// Copyright (c) 2006-2008 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 "chrome/common/win_util.h"

#include <atlbase.h>
#include <atlapp.h>
#include <commdlg.h>
#include <dwmapi.h>
#include <shellapi.h>
#include <shlobj.h>

#include "base/file_util.h"
#include "base/gfx/gdi_util.h"
#include "base/gfx/png_encoder.h"
#include "base/logging.h"
#include "base/registry.h"
#include "base/scoped_handle.h"
#include "base/string_util.h"
#include "base/win_util.h"
#include "chrome/common/l10n_util.h"
#include "net/base/mime_util.h"
#include "generated_resources.h"

// Ensure that we pick up this link library.
#pragma comment(lib, "dwmapi.lib")

namespace win_util {

namespace {

// Enforce visible dialog box.
UINT_PTR CALLBACK SaveAsDialogHook(HWND dialog, UINT message,
                                   WPARAM wparam, LPARAM lparam) {
  static const UINT kPrivateMessage = 0x2F3F;
  switch (message) {
    case WM_INITDIALOG: {
      // Do nothing here. Just post a message to defer actual processing.
      PostMessage(dialog, kPrivateMessage, 0, 0);
      return TRUE;
    }
    case kPrivateMessage: {
      // The dialog box is the parent of the current handle.
      HWND real_dialog = GetParent(dialog);

      // Retrieve the final size.
      RECT dialog_rect;
      GetWindowRect(real_dialog, &dialog_rect);

      // Verify that the upper left corner is visible.
      POINT point = { dialog_rect.left, dialog_rect.top };
      HMONITOR monitor1 = MonitorFromPoint(point, MONITOR_DEFAULTTONULL);
      point.x = dialog_rect.right;
      point.y = dialog_rect.bottom;

      // Verify that the lower right corner is visible.
      HMONITOR monitor2 = MonitorFromPoint(point, MONITOR_DEFAULTTONULL);
      if (monitor1 && monitor2)
        return 0;

      // Some part of the dialog box is not visible, fix it by moving is to the
      // client rect position of the browser window.
      HWND parent_window = GetParent(real_dialog);
      if (!parent_window)
        return 0;
      WINDOWINFO parent_info;
      parent_info.cbSize = sizeof(WINDOWINFO);
      GetWindowInfo(parent_window, &parent_info);
      SetWindowPos(real_dialog, NULL,
                   parent_info.rcClient.left,
                   parent_info.rcClient.top,
                   0, 0,  // Size.
                   SWP_NOACTIVATE | SWP_NOOWNERZORDER | SWP_NOSIZE |
                   SWP_NOZORDER);

      return 0;
    }
  }
  return 0;
}

}  // namespace

std::wstring FormatSystemTime(const SYSTEMTIME& time,
                              const std::wstring& format) {
  // If the format string is empty, just use the default format.
  LPCTSTR format_ptr = NULL;
  if (!format.empty())
    format_ptr = format.c_str();

  int buffer_size = GetTimeFormat(LOCALE_USER_DEFAULT, NULL, &time, format_ptr,
                                  NULL, 0);

  std::wstring output;
  GetTimeFormat(LOCALE_USER_DEFAULT, NULL, &time, format_ptr,
                WriteInto(&output, buffer_size), buffer_size);

  return output;
}

std::wstring FormatSystemDate(const SYSTEMTIME& date,
                              const std::wstring& format) {
  // If the format string is empty, just use the default format.
  LPCTSTR format_ptr = NULL;
  if (!format.empty())
    format_ptr = format.c_str();

  int buffer_size = GetDateFormat(LOCALE_USER_DEFAULT, NULL, &date, format_ptr,
                                  NULL, 0);

  std::wstring output;
  GetDateFormat(LOCALE_USER_DEFAULT, NULL, &date, format_ptr,
                WriteInto(&output, buffer_size), buffer_size);

