From 72a8748a624c443e07ee8de88a1c10f1069718fa Mon Sep 17 00:00:00 2001
From: Kristiyan Kostadinov <crisbeto@abv.bg>
Date: Fri, 30 Jul 2021 21:10:40 +0200
Subject: [PATCH] refactor(material/progress-spinner): clean up IE workarounds

Cleans up the various workarounds for IE from the progress spinner.
---
 .../progress-spinner/progress-spinner.html    |  3 +-
 .../progress-spinner/progress-spinner.scss    | 38 ++---------------
 .../progress-spinner/progress-spinner.spec.ts | 41 +++++++------------
 .../progress-spinner/progress-spinner.ts      | 23 ++++-------
 .../material/progress-spinner.md              |  3 +-
 5 files changed, 27 insertions(+), 81 deletions(-)

diff --git a/src/material/progress-spinner/progress-spinner.html b/src/material/progress-spinner/progress-spinner.html
index 92c082e7e749..29c093050abd 100644
--- a/src/material/progress-spinner/progress-spinner.html
+++ b/src/material/progress-spinner/progress-spinner.html
@@ -1,8 +1,7 @@
 <!--
   preserveAspectRatio of xMidYMid meet as the center of the viewport is the circle's
   center. The center of the circle will remain at the center of the mat-progress-spinner
-  element containing the SVG. `focusable="false"` prevents IE from allowing the user to
-  tab into the SVG element.
+  element containing the SVG.
 -->
 <!--
   All children need to be hidden for screen readers in order to support ChromeVox.
diff --git a/src/material/progress-spinner/progress-spinner.scss b/src/material/progress-spinner/progress-spinner.scss
index e416fd0a725e..fd7b1e45b111 100644
--- a/src/material/progress-spinner/progress-spinner.scss
+++ b/src/material/progress-spinner/progress-spinner.scss
@@ -3,10 +3,6 @@
 @use '../../cdk/a11y';
 
 
-// Animation config
-$stroke-rotate-fallback-duration: 10 * 1000ms !default;
-$stroke-rotate-fallback-ease: cubic-bezier(0.87, 0.03, 0.33, 1) !default;
-
 $_default-radius: 45px;
 $_default-circumference: variables.$pi * $_default-radius * 2;
 
@@ -35,10 +31,9 @@ $_default-circumference: variables.$pi * $_default-radius * 2;
 
     @include a11y.high-contrast(active, off) {
       // SVG colors aren't inverted automatically in high contrast mode. Set the
-      // stroke to currentColor in order to respect the user's color settings.
-      stroke: currentColor;
-      // currentColor blends in with the background in Chromium-based browsers
-      // so we have to fall back to `CanvasText` which isn't supported on IE.
+      // stroke to `CanvasText` in order to respect the user's color settings.
+      // Note that we use `CanvasText` instead of `currentColor`, because
+      // the latter blends in with the background on Chromium browsers.
       stroke: CanvasText;
     }
   }
@@ -59,21 +54,6 @@ $_default-circumference: variables.$pi * $_default-radius * 2;
       animation-iteration-count: infinite;
     }
   }
-
-  &.mat-progress-spinner-indeterminate-fallback-animation[mode='indeterminate'] {
-    svg {
-      @include private.private-animation-noop();
-      animation: mat-progress-spinner-stroke-rotate-fallback
-                 $stroke-rotate-fallback-duration
-                 $stroke-rotate-fallback-ease
-                 infinite;
-    }
-
-    circle {
-      @include private.private-animation-noop();
-      transition-property: stroke;
-    }
-  }
 }
 
 
@@ -86,7 +66,6 @@ $_default-circumference: variables.$pi * $_default-radius * 2;
 @at-root {
   $start: (1 - 0.05) * $_default-circumference; // start the animation at 5%
   $end: (1 - 0.8) * $_default-circumference; // end the animation at 80%
-  $fallback-iterations: 4;
 
