Gallery: Load images sequentially, stop chunking loading requests.

BUG=577345

Review URL: https://codereview.chromium.org/1751423002

Cr-Commit-Position: refs/heads/master@{#378714}

1 files changed, 17 insertions, 34 deletions

diff --git a/ui/file_manager/gallery/js/gallery.js b/ui/file_manager/gallery/js/gallery.js
index 13c0020..761a75b 100644
--- a/ui/file_manager/gallery/js/gallery.js
+++ b/ui/file_manager/gallery/js/gallery.js
@@ -368,19 +368,6 @@ Gallery.prototype.loadInternal_ = function(entries, selectedEntries) {
   }
   this.onSelection_();
 
-  // Obtains max chank size.
-  var maxChunkSize = 20;
-  var volumeInfo = this.volumeManager_.getVolumeInfo(entries[0]);
-  if (volumeInfo) {
-    if (GalleryUtil.isOnMTPVolume(entries[0], this.volumeManager_))
-      maxChunkSize = 1;
-
-    if (volumeInfo.isReadOnly ||
-        GalleryUtil.isOnMTPVolume(entries[0], this.volumeManager_)) {
-      this.context_.readonlyDirName = volumeInfo.label;
-    }
-  }
-
   // If items are empty, stop initialization.
   if (items.length === 0) {
     this.dataModel_.splice(0, this.dataModel_.length);
@@ -401,33 +388,29 @@ Gallery.prototype.loadInternal_ = function(entries, selectedEntries) {
   // Use the self variable capture-by-closure because it is faster than bind.
   var self = this;
   var thumbnailModel = new ThumbnailModel(this.metadataModel_);
-  var loadChunk = function() {
+  var loadNext = function(index) {
     // Extract chunk.
-    var chunk = items.splice(0, maxChunkSize);
-    if (!chunk.length)
+    if (index >= items.length)
       return;
-    var entries = chunk.map(function(chunkItem) {
-      return chunkItem.getEntry();
-    });
-    var metadataPromise = self.metadataModel_.get(
-        entries, Gallery.PREFETCH_PROPERTY_NAMES);
-    var thumbnailPromise = thumbnailModel.get(entries);
+    var item = items[index];
+    var entry = item.getEntry();
+    var metadataPromise = self.metadataModel_.get([entry],
+        Gallery.PREFETCH_PROPERTY_NAMES);
+    var thumbnailPromise = thumbnailModel.get([entry]);
     return Promise.all([metadataPromise, thumbnailPromise]).then(
         function(metadataLists) {
       // Add items to the model.
-      chunk.forEach(function(chunkItem, index) {
-        chunkItem.setMetadataItem(metadataLists[0][index]);
-        chunkItem.setThumbnailMetadataItem(metadataLists[1][index]);
-
-        var event = new Event('content');
-        event.item = chunkItem;
-        event.oldEntry = chunkItem.getEntry();
-        event.thumbnailChanged = true;
-        self.dataModel_.dispatchEvent(event);
-      });
+      item.setMetadataItem(metadataLists[0][0]);
+      item.setThumbnailMetadataItem(metadataLists[1][0]);
+
+      var event = new Event('content');
+      event.item = item;
+      event.oldEntry = entry;
+      event.thumbnailChanged = true;
+      self.dataModel_.dispatchEvent(event);
 
       // Continue to load chunks.
-      return loadChunk();
+      return loadNext(/* index */ index + 1);
     });
   };
   // init modes before loading images.
@@ -454,7 +437,7 @@ Gallery.prototype.loadInternal_ = function(entries, selectedEntries) {
     }
     this.initialized_ = true;
   }
-  loadChunk().catch(function(error) {
+  loadNext(/* index */ 0).catch(function(error) {
     console.error(error.stack || error);
   });
 };