Fix fonts.clear exception in IE11 (#19180)

ferhatb · web-flow · commit f16a16eaf631 · 2020-06-22T09:24:31.000-07:00
diff --git a/lib/web_ui/lib/src/engine/text/font_collection.dart b/lib/web_ui/lib/src/engine/text/font_collection.dart
@@ -98,7 +98,7 @@ class FontCollection {
   void clear() {
     _assetFontManager = null;
     _testFontManager = null;
-    if (supportsFontLoadingApi) {
+    if (supportsFontsClearApi) {
       html.document.fonts.clear();
     }
   }
@@ -313,4 +313,5 @@ class _PolyfillFontManager extends FontManager {
   }
 }
 
-final bool supportsFontLoadingApi = html.document.fonts != null;
+final bool supportsFontLoadingApi = js_util.hasProperty(html.window, 'FontFace');
+final bool supportsFontsClearApi = html.document.fonts != null && js_util.hasProperty(html.document.fonts, 'clear');

Original file line number	Diff line number	Diff line change
`@@ -98,7 +98,7 @@ class FontCollection {`
`98`	`98`	`void clear() {`
`99`	`99`	`_assetFontManager = null;`
`100`	`100`	`_testFontManager = null;`
`101`		`- if (supportsFontLoadingApi) {`
	`101`	`+ if (supportsFontsClearApi) {`
`102`	`102`	`html.document.fonts.clear();`
`103`	`103`	`}`
`104`	`104`	`}`
`@@ -313,4 +313,5 @@ class _PolyfillFontManager extends FontManager {`
`313`	`313`	`}`
`314`	`314`	`}`
`315`	`315`
`316`		`-final bool supportsFontLoadingApi = html.document.fonts != null;`
	`316`	`+final bool supportsFontLoadingApi = js_util.hasProperty(html.window, 'FontFace');`
	`317`	`+final bool supportsFontsClearApi = html.document.fonts != null && js_util.hasProperty(html.document.fonts, 'clear');`