md-icon

package.json

@@ -34,7 +34,7 @@
   },
   "devDependencies": {
     "add-stream": "^1.0.0",
-    "angular-cli": "^0.0.28",
+    "angular-cli": "^0.0.29",
     "angular-cli-github-pages": "^0.2.0",
     "broccoli-autoprefixer": "^4.1.0",
     "broccoli-caching-writer": "^2.2.1",

src/components/icon/icon-provider.ts

@@ -0,0 +1,255 @@
+import {Injectable, Renderer} from 'angular2/core';
+import {Http, Response, HTTP_PROVIDERS} from 'angular2/http';
+import {AsyncSubject, Observer, Observable} from 'rxjs/Rx';
+
+/**
+  *  Configuration for an icon, possibly including the cached SVG element.
+  */
+class IconConfig {
+  svgElement: SVGElement = null;
+  constructor(public url: string, public viewBoxSize: number) {
+  }
+}
+
+@Injectable()
+export class MdIconProvider {
+  // IconConfig objects and cached SVG elements for individual icons.
+  // First level of cache is icon set (which is the empty string for the default set).
+  // Second level is the icon name within the set.
+  private _iconConfigs = new Map<string, Map<string, IconConfig>>();
+
+  // IconConfig objects and cached SVG elements for icon sets.
+  // These are stored only by set name, but multiple URLs can be registered under the same name.
+  private _iconSetConfigs = new Map<string, [IconConfig]>();
+
+  // Cache for icons loaded by direct URLs.
+  private _cachedIconsByUrl = new Map<string, SVGElement>();
+
+  private _fontClassNamesByAlias = new Map<string, string>();
+
+  private _inProgressUrlFetches = new Map<string, Observable<string>>();
+
+  private _defaultViewBoxSize = 24;
+  private _defaultFontSetClass = 'material-icons';
+
+  constructor(private _http: Http) {
+  }
+
+  public addIcon(iconName: string, url: string, viewBoxSize:number=0): MdIconProvider {
+    return this.addIconInSet('', iconName, url, viewBoxSize);
+  }
+
+  public addIconInSet(
+      setName: string, iconName: string, url: string, viewBoxSize:number=0): MdIconProvider {
+    let iconSetMap = this._iconConfigs.get(setName);
+    if (!iconSetMap) {
+      iconSetMap = new Map<string, IconConfig>();
+      this._iconConfigs.set(setName, iconSetMap);
+    }
+    iconSetMap.set(iconName, new IconConfig(url, viewBoxSize || this._defaultViewBoxSize));
+    return this;
+  }
+
+  public addIconSet(setName: string, url: string, viewBoxSize=0): MdIconProvider {
+    const config = new IconConfig(url, viewBoxSize || this._defaultViewBoxSize);
+    if (this._iconSetConfigs.has(setName)) {
+      this._iconSetConfigs.get(setName).push(config);
+    } else {
+      this._iconSetConfigs.set(setName, [config]);
+    }
+    return this;
+  }
+
+  public registerFontSet(alias: string, className?: string): MdIconProvider {
+    this._fontClassNamesByAlias.set(alias, className || alias);
+    return this;
+  }
+
+  public setDefaultViewBoxSize(size: number) {
+    this._defaultViewBoxSize = size;
+    return this;
+  }
+
+  public getDefaultViewBoxSize(): number {
+    return this._defaultViewBoxSize;
+  }
+
+  public setDefaultFontSetClass(className: string) {
+    this._defaultFontSetClass = className;
+    return this;
+  }
+
+  public getDefaultFontSetClass(): string {
+    return this._defaultFontSetClass;
+  }
+
+  loadIconFromSetByName(setName: string, iconName: string): Observable<SVGElement> {
+    // Return (copy of) cached icon if possible.
+    if (this._iconConfigs.has(setName) && this._iconConfigs.get(setName).has(iconName)) {
+      const config = this._iconConfigs.get(setName).get(iconName);
+      if (config.svgElement) {
+        // We already have the SVG element for this icon, return a copy.
+        return Observable.of(config.svgElement.cloneNode(true));
+      } else {
+        // Fetch the icon from the config's URL, cache it, and return a copy.
