feat(icon): allow viewBox to be configured when registering icons

This has been a long-standing feature request that has recently popped up again. Allows consumers to specify a `viewBox` for icons and icon sets when they're being registered.

Fixes #2981.
Fixes #16293.

Author: crisbeto

src/material/icon/icon-registry.ts

@@ -73,9 +73,9 @@ class SvgIconConfig {
   url: SafeResourceUrl | null;
   svgElement: SVGElement | null;
 
-  constructor(url: SafeResourceUrl);
-  constructor(svgElement: SVGElement);
-  constructor(data: SafeResourceUrl | SVGElement) {
+  constructor(url: SafeResourceUrl, viewBox?: string);
+  constructor(svgElement: SVGElement, viewBox?: string);
+  constructor(data: SafeResourceUrl | SVGElement, public viewBox?: string) {
     // Note that we can't use `instanceof SVGElement` here,
     // because it'll break during server-side rendering.
     if (!!(data as any).nodeName) {
@@ -136,17 +136,17 @@ export class MatIconRegistry implements OnDestroy {
    * @param iconName Name under which the icon should be registered.
    * @param url
    */
-  addSvgIcon(iconName: string, url: SafeResourceUrl): this {
-    return this.addSvgIconInNamespace('', iconName, url);
+  addSvgIcon(iconName: string, url: SafeResourceUrl, viewBox?: string): this {
+    return this.addSvgIconInNamespace('', iconName, url, viewBox);
   }
 
   /**
    * Registers an icon using an HTML string in the default namespace.
    * @param iconName Name under which the icon should be registered.
    * @param literal SVG source of the icon.
    */
-  addSvgIconLiteral(iconName: string, literal: SafeHtml): this {
-    return this.addSvgIconLiteralInNamespace('', iconName, literal);
+  addSvgIconLiteral(iconName: string, literal: SafeHtml, viewBox?: string): this {
+    return this.addSvgIconLiteralInNamespace('', iconName, literal, viewBox);
   }
 
   /**
@@ -155,8 +155,9 @@ export class MatIconRegistry implements OnDestroy {
    * @param iconName Name under which the icon should be registered.
    * @param url
    */
-  addSvgIconInNamespace(namespace: string, iconName: string, url: SafeResourceUrl): this {
-    return this._addSvgIconConfig(namespace, iconName, new SvgIconConfig(url));
+  addSvgIconInNamespace(namespace: string, iconName: string, url: SafeResourceUrl,
+                        viewBox?: string): this {
+    return this._addSvgIconConfig(namespace, iconName, new SvgIconConfig(url, viewBox));
   }
 
   /**
@@ -165,56 +166,57 @@ export class MatIconRegistry implements OnDestroy {
    * @param iconName Name under which the icon should be registered.
    * @param literal SVG source of the icon.
    */
-  addSvgIconLiteralInNamespace(namespace: string, iconName: string, literal: SafeHtml): this {
+  addSvgIconLiteralInNamespace(namespace: string, iconName: string, literal: SafeHtml,
+                               viewBox?: string): this {
     const sanitizedLiteral = this._sanitizer.sanitize(SecurityContext.HTML, literal);
 
     if (!sanitizedLiteral) {
       throw getMatIconFailedToSanitizeLiteralError(literal);
     }
 
-    const svgElement = this._createSvgElementForSingleIcon(sanitizedLiteral);
-    return this._addSvgIconConfig(namespace, iconName, new SvgIconConfig(svgElement));
+    const svgElement = this._createSvgElementForSingleIcon(sanitizedLiteral, viewBox);
+    return this._addSvgIconConfig(namespace, iconName, new SvgIconConfig(svgElement, viewBox));
   }
 
   /**
    * Registers an icon set by URL in the default namespace.
    * @param url
    */
-  addSvgIconSet(url: SafeResourceUrl): this {
-    return this.addSvgIconSetInNamespace('', url);
+  addSvgIconSet(url: SafeResourceUrl, viewBox?: string): this {
+    return this.addSvgIconSetInNamespace('', url, viewBox);
   }
 
   /**
    * Registers an icon set using an HTML string in the default namespace.
    * @param literal SVG source of the icon set.
    */
-  addSvgIconSetLiteral(literal: SafeHtml): this {
-    return this.addSvgIconSetLiteralInNamespace('', literal);
+  addSvgIconSetLiteral(literal: SafeHtml, viewBox?: string): this {
+    return this.addSvgIconSetLiteralInNamespace('', literal, viewBox);
   }
 