  return output;
}

bool ConvertToLongPath(const std::wstring& short_path, std::wstring* long_path) {
  wchar_t long_path_buf[MAX_PATH];
  DWORD return_value = GetLongPathName(short_path.c_str(), long_path_buf,
                                       MAX_PATH);
  if (return_value != 0 && return_value < MAX_PATH) {
    *long_path = long_path_buf;
    return true;
  }

  return false;
}

bool IsDoubleClick(const POINT& origin,
                   const POINT& current,
                   DWORD elapsed_time) {
  // The CXDOUBLECLK and CYDOUBLECLK system metrics describe the width and
  // height of a rectangle around the origin position, inside of which clicks
  // within the double click time are considered double clicks.
  return (elapsed_time <= GetDoubleClickTime()) &&
      (abs(current.x - origin.x) <= (GetSystemMetrics(SM_CXDOUBLECLK) / 2)) &&
      (abs(current.y - origin.y) <= (GetSystemMetrics(SM_CYDOUBLECLK) / 2));
}

bool IsDrag(const POINT& origin, const POINT& current) {
  // The CXDRAG and CYDRAG system metrics describe the width and height of a
  // rectangle around the origin position, inside of which motion is not
  // considered a drag.
  return (abs(current.x - origin.x) > (GetSystemMetrics(SM_CXDRAG) / 2)) ||
         (abs(current.y - origin.y) > (GetSystemMetrics(SM_CYDRAG) / 2));
}

bool ShouldUseVistaFrame() {
  if (win_util::GetWinVersion() < win_util::WINVERSION_VISTA)
    return false;
  // If composition is not enabled, we behave like on XP.
  BOOL f;
  DwmIsCompositionEnabled(&f);
  return !!f;
}

void ShowItemInFolder(const std::wstring& full_path) {
  std::wstring dir = file_util::GetDirectoryFromPath(full_path);
  if (dir == L"" || !file_util::PathExists(full_path))
    return;

  // ParseDisplayName will fail if the directory is "C:", it must be "C:\\".
  FilePath dir_path(dir);
  file_util::EnsureEndsWithSeparator(&dir_path);
  dir = dir_path.value();

  typedef HRESULT (WINAPI *SHOpenFolderAndSelectItemsFuncPtr)(
              PCIDLIST_ABSOLUTE pidl_Folder,
              UINT cidl,
              PCUITEMID_CHILD_ARRAY pidls,
              DWORD flags);

  static SHOpenFolderAndSelectItemsFuncPtr open_folder_and_select_itemsPtr = NULL;
  static bool initialize_open_folder_proc = true;
  if (initialize_open_folder_proc) {
    initialize_open_folder_proc = false;
    // The SHOpenFolderAndSelectItems API is exposed by shell32 version 6
    // and does not exist in Win2K. We attempt to retrieve this function export
    // from shell32 and if it does not exist, we just invoke ShellExecute to
    // open the folder thus losing the functionality to select the item in
    // the process.
    HMODULE shell32_base = GetModuleHandle(L"shell32.dll");
    if (!shell32_base) {
      NOTREACHED();
      return;
    }
    open_folder_and_select_itemsPtr =
        reinterpret_cast<SHOpenFolderAndSelectItemsFuncPtr>
            (GetProcAddress(shell32_base, "SHOpenFolderAndSelectItems"));
  }
  if (!open_folder_and_select_itemsPtr) {
    ShellExecute(NULL, _T("open"), dir.c_str(), NULL, NULL, SW_SHOW);
    return;
  }

  CComPtr<IShellFolder> desktop;
  HRESULT hr = SHGetDesktopFolder(&desktop);
  if (FAILED(hr))
    return;

  CoMemReleaser<ITEMIDLIST> dir_item;
  hr = desktop->ParseDisplayName(NULL, NULL,
                                 const_cast<wchar_t *>(dir.c_str()),
                                 NULL, &dir_item, NULL);
  if (FAILED(hr))
    return;