   @keyframes mat-progress-spinner-stroke-rotate-100 {
     // stylelint-disable declaration-block-single-line-max-declarations
@@ -119,15 +98,4 @@ $_default-circumference: variables.$pi * $_default-radius * 2;
     100%      { stroke-dashoffset: $start;  transform: rotateX(180deg) rotate(341.5deg); }
     // stylelint-enable
   }
-
-  // For IE11 and Edge, we fall back to simply rotating the spinner because
-  // animating stroke-dashoffset is not supported. The fallback uses multiple
-  // iterations to vary where the spin "lands".
-  @keyframes mat-progress-spinner-stroke-rotate-fallback {
-    @for $i from 0 through $fallback-iterations {
-      $percent: private.private-div(100, $fallback-iterations) * $i;
-      $offset: private.private-div(360, $fallback-iterations);
-      #{$percent}% { transform: rotate(#{$i * (360 * 3 + $offset)}deg); }
-    }
-  }
 }
diff --git a/src/material/progress-spinner/progress-spinner.spec.ts b/src/material/progress-spinner/progress-spinner.spec.ts
index 8a5bd3384852..6961d4062a52 100644
--- a/src/material/progress-spinner/progress-spinner.spec.ts
+++ b/src/material/progress-spinner/progress-spinner.spec.ts
@@ -1,7 +1,7 @@
-import {TestBed, waitForAsync, inject} from '@angular/core/testing';
+import {TestBed, waitForAsync} from '@angular/core/testing';
 import {Component, ViewEncapsulation, ViewChild, ElementRef} from '@angular/core';
 import {By} from '@angular/platform-browser';
-import {Platform, _getShadowRoot, _supportsShadowDom} from '@angular/cdk/platform';
+import {_getShadowRoot, _supportsShadowDom} from '@angular/cdk/platform';
 import {CommonModule} from '@angular/common';
 import {
   MatProgressSpinnerModule,
@@ -158,13 +158,7 @@ describe('MatProgressSpinner', () => {
   });
 
   it('should add a style tag with the indeterminate animation to the document head when using a ' +
-    'non-default diameter', inject([Platform], (platform: Platform) => {
-      // On Edge and IE we use a fallback animation because the
-      // browser doesn't support animating SVG correctly.
-      if (platform.EDGE || platform.TRIDENT) {
-        return;
-      }
-
+    'non-default diameter', () => {
       const fixture = TestBed.createComponent(ProgressSpinnerCustomDiameter);
       fixture.componentInstance.diameter = 32;
       fixture.detectChanges();
@@ -184,7 +178,7 @@ describe('MatProgressSpinner', () => {
 
       expect(document.head.querySelectorAll('style[mat-spinner-animation="32"]').length).toBe(1);
       expect(document.head.querySelectorAll('style[mat-spinner-animation="64"]').length).toBe(1);
-  }));
+  });
 
   it('should allow floating point values for custom diameter', () => {
       const fixture = TestBed.createComponent(ProgressSpinnerCustomDiameter);
@@ -207,26 +201,19 @@ describe('MatProgressSpinner', () => {
         .toBe('0 0 25.75 25.75', 'Expected the custom diameter to be applied to the svg viewBox.');
   });
 
-  it('should handle creating animation style tags based on a floating point diameter',
-    inject([Platform], (platform: Platform) => {
-      // On Edge and IE we use a fallback animation because the
-      // browser doesn't support animating SVG correctly.
-      if (platform.EDGE || platform.TRIDENT) {
-        return;
-      }
-
-      const fixture = TestBed.createComponent(IndeterminateSpinnerCustomDiameter);
+  it('should handle creating animation style tags based on a floating point diameter', () => {
+    const fixture = TestBed.createComponent(IndeterminateSpinnerCustomDiameter);
 
-      fixture.componentInstance.diameter = 32.5;
-      fixture.detectChanges();
+    fixture.componentInstance.diameter = 32.5;
+    fixture.detectChanges();
 
-      const circleElement = fixture.nativeElement.querySelector('circle');
+    const circleElement = fixture.nativeElement.querySelector('circle');
 
-      expect(circleElement.style.animationName).toBe('mat-progress-spinner-stroke-rotate-32_5',
-      'Expected the spinner circle element to have an animation name based on the custom diameter');
-      expect(document.head.querySelectorAll('style[mat-spinner-animation="32_5"]').length).toBe(1,
-      'Expected a style tag with the indeterminate animation to be attached to the document head');
-  }));
+    expect(circleElement.style.animationName).toBe('mat-progress-spinner-stroke-rotate-32_5',
+    'Expected the spinner circle element to have an animation name based on the custom diameter');
+    expect(document.head.querySelectorAll('style[mat-spinner-animation="32_5"]').length).toBe(1,
+    'Expected a style tag with the indeterminate animation to be attached to the document head');
+  });
 
   it('should allow a custom stroke width', () => {
     const fixture = TestBed.createComponent(ProgressSpinnerCustomStrokeWidth);
diff --git a/src/material/progress-spinner/progress-spinner.ts b/src/material/progress-spinner/progress-spinner.ts
index 65cc4d58904c..93067cfebc73 100644
--- a/src/material/progress-spinner/progress-spinner.ts
+++ b/src/material/progress-spinner/progress-spinner.ts
@@ -128,7 +128,6 @@ export class MatProgressSpinner extends _MatProgressSpinnerBase implements OnIni
   private _diameter = BASE_SIZE;
   private _value = 0;
   private _strokeWidth: number;
-  private _fallbackAnimation = false;
 
