Refactor the Photo Editor to enable new feature work

chrome/browser/resources/file_manager/js/photo/gallery_item.js

+// Copyright (c) 2012 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.
+
+/**
+ * Object representing an image item (a photo or a video).
+ *
+ * @param {string} url Image url.
+ * @constructor
+ */
+Gallery.Item = function(url) {
+  this.url_ = url;
+  this.original_ = true;
+};
+
+/**
+ * @return {string} Image url.
+ */
+Gallery.Item.prototype.getUrl = function() { return this.url_ };
+
+/**
+ * @param {string} url New url.
+ */
+Gallery.Item.prototype.setUrl = function(url) { this.url_ = url };
+
+/**
+ * @return {string} File name.
+ */
+Gallery.Item.prototype.getFileName = function() {
+  return ImageUtil.getFullNameFromUrl(this.url_);
+};
+
+/**
+ * @return {boolean} True if this image has not been created in this session.
+ */
+Gallery.Item.prototype.isOriginal = function() { return this.original_ };
+
+// TODO: Localize?
+/**
+ * @type {string} Prefix for a edited copy file name.
+ */
+Gallery.Item.COPY_SIGNATURE = 'Edited';
+
+/**
+ * Regular exression to match 'Edited - ...'.
+ * @type {RegExp}
+ */
+Gallery.Item.REGEXP_COPY_0 =
+    new RegExp('^' + Gallery.Item.COPY_SIGNATURE + '( - .+)$');
+
+/**
+ * Regular exression to match 'Edited (N) - ...'.
+ * @type {RegExp}
+ */
+Gallery.Item.REGEXP_COPY_N =
+    new RegExp('^' + Gallery.Item.COPY_SIGNATURE + ' \\((\\d+)\\)( - .+)$');
+
+/**
+ * Create a name for an edited copy of the file.
+ *
+ * @param {Entry} dirEntry Entry.
+ * @param {function} callback Callback.
+ * @private
+ */
+Gallery.Item.prototype.createCopyName_ = function(dirEntry, callback) {
+  var name = this.getFileName();
+
+  // If the item represents a file created during the current Gallery session
+  // we reuse it for subsequent saves instead of creating multiple copies.
+  if (!this.original_) {
+    callback(name);
+    return;
+  }
+
+  var ext = '';
+  var index = name.lastIndexOf('.');
+  if (index != -1) {
+    ext = name.substr(index);
+    name = name.substr(0, index);
+  }
+
+  if (!ext.match(/jpe?g/i)) {
+    // Chrome can natively encode only two formats: JPEG and PNG.
+    // All non-JPEG images are saved in PNG, hence forcing the file extension.
+    ext = '.png';
+  }
+
+  function tryNext(tries) {
+    // All the names are used. Let's overwrite the last one.
+    if (tries == 0) {
+      setTimeout(callback, 0, name + ext);
+      return;
+    }
+
+    // If the file name contains the copy signature add/advance the sequential
+    // number.
+    var matchN = Gallery.Item.REGEXP_COPY_N.exec(name);
+    var match0 = Gallery.Item.REGEXP_COPY_0.exec(name);
+    if (matchN && matchN[1] && matchN[2]) {
+      var copyNumber = parseInt(matchN[1], 10) + 1;
+      name = Gallery.Item.COPY_SIGNATURE + ' (' + copyNumber + ')' + matchN[2];
+    } else if (match0 && match0[1]) {
+      name = Gallery.Item.COPY_SIGNATURE + ' (1)' + match0[1];
+    } else {
+      name = Gallery.Item.COPY_SIGNATURE + ' - ' + name;
+    }
+
+    dirEntry.getFile(name + ext, {create: false, exclusive: false},
+        tryNext.bind(null, tries - 1),
+        callback.bind(null, name + ext));
+  }
+
+  tryNext(10);
+};
+
+/**
+ * Write the new item content to the file.