+        return this._loadIconFromConfig(config)
+          .do((svg: SVGElement) => config.svgElement = svg)
+          .map((svg: SVGElement) => svg.cloneNode(true));
+      }
+    }
+    // See if we have any icon sets registered for the set name.
+    const iconSetConfigs = this._iconSetConfigs.get(setName);
+    if (iconSetConfigs) {
+      // For all the icon set SVG elements we've fetched, see if any contain an icon with the
+      // requested name.
+      const namedIcon = this._extractIconWithNameFromAnySet(iconName, iconSetConfigs);
+      if (namedIcon) {
+        // We could cache namedSvg in _iconConfigs, but since we have to make a copy every
+        // time anyway, there's probably not much advantage compared to just always extracting
+        // it from the icon set.
+        return Observable.of(namedIcon.cloneNode(true));
+      }
+      // Not found in any cached icon sets. If there are icon sets with URLs that we haven't
+      // fetched, fetch them now and look for iconName in the results.
+      const iconSetFetchRequests = <[Observable<SVGElement>]>[];
+      iconSetConfigs.forEach((setConfig) => {
+        if (!setConfig.svgElement) {
+          iconSetFetchRequests.push(
+              this._loadIconSetFromConfig(setConfig)
+                  .catch((err: any, source: any, caught: any): Observable<SVGElement> => {
+                    // Swallow errors fetching individual URLs so the combined Observable won't
+                    // necessarily fail.
+                    console.log(`Loading icon set URL: ${setConfig.url} failed with error: ${err}`);
+                    return Observable.of(null);
+                  })
+                  .do((svg: SVGElement) => {
+                    // Cache SVG element.
+                    if (svg) {
+                      setConfig.svgElement = svg;
+                    }
+                  })
+          );
+        }
+      });
+      // Fetch all the icon set URLs. When the requests complete, every IconSet should have a
+      // cached SVG element (unless the request failed), and we can check again for the icon.
+      return Observable.forkJoin(iconSetFetchRequests)
+        .map((ignoredResults: any) => {
+          const foundIcon = this._extractIconWithNameFromAnySet(iconName, iconSetConfigs);
+          if (!foundIcon) {
+            throw Error(`Failed to find icon name: ${iconName} in set: ${setName}`);
+          }
+          return foundIcon;
+        });
+    }
+    return Observable.throw(Error(`Unknown icon name: ${iconName} in set: ${setName}`));
+  }
+
+  private _extractIconWithNameFromAnySet(iconName: string, setConfigs: [IconConfig]): SVGElement {
+    // Iterate backwards, so icon sets added later have precedence.
+    for (let i = setConfigs.length - 1; i >= 0; i--) {
+      const config = setConfigs[i];
+      if (config.svgElement) {
+        const foundIcon = this._extractSvgIconFromSet(config.svgElement, iconName, config);
+        if (foundIcon) {
+          return foundIcon;
+        }
+      }
+    }
+    return null;
+  }
+
+  loadIconFromUrl(url: string): Observable<SVGElement> {
+    if (this._cachedIconsByUrl.has(url)) {
+      return Observable.of(this._cachedIconsByUrl.get(url).cloneNode(true));
+    }
+    return this._loadIconFromConfig(new IconConfig(url, this._defaultViewBoxSize))
+        .do((svg: SVGElement) => this._cachedIconsByUrl.set(url, svg));
+  }
+
+  classNameForFontAlias(alias: string): string {
+    if (!this._fontClassNamesByAlias.has(alias)) {
+      throw Error('Unknown font alias: ' + alias);
+    }
+    return this._fontClassNamesByAlias.get(alias);
+  }
+
+  private _fetchUrl(url: string): Observable<string> {