   /**
    * Registers an icon set by URL in the specified namespace.
    * @param namespace Namespace in which to register the icon set.
    * @param url
    */
-  addSvgIconSetInNamespace(namespace: string, url: SafeResourceUrl): this {
-    return this._addSvgIconSetConfig(namespace, new SvgIconConfig(url));
+  addSvgIconSetInNamespace(namespace: string, url: SafeResourceUrl, viewBox?: string): this {
+    return this._addSvgIconSetConfig(namespace, new SvgIconConfig(url, viewBox));
   }
 
   /**
    * Registers an icon set using an HTML string in the specified namespace.
    * @param namespace Namespace in which to register the icon set.
    * @param literal SVG source of the icon set.
    */
-  addSvgIconSetLiteralInNamespace(namespace: string, literal: SafeHtml): this {
+  addSvgIconSetLiteralInNamespace(namespace: string, literal: SafeHtml, viewBox?: string): this {
     const sanitizedLiteral = this._sanitizer.sanitize(SecurityContext.HTML, literal);
 
     if (!sanitizedLiteral) {
       throw getMatIconFailedToSanitizeLiteralError(literal);
     }
 
     const svgElement = this._svgElementFromString(sanitizedLiteral);
-    return this._addSvgIconSetConfig(namespace, new SvgIconConfig(svgElement));
+    return this._addSvgIconSetConfig(namespace, new SvgIconConfig(svgElement, viewBox));
   }
 
   /**
@@ -395,7 +397,7 @@ export class MatIconRegistry implements OnDestroy {
     for (let i = iconSetConfigs.length - 1; i >= 0; i--) {
       const config = iconSetConfigs[i];
       if (config.svgElement) {
-        const foundIcon = this._extractSvgIconFromSet(config.svgElement, iconName);
+        const foundIcon = this._extractSvgIconFromSet(config.svgElement, iconName, config.viewBox);
         if (foundIcon) {
           return foundIcon;
         }
@@ -410,7 +412,7 @@ export class MatIconRegistry implements OnDestroy {
    */
   private _loadSvgIconFromConfig(config: SvgIconConfig): Observable<SVGElement> {
     return this._fetchUrl(config.url)
-        .pipe(map(svgText => this._createSvgElementForSingleIcon(svgText)));
+        .pipe(map(svgText => this._createSvgElementForSingleIcon(svgText, config.viewBox)));
   }
 
   /**
@@ -437,9 +439,9 @@ export class MatIconRegistry implements OnDestroy {
   /**
    * Creates a DOM element from the given SVG string, and adds default attributes.
    */
-  private _createSvgElementForSingleIcon(responseText: string): SVGElement {
+  private _createSvgElementForSingleIcon(responseText: string, viewBox?: string): SVGElement {
     const svg = this._svgElementFromString(responseText);
-    this._setSvgAttributes(svg);
+    this._setSvgAttributes(svg, viewBox);
     return svg;
   }
 
@@ -448,7 +450,8 @@ export class MatIconRegistry implements OnDestroy {
    * tag matches the specified name. If found, copies the nested element to a new SVG element and
    * returns it. Returns null if no matching element is found.
    */
-  private _extractSvgIconFromSet(iconSet: SVGElement, iconName: string): SVGElement | null {
+  private _extractSvgIconFromSet(iconSet: SVGElement, iconName: string,
+                                 viewBox?: string): SVGElement | null {
     // Use the `id="iconName"` syntax in order to escape special
     // characters in the ID (versus using the #iconName syntax).
     const iconSource = iconSet.querySelector(`[id="${iconName}"]`);
@@ -465,14 +468,14 @@ export class MatIconRegistry implements OnDestroy {
     // If the icon node is itself an <svg> node, clone and return it directly. If not, set it as
     // the content of a new <svg> node.
     if (iconElement.nodeName.toLowerCase() === 'svg') {
-      return this._setSvgAttributes(iconElement as SVGElement);
+      return this._setSvgAttributes(iconElement as SVGElement, viewBox);
     }
 
