Eliminate last vestiges of the command system design.

Update ImportController to push all updates to a new 'CommandWidget' class. Add more test coverage.

BUG=420680
TEST=browser_test: FileManagerJsTest.*

Review URL: https://codereview.chromium.org/880303002

Cr-Commit-Position: refs/heads/master@{#313622}

ui/file_manager/file_manager/foreground/js/file_manager.js

@@ -485,14 +485,13 @@ FileManager.prototype = /** @struct */ {
     importer.importEnabled().then(
         function(enabled) {
           if (enabled) {
-            var commandAdapter = new importer.ButtonCommandAdapter(this);
             this.importController_ = new importer.ImportController(
                 new importer.RuntimeControllerEnvironment(this),
                 /** @type {!importer.MediaScanner} */ (
                     this.mediaScanner_),
                 /** @type {!importer.ImportRunner} */ (
                     this.mediaImportHandler_),
-                commandAdapter.update.bind(commandAdapter));
+                new importer.RuntimeCommandWidget());
           }
         }.bind(this));
 

ui/file_manager/file_manager/foreground/js/import_controller.js

@@ -36,10 +36,10 @@ importer.CommandUpdate;
  *     volume lookup and so-on.
  * @param {!importer.MediaScanner} scanner
  * @param {!importer.ImportRunner} importRunner
- * @param {function()} commandUpdateHandler
+ * @param {!importer.CommandWidget} commandWidget
  */
 importer.ImportController =
-    function(environment, scanner, importRunner, commandUpdateHandler) {
+    function(environment, scanner, importRunner, commandWidget) {
 
   /** @private {!importer.ControllerEnvironment} */
   this.environment_ = environment;
@@ -50,8 +50,8 @@ importer.ImportController =
   /** @private {!importer.MediaScanner} */
   this.scanner_ = scanner;
 
-  /** @private {function()} */
-  this.updateCommands_ = commandUpdateHandler;
+  /** @private {!importer.CommandWidget} */
+  this.commandWidget_ = commandWidget;
 
   /**
    * A cache of scans by volumeId, directory URL.
@@ -63,13 +63,20 @@ importer.ImportController =
   var listener = this.onScanEvent_.bind(this);
   this.scanner_.addObserver(listener);
   // Remove the observer when the foreground window is closed.
-  window.addEventListener('pagehide', function() {
-    this.scanner_.removeObserver(listener);
-  }.bind(this));
+  window.addEventListener(
+      'pagehide',
+      function() {
+        this.scanner_.removeObserver(listener);
+      }.bind(this));
+
   this.environment_.addVolumeUnmountListener(
       this.onVolumeUnmounted_.bind(this));
+
   this.environment_.addDirectoryChangedListener(
       this.onDirectoryChanged_.bind(this));
+
+  this.commandWidget_.addExecuteListener(
+      this.execute.bind(this));
 };
 
 /**
@@ -90,7 +97,7 @@ importer.ImportController.prototype.onScanEvent_ = function(event, result) {
   }
   if (event === importer.ScanEvent.FINALIZED ||
       event === importer.ScanEvent.INVALIDATED) {
-    this.updateCommands_();
+    this.pushUpdate_();
   }
 };
 
@@ -106,8 +113,15 @@ importer.ImportController.prototype.execute = function() {
 };
 
 /**
- * Called by the 'cloud-import' command when it wants an update
- * on the command state.
+ * Push an update to the command widget.
+ * @private
+ */
+importer.ImportController.prototype.pushUpdate_ = function() {
+  this.commandWidget_.update(this.getCommandUpdate());
+};
+
+/**
+ * Returns an update describing the state of the CommandWidget.
  *
  * @return {!importer.CommandUpdate} response
  */
@@ -264,14 +278,12 @@ importer.ImportController.prototype.onVolumeUnmounted_ = function(volumeId) {
   if (this.cachedScans_.hasOwnProperty(volumeId)) {
     delete this.cachedScans_[volumeId];
   }
+  this.pushUpdate_();
 };
 
-/**
- * @param {string} volumeId
- * @private
- */
+/** @private */
 importer.ImportController.prototype.onDirectoryChanged_ = function() {
-  this.updateCommands_();
+  this.pushUpdate_();
 };
 
