Minor code style cleanup. Added id3 metadata parser to filemanager.

BUG=14879
TEST=


Review URL: http://codereview.chromium.org/7217007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@93187 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 77 insertions, 0 deletions

diff --git a/chrome/browser/resources/file_manager/js/function_sequence.js b/chrome/browser/resources/file_manager/js/function_sequence.js
new file mode 100644
index 0000000..3ac6152
--- /dev/null
+++ b/chrome/browser/resources/file_manager/js/function_sequence.js
@@ -0,0 +1,77 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * @constructor
+ * @class FunctionSequence to invoke steps in sequence
+ *
+ * @param steps             array of functions to invoke in sequence
+ * @param callback          callback to invoke on success
+ * @param failureCallback   callback to invoke on failure
+ */
+function FunctionSequence(steps, callback, failureCallback, logger) {
+  // Private variables hidden in closure
+  var _currentStepIdx = -1;
+  var _self = this;
+  var _failed = false;
+
+  this.onError = function(err) {
+    logger.vlog('Failed step: ' + steps[_currentStepIdx].name + ': ' + err);
+    if (!_failed) {
+      _failed = true;
+      failureCallback.apply(this, err, steps[_currentStepIdx].name);
+    }
+  };
+
+  this.finish = function() {
+    if (!_failed) {
+      _currentStepIdx = steps.length;
+      callback();
+    }
+  };
+
+  this.nextStep = function(var_args) {
+    logger.vlog('Starting new step');
+
+    if (_failed) {
+      return;
+    }
+
+    _currentStepIdx++;
+
+    if (_currentStepIdx >= steps.length) {
+      callback.apply(_self, arguments);
+      return;
+    }
+
+    var currentStep = steps[_currentStepIdx];
+
+    logger.vlog('Current step type is' + (typeof currentStep));
+
+    if (typeof currentStep == 'function') {
+      logger.vlog('nextstep : ' + currentStep.name);
+      currentStep.apply(_self, arguments);
+    } else {
+      logger.vlog('nextsep forking ' + currentStep.length + ' chains');
+      var remaining = currentStep.length;
+
+      function resume() {
+        if (--remaining == 0) {
+          logger.vlog('barrier passed');
+          _self.nextStep();
+        } else {
+          logger.vlog('waiting for [' + remaining + '] at barrier');
+        }
+      }
+
+      for (var i = 0; i < currentStep.length; i++) {
+        var sequence = new FunctionSequence(currentStep[i], resume,
+            _self.onError, logger);
+        sequence.start.apply(sequence, arguments);
+      }
+    }
+  };
+
+  this.start = this.nextStep;
+}