Wallpaper manager backend APIs

chrome/common/extensions/api/wallpaper_manager_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":"wallpaperManagerPrivate",
+    "nodoc": "true",
+    "functions": [
+      {
+        "name": "getStrings",
+        "type": "function",
+        "description": "Gets translated strings.",
+        "nodoc": "true",

[Mihai Parparita -not on Chrome, 2012/07/16 23:14:25]

Since the root namespace has nodoc, I believe you don't need it for every
function/event too.

[bshe, 2012/07/18 18:28:56]

Done.

+        "parameters": [
+          {
+            "type": "function",
+            "name": "callback",
+            "parameters": [
+              {
+                "name": "result",
+                "type": "object",
+                "additionalProperties": {"type": "string"}
+              }
+            ]
+          }
+        ]
+      },
+      {
+        "name": "setWallpaper",
+        "type": "function",
+        "description": "Sets wallpaper to the image from url with specified layout",
+        "nodoc": "true",
+        "parameters": [
+          {
+            "type": "string",
+            "name": "url"

[Mihai Parparita -not on Chrome, 2012/07/16 23:14:25]

By making the API taken in a URL, you end up making the API more complex, since
it has to implement file downloading, fire progress and error events, etc. 

XMLHttpRequest already does all that. It can fetch data as ArrayBuffers (which I
believe you can pass into ExtensionFunction implementations) and extensions can
use it to load data from any host (just add "<all_urls>" to the permission list
in the manifest).

Can you implement the wallpaper manager in terms of a simpler
setWallpaper(ArrayBuffer) API, and have the client-side code use XMLHttpRequest?

[bshe, 2012/07/18 18:28:56]

Done.

+          },
+          {
+            "type": "string",
+            "name": "layout",
+            "enum": [ "STRETCH", "CENTER", "CENTER_CROPPED"]
+          }
+        ]
+      }
+    ],
+    "events": [
+      {
+        "name": "onDownloadStart",
+        "type": "function",
+        "description": "Fired when wallpaper downloading is started.",
+        "parameters": []
+      },
+      {
+        "name": "onDownloadProgress",
+        "type": "function",
+        "description": "Fired when wallpaper downloading is in progress.",
+        "parameters": [
+          {
+            "name": "event",
+            "type": "object",
+            "properties": {
+              "remainingTime": {
+                "type": "integer",
+                "description": "The remaining download time in millseconds."
+              },
+              "progress": {
+                "type": "number",
+                "description": "The downloading precentage."
+              }
+            }
+          }
+        ]
+      },
+      {
+        "name": "onDownloadDone",
+        "type": "function",
+        "description": "Fired when wallpaper downloading is finished.",
+        "parameters": []
+      },
+      {
+        "name": "onDownloadError",
+        "type": "function",
+        "description": "Fired when wallpaper downloading has an error.",
+        "parameters": [
+          {
+            "name": "event",
+            "type": "object",
+            "properties": {
+              "errorMessageID": {
+                "type": "string",
+                "description": "The error message ID."
+              }
+            }
+          }
+        ]
+      }
+    ]
+  }
+]