Fix crash bug of IME extension API.

chromeos/dbus/ibus/ibus_engine_service.cc

 // 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.
 
 #include "chromeos/dbus/ibus/ibus_engine_service.h"
 
 #include <string>
 #include "base/bind.h"
 #include "base/callback.h"
 #include "chromeos/dbus/ibus/ibus_constants.h"
 #include "chromeos/dbus/ibus/ibus_lookup_table.h"
 #include "chromeos/dbus/ibus/ibus_property.h"
 #include "chromeos/dbus/ibus/ibus_text.h"
 #include "dbus/bus.h"
 #include "dbus/exported_object.h"
 #include "dbus/message.h"
 #include "dbus/object_path.h"
 #include "dbus/object_proxy.h"
 
 namespace chromeos {
 
 class IBusEngineServiceImpl : public IBusEngineService {
  public:
   IBusEngineServiceImpl(dbus::Bus* bus,
                         const dbus::ObjectPath& object_path)
       : bus_(bus),
+        engine_handler_(NULL),
         object_path_(object_path),
         weak_ptr_factory_(this) {
     exported_object_ = bus->GetExportedObject(object_path_);
 
     exported_object_->ExportMethod(
         ibus::engine::kServiceInterface,
         ibus::engine::kFocusInMethod,
         base::Bind(&IBusEngineServiceImpl::FocusIn,
                    weak_ptr_factory_.GetWeakPtr()),
         base::Bind(&IBusEngineServiceImpl::OnMethodExported,
@@ skipping 86 matching lines @@
                    weak_ptr_factory_.GetWeakPtr()),
         base::Bind(&IBusEngineServiceImpl::OnMethodExported,
                    weak_ptr_factory_.GetWeakPtr()));
   }
 
   virtual ~IBusEngineServiceImpl() {
     bus_->UnregisterExportedObject(object_path_);
   }
 
   // IBusEngineService override.
-  virtual void Initialize(IBusEngineHandlerInterface* handler) OVERRIDE {
-    if (engine_handler_.get() == NULL) {
-      engine_handler_.reset(handler);
-    } else {
-      LOG(ERROR) << "Already initialized.";
-    }
+  virtual void SetEngine(IBusEngineHandlerInterface* handler) OVERRIDE {
+    DVLOG_IF(1, engine_handler_ != NULL) << "Replace engine.";
+    engine_handler_ = handler;
   }
 
   // IBusEngineService override.
+  virtual void UnsetEngine() OVERRIDE {
+    LOG_IF(ERROR, engine_handler_ == NULL) << "There is no engine.";
+    engine_handler_ = NULL;
+  }
+
+  // IBusEngineService override.
   virtual void RegisterProperties(
       const ibus::IBusPropertyList& property_list) OVERRIDE {
     dbus::Signal signal(ibus::engine::kServiceInterface,
                         ibus::engine::kRegisterPropertiesSignal);
     dbus::MessageWriter writer(&signal);
     AppendIBusPropertyList(property_list, &writer);
     exported_object_->SendSignal(&signal);
   }
 
   // IBusEngineService override.
@@ skipping 66 matching lines @@
                         ibus::engine::kCommitTextSignal);
     dbus::MessageWriter writer(&signal);
     ibus::AppendStringAsIBusText(text, &writer);
     exported_object_->SendSignal(&signal);
   }
 
  private:
   // Handles FocusIn method call from ibus-daemon.
   void FocusIn(dbus::MethodCall* method_call,
                dbus::ExportedObject::ResponseSender response_sender) {
-    DCHECK(engine_handler_.get());
+    if (engine_handler_ == NULL)
+      return;
     engine_handler_->FocusIn();
     dbus::Response* response = dbus::Response::FromMethodCall(method_call);
     response_sender.Run(response);
   }
 
   // Handles FocusOut method call from ibus-daemon.
   void FocusOut(dbus::MethodCall* method_call,
                 dbus::ExportedObject::ResponseSender response_sender) {
-    DCHECK(engine_handler_.get());
+    if (engine_handler_ == NULL)
+      return;
     engine_handler_->FocusOut();
     dbus::Response* response = dbus::Response::FromMethodCall(method_call);
     response_sender.Run(response);
   }
 
   // Handles Enable method call from ibus-daemon.
   void Enable(dbus::MethodCall* method_call,
               dbus::ExportedObject::ResponseSender response_sender) {
-    DCHECK(engine_handler_.get());
+    if (engine_handler_ == NULL)
+      return;
     engine_handler_->Enable();
     dbus::Response* response = dbus::Response::FromMethodCall(method_call);
     response_sender.Run(response);
   }
 
   // Handles Disable method call from ibus-daemon.
   void Disable(dbus::MethodCall* method_call,
                dbus::ExportedObject::ResponseSender response_sender) {
-    DCHECK(engine_handler_.get());
+    if (engine_handler_ == NULL)
+      return;
     engine_handler_->Disable();
     dbus::Response* response = dbus::Response::FromMethodCall(method_call);
     response_sender.Run(response);
   }
 
