[Chromoting] Add a simple Windows app that registers and starts a host.

remoting/host/setup/win/host_configurer_window.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 "remoting/host/setup/win/host_configurer_window.h"
+
+#include <atlbase.h>
+#include <atlstr.h>
+#include <atlwin.h>
+#include <windows.h>
+
+#include "base/run_loop.h"
+#include "base/string16.h"
+#include "remoting/host/setup/win/load_string_from_resource.h"
+#include "remoting/host/setup/win/start_host_window.h"
+
+namespace remoting {
+
+HostConfigurerWindow::HostConfigurerWindow(
+    scoped_refptr<net::URLRequestContextGetter> url_request_context_getter,
+    scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner,
+    base::Closure quit)
+    : url_request_context_getter_(url_request_context_getter),
+      ui_task_runner_(ui_task_runner),
+      quit_(quit) {
+}
+
+void HostConfigurerWindow::OnCancel(UINT code, int id, HWND control) {
+  Finish();
+}
+
+void HostConfigurerWindow::OnClose() {
+  Finish();
+}
+
+LRESULT HostConfigurerWindow::OnInitDialog(HWND wparam, LPARAM lparam) {
+  SetWindowText(LoadStringFromResource(IDS_TITLE));
+  GetDlgItem(IDC_CHANGE_PIN).EnableWindow(FALSE);

[alexeypa (please no reviews), 2012/10/15 18:48:55]

nit: I'm not fun of zillions of UI calls none of them checking the return value.
I believe the same rules should apply to UI calls as to any other API calls. The
problem is that when the return value is ignored the reader has to read the code
as if there are two branches instead of one. The code following the call is
executed both in case of success and failure. The reader has to understand why
it is safe. An explicit condition statement make the error handling logic more
apparent.

Here for instance the first question that I have is why is it safe ti ignore the
error? It is followed by what does the error mean? Can an attacker exploit this
somehow?

I believe each case of ignoring the result should be explained in the comments,
explicitly stating why it is safe.

It is OK to do it in a follow up CL.

[simonmorris, 2012/10/15 21:20:14]

I've added comments indicating that it's acceptable for these calls to fail.

+  GetDlgItem(IDC_STOP_HOST).EnableWindow(FALSE);
+  PositionWindow();
+  return TRUE;
+}
+
+void HostConfigurerWindow::OnOk(UINT code, int id, HWND control) {
+  Finish();
+}
+
+void HostConfigurerWindow::OnStartHost(UINT code, int id, HWND control) {
+  StartHostWindow start_host_window(url_request_context_getter_,
+                                    ui_task_runner_);
+  start_host_window.DoModal();
+}
+
+void HostConfigurerWindow::PositionWindow() {
+  // Get the window dimensions.
+  RECT rect;
+  if (!GetWindowRect(&rect)) {
+    return;
+  }
+
+  // Position against the owner window unless it is minimized or invisible.
+  HWND owner = ::GetWindow(m_hWnd, GW_OWNER);
+  if (owner != NULL) {
+    DWORD style = ::GetWindowLong(owner, GWL_STYLE);
+    if ((style & WS_MINIMIZE) != 0 || (style & WS_VISIBLE) == 0) {
+      owner = NULL;
+    }
+  }
+
+  // Make sure that the window will not end up split by a monitor's boundary.
+  RECT area_rect;
+  if (!::SystemParametersInfo(SPI_GETWORKAREA, NULL, &area_rect, NULL)) {
+    return;
+  }
+
+  // On a multi-monitor system use the monitor where the owner window is shown.
+  RECT owner_rect = area_rect;
+  if (owner != NULL && ::GetWindowRect(owner, &owner_rect)) {
+    HMONITOR monitor = ::MonitorFromRect(&owner_rect, MONITOR_DEFAULTTONEAREST);
+    if (monitor != NULL) {
+      MONITORINFO monitor_info = {0};
+      monitor_info.cbSize = sizeof(monitor_info);
+      if (::GetMonitorInfo(monitor, &monitor_info)) {
+        area_rect = monitor_info.rcWork;
+      }
+    }
+  }
+
+  LONG width = rect.right - rect.left;
+  LONG height = rect.bottom - rect.top;
+  // Avoid the center of the owner rectangle, because the host controller will
+  // put its confirmation window there.
+  LONG x = (3 * owner_rect.left + owner_rect.right) / 4 - (width / 2);
+  LONG y = (3 * owner_rect.top + owner_rect.bottom) / 4 - (height / 2);
+
+  x = std::max(x, area_rect.left);
+  x = std::min(x, area_rect.right - width);
+  y = std::max(y, area_rect.top);
+  y = std::min(y, area_rect.bottom - width);
+
+  SetWindowPos(NULL, x, y, -1, -1, SWP_NOSIZE | SWP_NOZORDER | SWP_NOACTIVATE);
+}
+
+void HostConfigurerWindow::Finish() {
+  DestroyWindow();

[alexeypa (please no reviews), 2012/10/15 18:48:55]

DestroyWindow() should be called on the same thread that was used to create the
window, i.e. the UI thread. Is it possible that Finish() will be called on a
different thread? If so - just to the IU thread first.

[simonmorris, 2012/10/15 21:20:14]

Done.

+  ui_task_runner_->PostTask(FROM_HERE, quit_);

[alexeypa (please no reviews), 2012/10/15 18:48:55]

This function is probably running on the UI thread. Do you have to post |quit_|?
Can you call it directly instead?

[simonmorris, 2012/10/15 21:20:14]

Done.

+}
+
+}  // namespace remoting