  CoMemReleaser<ITEMIDLIST> file_item;
  hr = desktop->ParseDisplayName(NULL, NULL,
                                 const_cast<wchar_t *>(full_path.c_str()),
                                 NULL, &file_item, NULL);
  if (FAILED(hr))
    return;

  const ITEMIDLIST* highlight[] = {
    {file_item},
  };
  (*open_folder_and_select_itemsPtr)(dir_item, arraysize(highlight),
                                     highlight, NULL);
}

// Open an item via a shell execute command. Error code checking and casting
// explanation: http://msdn2.microsoft.com/en-us/library/ms647732.aspx
bool OpenItemViaShell(const FilePath& full_path, bool ask_for_app) {
  HINSTANCE h = ::ShellExecuteW(
      NULL, NULL, full_path.value().c_str(), NULL,
      full_path.DirName().value().c_str(), SW_SHOWNORMAL);

  LONG_PTR error = reinterpret_cast<LONG_PTR>(h);
  if (error > 32)
    return true;

  if ((error == SE_ERR_NOASSOC) && ask_for_app)
    return OpenItemWithExternalApp(full_path.value());

  return false;
}

bool OpenItemViaShellNoZoneCheck(const FilePath& full_path,
                                 bool ask_for_app) {
  SHELLEXECUTEINFO sei = { sizeof(sei) };
  sei.fMask = SEE_MASK_NOZONECHECKS | SEE_MASK_FLAG_DDEWAIT;
  sei.nShow = SW_SHOWNORMAL;
  sei.lpVerb = NULL;
  sei.lpFile = full_path.value().c_str();
  if (::ShellExecuteExW(&sei))
    return true;
  LONG_PTR error = reinterpret_cast<LONG_PTR>(sei.hInstApp);
  if ((error == SE_ERR_NOASSOC) && ask_for_app)
    return OpenItemWithExternalApp(full_path.value());
  return false;
}

// Show the Windows "Open With" dialog box to ask the user to pick an app to
// open the file with.
bool OpenItemWithExternalApp(const std::wstring& full_path) {
  SHELLEXECUTEINFO sei = { sizeof(sei) };
  sei.fMask = SEE_MASK_FLAG_DDEWAIT;
  sei.nShow = SW_SHOWNORMAL;
  sei.lpVerb = L"openas";
  sei.lpFile = full_path.c_str();
  return (TRUE == ::ShellExecuteExW(&sei));
}

// Get the file type description from the registry. This will be "Text Document"
// for .txt files, "JPEG Image" for .jpg files, etc. If the registry doesn't
// have an entry for the file type, we return false, true if the description was
// found. 'file_ext' must be in form ".txt".
static bool GetRegistryDescriptionFromExtension(const std::wstring& file_ext,
                                                std::wstring* reg_description) {
  DCHECK(reg_description);
  RegKey reg_ext(HKEY_CLASSES_ROOT, file_ext.c_str(), KEY_READ);
  std::wstring reg_app;
  if (reg_ext.ReadValue(NULL, &reg_app) && !reg_app.empty()) {
    RegKey reg_link(HKEY_CLASSES_ROOT, reg_app.c_str(), KEY_READ);
    if (reg_link.ReadValue(NULL, reg_description))
      return true;
  }
  return false;
}

// Set up a filter for a Save/Open dialog, which will consist of 'file_ext'
// file extension, 'ext_desc' as the text description of the 'file_ext' type,
// and (optionally) the default 'All Files' view. The purpose of the filter is
// to show only files of a particular type in a Windows Save/Open dialog box.
// The resulting filter is stored in 'buffer', which is a vector since multiple
// NULLs are embedded. The  filters created here are:
//   1. only files that have 'file_ext' as their extension
//   2. all files (only added if 'include_all_files' is true)
// Example:
//   file_ext: ".txt"
//   ext_desc: "Text Document"
//   returned (in buffer): "Text Document\0*.txt\0All Files\0*.*\0\0"
// This is painful to build, as you will soon see.
static void FormatFilterForExtension(const std::wstring& file_ext,
                                     const std::wstring& ext_desc,
                                     bool include_all_files,
                                     std::vector<wchar_t>* buffer) {
  DCHECK(buffer);

