Refactoring file manager: moving volume mounting related code to a separate class.

chrome/browser/resources/file_manager/js/directory_model.js

Index: chrome/browser/resources/file_manager/js/directory_model.js
diff --git a/chrome/browser/resources/file_manager/js/directory_model.js b/chrome/browser/resources/file_manager/js/directory_model.js
index 89747a4c7b3822cf40c6b3c83dc1c1cb2342bc9f..4ba537ff14b5442ba98b916df5cab70ff2578181 100644
--- a/chrome/browser/resources/file_manager/js/directory_model.js
+++ b/chrome/browser/resources/file_manager/js/directory_model.js
@@ -19,7 +19,8 @@ var SHORT_RESCAN_INTERVAL = 100;
  *   (regardless of its mounts status).
  * @param {MetadataCache} metadataCache The metadata cache service.
  */
-function DirectoryModel(root, singleSelection, showGData, metadataCache) {
+function DirectoryModel(root, singleSelection, showGData,
+                        metadataCache, volumeManager) {
   this.root_ = root;
   this.metadataCache_ = metadataCache;
   this.fileList_ = new cr.ui.ArrayDataModel([]);
@@ -54,11 +55,18 @@ function DirectoryModel(root, singleSelection, showGData, metadataCache) {
   this.filters_ = {};
   this.setFilterHidden(true);
 
-  /**
-   * @private
-   * @type {Object.<string, boolean>}
-   */
-  this.volumeReadOnlyStatus_ = {};
+  if (this.showGData_) {
+    this.unmountedGDataEntry_ = {
+      unmouted: true,
+      fullPath: '/' + DirectoryModel.GDATA_DIRECTORY
+    };
+  }
+
+  this.volumeManager_ = volumeManager;
+  var volumesChangeHandler = this.onMountChanged_.bind(this);
+  this.updateRoots(function() {

[Vladislav Kaznacheev, 2012/05/15 11:11:54]

Calling updateRoots from the constructor somehow feels unnatural. Adding a
listener from a callback is strange too, at least it needs a comment.

+    volumeManager.addEventListener('change', volumesChangeHandler);
+  });
 }
 
 /**
@@ -92,7 +100,11 @@ DirectoryModel.DOWNLOADS_DIRECTORY = 'Downloads';
 /**
 * The name of the gdata provider directory.
 */
-DirectoryModel.GDATA_DIRECTORY = 'drive';
+DirectoryModel.GDATA_DIRECTORY = 'gdata';  // TODO(serya): return 'drive'
+
+DirectoryModel.fakeGDataEntry_ = {
+  fullPath: '/' + DirectoryModel.GDATA_DIRECTORY
+};
 
 /**
  * DirectoryModel extends cr.EventTarget.
@@ -172,7 +184,7 @@ DirectoryModel.prototype.isReadOnly = function() {
 DirectoryModel.prototype.isPathReadOnly = function(path) {
   switch (DirectoryModel.getRootType(path)) {
     case DirectoryModel.RootType.REMOVABLE:
-      return !!this.volumeReadOnlyStatus_[DirectoryModel.getRootPath(path)];
+      return !!this.volumeManager_.isReadOnly(DirectoryModel.getRootPath(path));
     case DirectoryModel.RootType.ARCHIVE:
       return true;
     case DirectoryModel.RootType.DOWNLOADS:
@@ -313,6 +325,10 @@ DirectoryModel.prototype.getCurrentRootPath = function() {
   return DirectoryModel.getRootPath(this.currentDirEntry_.fullPath);
 };
 
