Implement chrome.browserAction.setIcon({path:...});

chrome/renderer/resources/extension_process_bindings.js

 // Copyright (c) 2009 The chrome Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This script contains privileged chrome extension related javascript APIs.
 // It is loaded by pages whose URL has the chrome-extension protocol.
 
 var chrome = chrome || {};
 (function() {
   native function GetExtensionAPIDefinition();
@@ skipping 315 matching lines @@
         tabIdProxy[name] = new chrome.Event("devtools." + tabId + "." + name);
       });
       return tabIdProxy;
     }
 
     apiFunctions["i18n.getMessage"].handleRequest =
         function(message_name, placeholders) {
       return GetL10nMessage(message_name, placeholders);
     }
 
+    var canvas_context;
     apiFunctions["browserAction.setIcon"].handleRequest = function(details) {
       if ("iconIndex" in details) {
         sendRequest(this.name, arguments, this.definition.parameters);
       } else if ("imageData" in details) {
         // Verify that this at least looks like an ImageData element.
         // Unfortunately, we cannot use instanceof because the ImageData
         // constructor is not public.
         //
         // We do this manually instead of using JSONSchema to avoid having these
         // properties show up in the doc.
         if (!("width" in details.imageData) ||
             !("height" in details.imageData) ||
             !("data" in details.imageData)) {
           throw new Error(
               "The imageData property must contain an ImageData object.");
         }
 
         sendCustomRequest(SetBrowserActionIcon, "browserAction.setIcon",
                           details, this.definition.parameters);
+      } else if ("path" in details) {
+        if (!canvas_context) {
+          var canvas = document.createElement("canvas");
+          canvas.width = 19;

[Matt Perry, 2009/10/16 19:06:05]

isn't it 21 now?

+          canvas.height = 19;
+          canvas_context = canvas.getContext('2d');
+        }
+        
+        var img = new Image();
+        var self = this;
+        img.onerror = function() {
+          console.error("Could not load browser action icon '" + details.path +
+                        "'.");
+        }
+        img.onload = function() {
+          canvas_context.clearRect(0, 0, context.width, context.height);
+          canvas_context.drawImage(img, 0, 0, context.width, context.height);
+          delete details.path;
+          details.imageData = canvas_context.getImageData(0, 0, context.width,
+                                                          context.height);
+          sendCustomRequest(SetBrowserActionIcon, "browserAction.setIcon",
+                            details, self.definition.parameters);
+        }
+        img.src = details.path;
       } else {
         throw new Error(
             "Either the iconIndex or imageData property must be specified.");
       }
     }
 
     setupBrowserActionEvent(extensionId);
     setupPageActionEvents(extensionId);
     setupToolstripEvents(GetRenderViewId());
   });
 })();