   /**
    * Element to which we should add the generated style tags for the indeterminate animation.
@@ -159,7 +158,7 @@ export class MatProgressSpinner extends _MatProgressSpinnerBase implements OnIni
     this._spinnerAnimationLabel = this._getSpinnerAnimationLabel();
 
     // If this is set before `ngOnInit`, the style root may not have been resolved yet.
-    if (!this._fallbackAnimation && this._styleRoot) {
+    if (this._styleRoot) {
       this._attachStyleNode();
     }
   }
@@ -186,7 +185,11 @@ export class MatProgressSpinner extends _MatProgressSpinnerBase implements OnIni
   }
 
   constructor(elementRef: ElementRef<HTMLElement>,
-              platform: Platform,
+              /**
+               * @deprecated `_platform` parameter no longer being used.
+               * @breaking-change 14.0.0
+               */
+              _platform: Platform,
               @Optional() @Inject(DOCUMENT) private _document: any,
               @Optional() @Inject(ANIMATION_MODULE_TYPE) animationMode: string,
               @Inject(MAT_PROGRESS_SPINNER_DEFAULT_OPTIONS)
@@ -203,7 +206,6 @@ export class MatProgressSpinner extends _MatProgressSpinnerBase implements OnIni
       trackedDiameters.set(_document.head, new Set<number>([BASE_SIZE]));
     }
 
-    this._fallbackAnimation = platform.EDGE || platform.TRIDENT;
     this._noopAnimations = animationMode === 'NoopAnimations' &&
         (!!defaults && !defaults._forceAnimations);
 
@@ -226,13 +228,7 @@ export class MatProgressSpinner extends _MatProgressSpinnerBase implements OnIni
     // node is inside an `ngIf` and a ShadowDom-encapsulated component.
     this._styleRoot = _getShadowRoot(element) || this._document.head;
     this._attachStyleNode();
-
-    // On IE and Edge, we can't animate the `stroke-dashoffset`
-    // reliably so we fall back to a non-spec animation.
-    const animationClass =
-      `mat-progress-spinner-indeterminate${this._fallbackAnimation ? '-fallback' : ''}-animation`;
-
-    element.classList.add(animationClass);
+    element.classList.add('mat-progress-spinner-indeterminate-animation');
   }
 
   /** The radius of the spinner, adjusted for stroke width. */
@@ -257,11 +253,6 @@ export class MatProgressSpinner extends _MatProgressSpinnerBase implements OnIni
       return this._getStrokeCircumference() * (100 - this._value) / 100;
     }
 
-    // In fallback mode set the circle to 80% and rotate it with CSS.
-    if (this._fallbackAnimation && this.mode === 'indeterminate') {
-      return this._getStrokeCircumference() * 0.2;
-    }
-
     return null;
   }
 
diff --git a/tools/public_api_guard/material/progress-spinner.md b/tools/public_api_guard/material/progress-spinner.md
index 1f65b19418dd..8d6b27bc30a5 100644
--- a/tools/public_api_guard/material/progress-spinner.md
+++ b/tools/public_api_guard/material/progress-spinner.md
@@ -24,7 +24,8 @@ export function MAT_PROGRESS_SPINNER_DEFAULT_OPTIONS_FACTORY(): MatProgressSpinn
 
 // @public
 export class MatProgressSpinner extends _MatProgressSpinnerBase implements OnInit, CanColor {
-    constructor(elementRef: ElementRef<HTMLElement>, platform: Platform, _document: any, animationMode: string, defaults?: MatProgressSpinnerDefaultOptions);
+    constructor(elementRef: ElementRef<HTMLElement>,
+    _platform: Platform, _document: any, animationMode: string, defaults?: MatProgressSpinnerDefaultOptions);
     get diameter(): number;
     set diameter(size: number);
     _getCircleRadius(): number;