+DirectoryModel.prototype.getCurrentRootType = function() {
+  return DirectoryModel.getRootType(this.currentDirEntry_.fullPath);
+};
+
 /**
  * @return {cr.ui.ListSingleSelectionModel} Root list selection model.
  */
@@ -488,7 +504,7 @@ DirectoryModel.prototype.scan_ = function(callback) {
   // Clear the table first.
   this.fileList_.splice(0, this.fileList_.length);
   cr.dispatchSimpleEvent(this, 'scan-started');
-  if (this.currentDirEntry_ == this.unmountedGDataEntry_) {
+  if (this.currentDirEntry_ == DirectoryModel.fakeGDataEntry_) {
     onDone();
     return;
   }
@@ -691,16 +707,20 @@ DirectoryModel.prototype.changeDirectory = function(path) {
  */
 DirectoryModel.prototype.resolveDirectory = function(path, successCallback,
                                                      errorCallback) {
-  if (this.unmountedGDataEntry_ &&
-      DirectoryModel.getRootType(path) == DirectoryModel.RootType.GDATA) {
+  if (DirectoryModel.getRootType(path) == DirectoryModel.RootType.GDATA) {
     // TODO(kaznacheeev): Currently if path points to some GData subdirectory
     // and GData is not mounted we will change to the fake GData root and
     // ignore the rest of the path. Consider remembering the path and
     // changing to it once GDdata is mounted. This is only relevant for cases
     // when we open the File Manager with an URL pointing to GData (e.g. via
     // a bookmark).
-    successCallback(this.unmountedGDataEntry_);
-    return;
+    if (!this.isGDataMounted_()) {
+      if (path == DirectoryModel.fakeGDataEntry_.fullPath)
+        successCallback(DirectoryModel.fakeGDataEntry_);
+      else  // Subdirectory.
+        errorCallback({ code: FileError.NOT_FOUND_ERR });
+      return;
+    }
   }
 
   if (path == '/') {
@@ -776,6 +796,51 @@ DirectoryModel.prototype.changeDirectoryEntry_ = function(initial, dirEntry,
   e.newDirEntry = dirEntry;
   e.initial = initial;
   this.dispatchEvent(e);
+
+  if (dirEntry == DirectoryModel.fakeGDataEntry_) {
+    this.volumeManager_.mountGData(function() {}, function() {});
+  }
+};
+
+/**
+ * Creates an object wich could cay wether directory has changed while it has

[Vladislav Kaznacheev, 2012/05/15 11:11:54]

"cay", "canncelled" = typo?

+ * been active or not. Designed for long operations that should be canncelled
+ * if the used change current directory.
+ * @return {Object} Created object.
+ */
+DirectoryModel.prototype.createDirectoryChangeTracker = function() {
+  var tracker = {
+    dm_: this,
+    active_: false,
+    hasChanged: false,
+    exceptInitialChange: false,
+
+    start: function() {
+      if (!this.active_) {
+        this.dm_.addEventListener('directory-changed',
+                                  this.onDirectoryChange_);
+        this.active_ = true;
+        this.hasChanged = false;
+      }
+    },
+
+    stop: function() {
+      if (this.active_) {
+        this.dm_.removeEventListener('directory-changed',
+                                     this.onDirectoryChange_);
+        active_ = false;
+      }
+    },
+
+    onDirectoryChange_: function(event) {
+      if (tracker.exceptInitialChange && event.initial)
+        return;
+      // This is incorrect here.
+      tracker.stop();
+      tracker.hasChange = true;
+    }
+  };
+  return tracker;
 };
 
 /**
@@ -796,19 +861,21 @@ DirectoryModel.prototype.changeDirectoryEntry_ = function(initial, dirEntry,
  */
 DirectoryModel.prototype.setupPath = function(path, opt_loadedCallback,
                                               opt_pathResolveCallback) {
-  var overridden = false;
-  function onExternalDirChange() { overridden = true }
-  this.addEventListener('directory-changed', onExternalDirChange);
+  var tracker = this.createDirectoryChangeTracker();
+  tracker.start();
 
   var resolveCallback = function(exists) {
-    this.removeEventListener('directory-changed', onExternalDirChange);
-    if (opt_pathResolveCallback)
-      opt_pathResolveCallback(baseName, leafName, exists && !overridden);
+    tracker.stop();
+    if (opt_pathResolveCallback) {
+      opt_pathResolveCallback(baseName, leafName,
+                              exists && !tracker.hasChanged);
+    }
   }.bind(this);
 
   var changeDirectoryEntry = function(entry, initial, exists, opt_callback) {
+    tracker.stop();
     resolveCallback(exists);
-    if (!overridden)
+    if (!tracker.hasChanged)
       this.changeDirectoryEntry_(initial, entry, opt_callback);
   }.bind(this);
 