 /**
@@ -398,49 +410,60 @@ importer.RuntimeControllerEnvironment.prototype.addDirectoryChangedListener =
  * Class that adapts from the new non-command button to the old
  * command style interface.
  *
- * <p>NOTE: This adapter is a stop gap bridge between the old-style
- * Command button and our new do-it-yourself toolbar button. We used
- * an adapter to minimize changes to RuntimeImportController while other
- * people are working on that file. Once the dust settles we can make
- * more transformative changes.
- *
- * @constructor
- * @struct
+ * @interface
+ */
+importer.CommandWidget = function() {};
+
+/**
+ * Install a listener that get's called when the user wants to initiate
+ * import.
  *
- * @param {!FileManager} fileManager
+ * @param {function()} listener
  */
-importer.ButtonCommandAdapter = function(fileManager) {
+importer.CommandWidget.prototype.addExecuteListener;
 
-  /** @param {!FileManager} */
-  this.fileManager_ = fileManager;
+/**
+ * @param {!importer.CommandUpdate} update
+ */
+importer.CommandWidget.prototype.update;
 
-  /** @param {Element} */
+/**
+ * Runtime implementation of CommandWidget.
+ *
+ * @constructor
+ * @implements {importer.CommandWidget}
+ * @struct
+ */
+importer.RuntimeCommandWidget = function() {
+  /** @private {Element} */
   this.buttonElement_ = document.querySelector('#cloud-import-button');
 
-  this.buttonElement_.onclick = this.execute_.bind(this);
+  this.buttonElement_.onclick = this.notifyExecuteListener_.bind(this);
 
-  /** @param {Element} */
+  /** @private {Element} */
   this.iconElement_ = document.querySelector('#cloud-import-button core-icon');
+
+  /** @private {function()} */
+  this.listener_;
+};
+
+/** @override */
+importer.RuntimeCommandWidget.prototype.addExecuteListener =
+    function(listener) {
+  console.assert(!this.listener_);
+  this.listener_ = listener;
 };
 
 /** @private */
-importer.ButtonCommandAdapter.prototype.execute_ = function() {
-  this.fileManager_.importController.execute();
+importer.RuntimeCommandWidget.prototype.notifyExecuteListener_ = function() {
+  console.assert(!!this.listener_);
+  this.listener_();
 };
 
-/**
- * @param {!Event} event Command event.
- * @param {!FileManager} fileManager
- */
-importer.ButtonCommandAdapter.prototype.update = function() {
-  if (this.fileManager_.importController) {
-    var update = fileManager.importController.getCommandUpdate();
+/** @override */
+importer.RuntimeCommandWidget.prototype.update = function(update) {
     this.buttonElement_.setAttribute('title', update.label);
     this.buttonElement_.disabled = !update.executable;
     this.buttonElement_.style.display  = update.visible ? 'block' : 'none';
     this.iconElement_.setAttribute('icon', update.coreIcon);
-  } else {
-    this.buttonElement_.setAttribute('display', 'none');
-    this.iconElement_.setAttribute('icon', 'cloud-off');
-  }
 };

ui/file_manager/file_manager/foreground/js/import_controller_unittest.js

@@ -20,8 +20,8 @@ var sourceVolume;
 /** @type {!VolumeInfo} */
 var destinationVolume;
 
-/** @type {!TestCallRecorder} */
-var commandUpdateRecorder;
+/** @type {!importer.TestCommandWidget} */
+var widget;
 
 // Set up string assets.
 loadTimeData.data = {
@@ -39,7 +39,7 @@ function setUp() {
     recordEnum: function() {}
   };
 
-  commandUpdateRecorder = new TestCallRecorder();
+  widget = new importer.TestCommandWidget();
 
   volumeManager = new MockVolumeManager();
   MockVolumeManager.installMockSingleton(volumeManager);
@@ -113,7 +113,7 @@ function testGetCommandUpdate_InitiatesScan() {
   mediaScanner.assertScanCount(1);
 }
 
-function testDirectoryChange_InitiatesUpdate() {
+function testDirectoryChange_PushesUpdate() {
   var controller = createController(
       VolumeManagerCommon.VolumeType.MTP,
       'mtp-volume',
@@ -121,15 +121,11 @@ function testDirectoryChange_InitiatesUpdate() {
         '/DCIM/',
         '/DCIM/photos0/',
         '/DCIM/photos0/IMG00001.jpg',
-        '/DCIM/photos0/IMG00002.jpg',
-        '/DCIM/photos1/',
-        '/DCIM/photos1/IMG00001.jpg',
-        '/DCIM/photos1/IMG00003.jpg'
       ],
       '/DCIM');
 
   environment.directoryChangedListener_();
-  commandUpdateRecorder.assertCallCount(1);
+  widget.updates.assertCallCount(1);
 }
 
 function testUnmountInvalidatesScans() {
@@ -157,6 +153,23 @@ function testUnmountInvalidatesScans() {
   mediaScanner.assertScanCount(2);
 }
 
