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

chrome/browser/resources/downloads.js

Index: chrome/browser/resources/downloads.js
diff --git a/chrome/browser/resources/downloads.js b/chrome/browser/resources/downloads.js
index ddfdb40c813338fe0b5f61134fe6c2e8cd085f8d..35b55c9958c6c2e107eb10da5f13306ae2dc3634 100644
--- a/chrome/browser/resources/downloads.js
+++ b/chrome/browser/resources/downloads.js
@@ -292,6 +292,7 @@ Download.States = {
   IN_PROGRESS : "IN_PROGRESS",
   CANCELLED : "CANCELLED",
   COMPLETE : "COMPLETE",
+  REMOVED : "REMOVED",

[hendrickson_a, 2011/06/07 15:38:52]

I don't like this mismatch between the states in DownloadItem and in JavaScript.

[Randy Smith (Not in Mondays), 2011/06/07 18:51:10]

I'm sorry if this was covered earlier and the state's not in my brain anymore,
but why include the REMOVED status?  I'd rather not do that; a) it's not really
a state of a download, and b) what an C++ observer seeing "REMOVED" should do is
immediately stop observing the download item and remove it from any lists it
contains.   Extending that to an asynchronous renderer interaction seems like
asking for trouble.   

[haraken1, 2011/06/08 05:11:49]

I got it. I removed REMOVED state from Download.States. Instead, I introduced
this.fileExternallyRemoved_, which corresponds to
DownloadItem::file_externally_removed_ in C++. 


On 2011/06/07 18:51:10, rdsmith wrote:

   PAUSED : "PAUSED",
   DANGEROUS : "DANGEROUS",
   INTERRUPTED : "INTERRUPTED",
@@ -448,6 +449,8 @@ Download.prototype.getStatusText_ = function() {
       return this.progressStatusText_;
     case Download.States.CANCELLED:
       return localStrings.getString('status_cancelled');
+    case Download.States.REMOVED:
+      return localStrings.getString('status_removed');
     case Download.States.PAUSED:
       return localStrings.getString('status_paused');
     case Download.States.DANGEROUS:
@@ -532,7 +535,15 @@ Download.prototype.cancel_ = function() {
 // 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();
@@ -540,12 +551,14 @@ function load() {
 }
 
 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', []);
@@ -562,6 +575,7 @@ function downloadsList(results) {
   if (resultsTimeout)
     clearTimeout(resultsTimeout);
   window.console.log('results');
+  fifo_results.length = 0;
   downloads.clear();
   downloadUpdated(results);
   downloads.updateSummary();
@@ -575,13 +589,23 @@ function downloadUpdated(results) {
   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;
     }
   }