@@ -862,7 +929,7 @@ DirectoryModel.prototype.setupPath = function(path, opt_loadedCallback,
     if (path != this.getDefaultDirectory()) {
       // Can't find the provided path, let's go to default one instead.
       resolveCallback(!EXISTS);
-      if (!overridden)
+      if (!tracker.hasChanged)
         this.setupDefaultPath(opt_loadedCallback);
     } else {
       // Well, we can't find the downloads dir. Let's just show something,
@@ -958,9 +1025,8 @@ DirectoryModel.prototype.prepareSortEntries_ = function(entries, field,
  * Get root entries asynchronously.
  * @private
  * @param {function(Array.<Entry>)} callback Called when roots are resolved.
- * @param {boolean} resolveGData See comment for updateRoots.
  */
-DirectoryModel.prototype.resolveRoots_ = function(callback, resolveGData) {
+DirectoryModel.prototype.resolveRoots_ = function(callback) {
   var groups = {
     downloads: null,
     archives: null,
@@ -975,7 +1041,6 @@ DirectoryModel.prototype.resolveRoots_ = function(callback, resolveGData) {
       if (!groups[i])
         return;
 
-    self.updateVolumeReadOnlyStatus_(groups.removables);
     callback(groups.downloads.
              concat(groups.gdata).
              concat(groups.archives).
@@ -988,60 +1053,43 @@ DirectoryModel.prototype.resolveRoots_ = function(callback, resolveGData) {
     done();
   }
 
-  function onDownloads(entry) {
-    groups.downloads = [entry];
+  function appendSingle(index, entry) {
+    groups[index] = [entry];
     done();
   }
 
-  function onDownloadsError(error) {
-    groups.downloads = [];
+  function onSingleError(index, error, defaultValue) {
+    groups[index] = defailtValue || [];
     done();
   }
 
-  function onGData(entry) {
-    console.log('GData found:', entry);
-    self.unmountedGDataEntry_ = null;
-    groups.gdata = [entry];
-    done();
-  }
-
-  function onGDataError(error) {
-    console.log('GData error: ' + error);
-    self.unmountedGDataEntry_ = {
-      unmounted: true,  // Clients use this field to distinguish a fake root.
-      toURL: function() { return '' },
-      fullPath: '/' + DirectoryModel.GDATA_DIRECTORY
-    };
-    groups.gdata = [self.unmountedGDataEntry_];
-    done();
+  var root = this.root_;
+  function readSingle(dir, index, defaultValue) {
+    root.getDirectory(dir, { create: false },
+                      appendSingle.bind(this, index),
+                      onSingleError.bind(this, index, defaultValue));
   }
 
-  var root = this.root_;
-  root.getDirectory(DirectoryModel.DOWNLOADS_DIRECTORY, { create: false },
-                    onDownloads, onDownloadsError);
+  readSingle(DirectoryModel.DOWNLOADS_DIRECTORY, 'downloads');
   util.readDirectory(root, DirectoryModel.ARCHIVE_DIRECTORY,
                      append.bind(this, 'archives'));
   util.readDirectory(root, DirectoryModel.REMOVABLE_DIRECTORY,
                      append.bind(this, 'removables'));
   if (this.showGData_) {
-    if (resolveGData) {
-      root.getDirectory(DirectoryModel.GDATA_DIRECTORY, { create: false },
-                        onGData, onGDataError);
-    } else {
-      onGDataError('lazy mount');
-    }
+    var fake = [DirectoryModel.fakeGDataEntry_];
+    if (this.isGDataMounted_())
+      readSingle(DirectoryModel.GDATA_DIRECTORY, 'gdata', fake);
+    else
+      groups.gdata = fake;
   } else {
     groups.gdata = [];
   }
 };
 
