Make wallpaper picker manifest and thumbnails available when offline.

chrome/common/extensions/api/wallpaper_private.json

 // Copyright (c) 2012 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.
 
 [
   {
     "namespace":"wallpaperPrivate",
     "nodoc": "true",
     "functions": [
       {
@@ skipping 69 matching lines @@
         "description": "Minimizes all inactive open windows.",
         "nodoc": "true",
         "parameters": []
       },
       {
         "name": "restoreMinimizedWindows",
         "type": "function",
         "description": "Restores all previously minimized windows.",
         "nodoc": "true",
         "parameters": []
+      },
+      {
+        "name": "getThumbnail",
+        "type": "function",
+        "description": "Gets thumbnail of wallpaper from thumbnail directory.",
+        "nodoc": "true",
+        "parameters": [
+          {
+            "type": "string",
+            "name": "url",
+            "description": "Wallpaper url."
+          },
+          {
+            "type": "function",
+            "name": "callback",
+            "description": "Function called upon completion.",
+            "parameters": [
+              {
+                "type": "object",
+                "name": "results",
+                "description": "Results of the method.",
+                "properties": {
+                  "success": {
+                    "type": "boolean",
+                    "description": "Is the requested thumbnail found and loaded."
+                  },
+                  "data": {
+                    "type": "binary",
+                    "optional": true,
+                    "description": "The binary data of loaded thumbnail."
+                  }
+                }
+              }
+            ]
+          }
+        ]
+      },
+      {
+        "name": "saveThumbnail",
+        "type": "function",
+        "description": "Saves thumbnail to thumbnail directory.",
+        "nodoc": "true",
+        "parameters": [
+          {
+            "type": "binary",
+            "name": "data",
+            "description": "The binary data of downloaded thumbnail."
+          },
+          {
+            "type": "string",
+            "name": "url",
+            "description": "Wallpaper url."

[flackr, 2012/11/27 22:04:36]

Just out of convention I think the url "key" should be first. We're setting the
wallpaper thumbnail with key "url" to be "data" or thumbnail[key] = url.

[bshe, 2012/11/28 18:54:26]

Done.

+          },
+          {
+            "type": "function",
+            "name": "callback",
+            "description": "Function called upon completion.",
+            "parameters": [],

[flackr, 2012/11/27 22:04:36]

Saving the thumbnail can also fail, you may want to add this parameter to the
callback so that the test can accurately detect what the failure is.

[bshe, 2012/11/28 18:54:26]

I believe the convention for extension function is using SetError("error
string") in the function implementation, and use chrome.runtime.lastError to get
the error string in javascript. miket@ could you confirm?

On 2012/11/27 22:04:36, flackr wrote:

[flackr, 2012/12/03 19:02:30]

But this is an asynchronous call, you wouldn't know when to check
chrome.runtime.lastError unless it failed immediately.

[bshe, 2012/12/03 19:39:32]

Maybe I understand you wrong. But you should be able to check
chrome.runtime.lastError in the callback function of the api call? When you
request it from the callback, you should be able to get the error string that
you have set in the SetError. And also, the js console displays the string as a
js error. See comment 11 at https://chromiumcodereview.appspot.com/11092078



On 2012/12/03 19:02:30, flackr wrote:

[flackr, 2012/12/03 20:03:46]

Ah, I follow. So in theory the success parameter in getThumbail may be
unnecessary although it seems that SetError is meant for unexpected errors like
being unable to save thumbnails whereas thumbnails would regularly be expected
to not be on the computer.

[bshe, 2012/12/03 22:18:01]

Right. Sorry for confusion. For the case thumbnails regularly be expected to not
be on the computer, I want to avoid to use SetError since it usually output
error message in js console and in chrome log message. I am hoping to avoid to
show these error messages when it happens.

I can probably remove the success parameter and use the existence of data
parameter to infer the success state. If data is undefined, we didn't find the
thumbnail on the computer.

On 2012/12/03 20:03:46, flackr wrote:

+            "optional": true
+          }
+        ]
       }
     ]
   }
 ]