Detect removed files and reflect the state in chrome://downloads and the download shelf

chrome/browser/resources/downloads.js

 // 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.
 
 ///////////////////////////////////////////////////////////////////////////////
 // Helper functions
 function $(o) {return document.getElementById(o);}
 
 /**
  * Sets the display style of a node.
@@ skipping 169 matching lines @@
   this.nodeSince_ = createElementWithClassName('div', 'since');
   this.nodeDate_ = createElementWithClassName('div', 'date');
   this.dateContainer_.appendChild(this.nodeSince_);
   this.dateContainer_.appendChild(this.nodeDate_);
 
   // Container for all 'safe download' UI.
   this.safe_ = createElementWithClassName('div', 'safe');
   this.safe_.ondragstart = this.drag_.bind(this);
   this.node.appendChild(this.safe_);
 
-  if (download.state != Download.States.COMPLETE) {
+  if (this.state_ != Download.States.COMPLETE || this.fileExternallyRemoved_) {
     this.nodeProgressBackground_ =
         createElementWithClassName('div', 'progress background');
     this.safe_.appendChild(this.nodeProgressBackground_);
 
     this.canvasProgress_ =
         document.getCSSCanvasContext('2d', 'canvas_' + download.id,
             Download.Progress.width,
             Download.Progress.height);
 
     this.nodeProgressForeground_ =
@@ skipping 121 matching lines @@
 /**
  * Updates the download to reflect new data.
  * @param {Object} download A backend download object (see downloads_ui.cc)
  */
 Download.prototype.update = function(download) {
   this.id_ = download.id;
   this.filePath_ = download.file_path;
   this.fileName_ = download.file_name;
   this.url_ = download.url;
   this.state_ = download.state;
+  this.fileExternallyRemoved_ = download.file_externally_removed;
   this.dangerType_ = download.danger_type;
 
   this.since_ = download.since_string;
   this.date_ = download.date_string;
 
   // See DownloadItem::PercentComplete
   this.percent_ = Math.max(download.percent, 0);
   this.progressStatusText_ = download.progress_status_text;
   this.received_ = download.received;
 
   if (this.state_ == Download.States.DANGEROUS) {
     if (this.dangerType_ == Download.DangerType.DANGEROUS_FILE) {
       this.dangerDesc_.innerHTML = localStrings.getStringF('danger_file_desc',
                                                            this.fileName_);
     } else {
       this.dangerDesc_.innerHTML = localStrings.getString('danger_url_desc');
     }
     this.danger_.style.display = 'block';
     this.safe_.style.display = 'none';
   } else {
     this.nodeImg_.src = 'chrome://fileicon/' + this.filePath_;
 
-    if (this.state_ == Download.States.COMPLETE) {
+    if (this.state_ == Download.States.COMPLETE &&
+        !this.fileExternallyRemoved_) {
       this.nodeFileLink_.innerHTML = this.fileName_;
       this.nodeFileLink_.href = this.filePath_;
     } else {
       this.nodeFileName_.innerHTML = this.fileName_;
     }
 
-    showInline(this.nodeFileLink_, this.state_ == Download.States.COMPLETE);
+    showInline(this.nodeFileLink_,
+               this.state_ == Download.States.COMPLETE &&
+                   !this.fileExternallyRemoved_);
     // nodeFileName_ has to be inline-block to avoid the 'interaction' with
     // nodeStatus_. If both are inline, it appears that their text contents
     // are merged before the bidi algorithm is applied leading to an
     // undesirable reordering. http://crbug.com/13216
-    showInlineBlock(this.nodeFileName_, this.state_ != Download.States.COMPLETE);
+    showInlineBlock(this.nodeFileName_,
+                    this.state_ != Download.States.COMPLETE ||
+                        this.fileExternallyRemoved_);
 
     if (this.state_ == Download.States.IN_PROGRESS) {
       this.nodeProgressForeground_.style.display = 'block';
       this.nodeProgressBackground_.style.display = 'block';
 