  // Force something reasonable to appear in the dialog box if there is no
  // description provided.
  if (file_ext.empty() || ext_desc.empty())
    include_all_files = true;

  size_t size;
  size_t offset = 0;
  const std::wstring all_ext = L"*.*";
  const std::wstring all_desc = l10n_util::GetString(IDS_SAVEAS_ALL_FILES);

  // Includes 2 internal NULLs + "*".
  const size_t ext_size = ext_desc.length() + file_ext.length() + 3;
  // Includes 2 internal NULLs.
  const size_t all_size = all_desc.length() + all_ext.length() + 2;
  // Includes double terminating NULL.
  const size_t buf_size = (!ext_desc.empty() ? ext_size : 0) +
                          (include_all_files ? all_size : 0) + 1;
  buffer->resize(buf_size);

  if (!file_ext.empty() && !ext_desc.empty()) {
    // Copy in the text description ("JPEG Image") + NULL.
    size = ext_desc.length() + 1;
    memcpy(&(*buffer)[offset], ext_desc.c_str(), size * sizeof(wchar_t));
    offset += size;

    // Copy in the file type ("*.jpg") + NULL.
    const std::wstring wildcard_ext = L"*" + file_ext;
    size = wildcard_ext.length() + 1;
    memcpy(&(*buffer)[offset], wildcard_ext.c_str(), size * sizeof(wchar_t));
    offset += size;
  }

  if (include_all_files) {
    // Copy in the default description ("All Files") + NULL.
    size = all_desc.length() + 1;
    memcpy(&(*buffer)[offset], all_desc.c_str(), size * sizeof(wchar_t));
    offset += size;

    // Copy in the default file extension ("*.*") + NULL.
    size = all_ext.length() + 1;
    memcpy(&(*buffer)[offset], all_ext.c_str(), size * sizeof(wchar_t));
    offset += size;
  }

  (*buffer)[offset] = L'\0';  // Double NULL required.
}

std::wstring GetFileFilterFromPath(const std::wstring& file_name) {
  std::wstring reg_description;
  std::wstring file_ext = file_util::GetFileExtensionFromPath(file_name);
  if (!file_ext.empty()) {
    file_ext = L"." + file_ext;
    GetRegistryDescriptionFromExtension(file_ext, &reg_description);
  }

  std::vector<wchar_t> filter;
  FormatFilterForExtension(file_ext, reg_description, true, &filter);
  return std::wstring(&filter[0], filter.size());
}

std::wstring GetFileFilterFromExtensions(const std::wstring& extensions,
                                         bool include_all_files) {
  DCHECK(extensions.find(L'.') != std::wstring::npos);
  std::wstring first_extension = extensions.substr(extensions.find(L'.'));
  size_t first_separator_index = first_extension.find(L';');
  if (first_separator_index != std::wstring::npos)
    first_extension = first_extension.substr(0, first_separator_index);

  std::wstring description;
  GetRegistryDescriptionFromExtension(first_extension, &description);
  if (description.empty())
    description = L"*." + first_extension;

  std::vector<wchar_t> filter;
  FormatFilterForExtension(extensions, description, true, &filter);
  return std::wstring(&filter[0], filter.size());
}

bool SaveFileAs(HWND owner,
                const std::wstring& suggested_name,
                std::wstring* final_name) {
  std::wstring filter = GetFileFilterFromPath(suggested_name);
  unsigned index = 1;
  return SaveFileAsWithFilter(owner,
                              suggested_name,
                              filter,
                              L"",
                              false,
                              &index,
                              final_name);
}

bool SaveFileAsWithFilter(HWND owner,
                          const std::wstring& suggested_name,
                          const std::wstring& filter,
                          const std::wstring& def_ext,
                          bool ignore_suggested_ext,
                          unsigned* index,
                          std::wstring* final_name) {
  DCHECK(final_name);
  // Having an empty filter makes for a bad user experience. We should always
  // specify a filter when saving.
  DCHECK(!filter.empty());
  std::wstring file_part = file_util::GetFilenameFromPath(suggested_name);