   // Handles PropertyActivate method call from ibus-daemon.
   void PropertyActivate(dbus::MethodCall* method_call,
                         dbus::ExportedObject::ResponseSender response_sender) {
+    if (engine_handler_ == NULL)
+      return;
     dbus::MessageReader reader(method_call);
     std::string property_name;
     if (!reader.PopString(&property_name)) {
       LOG(WARNING) << "PropertyActivate called with incorrect parameters: "
                    << method_call->ToString();
       return;
     }
     uint32 property_state = 0;
     if (!reader.PopUint32(&property_state)) {
       LOG(WARNING) << "PropertyActivate called with incorrect parameters: "
                    << method_call->ToString();
       return;
     }
-    DCHECK(engine_handler_.get());
     engine_handler_->PropertyActivate(
         property_name,
         static_cast<IBusEngineHandlerInterface::IBusPropertyState>(
             property_state));
     dbus::Response* response = dbus::Response::FromMethodCall(method_call);
     response_sender.Run(response);
   }
 
   // Handles PropertyShow method call from ibus-daemon.
   void PropertyShow(dbus::MethodCall* method_call,
                     dbus::ExportedObject::ResponseSender response_sender) {
+    if (engine_handler_ == NULL)
+      return;
     dbus::MessageReader reader(method_call);
     std::string property_name;
     if (!reader.PopString(&property_name)) {
       LOG(WARNING) << "PropertyShow called with incorrect parameters: "
                    << method_call->ToString();
       return;
     }
-    DCHECK(engine_handler_.get());
     engine_handler_->PropertyShow(property_name);
     dbus::Response* response = dbus::Response::FromMethodCall(method_call);
     response_sender.Run(response);
   }
 
   // Handles PropertyHide method call from ibus-daemon.
   void PropertyHide(dbus::MethodCall* method_call,
                     dbus::ExportedObject::ResponseSender response_sender) {
+    if (engine_handler_ == NULL)
+      return;
     dbus::MessageReader reader(method_call);
     std::string property_name;
     if (!reader.PopString(&property_name)) {
       LOG(WARNING) << "PropertyHide called with incorrect parameters: "
                    << method_call->ToString();
       return;
     }
-    DCHECK(engine_handler_.get());
     engine_handler_->PropertyHide(property_name);
     dbus::Response* response = dbus::Response::FromMethodCall(method_call);
     response_sender.Run(response);
   }
 
   // Handles SetCapability method call from ibus-daemon.
   void SetCapability(dbus::MethodCall* method_call,
                      dbus::ExportedObject::ResponseSender response_sender) {
+    if (engine_handler_ == NULL)
+      return;
     dbus::MessageReader reader(method_call);
     uint32 capability = 0;
     if (!reader.PopUint32(&capability)) {
       LOG(WARNING) << "SetCapability called with incorrect parameters: "
                    << method_call->ToString();
       return;
     }
-    DCHECK(engine_handler_.get());
     engine_handler_->SetCapability(
         static_cast<IBusEngineHandlerInterface::IBusCapability>(capability));
     dbus::Response* response = dbus::Response::FromMethodCall(method_call);
     response_sender.Run(response);
   }
 
   void Reset(dbus::MethodCall* method_call,
              dbus::ExportedObject::ResponseSender response_sender) {
-    DCHECK(engine_handler_.get());
+    if (engine_handler_ == NULL)
+      return;
     engine_handler_->Reset();
     dbus::Response* response = dbus::Response::FromMethodCall(method_call);
     response_sender.Run(response);
   }
 
   // Handles ProcessKeyEvent method call from ibus-daemon.
   void ProcessKeyEvent(dbus::MethodCall* method_call,
                        dbus::ExportedObject::ResponseSender response_sender) {
+    if (engine_handler_ == NULL)
+      return;
     dbus::MessageReader reader(method_call);
     uint32 keysym = 0;
     if (!reader.PopUint32(&keysym)) {
       LOG(WARNING) << "ProcessKeyEvent called with incorrect parameters: "
                    << method_call->ToString();
       return;
     }
     uint32 keycode = 0;
     if (!reader.PopUint32(&keycode)) {
       LOG(WARNING) << "ProcessKeyEvent called with incorrect parameters: "
                    << method_call->ToString();
       return;
     }
     uint32 state = 0;
     if (!reader.PopUint32(&state)) {
       LOG(WARNING) << "ProcessKeyEvent called with incorrect parameters: "
                    << method_call->ToString();
       return;
     }
-    DCHECK(engine_handler_.get());
     engine_handler_->ProcessKeyEvent(
         keysym, keycode, state,
         base::Bind(&IBusEngineServiceImpl::KeyEventDone,
                    weak_ptr_factory_.GetWeakPtr(),
                    base::Unretained(
                        dbus::Response::FromMethodCall(method_call)),
                    response_sender));
   }
 
   void KeyEventDone(dbus::Response* response,
                     const dbus::ExportedObject::ResponseSender& response_sender,
                     bool consume) {
+    if (engine_handler_ == NULL)
+      return;
     dbus::MessageWriter writer(response);
     writer.AppendBool(consume);
     response_sender.Run(response);
   }
 