 /**
-* @param {function} opt_callback Called when all roots are resolved.
-* @param {boolean} opt_resolveGData If true GData should be resolved for real,
-*                                   If false a stub entry should be created.
+* @param {functioni?} opt_callback Called when all roots are resolved.
 */
-DirectoryModel.prototype.updateRoots = function(opt_callback,
-                                                opt_resolveGData) {
+DirectoryModel.prototype.updateRoots = function(opt_callback) {
   var self = this;
   this.resolveRoots_(function(rootEntries) {
     var dm = self.rootsList_;
@@ -1049,10 +1097,8 @@ DirectoryModel.prototype.updateRoots = function(opt_callback,
     dm.splice.apply(dm, args);
 
     self.updateRootsListSelection_();
-
-    if (opt_callback)
-      opt_callback();
-  }, opt_resolveGData);
+    opt_callback && opt_callback();
+  });
 };
 
 /**
@@ -1079,45 +1125,38 @@ DirectoryModel.prototype.updateRootsListSelection_ = function() {
   this.rootsListSelection_.selectedIndex = this.findRootsListItem_(rootPath);
 };
 
-/**
- * @param {Array.<DirectoryEntry>} roots Removable volumes entries.
- * @private
- */
-DirectoryModel.prototype.updateVolumeReadOnlyStatus_ = function(roots) {
-  var status = this.volumeReadOnlyStatus_ = {};
-  for (var i = 0; i < roots.length; i++) {
-    status[roots[i].fullPath] = false;
-    chrome.fileBrowserPrivate.getVolumeMetadata(roots[i].toURL(),
-        function(systemMetadata, path) {
-          status[path] = !!(systemMetadata && systemMetadata.isReadOnly);
-        }.bind(null, roots[i].fullPath));
-  }
+DirectoryModel.prototype.isGDataMounted_ = function() {
+  return this.volumeManager_.isMounted('/' + DirectoryModel.GDATA_DIRECTORY);
 };
 
-/**
- * Prepare the root for the unmount.
- *
- * @param {string} rootPath The path to the root.
- */
-DirectoryModel.prototype.prepareUnmount = function(rootPath) {
-  var index = this.findRootsListItem_(rootPath);
-  if (index == -1) {
-    console.error('Unknown root entry', rootPath);
-    return;
-  }
-  var entry = this.rootsList_.item(index);
+DirectoryModel.prototype.onMountChanged_ = function() {
+  this.updateRoots();
 
-  // We never need to remove this attribute because even if the unmount fails
-  // the onMountCompleted handler calls updateRoots which creates a new entry
-  // object for this volume.
-  entry.unmounting = true;
-
-  // Re-place the entry into the roots data model to force re-rendering.
-  this.rootsList_.splice(index, 1, entry);
+  if (this.getCurrentRootType() != DirectoryModel.RootType.GDATA)
+    return;
 
-  if (rootPath == this.rootPath) {
-    // TODO(kaznacheev): Consider changing to the most recently used root.
-    this.changeDirectory(this.getDefaultDirectory());
+  var mounted = this.isGDataMounted_();
+  if (this.currentDirEntry_ == DirectoryModel.fakeGDataEntry_) {
+    if (mounted) {
+      // Change fake entry to real one and rescan.
+      this.root_.getDirectory('/' + DirectoryModel.GDATA_DIRECTORY, {},
+          function(entry) {
+        if (this.currentDirEntry_ == DirectoryModel.fakeGDataEntry_) {
+          this.currentDirEntry_ = entry;
+          this.rescan();
+        }
+      }.bind(this));
+    }
+  } else if (!mounted) {
+    // Current entry unmounted. replace with fake one.
+    if (this.currentDirEntry_.fullPath ==
+        DirectoryModel.fakeGDataEntry_.fullPath) {
+      // Replace silently and rescan.
+      this.currentDirEntry_ = DirectoryModel.fakeGDataEntry_;
+      this.rescan();
+    } else {
+      this.changeDirectoryEntry_(false, DirectoryModel.fakeGDataEntry_);
+    }
   }
 };
 
