Converted PluginResource reply message handling to use base::Callback

Previously each PluginResource had to write a reply handler (|OnReplyReceived|) for any replies to resource messages. This approach had several problems including the fact that the PluginResource had to track the state of any outstanding calls.

This change allows you to register a base::Callback when calling CallToBrowser/CallToRenderer. The callback will be run when a reply message is received with a sequence number matching the call. The parameters of the reply will be passed to the callback. An example of usage:

CallBrowser<PpapiPluginMsg_MyResourceType_MyReplyMessage>(
    PpapiHostMsg_MyResourceType_MyRequestMessage(),
    base::Bind(&MyPluginResource::ReplyHandler, this));

If a reply message to this call is received whose type does not match the expected reply message (for example, in the case of an error), the callback will still be invoked but with the default values of the message parameters.


BUG=


Review URL: https://chromiumcodereview.appspot.com/11022005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@160015 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 11 insertions, 25 deletions

diff --git a/ppapi/proxy/printing_resource.cc b/ppapi/proxy/printing_resource.cc
index 9fd8fde..22950c2 100644
--- a/ppapi/proxy/printing_resource.cc
+++ b/ppapi/proxy/printing_resource.cc
@@ -4,6 +4,7 @@
 
 #include "ppapi/proxy/printing_resource.h"
 
+#include "base/bind.h"
 #include "ipc/ipc_message.h"
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/proxy/dispatch_reply_message.h"
@@ -12,10 +13,8 @@
 namespace ppapi {
 namespace proxy {
 
-PrintingResource::PrintingResource(Connection connection,
-                                   PP_Instance instance)
-    : PluginResource(connection, instance),
-      print_settings_(NULL) {
+PrintingResource::PrintingResource(Connection connection, PP_Instance instance)
+    : PluginResource(connection, instance) {
 }
 
 PrintingResource::~PrintingResource() {
@@ -31,39 +30,26 @@ int32_t PrintingResource::GetDefaultPrintSettings(
   if (!print_settings)
     return PP_ERROR_BADARGUMENT;
 
-  if (TrackedCallback::IsPending(callback_))
-    return PP_ERROR_INPROGRESS;
-
   if (!sent_create_to_browser())
     SendCreateToBrowser(PpapiHostMsg_Printing_Create());
 
-  DCHECK(!print_settings_);
-  print_settings_ = print_settings;
-  callback_ = callback;
-
-  CallBrowser(PpapiHostMsg_Printing_GetDefaultPrintSettings());
+  CallBrowser<PpapiPluginMsg_Printing_GetDefaultPrintSettingsReply>(
+      PpapiHostMsg_Printing_GetDefaultPrintSettings(),
+      base::Bind(&PrintingResource::OnPluginMsgGetDefaultPrintSettingsReply,
+          this, print_settings, callback));
   return PP_OK_COMPLETIONPENDING;
 }
 
-void PrintingResource::OnReplyReceived(
-    const ResourceMessageReplyParams& params,
-    const IPC::Message& msg) {
-  IPC_BEGIN_MESSAGE_MAP(PrintingResource, msg)
-    PPAPI_DISPATCH_RESOURCE_REPLY(
-        PpapiPluginMsg_Printing_GetDefaultPrintSettingsReply,
-        OnPluginMsgGetDefaultPrintSettingsReply)
-  IPC_END_MESSAGE_MAP()
-}
-
 void PrintingResource::OnPluginMsgGetDefaultPrintSettingsReply(
+    PP_PrintSettings_Dev* settings_out,
+    scoped_refptr<TrackedCallback> callback,
     const ResourceMessageReplyParams& params,
     const PP_PrintSettings_Dev& settings) {
   if (params.result() == PP_OK)
-    *print_settings_ = settings;
-  print_settings_ = NULL;
+    *settings_out = settings;
 
   // Notify the plugin of the new data.
-  TrackedCallback::ClearAndRun(&callback_, params.result());
+  TrackedCallback::ClearAndRun(&callback, params.result());
   // DANGER: May delete |this|!
 }