+function testVolumeUnmount_PushesUpdate() {
+  var controller = createController(
+      VolumeManagerCommon.VolumeType.MTP,
+      'mtp-volume',
+      [
+        '/DCIM/',
+        '/DCIM/photos0/',
+        '/DCIM/photos0/IMG00001.jpg',
+      ],
+      '/DCIM');
+
+  // Faux unmount the volume, then request an update again.
+  // A fresh new scan should be started.
+  environment.simulateUnmount();
+  widget.updates.assertCallCount(1);
+}
+
 function testGetCommandUpdate_CanExecuteAfterScanIsFinalized() {
   var controller = createController(
       VolumeManagerCommon.VolumeType.MTP,
@@ -183,6 +196,26 @@ function testGetCommandUpdate_CanExecuteAfterScanIsFinalized() {
   assertTrue(response.executable);
 }
 
+function testFinalizeScans_PushesUpdate() {
+  var controller = createController(
+      VolumeManagerCommon.VolumeType.MTP,
+      'mtp-volume',
+      [
+        '/DCIM/',
+        '/DCIM/photos0/',
+        '/DCIM/photos0/IMG00001.jpg',
+      ],
+      '/DCIM');
+
+  var fileSystem = new MockFileSystem('testFs');
+  mediaScanner.fileEntries.push(
+      new MockFileEntry(fileSystem, '/DCIM/photos0/IMG00001.jpg', {size: 0}));
+  controller.getCommandUpdate();
+  mediaScanner.finalizeScans();
+
+  widget.updates.assertCallCount(1);
+}
+
 function testGetCommandUpdate_CannotExecuteEmptyScanResult() {
   var controller = createController(
       VolumeManagerCommon.VolumeType.MTP,
@@ -206,7 +239,7 @@ function testGetCommandUpdate_CannotExecuteEmptyScanResult() {
   assertFalse(response.executable);
 }
 
-function testExecute_StartsImport() {
+function testClick_StartsImport() {
   var controller = createController(
       VolumeManagerCommon.VolumeType.MTP,
       'mtp-volume',
@@ -215,16 +248,12 @@ function testExecute_StartsImport() {
         '/DCIM/photos0/',
         '/DCIM/photos0/IMG00001.jpg',
         '/DCIM/photos0/IMG00002.jpg',
-        '/DCIM/photos1/',
-        '/DCIM/photos1/IMG00001.jpg',
-        '/DCIM/photos1/IMG00003.jpg'
       ],
       '/DCIM');
 
-  controller.getCommandUpdate();
-  mediaScanner.finalizeScans();
-  controller.getCommandUpdate();
-  controller.execute();
+  // First we need to force the controller into a scanning state.
+  environment.directoryChangedListener_();
+  widget.executeListener();
   mediaImporter.assertImportsStarted(1);
 }
 
@@ -372,6 +401,32 @@ TestControllerEnvironment.prototype.whenCurrentDirectoryIsSet = function() {
   return this.directoryWasSetPromise_;
 };
 
+/**
+ * Test implementation of importer.CommandWidget.
+ *
+ * @constructor
+ * @implements {importer.CommandWidget}
+ * @struct
+ */
+importer.TestCommandWidget = function() {
+
+  /** @public {function()} */
+  this.executeListener;
+
+  /** @public {!TestCallRecorder} */
+  this.updates = new TestCallRecorder();
+};
+
+/** @override */
+importer.TestCommandWidget.prototype.addExecuteListener = function(listener) {
+  this.executeListener = listener;
+};
+
+/** @override */
+importer.TestCommandWidget.prototype.update = function(update) {
+  this.updates.callback(update);
+};
+
 /**
  * @param {!VolumeManagerCommon.VolumeType} volumeType
  * @param {string} volumeId
@@ -393,7 +448,7 @@ function createController(volumeType, volumeId, fileNames, currentDirectory) {
       environment,
       mediaScanner,
       mediaImporter,
-      commandUpdateRecorder.callback);
+      widget);
 }
 
 /**