  // The size of the in/out buffer in number of characters we pass to win32
  // GetSaveFileName.  From MSDN "The buffer must be large enough to store the
  // path and file name string or strings, including the terminating NULL
  // character.  ... The buffer should be at least 256 characters long.".
  // _IsValidPathComDlg does a copy expecting at most MAX_PATH, otherwise will
  // result in an error of FNERR_INVALIDFILENAME.  So we should only pass the
  // API a buffer of at most MAX_PATH.
  wchar_t file_name[MAX_PATH];
  base::wcslcpy(file_name, file_part.c_str(), arraysize(file_name));

  OPENFILENAME save_as;
  // We must do this otherwise the ofn's FlagsEx may be initialized to random
  // junk in release builds which can cause the Places Bar not to show up!
  ZeroMemory(&save_as, sizeof(save_as));
  save_as.lStructSize = sizeof(OPENFILENAME);
  save_as.hwndOwner = owner;
  save_as.hInstance = NULL;

  save_as.lpstrFilter = filter.empty() ? NULL : filter.c_str();

  save_as.lpstrCustomFilter = NULL;
  save_as.nMaxCustFilter = 0;
  save_as.nFilterIndex = *index;
  save_as.lpstrFile = file_name;
  save_as.nMaxFile = arraysize(file_name);
  save_as.lpstrFileTitle = NULL;
  save_as.nMaxFileTitle = 0;

  // Set up the initial directory for the dialog.
  std::wstring directory = file_util::GetDirectoryFromPath(suggested_name);
  save_as.lpstrInitialDir = directory.c_str();
  save_as.lpstrTitle = NULL;
  save_as.Flags = OFN_OVERWRITEPROMPT | OFN_EXPLORER | OFN_ENABLESIZING |
                  OFN_ENABLEHOOK | OFN_NOCHANGEDIR | OFN_PATHMUSTEXIST;
  save_as.lpstrDefExt = &def_ext[0];
  save_as.lCustData = NULL;
  save_as.lpfnHook = &SaveAsDialogHook;

  // Must be NULL or 0.
  save_as.pvReserved = NULL;
  save_as.dwReserved = 0;

  if (!GetSaveFileName(&save_as)) {
    // Zero means the dialog was closed, otherwise we had an error.
    DWORD error_code = CommDlgExtendedError();
    if (error_code != 0) {
      NOTREACHED() << "GetSaveFileName failed with code: " << error_code;
    }
    return false;
  }

  // Return the user's choice.
  final_name->assign(save_as.lpstrFile);
  *index = save_as.nFilterIndex;

  // Figure out what filter got selected from the vector with embedded nulls.
  // NOTE: The filter contains a string with embedded nulls, such as:
  // JPG Image\0*.jpg\0All files\0*.*\0\0
  // The filter index is 1-based index for which pair got selected. So, using
  // the example above, if the first index was selected we need to skip 1
  // instance of null to get to "*.jpg".
  std::vector<std::wstring> filters;
  if (!filter.empty() && save_as.nFilterIndex > 0)
    SplitString(filter, '\0', &filters);
  std::wstring filter_selected;
  if (!filters.empty())
    filter_selected = filters[(2 * (save_as.nFilterIndex - 1)) + 1];

  // Get the extension that was suggested to the user (when the Save As dialog
  // was opened). For saving web pages, we skip this step since there may be
  // 'extension characters' in the title of the web page.
  std::wstring suggested_ext;
  if (!ignore_suggested_ext)
    suggested_ext = file_util::GetFileExtensionFromPath(suggested_name);

  // If we can't get the extension from the suggested_name, we use the default
  // extension passed in. This is to cover cases like when saving a web page,
  // where we get passed in a name without an extension and a default extension
  // along with it.
  if (suggested_ext.empty())
    suggested_ext = def_ext;