@@ -1282,3 +1321,86 @@ DirectoryModel.Scanner.prototype.recordMetrics_ = function() {
     metrics.recordMediumCount('DownloadsCount', this.list_.length);
   }
 };
+
+function FileWatcher(root, directoryModel, volumeManager) {
+  this.root_ = root;
+  this.dm_ = directoryModel;
+  this.vm_ = volumeManager;
+  this.watchedDirectoryEntry_ = null;
+  this.updateWatchedDirectoryBound_ =
+      this.updateWatchedDirectory_.bind(this);
+  this.onFileChangedBound_ =
+      this.onFileChanged_.bind(this);
+}
+
+FileWatcher.prototype.start = function() {
+  chrome.fileBrowserPrivate.onFileChanged.addListener(
+        this.onFileChangedBound_);
+
+  this.dm_.addEventListener('directory-changed',
+      this.updateWatchedDirectoryBound_);
+  this.vm_.addEventListener('changed',
+      this.updateWatchedDirectoryBound_);
+
+  this.updateWatchedDirectory_();
+};
+
+FileWatcher.prototype.stop = function() {
+  chrome.fileBrowserPrivate.onFileChanged.removeListener(
+        this.onFileChangedBound_);
+
+  this.dm_.removeEventListener('directory-changed',
+      this.updateWatchedDirectoryBound_);
+  this.vm_.removeEventListener('changed',
+      this.updateWatchedDirectoryBound_);
+
+  if (this.watchedDirectoryEntry_)
+    this.changeWatchedEntry(null);
+};
+
+FileWatcher.prototype.onFileChanged_ = function(event) {
+  if (encodeURI(event.fileUrl) == this.watchedDirectoryEntry_.toURL())
+    this.dm_.rescanLater();
+};
+
+FileWatcher.prototype.updateWatchedDirectory_ = function() {
+  var current = this.watchedDirectoryEntry_;
+  switch (this.dm_.getCurrentRootType()) {
+    case DirectoryModel.RootType.GDATA:
+      if (!this.vm_.isMounted('/' + DirectoryModel.GDATA_DIRECTORY))
+         break;
+    case DirectoryModel.RootType.DOWNLOADS:
+    case DirectoryModel.RootType.REMOVABLE:
+      if (!current || current.fullPath != this.dm_.getCurrentDirPath()) {
+        this.root_.getDirectory(this.dm_.getCurrentDirPath(), {},
+                                this.changeWatchedEntry.bind(this));
+      }
+      break;
+  }
+  if (current)
+    this.changeWatchedEntry(null);
+};
+
+FileWatcher.prototype.changeWatchedEntry = function(entry) {
+  if (this.watchedDirectoryEntry_) {
+    chrome.fileBrowserPrivate.removeFileWatch(
+        this.watchedDirectoryEntry_.toURL(),
+        function(result) {
+          if (!result) {
+            console.log('Failed to remove file watch');
+          }
+        });
+  }
+  this.watchedDirectoryEntry_ = entry;
+
+  if (this.watchedDirectoryEntry_) {
+    chrome.fileBrowserPrivate.addFileWatch(
+        this.watchedDirectoryEntry_.toURL(),
+        function(result) {
+          if (!result) {
+            console.log('Failed to add file watch');
+            this.watchedDirectoryEntry_ = null;
+          }
+        }.bind(this));
+  }
+};