A proposal and implementation for an initial postMessage interface. These in...

webkit/plugins/ppapi/ppapi_plugin_instance.cc

 // Copyright (c) 2011 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.
 
 #include "webkit/plugins/ppapi/ppapi_plugin_instance.h"
 
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "base/scoped_ptr.h"
 #include "base/utf_string_conversions.h"
 #include "ppapi/c/dev/ppb_find_dev.h"
 #include "ppapi/c/dev/ppb_fullscreen_dev.h"
+#include "ppapi/c/dev/ppb_messaging_dev.h"
 #include "ppapi/c/dev/ppb_zoom_dev.h"
 #include "ppapi/c/dev/ppp_find_dev.h"
+#include "ppapi/c/dev/ppp_messaging_dev.h"
 #include "ppapi/c/dev/ppp_selection_dev.h"
 #include "ppapi/c/dev/ppp_zoom_dev.h"
 #include "ppapi/c/pp_input_event.h"
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_rect.h"
 #include "ppapi/c/pp_resource.h"
 #include "ppapi/c/pp_var.h"
 #include "ppapi/c/ppb_core.h"
 #include "ppapi/c/ppb_instance.h"
 #include "ppapi/c/ppp_instance.h"
 #include "printing/units.h"
 #include "skia/ext/vector_platform_device.h"
 #include "skia/ext/platform_canvas.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebBindings.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebCursorInfo.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebDocument.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebElement.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebInputEvent.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebPluginContainer.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebRect.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebString.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebURLRequest.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebView.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/skia_util.h"
 #include "webkit/plugins/ppapi/common.h"
 #include "webkit/plugins/ppapi/event_conversion.h"
 #include "webkit/plugins/ppapi/fullscreen_container.h"
+#include "webkit/plugins/ppapi/message_channel.h"
 #include "webkit/plugins/ppapi/plugin_delegate.h"
 #include "webkit/plugins/ppapi/plugin_module.h"
 #include "webkit/plugins/ppapi/plugin_object.h"
 #include "webkit/plugins/ppapi/ppb_buffer_impl.h"
 #include "webkit/plugins/ppapi/ppb_graphics_2d_impl.h"
 #include "webkit/plugins/ppapi/ppb_image_data_impl.h"
 #include "webkit/plugins/ppapi/ppb_surface_3d_impl.h"
 #include "webkit/plugins/ppapi/ppb_url_loader_impl.h"
 #include "webkit/plugins/ppapi/ppp_pdf.h"
 #include "webkit/plugins/ppapi/string.h"
@@ skipping 38 matching lines @@
 typedef bool (*RenderPDFPageToDCProc)(
     const unsigned char* pdf_buffer, int buffer_size, int page_number, HDC dc,
     int dpi_x, int dpi_y, int bounds_origin_x, int bounds_origin_y,
     int bounds_width, int bounds_height, bool fit_to_bounds,
     bool stretch_to_bounds, bool keep_aspect_ratio, bool center_in_bounds);
 #endif  // defined(OS_WIN)
 
 namespace {
 
 #define COMPILE_ASSERT_MATCHING_ENUM(webkit_name, np_name) \
-    COMPILE_ASSERT(int(WebCursorInfo::webkit_name) == int(np_name), \
+    COMPILE_ASSERT(static_cast<int>(WebCursorInfo::webkit_name) \
+                       == static_cast<int>(np_name), \
                    mismatching_enums)
 
 COMPILE_ASSERT_MATCHING_ENUM(TypePointer, PP_CURSORTYPE_POINTER);
 COMPILE_ASSERT_MATCHING_ENUM(TypeCross, PP_CURSORTYPE_CROSS);
 COMPILE_ASSERT_MATCHING_ENUM(TypeHand, PP_CURSORTYPE_HAND);
 COMPILE_ASSERT_MATCHING_ENUM(TypeIBeam, PP_CURSORTYPE_IBEAM);
 COMPILE_ASSERT_MATCHING_ENUM(TypeWait, PP_CURSORTYPE_WAIT);
 COMPILE_ASSERT_MATCHING_ENUM(TypeHelp, PP_CURSORTYPE_HELP);
 COMPILE_ASSERT_MATCHING_ENUM(TypeEastResize, PP_CURSORTYPE_EASTRESIZE);
 COMPILE_ASSERT_MATCHING_ENUM(TypeNorthResize, PP_CURSORTYPE_NORTHRESIZE);
@@ skipping 141 matching lines @@
 