  *final_name =
      AppendExtensionIfNeeded(*final_name, filter_selected, suggested_ext);
  return true;
}

std::wstring AppendExtensionIfNeeded(const std::wstring& filename,
                                     const std::wstring& filter_selected,
                                     const std::wstring& suggested_ext) {
  std::wstring return_value = filename;

  // Get the extension the user ended up selecting.
  std::wstring selected_ext = file_util::GetFileExtensionFromPath(filename);

  if (filter_selected.empty() || filter_selected == L"*.*") {
    // If the user selects 'All files' we respect any extension given to us from
    // the File Save dialog. We also strip any trailing dots, which matches
    // Windows Explorer and is needed because Windows doesn't allow filenames
    // to have trailing dots. The GetSaveFileName dialog will not return a
    // string with only one or more dots.
    size_t index = return_value.find_last_not_of(L'.');
    if (index < return_value.size() - 1)
      return_value.resize(index + 1);
  } else {
    // User selected a specific filter (not *.*) so we need to check if the
    // extension provided has the same mime type. If it doesn't we append the
    // extension.
    std::string suggested_mime_type, selected_mime_type;
    if (suggested_ext != selected_ext &&
        (!net::GetMimeTypeFromExtension(suggested_ext, &suggested_mime_type) ||
         !net::GetMimeTypeFromExtension(selected_ext, &selected_mime_type) ||
         suggested_mime_type != selected_mime_type)) {
      return_value.append(L".");
      return_value.append(suggested_ext);
    }
  }

  return return_value;
}

// Adjust the window to fit, returning true if the window was resized or moved.
static bool AdjustWindowToFit(HWND hwnd, const RECT& bounds) {
  // Get the monitor.
  HMONITOR hmon = MonitorFromRect(&bounds, MONITOR_DEFAULTTONEAREST);
  if (!hmon) {
    NOTREACHED() << "Unable to find default monitor";
    // No monitor available.
    return false;
  }

  MONITORINFO mi;
  mi.cbSize = sizeof(mi);
  GetMonitorInfo(hmon, &mi);
  gfx::Rect window_rect(bounds);
  gfx::Rect monitor_rect(mi.rcWork);
  gfx::Rect new_window_rect = window_rect.AdjustToFit(monitor_rect);
  if (!new_window_rect.Equals(window_rect)) {
    // Window doesn't fit on monitor, move and possibly resize.
    SetWindowPos(hwnd, 0, new_window_rect.x(), new_window_rect.y(),
                 new_window_rect.width(), new_window_rect.height(),
                 SWP_NOACTIVATE | SWP_NOZORDER);
    return true;
  } else {
    return false;
  }
}

void AdjustWindowToFit(HWND hwnd) {
  // Get the window bounds.
  RECT r;
  GetWindowRect(hwnd, &r);
  AdjustWindowToFit(hwnd, r);
}

void CenterAndSizeWindow(HWND parent, HWND window, const SIZE& pref,
                         bool pref_is_client) {
  DCHECK(window && pref.cx > 0 && pref.cy > 0);
  // Calculate the ideal bounds.
  RECT window_bounds;
  RECT center_bounds = {0};
  if (parent) {
    // If there is a parent, center over the parents bounds.
    ::GetWindowRect(parent, &center_bounds);
  } else {
    // No parent. Center over the monitor the window is on.
    HMONITOR monitor = MonitorFromWindow(window, MONITOR_DEFAULTTONEAREST);
    if (monitor) {
      MONITORINFO mi = {0};
      mi.cbSize = sizeof(mi);
      GetMonitorInfo(monitor, &mi);
      center_bounds = mi.rcWork;
    } else {
      NOTREACHED() << "Unable to get default monitor";
    }
  }
  window_bounds.left = center_bounds.left +
                       (center_bounds.right - center_bounds.left - pref.cx) / 2;
  window_bounds.right = window_bounds.left + pref.cx;
  window_bounds.top = center_bounds.top +
                      (center_bounds.bottom - center_bounds.top - pref.cy) / 2;
  window_bounds.bottom = window_bounds.top + pref.cy;