       // Draw a pie-slice for the progress.
       this.canvasProgress_.clearRect(0, 0,
                                      Download.Progress.width,
                                      Download.Progress.height);
       this.canvasProgress_.beginPath();
@@ skipping 12 matching lines @@
       this.canvasProgress_.lineTo(Download.Progress.centerX,
                                   Download.Progress.centerY);
       this.canvasProgress_.fill();
       this.canvasProgress_.closePath();
     } else if (this.nodeProgressBackground_) {
       this.nodeProgressForeground_.style.display = 'none';
       this.nodeProgressBackground_.style.display = 'none';
     }
 
     if (this.controlShow_) {
-      showInline(this.controlShow_, this.state_ == Download.States.COMPLETE);
+      showInline(this.controlShow_,
+                 this.state_ == Download.States.COMPLETE &&
+                     !this.fileExternallyRemoved_);
     }
     showInline(this.controlRetry_, this.state_ == Download.States.CANCELLED);
     this.controlRetry_.href = this.url_;
     showInline(this.controlPause_, this.state_ == Download.States.IN_PROGRESS);
     showInline(this.controlResume_, this.state_ == Download.States.PAUSED);
     var showCancel = this.state_ == Download.States.IN_PROGRESS ||
                      this.state_ == Download.States.PAUSED;
     showInline(this.controlCancel_, showCancel);
     showInline(this.controlRemove_, !showCancel);
 
@@ skipping 40 matching lines @@
       return localStrings.getString('status_cancelled');
     case Download.States.PAUSED:
       return localStrings.getString('status_paused');
     case Download.States.DANGEROUS:
       var desc = this.dangerType_ == Download.DangerType.DANGEROUS_FILE ?
           'danger_file_desc' : 'danger_url_desc';
       return localStrings.getString(desc);
     case Download.States.INTERRUPTED:
       return localStrings.getString('status_interrupted');
     case Download.States.COMPLETE:
-      return '';
+      return this.fileExternallyRemoved_ ?
+          localStrings.getString('status_removed') : '';
   }
 }
 
 /**
  * Tells the backend to initiate a drag, allowing users to drag
  * files from the download page and have them appear as native file
  * drags.
  */
 Download.prototype.drag_ = function() {
   chrome.send('drag', [this.id_.toString()]);
@@ skipping 54 matching lines @@
  */
 Download.prototype.cancel_ = function() {
   chrome.send('cancel', [this.id_.toString()]);
   return false;
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 // Page:
 var downloads, localStrings, resultsTimeout;
 
+/**
+ * The FIFO array that stores updates of download files to be appeared
+ * on the download page. It is guaranteed that the updates in this array
+ * are reflected to the download page in a FIFO order.
+*/
+var fifo_results;
+
 function load() {
+  fifo_results = new Array();
   localStrings = new LocalStrings();
   downloads = new Downloads();
   $('term').focus();
   setSearch('');
 }
 
 function setSearch(searchText) {
+  fifo_results.length = 0;
   downloads.clear();
   downloads.setSearchText(searchText);
   chrome.send('getDownloads', [searchText.toString()]);
 }
 
 function clearAll() {
+  fifo_results.length = 0;
   downloads.clear();
   downloads.setSearchText('');
   chrome.send('clearAll', []);
   return false;
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 // Chrome callbacks:
 /**
  * Our history system calls this function with results from searches or when
  * downloads are added or removed.
  */
 function downloadsList(results) {
   if (resultsTimeout)
     clearTimeout(resultsTimeout);
   window.console.log('results');
+  fifo_results.length = 0;
   downloads.clear();
   downloadUpdated(results);
   downloads.updateSummary();
 }
 
 /**
  * When a download is updated (progress, state change), this is called.
  */
 function downloadUpdated(results) {
   // Sometimes this can get called too early.
   if (!downloads)
     return;
 
+  fifo_results = fifo_results.concat(results);
+  tryDownloadUpdatedPeriodically();
+}
+
+/**
+ * Try to reflect as much updates as possible within 50ms.
+ * This function is scheduled again and again until all updates are reflected.
+ */
+function tryDownloadUpdatedPeriodically() {
   var start = Date.now();
-  for (var i = 0; i < results.length; i++) {
-    downloads.updated(results[i]);
+  while (fifo_results.length) {
+    var result = fifo_results.shift();
+    downloads.updated(result);
     // Do as much as we can in 50ms.
     if (Date.now() - start > 50) {
       clearTimeout(resultsTimeout);
-      resultsTimeout = setTimeout(downloadUpdated, 5, results.slice(i + 1));
+      resultsTimeout = setTimeout(tryDownloadUpdatedPeriodically, 5);
       break;
     }
   }
 }
 
 // Add handlers to HTML elements.
 document.body.onload = load;
 $('clear-all').onclick = function () { clearAll(''); };
 $('search-link').onclick = function () {
   setSearch('');
   return false;
 };
 $('search-form').onsubmit = function () {
   setSearch(this.term.value);
   return false;
 };