     // If the node is a <symbol>, it won't be rendered so we have to convert it into <svg>. Note
     // that the same could be achieved by referring to it via <use href="#id">, however the <use>
     // tag is problematic on Firefox, because it needs to include the current page path.
     if (iconElement.nodeName.toLowerCase() === 'symbol') {
-      return this._setSvgAttributes(this._toSvgElement(iconElement));
+      return this._setSvgAttributes(this._toSvgElement(iconElement), viewBox);
     }
 
     // createElement('SVG') doesn't work as expected; the DOM ends up with
@@ -484,7 +487,7 @@ export class MatIconRegistry implements OnDestroy {
     // Clone the node so we don't remove it from the parent icon set element.
     svg.appendChild(iconElement);
 
-    return this._setSvgAttributes(svg);
+    return this._setSvgAttributes(svg, viewBox);
   }
 
   /**
@@ -520,12 +523,17 @@ export class MatIconRegistry implements OnDestroy {
   /**
    * Sets the default attributes for an SVG element to be used as an icon.
    */
-  private _setSvgAttributes(svg: SVGElement): SVGElement {
+  private _setSvgAttributes(svg: SVGElement, viewBox?: string): SVGElement {
     svg.setAttribute('fit', '');
     svg.setAttribute('height', '100%');
     svg.setAttribute('width', '100%');
     svg.setAttribute('preserveAspectRatio', 'xMidYMid meet');
     svg.setAttribute('focusable', 'false'); // Disable IE11 default behavior to make SVGs focusable.
+
+    if (viewBox) {
+      svg.setAttribute('viewBox', viewBox);
+    }
+
     return svg;
   }
 

src/material/icon/icon.spec.ts

@@ -215,6 +215,29 @@ describe('MatIcon', () => {
       tick();
     }));
 
+    it('should be able to set the viewBox when registering a single SVG icon', fakeAsync(() => {
+      iconRegistry.addSvgIcon('fluffy', trustUrl('cat.svg'), '0 0 27 27');
+      iconRegistry.addSvgIcon('fido', trustUrl('dog.svg'), '0 0 43 43');
+
+      let fixture = TestBed.createComponent(IconFromSvgName);
+      let svgElement: SVGElement;
+      const testComponent = fixture.componentInstance;
+      const iconElement = fixture.debugElement.nativeElement.querySelector('mat-icon');
+
+      testComponent.iconName = 'fido';
+      fixture.detectChanges();
+      http.expectOne('dog.svg').flush(FAKE_SVGS.dog);
+      svgElement = verifyAndGetSingleSvgChild(iconElement);
+      expect(svgElement.getAttribute('viewBox')).toBe('0 0 43 43');
+
+      // Change the icon, and the SVG element should be replaced.
+      testComponent.iconName = 'fluffy';
+      fixture.detectChanges();
+      http.expectOne('cat.svg').flush(FAKE_SVGS.cat);
+      svgElement = verifyAndGetSingleSvgChild(iconElement);
+      expect(svgElement.getAttribute('viewBox')).toBe('0 0 27 27');
+    }));
+
     it('should throw an error when using an untrusted icon url', () => {
       iconRegistry.addSvgIcon('fluffy', 'farm-set-1.svg');
 
@@ -449,6 +472,22 @@ describe('MatIcon', () => {
       }).not.toThrow();
     });
 
+    it('should be able to configure the viewBox for the icon set', () => {
+      iconRegistry.addSvgIconSet(trustUrl('arrow-set.svg'), '0 0 43 43');
+
+      const fixture = TestBed.createComponent(IconFromSvgName);
+      const testComponent = fixture.componentInstance;
+      const matIconElement = fixture.debugElement.nativeElement.querySelector('mat-icon');
+      let svgElement: any;
+
+      testComponent.iconName = 'left-arrow';
+      fixture.detectChanges();
+      http.expectOne('arrow-set.svg').flush(FAKE_SVGS.arrows);
+      svgElement = verifyAndGetSingleSvgChild(matIconElement);
+
+      expect(svgElement.getAttribute('viewBox')).toBe('0 0 43 43');
+    });
+
     it('should remove the SVG element from the DOM when the binding is cleared', () => {
       iconRegistry.addSvgIconSet(trustUrl('arrow-set.svg'));
 
@@ -518,6 +557,26 @@ describe('MatIcon', () => {
       tick();
     }));
 