+    // FIXME: This is trying to avoid sending a duplicate request for a URL when there is already
+    // a request in progress for that URL. But it's not working; even though we return the cached
+    // Observable, a second request is still sent.
+    console.log('*** fetchUrl: ' + url);
+    if (this._inProgressUrlFetches.has(url)) {
+      console.log("*** Using existing request");
+      return this._inProgressUrlFetches.get(url);
+    }
+    console.log(`*** Sending request for ${url}`);
+    const req = this._http.get(url)
+        .do((response) => {
+          console.log(`*** Got response for ${url}`);
+          console.log('*** Removing request: ' + url);
+          this._inProgressUrlFetches.delete(url);
+        })
+        .map((response) => response.text());
+    this._inProgressUrlFetches.set(url, req);
+    return req;
+  }
+
+  private _loadIconFromConfig(config: IconConfig): Observable<SVGElement> {
+    return this._fetchUrl(config.url)
+        .map(svgText => this._createSvgElementForSingleIcon(svgText, config));
+  }
+
+  private _loadIconSetFromConfig(config: IconConfig): Observable<SVGElement> {
+    return this._fetchUrl(config.url)
+        .map((svgText) => this._svgElementFromString(svgText));
+  }
+
+  private _createSvgElementForSingleIcon(responseText: string, config: IconConfig): SVGElement {
+    const svg = this._svgElementFromString(responseText);
+    this._setSvgAttributes(svg, config);
+    return svg;
+  }
+
+  private _setSvgAttributes(svg: SVGElement, config: IconConfig) {
+    const viewBoxSize = config.viewBoxSize || this._defaultViewBoxSize;
+    if (!svg.getAttribute('xmlns')) {
+      svg.setAttribute('xmlns', 'http://www.w3.org/2000/svg');
+    }
+    svg.setAttribute('fit', '');
+    svg.setAttribute('height', '100%');
+    svg.setAttribute('width', '100%');
+    svg.setAttribute('preserveAspectRatio', 'xMidYMid meet');
+    svg.setAttribute('viewBox',
+        svg.getAttribute('viewBox') || ('0 0 ' + viewBoxSize + ' ' + viewBoxSize));
+    svg.setAttribute('focusable', 'false'); // Disable IE11 default behavior to make SVGs focusable.
+  }
+
+  private _extractSvgIconFromSet(
+      iconSet: SVGElement, iconName: string, config: IconConfig): SVGElement {
+    const iconNode = iconSet.querySelector('#' + iconName);
+    if (!iconNode) {
+      return null;
+    }
+    // createElement('SVG') doesn't work as expected; the DOM ends up with
+    // the correct nodes, but the SVG content doesn't render. Instead we
+    // have to create an empty SVG node using innerHTML and append its content.
+    // http://stackoverflow.com/questions/23003278/svg-innerhtml-in-firefox-can-not-display
+    const svg = this._svgElementFromString('<svg></svg>');
+    svg.appendChild(iconNode);
+    this._setSvgAttributes(svg, config);
+    return svg;
+  }
+
+  private _svgElementFromString(str: string): SVGElement {
+    // TODO: Is there a better way than innerHTML? Renderer doesn't appear to have a method for
+    // creating an element from an HTML string.
+    const div = document.createElement('DIV');
+    div.innerHTML = str;
+    const svg = <SVGElement>div.querySelector('svg');
+    if (!svg) {
+      throw Error('<svg> tag not found');
+    }
+    return svg;
+  }
+}

src/components/icon/icon.scss

@@ -0,0 +1,19 @@
+@import "variables";
+@import "default-theme";
+
+/** The width/height of the icon element. */
+$md-icon-size: 24px !default;
+
+/**
+This works because we're using ViewEncapsulation.None. If we used the default
+encapsulation, the selector would need to be ":host".
+*/
+md-icon {
+    background-repeat: no-repeat;
+    display: inline-block;
+    fill: currentColor;
+    height: $md-icon-size;
+    margin: auto;
+    vertical-align: middle;
+    width: $md-icon-size;
+}