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

chrome/browser/resources/downloads.html

Index: chrome/browser/resources/downloads.html
diff --git a/chrome/browser/resources/downloads.html b/chrome/browser/resources/downloads.html
index 7aee1a3aec950c89a655debacd42489f79758ae9..3507edb16653b3b19b2211c63cbda9adde683987 100644
--- a/chrome/browser/resources/downloads.html
+++ b/chrome/browser/resources/downloads.html
@@ -471,6 +471,7 @@ Download.States = {
   IN_PROGRESS : "IN_PROGRESS",
   CANCELLED : "CANCELLED",
   COMPLETE : "COMPLETE",
+  REMOVED : "REMOVED",
   PAUSED : "PAUSED",
   DANGEROUS : "DANGEROUS",
   INTERRUPTED : "INTERRUPTED",
@@ -627,6 +628,8 @@ 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:
@@ -711,7 +714,15 @@ 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();
@@ -719,12 +730,14 @@ 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', []);
@@ -741,6 +754,7 @@ function downloadsList(results) {
   if (resultsTimeout)
     clearTimeout(resultsTimeout);
   window.console.log('results');
+  fifo_results.length = 0;
   downloads.clear();
   downloadUpdated(results);
   downloads.updateSummary();
@@ -754,13 +768,27 @@ 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() {
+  // Sometimes this can get called too early.
+  if (!downloads)
+    return;

[Randy Smith (Not in Mondays), 2011/05/16 20:57:12]

Do we still need this comment and the null check for downloads?  Once downloads
has been created, won't the object stick around even if it's cleared (based on
my reading of the code, but I may be wrong; I'm not a JS expert).

[haraken1, 2011/06/07 12:49:18]

Done.

+
   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;
     }
   }