Throw an exception in Image.toByteData rather than hang forever. (flutter#15152)

Harry Terkelsen · web-flow · commit dba9cce137ec · 2020-01-08T11:20:27.000-08:00
diff --git a/lib/web_ui/lib/src/engine/html_image_codec.dart b/lib/web_ui/lib/src/engine/html_image_codec.dart
@@ -136,6 +136,11 @@ class HtmlImage implements ui.Image {
     }
   }
 
+  // TODO(het): Support this for asset images and images generated from
+  // `Picture`s.
   /// Returns an error message on failure, null on success.
-  String _toByteData(int format, Callback<Uint8List> callback) => null;
+  String _toByteData(int format, Callback<Uint8List> callback) {
+    callback(null);
+    return 'Image.toByteData is not supported in Flutter for Web';
+  }
 }

Original file line number	Diff line number	Diff line change
`@@ -136,6 +136,11 @@ class HtmlImage implements ui.Image {`
`136`	`136`	`}`
`137`	`137`	`}`
`138`	`138`
	`139`	`+ // TODO(het): Support this for asset images and images generated from`
	`140`	+ // `Picture`s.
`139`	`141`	`/// Returns an error message on failure, null on success.`
`140`		`- String _toByteData(int format, Callback<Uint8List> callback) => null;`
	`142`	`+ String _toByteData(int format, Callback<Uint8List> callback) {`
	`143`	`+ callback(null);`
	`144`	`+ return 'Image.toByteData is not supported in Flutter for Web';`
	`145`	`+ }`
`141`	`146`	`}`