   // Handles CandidateClicked method call from ibus-daemon.
   void CandidateClicked(dbus::MethodCall* method_call,
                         dbus::ExportedObject::ResponseSender response_sender) {
+    if (engine_handler_ == NULL)
+      return;
     dbus::MessageReader reader(method_call);
     uint32 index = 0;
     if (!reader.PopUint32(&index)) {
       LOG(WARNING) << "CandidateClicked called with incorrect parameters: "
                    << method_call->ToString();
       return;
     }
     uint32 button = 0;
     if (!reader.PopUint32(&button)) {
       LOG(WARNING) << "CandidateClicked called with incorrect parameters: "
                    << method_call->ToString();
       return;
     }
     uint32 state = 0;
     if (!reader.PopUint32(&state)) {
       LOG(WARNING) << "CandidateClicked called with incorrect parameters: "
                    << method_call->ToString();
       return;
     }
-    DCHECK(engine_handler_.get());
     engine_handler_->CandidateClicked(
         index,
         static_cast<IBusEngineHandlerInterface::IBusMouseButton>(button),
         state);
     dbus::Response* response = dbus::Response::FromMethodCall(method_call);
     response_sender.Run(response);
   }
 
   // Handles SetSurroundingText method call from ibus-daemon.
   void SetSurroundingText(
       dbus::MethodCall* method_call,
       dbus::ExportedObject::ResponseSender response_sender) {
+    if (engine_handler_ == NULL)
+      return;
     dbus::MessageReader reader(method_call);
     std::string text;
     if (!reader.PopString(&text)) {
       LOG(WARNING) << "SetSurroundingText called with incorrect parameters: "
                    << method_call->ToString();
       return;
     }
     uint32 cursor_pos = 0;
     if (!reader.PopUint32(&cursor_pos)) {
       LOG(WARNING) << "CandidateClicked called with incorrect parameters: "
                    << method_call->ToString();
       return;
     }
     uint32 anchor_pos = 0;
     if (!reader.PopUint32(&anchor_pos)) {
       LOG(WARNING) << "CandidateClicked called with incorrect parameters: "
                    << method_call->ToString();
       return;
     }
 
-    DCHECK(engine_handler_.get());
     engine_handler_->SetSurroundingText(text, cursor_pos, anchor_pos);
     dbus::Response* response = dbus::Response::FromMethodCall(method_call);
     response_sender.Run(response);
   }
 
   // Called when the method call is exported.
   void OnMethodExported(const std::string& interface_name,
                         const std::string& method_name,
                         bool success) {
     LOG_IF(WARNING, !success) << "Failed to export "
                               << interface_name << "." << method_name;
   }
 
   // D-Bus bus object used for unregistering exported methods in dtor.
   dbus::Bus* bus_;
 
   // All incoming method calls are passed on to the |engine_handler_|.
-  scoped_ptr<IBusEngineHandlerInterface> engine_handler_;
+  IBusEngineHandlerInterface* engine_handler_;
 
   dbus::ObjectPath object_path_;
   scoped_refptr<dbus::ExportedObject> exported_object_;
   base::WeakPtrFactory<IBusEngineServiceImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(IBusEngineServiceImpl);
 };
 
 class IBusEngineServiceStubImpl : public IBusEngineService {
  public:
   IBusEngineServiceStubImpl() {}
   virtual ~IBusEngineServiceStubImpl() {}
   // IBusEngineService overrides.
-  virtual void Initialize(IBusEngineHandlerInterface* handler) OVERRIDE {}
+  virtual void SetEngine(IBusEngineHandlerInterface* handler) OVERRIDE {}
+  virtual void UnsetEngine() OVERRIDE {}
   virtual void RegisterProperties(
       const ibus::IBusPropertyList& property_list) OVERRIDE {}
   virtual void UpdatePreedit(const ibus::IBusText& ibus_text,
                              uint32 cursor_pos,
                              bool is_visible,
                              IBusEnginePreeditFocusOutMode mode) OVERRIDE {}
   virtual void UpdateAuxiliaryText(const ibus::IBusText& ibus_text,
                                    bool is_visible) OVERRIDE {}
   virtual void UpdateLookupTable(const ibus::IBusLookupTable& lookup_table,
                                  bool is_visible) OVERRIDE {}
@@ skipping 18 matching lines @@
     DBusClientImplementationType type,
     dbus::Bus* bus,
     const dbus::ObjectPath& object_path) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
     return new IBusEngineServiceImpl(bus, object_path);
   else
     return new IBusEngineServiceStubImpl();
 }
 
 }  // namespace chromeos