 PP_Bool GetScreenSize(PP_Instance instance_id, PP_Size* size) {
   PluginInstance* instance = ResourceTracker::Get()->GetInstance(instance_id);
   if (!instance || !size)
     return PP_FALSE;
   gfx::Size screen_size = instance->delegate()->GetScreenSize();
   *size = PP_MakeSize(screen_size.width(), screen_size.height());
   return PP_TRUE;
 }
 
-
 const PPB_Fullscreen_Dev ppb_fullscreen = {
   &IsFullscreen,
   &SetFullscreen,
   &GetScreenSize
 };
 
+void PostMessage(PP_Instance instance_id, PP_Var message) {
+  PluginInstance* instance = ResourceTracker::Get()->GetInstance(instance_id);
+  if (!instance)
+    return;
+  instance->PostMessage(message);
+}
+
+const PPB_Messaging_Dev ppb_messaging = {
+  &PostMessage
+};
+
 void ZoomChanged(PP_Instance instance_id, double factor) {
   PluginInstance* instance = ResourceTracker::Get()->GetInstance(instance_id);
   if (!instance)
     return;
 
   // We only want to tell the page to change its zoom if the whole page is the
   // plugin.  If we're in an iframe, then don't do anything.
   if (!instance->IsFullPagePlugin())
     return;
 
@@ skipping 37 matching lines @@
     : delegate_(delegate),
       module_(module),
       instance_interface_(instance_interface),
       pp_instance_(0),
       container_(NULL),
       full_frame_(false),
       has_webkit_focus_(false),
       has_content_area_focus_(false),
       find_identifier_(-1),
       plugin_find_interface_(NULL),
+      plugin_messaging_interface_(NULL),
       plugin_pdf_interface_(NULL),
       plugin_selection_interface_(NULL),
       plugin_zoom_interface_(NULL),
 #if defined(OS_LINUX)
       canvas_(NULL),
 #endif  // defined(OS_LINUX)
       plugin_print_interface_(NULL),
       plugin_graphics_3d_interface_(NULL),
       always_on_top_(false),
       fullscreen_container_(NULL),
       fullscreen_(false),
+      message_channel_(NULL),
       sad_plugin_(NULL) {
   pp_instance_ = ResourceTracker::Get()->AddInstance(this);
 
   memset(&current_print_settings_, 0, sizeof(current_print_settings_));
   DCHECK(delegate);
   module_->InstanceCreated(this);
   delegate_->InstanceCreated(this);
+  message_channel_.reset(new MessageChannel(this));
 }
 
 PluginInstance::~PluginInstance() {
   // Free all the plugin objects. This will automatically clear the back-
   // pointer from the NPObject so WebKit can't call into the plugin any more.
   //
   // Swap out the set so we can delete from it (the objects will try to
   // unregister themselves inside the delete call).
   PluginObjectSet plugin_object_copy;
   live_plugin_objects_.swap(plugin_object_copy);
@@ skipping 19 matching lines @@
 const PPB_Find_Dev* PluginInstance::GetFindInterface() {
   return &ppb_find;
 }
 
 // static
 const PPB_Fullscreen_Dev* PluginInstance::GetFullscreenInterface() {
   return &ppb_fullscreen;
 }
 
 // static
+const PPB_Messaging_Dev* PluginInstance::GetMessagingInterface() {
+  return &ppb_messaging;
+}
+
+// static
 const PPB_Zoom_Dev* PluginInstance::GetZoomInterface() {
   return &ppb_zoom;
 }
 
 // NOTE: Any of these methods that calls into the plugin needs to take into
 // account that the plugin may use Var to remove the <embed> from the DOM, which
 // will make the WebPluginImpl drop its reference, usually the last one. If a
 // method needs to access a member of the instance after the call has returned,
 // then it needs to keep its own reference on the stack.
 