+    it('should be able to configure the icon viewBox', fakeAsync(() => {
+      iconRegistry.addSvgIconLiteral('fluffy', trustHtml(FAKE_SVGS.cat), '0 0 43 43');
+      iconRegistry.addSvgIconLiteral('fido', trustHtml(FAKE_SVGS.dog), '0 0 27 27');
+
+      let fixture = TestBed.createComponent(IconFromSvgName);
+      let svgElement: SVGElement;
+      const testComponent = fixture.componentInstance;
+      const iconElement = fixture.debugElement.nativeElement.querySelector('mat-icon');
+
+      testComponent.iconName = 'fido';
+      fixture.detectChanges();
+      svgElement = verifyAndGetSingleSvgChild(iconElement);
+      expect(svgElement.getAttribute('viewBox')).toBe('0 0 27 27');
+
+      testComponent.iconName = 'fluffy';
+      fixture.detectChanges();
+      svgElement = verifyAndGetSingleSvgChild(iconElement);
+      expect(svgElement.getAttribute('viewBox')).toBe('0 0 43 43');
+    }));
+
     it('should throw an error when using untrusted HTML', () => {
       // Stub out console.warn so we don't pollute our logs with Angular's warnings.
       // Jasmine will tear the spy down at the end of the test.
@@ -631,6 +690,21 @@ describe('MatIcon', () => {
       expect(svgElement.getAttribute('viewBox')).toBeFalsy();
     });
 
+    it('should be able to configure the viewBox for the icon set', () => {
+      iconRegistry.addSvgIconSetLiteral(trustHtml(FAKE_SVGS.arrows), '0 0 43 43');
+
+      const fixture = TestBed.createComponent(IconFromSvgName);
+      const testComponent = fixture.componentInstance;
+      const matIconElement = fixture.debugElement.nativeElement.querySelector('mat-icon');
+      let svgElement: any;
+
+      testComponent.iconName = 'left-arrow';
+      fixture.detectChanges();
+      svgElement = verifyAndGetSingleSvgChild(matIconElement);
+
+      expect(svgElement.getAttribute('viewBox')).toBe('0 0 43 43');
+    });
+
     it('should add an extra string to the end of `style` tags inside SVG', fakeAsync(() => {
       iconRegistry.addSvgIconLiteral('fido', trustHtml(`
         <svg>

tools/public_api_guard/material/icon.d.ts

@@ -40,14 +40,14 @@ export declare class MatIconModule {
 
 export declare class MatIconRegistry implements OnDestroy {
     constructor(_httpClient: HttpClient, _sanitizer: DomSanitizer, document: any);
-    addSvgIcon(iconName: string, url: SafeResourceUrl): this;
-    addSvgIconInNamespace(namespace: string, iconName: string, url: SafeResourceUrl): this;
-    addSvgIconLiteral(iconName: string, literal: SafeHtml): this;
-    addSvgIconLiteralInNamespace(namespace: string, iconName: string, literal: SafeHtml): this;
-    addSvgIconSet(url: SafeResourceUrl): this;
-    addSvgIconSetInNamespace(namespace: string, url: SafeResourceUrl): this;
-    addSvgIconSetLiteral(literal: SafeHtml): this;
-    addSvgIconSetLiteralInNamespace(namespace: string, literal: SafeHtml): this;
+    addSvgIcon(iconName: string, url: SafeResourceUrl, viewBox?: string): this;
+    addSvgIconInNamespace(namespace: string, iconName: string, url: SafeResourceUrl, viewBox?: string): this;
+    addSvgIconLiteral(iconName: string, literal: SafeHtml, viewBox?: string): this;
+    addSvgIconLiteralInNamespace(namespace: string, iconName: string, literal: SafeHtml, viewBox?: string): this;
+    addSvgIconSet(url: SafeResourceUrl, viewBox?: string): this;
+    addSvgIconSetInNamespace(namespace: string, url: SafeResourceUrl, viewBox?: string): this;
+    addSvgIconSetLiteral(literal: SafeHtml, viewBox?: string): this;
+    addSvgIconSetLiteralInNamespace(namespace: string, literal: SafeHtml, viewBox?: string): this;
     classNameForFontAlias(alias: string): string;
     getDefaultFontSetClass(): string;
     getNamedSvgIcon(name: string, namespace?: string): Observable<SVGElement>;