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() {
+  static bool checked_interface(false);

[brettw, 2011/03/22 21:39:06]

This won't work since there can be many PluginInstances for different plugins
that may support different interfaces. Just put this on the class.

I'm less concerned about find and zoom since these are instantiated by unusual
user actions. Potentially postMessage might be called a lot by script.

[dmichael(do not use this one), 2011/03/22 21:59:01]

Of course, thanks for catching that.
I tend to think people won't bother writing JS that calls postMessage on plugins
that don't support it, since presumably they know what plugin they are
developing for. But it's not a big deal to me; it's easy to optimize for.

+  if (!checked_interface) {
+    checked_interface = true;
+    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