Implementing window.createObjectURL*

tests/html/url_test.dart

+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#library('url_test');
+#import('../../pkg/unittest/unittest.dart');
+#import('../../pkg/unittest/html_config.dart');
+#import('dart:html');
+
+main() {
+  useHtmlConfiguration();
+
+  Blob createImageBlob() {
+    var canvas = new CanvasElement();
+    canvas.width = 100;
+    canvas.height = 100;
+
+    var context = canvas.context2d;
+    context.fillStyle = 'red';
+    context.fillRect(0, 0, canvas.width, canvas.height);
+
+    var dataUri = canvas.toDataURL('image/png');
+    var byteString = window.atob(dataUri.split(',')[1]);
+    var mimeString = dataUri.split(',')[0].split(':')[1].split(';')[0];
+
+    var arrayBuffer = new ArrayBuffer(byteString.length);
+    var dataArray = new Uint8Array.fromBuffer(arrayBuffer);
+    for (var i = 0; i < byteString.length; i++) {
+      dataArray[i] = byteString.charCodeAt(i);
+    }
+
+    var blob = new Blob([arrayBuffer], 'image/png');
+    return blob;
+  }
+
+  group('blob', () {
+    test('createObjectUrl', () {
+      var blob = createImageBlob();
+      var url = window.createObjectUrl(blob);
+      expect(url.length, greaterThan(0));
+      expect(url.startsWith('blob:'));
+
+      var img = new ImageElement();
+      img.on.load.add(expectAsync1((_) {
+        expect(img.complete, true);
+      }));
+      img.on.error.add((_) {
+        guardAsync(() {
+          expect(true, isFalse, 'URL failed to load.');
+        });
+      });
+      img.src = url;
+    });
+
+    test('revokeObjectUrl', () {
+      var blob = createImageBlob();
+      var url = window.createObjectUrl(blob);
+      expect(url.startsWith('blob:'));
+      window.revokeObjectUrl(url);
+
+      var img = new ImageElement();
+      // Image should fail to load since the URL was revoked.
+      img.on.error.add(expectAsync1((_) {
+      }));
+      img.on.load.add((_) {
+        guardAsync(() {
+          expect(true, isFalse, 'URL should not have loaded.');
+        });
+      });
+      img.src = url;
+    });
+
+  });
+}