+ *
+ * @param {Entry} dirEntry Directory entry.
+ * @param {boolean} overwrite True if overwrite, false if copy.
+ * @param {HTMLCanvasElement} canvas Source canvas.
+ * @param {ImageEncoder.MetadataEncoder} metadataEncoder MetadataEncoder.
+ * @param {function(boolean)} opt_callback Callback accepting true for success.
+ */
+Gallery.Item.prototype.saveToFile = function(
+    dirEntry, overwrite, canvas, metadataEncoder, opt_callback) {
+  ImageUtil.metrics.startInterval(ImageUtil.getMetricName('SaveTime'));
+
+  var name = this.getFileName();
+
+  var onSuccess = function(url) {
+    console.log('Saved from gallery', name);
+    ImageUtil.metrics.recordEnum(ImageUtil.getMetricName('SaveResult'), 1, 2);
+    ImageUtil.metrics.recordInterval(ImageUtil.getMetricName('SaveTime'));
+    this.setUrl(url);
+    if (opt_callback) opt_callback(true);
+  }.bind(this);
+
+  function onError(error) {
+    console.log('Error saving from gallery', name, error);
+    ImageUtil.metrics.recordEnum(ImageUtil.getMetricName('SaveResult'), 0, 2);
+    if (opt_callback) opt_callback(false);
+  }
+
+  function doSave(newFile, fileEntry) {
+    fileEntry.createWriter(function(fileWriter) {
+      function writeContent() {
+        fileWriter.onwriteend = onSuccess.bind(null, fileEntry.toURL());
+        fileWriter.write(ImageEncoder.getBlob(canvas, metadataEncoder));
+      }
+      fileWriter.onerror = function(error) {
+        onError(error);
+        // Disable all callbacks on the first error.
+        fileWriter.onerror = null;
+        fileWriter.onwriteend = null;
+      };
+      if (newFile) {
+        writeContent();
+      } else {
+        fileWriter.onwriteend = writeContent;
+        fileWriter.truncate(0);
+      }
+    }, onError);
+  }
+
+  function getFile(newFile) {
+    dirEntry.getFile(name, {create: newFile, exclusive: newFile},
+        doSave.bind(null, newFile), onError);
+  }
+
+  function checkExistence() {
+    dirEntry.getFile(name, {create: false, exclusive: false},
+        getFile.bind(null, false /* existing file */),
+        getFile.bind(null, true /* create new file */));
+  }
+
+  if (overwrite) {
+    checkExistence();
+  } else {
+    this.createCopyName_(dirEntry, function(copyName) {
+      this.original_ = false;
+      name = copyName;
+      checkExistence();
+    }.bind(this));
+  }
+};
+
+/**
+ * Rename the file.
+ *
+ * @param {Entry} dir Directory entry.
+ * @param {string} name New file name.
+ * @param {function} onSuccess Success callback.
+ * @param {function} onExists Called if the file with the new name exists.
+ */
+Gallery.Item.prototype.rename = function(dir, name, onSuccess, onExists) {
+  var oldName = this.getFileName();
+  if (ImageUtil.getExtensionFromFullName(name) ==
+      ImageUtil.getExtensionFromFullName(oldName)) {
+    name = ImageUtil.getFileNameFromFullName(name);
+  }
+  var newName = ImageUtil.replaceFileNameInFullName(oldName, name);
+  if (oldName == newName) return;
+
+  function onError() {
+    console.log('Rename error: "' + oldName + '" to "' + newName + '"');
+  }
+
+  var onRenamed = function(entry) {
+    this.setUrl(entry.toURL());
+    onSuccess();
+  }.bind(this);
+
+  var doRename = function() {
+    dir.getFile(
+        this.getFileName(),
+        {create: false},
+        function(entry) { entry.moveTo(dir, newName, onRenamed, onError); },
+        onError);
+  }.bind(this);
+
+  dir.getFile(newName, {create: false, exclusive: false}, onExists, doRename);
+};