  .mat-mdc-form-field label {
-    .mat-icon {
-      width: 1em;
-      height: 1em;
-      font-size: inherit;
-    }
+  .mat-mdc-form-field-hint-end {
+    order: 1;
   }
 
   // Clears the floats on the hints. This is necessary for the hint animation to work.

src/material-experimental/mdc-form-field/_form-field-theme.scss

@@ -3,7 +3,7 @@
 @use '@material/notched-outline' as mdc-notched-outline;
 @use '@material/line-ripple' as mdc-line-ripple;
 @use '@material/theme/theme-color' as mdc-theme-color;
-@use '@material/typography' as mdc-typography;
+@use '@material/typography/typography' as mdc-typography;
 @use '../mdc-helpers/mdc-helpers';
 @use '../../material/core/typography/typography';
 @use 'form-field-density';
@@ -72,14 +72,30 @@
     @include mdc-line-ripple.core-styles($query: mdc-helpers.$mat-typography-styles-query);
     @include form-field-subscript.private-form-field-subscript-typography($config);
 
-    // MDC uses the `subtitle1` level for the input label and value, but the spec shows `body1` as
-    // the correct level.
-    .mat-mdc-form-field-control,
-    .mat-mdc-form-field label,
-    .mat-mdc-form-field-text-prefix,
-    .mat-mdc-form-field-text-suffix {
+    // MDC uses `subtitle1` for the input value, placeholder and floating label. The spec
+    // shows `body1` for text fields though, so we manually override the typography.
+    // Note: Form controls inherit the typography from the parent form field.
+    .mat-mdc-form-field,
+    .mat-mdc-form-field .mdc-floating-label {
       @include mdc-typography.typography(body1, $query: mdc-helpers.$mat-typography-styles-query);
     }
+
+    // Above, we updated the floating label to use the `body1` typography level. The MDC notched
+    // outline overrides this accidentally (only when the label floats) to a `rem`-based value.
+    // This results in different label widths when floated/docked and ultimately breaks the notch
+    // width as it has been measured in the docked state (where `body1` is applied). We try to
+    // unset these styles set by the `mdc-notched-outline`:
+    // https://github.com/material-components/material-components-web/blob/master/packages/mdc-notched-outline/_mixins.scss#L272-L292.
+    .mat-mdc-form-field .mdc-text-field--outlined {
+      // For the non-upgraded notch label (i.e. when rendered on the server), also
+      // use the correct `body1` typography level.
+      .mdc-floating-label--float-above {
+        font-size: mdc-typography.get-size(body1) * 0.75;
+      }
+      .mdc-notched-outline--upgraded .mdc-floating-label--float-above {
+        font-size: mdc-typography.get-size(body1);
+      }
+    }
   }
 }
 

src/material-experimental/mdc-form-field/_mdc-text-field-structure-overrides.scss

@@ -1,4 +1,4 @@
-@use 'form-field-sizing';
+@use '@material/textfield/variables' as mdc-textfield-variables;
 @use '../../cdk/a11y';
 
 // Mixin that can be included to override the default MDC text-field
@@ -7,8 +7,12 @@
 @mixin private-text-field-structure-overrides() {
   // Unset the border set by MDC. We move the border (which serves as the Material Design
   // text-field bottom line) into its own element. This is necessary because we want the
-  // bottom-line to span across the whole form-field (including prefixes and suffixes).
-  .mat-mdc-form-field-control {
+  // bottom-line to span across the whole form-field (including prefixes and suffixes). Also
+  // we ensure that font styles are inherited for input elements. We do this because inputs by
+  // default have explicit font styles from the user agent, and we set the desired font styles
+  // in the parent `mat-form-field` element (for better custom form-field control support).
+  .mat-mdc-form-field-input-control {
+    font: inherit;
     border: none;
   }
 
@@ -25,8 +29,8 @@
   // not work for us since we support arbitrary form field controls which don't necessarily
   // use an `input` element. We organize the vertical spacing on the infix container.
   .mdc-text-field--no-label:not(.mdc-text-field--textarea)
-  .mat-mdc-form-field-control.mdc-text-field__input,
-  .mat-mdc-text-field-wrapper .mat-mdc-form-field-control {
+  .mat-mdc-form-field-input-control.mdc-text-field__input,
+  .mat-mdc-text-field-wrapper .mat-mdc-form-field-input-control {
     height: auto;
   }
 
@@ -51,8 +55,8 @@
   [dir='rtl'] {
     // Undo the above padding removals which only apply in LTR languages.
     .mat-mdc-text-field-wrapper {
-      padding-left: form-field-sizing.$mat-form-field-end-padding;
-      padding-right: form-field-sizing.$mat-form-field-end-padding;
+      padding-left: mdc-textfield-variables.$padding-horizontal;
+      padding-right: mdc-textfield-variables.$padding-horizontal;
     }
     // ...and apply the correct padding resets for RTL languages.
     .mat-mdc-form-field-has-icon-suffix .mat-mdc-text-field-wrapper {

src/material-experimental/mdc-form-field/_mdc-text-field-textarea-overrides.scss

@@ -10,7 +10,11 @@
 @mixin private-text-field-textarea-overrides() {
   // Ensures that textarea elements inside of the form-field have proper vertical spacing
   // to account for the floating label. Also ensures that there is no vertical text overflow.
-  .mat-mdc-textarea-input {
+  .mat-mdc-form-field-input-control.mat-mdc-textarea-input {
+    // Set the vertical alignment for textareas inside form fields to be the middle. This
+    // ensures that textareas do not stretch the infix container vertically without having
+    // multiple rows of text. See: https://github.com/angular/components/pull/22089.
+    vertical-align: middle;
     resize: vertical;
     box-sizing: border-box;
     height: auto;

src/material-experimental/mdc-form-field/form-field.scss

@@ -88,13 +88,21 @@
   }
 }
 
+// Scale down icons in the subscript and floating label to be the same size
+// as the text.
+.mat-mdc-form-field-subscript-wrapper,
+.mat-mdc-form-field label {
+  .mat-icon {
+    width: 1em;
+    height: 1em;
+    font-size: inherit;
+  }
+}
+
 // Infix that contains the projected content (usually an input or a textarea). We ensure
 // that the projected form-field control and content can stretch as needed, but we also
 // apply a default infix width to make the form-field's look natural.
 .mat-mdc-form-field-infix {
-  // Prevent extra height from being added around the textarea, which throws off the overall
-  // height of the form-field
-  line-height: 0;
   flex: auto;
   min-width: 0;
   width: form-field-sizing.$mat-form-field-default-infix-width;
@@ -103,10 +111,6 @@
   box-sizing: border-box;
 }
 
-.mat-mdc-form-field-hint-end {
-  order: 1;
-}
-
 // In order to make it possible for developers to disable animations for form-fields,
 // we only activate the animation styles if animations are not explicitly disabled.
 .mat-mdc-form-field:not(.mat-form-field-no-animations) {