Reduce blinking of icons in the preview panel.

chrome/browser/resources/file_manager/js/file_manager.js

Index: chrome/browser/resources/file_manager/js/file_manager.js
diff --git a/chrome/browser/resources/file_manager/js/file_manager.js b/chrome/browser/resources/file_manager/js/file_manager.js
index 8985495e28fa273055337f72ae87641cf5ba207c..99a04e30cf34d717c30067200d3edc1063d0c358 100644
--- a/chrome/browser/resources/file_manager/js/file_manager.js
+++ b/chrome/browser/resources/file_manager/js/file_manager.js
@@ -2249,12 +2249,31 @@ FileManager.prototype = {
     }
 
     this.previewSummary_.textContent = str('COMPUTING_SELECTION');
-    removeChildren(this.previewThumbnails_);
+    var thumbnails = this.document_.createDocumentFragment();
 
     var fileCount = 0;
     var byteCount = 0;
     var pendingFiles = [];
     var thumbnailCount = 0;
+    var thumbnailLoaded = -1;
+    var forcedShowTimeout = null;
+    var self = this;
+
+    function showThumbnails() {
+      if (forcedShowTimeout == null)
+        return;
+      clearTimeout(forcedShowTimeout);
+      forcedShowTimeout = null;
+
+      removeChildren(self.previewThumbnails_);
+      self.previewThumbnails_.appendChild(thumbnails);
+    }
+
+    function onThumbnailLoaded() {
+      thumbnailLoaded++;
+      if (thumbnailLoaded == thumbnailCount)
+        showThumbnails();
+    }
 
     for (var i = 0; i < selection.indexes.length; i++) {
       var entry = this.directoryModel_.fileList.item(selection.indexes[i]);
@@ -2274,16 +2293,20 @@ FileManager.prototype = {
 
       if (thumbnailCount < MAX_PREVIEW_THUMBAIL_COUNT) {
         var box = this.document_.createElement('div');
-        var imageLoadCalback = thumbnailCount == 0 &&
-                               this.initThumbnailZoom_.bind(this, box);
-        var thumbnail = this.renderThumbnailBox_(entry, true, imageLoadCalback);
+        function imageLoadCalback(box) {
+          if (thumbnailCount == 0)
+            self.initThumbnailZoom_(box);
+          onThumbnailLoaded();
+        }
+        thumbnailCount++;
+        var thumbnail = this.renderThumbnailBox_(entry, true,
+            imageLoadCalback.bind(box));

[dgozman, 2012/04/17 13:33:43]

imageLoadCallback.bind(null, box)

[SeRya, 2012/04/17 13:51:32]

Done.

         box.appendChild(thumbnail);
         box.style.zIndex = MAX_PREVIEW_THUMBAIL_COUNT + 1 - i;
         box.addEventListener('click',
             this.dispatchDefaultTask_.bind(this, selection));
 
-        this.previewThumbnails_.appendChild(box);
-        thumbnailCount++;
+        thumbnails.appendChild(box);
       }
 
       selection.totalCount++;
@@ -2309,8 +2332,8 @@ FileManager.prototype = {
     // Now this.selection is complete. Update buttons.
     this.updateCommonActionButtons_();
     this.updatePreviewPanelVisibility_();
-
-    var self = this;
+    forcedShowTimeout = setTimeout(showThumbnails, 100);

[dgozman, 2012/04/17 13:33:43]

Cancel the previous timeout, if selection changed again during 100ms.

[SeRya, 2012/04/17 13:51:32]

Check the selection has not changed instead.

+    onThumbnailLoaded();
 
     function cacheNextFile(fileEntry) {
       if (fileEntry) {