Moved code implementing message-only windows to a dedicated class (Windows only).

remoting/host/local_input_monitor_win.cc

Index: remoting/host/local_input_monitor_win.cc
diff --git a/remoting/host/local_input_monitor_win.cc b/remoting/host/local_input_monitor_win.cc
index 28deebc030ed561d2daebdb963c2a9e2782ec399..454dd759ad642bc14294da22147877409c92b576 100644
--- a/remoting/host/local_input_monitor_win.cc
+++ b/remoting/host/local_input_monitor_win.cc
@@ -11,8 +11,8 @@
 #include "base/single_thread_task_runner.h"
 #include "base/stringprintf.h"
 #include "base/threading/non_thread_safe.h"
-#include "base/win/wrapped_window_proc.h"
 #include "remoting/host/client_session_control.h"
+#include "remoting/host/win/message_window.h"
 #include "third_party/skia/include/core/SkPoint.h"
 
 namespace remoting {
@@ -36,7 +36,8 @@ class LocalInputMonitorWin : public base::NonThreadSafe,
 
  private:
   // The actual implementation resides in LocalInputMonitorWin::Core class.
-  class Core : public base::RefCountedThreadSafe<Core> {
+  class Core : public base::RefCountedThreadSafe<Core>,
+               public win::MessageWindow::Delegate {
    public:
     Core(scoped_refptr<base::SingleThreadTaskRunner> caller_task_runner,
          scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner,
@@ -52,15 +53,15 @@ class LocalInputMonitorWin : public base::NonThreadSafe,
     void StartOnUiThread();
     void StopOnUiThread();
 
-    // Handles WM_CREATE messages.
-    LRESULT OnCreate(HWND hwnd);
+    // Enables |window_| to receive the raw input.
+    void EnableRawInput();
 
     // Handles WM_INPUT messages.
     LRESULT OnInput(HRAWINPUT input_handle);
 
-    // Window procedure invoked by the OS to process window messages.
-    static LRESULT CALLBACK WindowProc(HWND hwnd, UINT message,
-                                       WPARAM wparam, LPARAM lparam);
+    // win::MessageWindow::Delegate interface.
+    virtual bool HandleMessage(UINT message, WPARAM wparam, LPARAM lparam,
+                               LRESULT* result) OVERRIDE;
 
     // Task runner on which public methods of this class must be called.
     scoped_refptr<base::SingleThreadTaskRunner> caller_task_runner_;
@@ -68,14 +69,8 @@ class LocalInputMonitorWin : public base::NonThreadSafe,
     // Task runner on which |window_| is created.
     scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner_;
 
-    // Atom representing the input window class.
-    ATOM atom_;
-
-    // Instance of the module containing the window procedure.
-    HINSTANCE instance_;
-
-    // Handle of the input window.
-    HWND window_;
+    // Used to receive raw input.
+    scoped_ptr<win::MessageWindow> window_;
 
     // Points to the object receiving mouse event notifications.
     base::WeakPtr<ClientSessionControl> client_session_control_;
@@ -108,9 +103,6 @@ LocalInputMonitorWin::Core::Core(
     base::WeakPtr<ClientSessionControl> client_session_control)
     : caller_task_runner_(caller_task_runner),
       ui_task_runner_(ui_task_runner),
-      atom_(0),
-      instance_(NULL),
-      window_(NULL),
       client_session_control_(client_session_control) {
   DCHECK(client_session_control_);
 }
@@ -129,68 +121,63 @@ void LocalInputMonitorWin::Core::Stop() {
 }
 
 LocalInputMonitorWin::Core::~Core() {
-  DCHECK(!atom_);
-  DCHECK(!instance_);
   DCHECK(!window_);
 }
 
 void LocalInputMonitorWin::Core::StartOnUiThread() {
   DCHECK(ui_task_runner_->BelongsToCurrentThread());
 
-  // Create a window for receiving raw input.
-  string16 window_class_name = base::StringPrintf(kWindowClassFormat, this);
-  WNDCLASSEX window_class;
-  base::win::InitializeWindowClass(
-      window_class_name.c_str(),
-      &base::win::WrappedWindowProc<WindowProc>,
-      0, 0, 0, NULL, NULL, NULL, NULL, NULL,
-      &window_class);
-  instance_ = window_class.hInstance;
-  atom_ = RegisterClassEx(&window_class);
-  if (atom_ == 0) {
-    LOG_GETLASTERROR(ERROR)
-        << "Failed to register the window class '" << window_class_name << "'";
-    return;
-  }
-
-  window_ = CreateWindow(MAKEINTATOM(atom_), 0, 0, 0, 0, 0, 0, HWND_MESSAGE, 0,
-                         instance_, this);
-  if (window_ == NULL) {
+  window_.reset(new win::MessageWindow());
+  if (!window_->Create(this)) {
     LOG_GETLASTERROR(ERROR) << "Failed to create the raw input window";
-    return;
+
+    // If the local input cannot be monitored, the remote user can take over
+    // the session. Disconnect the session now to prevent this.
+    caller_task_runner_->PostTask(
+        FROM_HERE, base::Bind(&ClientSessionControl::DisconnectSession,
+                              client_session_control_));
   }
 }
 
 void LocalInputMonitorWin::Core::StopOnUiThread() {
   DCHECK(ui_task_runner_->BelongsToCurrentThread());
 