@@ skipping 201 matching lines @@
     try_catch.SetException("Exception caught");
     WebBindings::releaseVariantValue(&result);
     return PP_MakeUndefined();
   }
 
   PP_Var ret = Var::NPVariantToPPVar(this, &result);
   WebBindings::releaseVariantValue(&result);
   return ret;
 }
 
+void PluginInstance::PostMessage(PP_Var message) {
+  message_channel_->PostMessageToJavaScript(message);
+}
+
 void PluginInstance::Delete() {
   // Keep a reference on the stack. See NOTE above.
   scoped_refptr<PluginInstance> ref(this);
   instance_interface_->DidDestroy(pp_instance());
 
   if (fullscreen_container_) {
     fullscreen_container_->Destroy();
     fullscreen_container_ = NULL;
   }
   container_ = NULL;
@@ skipping 39 matching lines @@
   for (size_t i = 0; i < pp_events.size(); i++) {
     rv |= PPBoolToBool(instance_interface_->HandleInputEvent(pp_instance(),
                                                              &pp_events[i]));
   }
 
   if (cursor_.get())
     *cursor_info = *cursor_;
   return rv;
 }
 
+void PluginInstance::HandleMessage(PP_Var message) {
+  // Keep a reference on the stack. See NOTE above.
+  scoped_refptr<PluginInstance> ref(this);
+  if (!LoadMessagingInterface())
+    return;
+  plugin_messaging_interface_->HandleMessage(pp_instance(), message);
+}
+
 PP_Var PluginInstance::GetInstanceObject() {
   return instance_interface_->GetInstanceObject(pp_instance());
 }
 
 void PluginInstance::ViewChanged(const gfx::Rect& position,
                                  const gfx::Rect& clip) {
   fullscreen_ = (fullscreen_container_ != NULL);
   position_ = position;
 
   if (clip.IsEmpty()) {
@@ skipping 156 matching lines @@
 bool PluginInstance::LoadFindInterface() {
   if (!plugin_find_interface_) {
     plugin_find_interface_ =
         reinterpret_cast<const PPP_Find_Dev*>(module_->GetPluginInterface(
             PPP_FIND_DEV_INTERFACE));
   }
 
   return !!plugin_find_interface_;
 }
 
+bool PluginInstance::LoadMessagingInterface() {
+  if (!plugin_messaging_interface_) {

[brettw, 2011/03/22 05:59:11]

This will query the plugin every single time if it doesn't support the
interface. Do you think we should remember whether we've previously asked so we
can avoid re-querying if it returns NULL?

[dmichael(do not use this one), 2011/03/22 15:39:00]

I'm fine either way...  it only happens when the JS calls postMessage on a
plugin which doesn't support it;  I'm okay with exceptional cases being slow. 
And this is almost a straight copy of other functions.

But I took a stab at it anyway.  Are function-local static variables okay? 
Since all of this code already assumes it's only run on the main thread, it
should be fine;  I just feel dirty any time I use them.

Is this approach okay for you, and if so, do you want me to throw it in for
Find, Zoom, et al?

+    plugin_messaging_interface_ =
+        reinterpret_cast<const PPP_Messaging_Dev*>(module_->GetPluginInterface(
+            PPP_MESSAGING_DEV_INTERFACE));
+  }
+
+  return !!plugin_messaging_interface_;
+}
+
 bool PluginInstance::LoadPdfInterface() {
   if (!plugin_pdf_interface_) {
     plugin_pdf_interface_ =
         reinterpret_cast<const PPP_Pdf*>(module_->GetPluginInterface(
             PPP_PDF_INTERFACE));
   }
 
   return !!plugin_pdf_interface_;
 }
 
@@ skipping 514 matching lines @@
   return found->second;
 }
 
 bool PluginInstance::IsFullPagePlugin() const {
   WebFrame* frame = container()->element().document().frame();
   return frame->view()->mainFrame()->document().isPluginDocument();
 }
 
 }  // namespace ppapi
 }  // namespace webkit