-  if (window_ != NULL) {
-    DestroyWindow(window_);
-    window_ = NULL;
-  }
+  // Stop receiving  raw mouse input.
+  if (window_ && window_->hwnd()) {
+    RAWINPUTDEVICE device = {0};
+    device.dwFlags = RIDEV_REMOVE;
+    device.usUsagePage = kGenericDesktopPage;
+    device.usUsage = kMouseUsage;
+    device.hwndTarget = window_->hwnd();
 
-  if (atom_ != 0) {
-    UnregisterClass(MAKEINTATOM(atom_), instance_);
-    atom_ = 0;
-    instance_ = NULL;
+    // The error is harmless, ignore it.
+    RegisterRawInputDevices(&device, 1, sizeof(device));
   }
+
+  window_.reset();
 }
 
-LRESULT LocalInputMonitorWin::Core::OnCreate(HWND hwnd) {
+void LocalInputMonitorWin::Core::EnableRawInput() {
   DCHECK(ui_task_runner_->BelongsToCurrentThread());
 
-  // Register to receive raw mouse input.
-  RAWINPUTDEVICE device = {0};
-  device.dwFlags = RIDEV_INPUTSINK;
-  device.usUsagePage = kGenericDesktopPage;
-  device.usUsage = kMouseUsage;
-  device.hwndTarget = hwnd;
-  if (!RegisterRawInputDevices(&device, 1, sizeof(device))) {
+  if (window_ && window_->hwnd()) {
+    // Register to receive raw mouse input.
+    RAWINPUTDEVICE device = {0};
+    device.dwFlags = RIDEV_INPUTSINK;
+    device.usUsagePage = kGenericDesktopPage;
+    device.usUsage = kMouseUsage;
+    device.hwndTarget = window_->hwnd();
+    if (RegisterRawInputDevices(&device, 1, sizeof(device)))
+      return;
+
     LOG_GETLASTERROR(ERROR) << "RegisterRawInputDevices() failed";
-    return -1;
   }
 
-  return 0;
+  // If the local input cannot be monitored, the remote user can take over
+  // the session. Disconnect the session now to prevent this.
+  caller_task_runner_->PostTask(
+      FROM_HERE, base::Bind(&ClientSessionControl::DisconnectSession,
+                            client_session_control_));
 }
 
 LRESULT LocalInputMonitorWin::Core::OnInput(HRAWINPUT input_handle) {
@@ -240,28 +227,23 @@ LRESULT LocalInputMonitorWin::Core::OnInput(HRAWINPUT input_handle) {
   return DefRawInputProc(&input, 1, sizeof(RAWINPUTHEADER));
 }
 
-// static
-LRESULT CALLBACK LocalInputMonitorWin::Core::WindowProc(
-    HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam) {
-  // Store |this| to the window's user data.
-  if (message == WM_CREATE) {
-    CREATESTRUCT* cs = reinterpret_cast<CREATESTRUCT*>(lparam);
-    SetLastError(ERROR_SUCCESS);
-    LONG_PTR result = SetWindowLongPtr(
-        hwnd, GWLP_USERDATA, reinterpret_cast<LONG_PTR>(cs->lpCreateParams));
-    CHECK(result != 0 || GetLastError() == ERROR_SUCCESS);
-  }
-
-  Core* self = reinterpret_cast<Core*>(GetWindowLongPtr(hwnd, GWLP_USERDATA));
+bool LocalInputMonitorWin::Core::HandleMessage(
+    UINT message, WPARAM wparam, LPARAM lparam, LRESULT* result) {
   switch (message) {
     case WM_CREATE:
-      return self->OnCreate(hwnd);
+      // |window_->hwnd()| is not available yet. Enable raw mouse input once

[dcaiafa, 2013/03/28 23:25:35]

Refer to my comment on MessageWindow. I think hwnd() should be available on
WM_CREATE. If I were writing a Delegate, I'd certainly expect it so.

[alexeypa (please no reviews), 2013/03/29 16:57:01]

Done.

+      // the window is fully created.
+      ui_task_runner_->PostTask(FROM_HERE,
+                                base::Bind(&Core::EnableRawInput, this));
+      *result = 0;
+      return true;
 
     case WM_INPUT:
-      return self->OnInput(reinterpret_cast<HRAWINPUT>(lparam));
+      *result = OnInput(reinterpret_cast<HRAWINPUT>(lparam));
+      return true;
 
     default:
-      return DefWindowProc(hwnd, message, wparam, lparam);
+      return false;
   }
 }