  // If we're centering a child window, we are positioning in client
  // coordinates, and as such we need to offset the target rectangle by the
  // position of the parent window.
  if (::GetWindowLong(window, GWL_STYLE) & WS_CHILD) {
    DCHECK(parent && ::GetParent(window) == parent);
    POINT topleft = { window_bounds.left, window_bounds.top };
    ::MapWindowPoints(HWND_DESKTOP, parent, &topleft, 1);
    window_bounds.left = topleft.x;
    window_bounds.top = topleft.y;
    window_bounds.right = window_bounds.left + pref.cx;
    window_bounds.bottom = window_bounds.top + pref.cy;
  }

  // Get the WINDOWINFO for window. We need the style to calculate the size
  // for the window.
  WINDOWINFO win_info = {0};
  win_info.cbSize = sizeof(WINDOWINFO);
  GetWindowInfo(window, &win_info);

  // Calculate the window size needed for the content size.

  if (!pref_is_client ||
      AdjustWindowRectEx(&window_bounds, win_info.dwStyle, FALSE,
                         win_info.dwExStyle)) {
    if (!AdjustWindowToFit(window, window_bounds)) {
      // The window fits, reset the bounds.
      SetWindowPos(window, 0, window_bounds.left, window_bounds.top,
                   window_bounds.right - window_bounds.left,
                   window_bounds.bottom - window_bounds.top,
                   SWP_NOACTIVATE | SWP_NOZORDER);
    }  // else case, AdjustWindowToFit set the bounds for us.
  } else {
    NOTREACHED() << "Unable to adjust window to fit";
  }
}

HANDLE GetSectionFromProcess(HANDLE section, HANDLE process, bool read_only) {
  HANDLE valid_section = NULL;
  DWORD access = STANDARD_RIGHTS_REQUIRED | FILE_MAP_READ;
  if (!read_only)
    access |= FILE_MAP_WRITE;
  DuplicateHandle(process, section, GetCurrentProcess(), &valid_section, access,
                  FALSE, 0);
  return valid_section;
}

bool DoesWindowBelongToActiveWindow(HWND window) {
  DCHECK(window);
  HWND top_window = ::GetAncestor(window, GA_ROOT);
  if (!top_window)
    return false;

  HWND active_top_window = ::GetAncestor(::GetForegroundWindow(), GA_ROOT);
  return (top_window == active_top_window);
}

void EnsureRectIsVisibleInRect(const gfx::Rect& parent_rect,
                               gfx::Rect* child_rect,
                               int padding) {
  DCHECK(child_rect);

  // We use padding here because it allows some of the original web page to
  // bleed through around the edges.
  int twice_padding = padding * 2;

  // FIRST, clamp width and height so we don't open child windows larger than
  // the containing parent.
  if (child_rect->width() > (parent_rect.width() + twice_padding))
    child_rect->set_width(std::max(0, parent_rect.width() - twice_padding));
  if (child_rect->height() > parent_rect.height() + twice_padding)
    child_rect->set_height(std::max(0, parent_rect.height() - twice_padding));

  // SECOND, clamp x,y position to padding,padding so we don't position child
  // windows in hyperspace.
  // TODO(mpcomplete): I don't see what the second check in each 'if' does that
  // isn't handled by the LAST set of 'ifs'.  Maybe we can remove it.
  if (child_rect->x() < parent_rect.x() ||
      child_rect->x() > parent_rect.right()) {
    child_rect->set_x(parent_rect.x() + padding);
  }
  if (child_rect->y() < parent_rect.y() ||
      child_rect->y() > parent_rect.bottom()) {
    child_rect->set_y(parent_rect.y() + padding);
  }

  // LAST, nudge the window back up into the client area if its x,y position is
  // within the parent bounds but its width/height place it off-screen.
  if (child_rect->bottom() > parent_rect.bottom())
    child_rect->set_y(parent_rect.bottom() - child_rect->height() - padding);
  if (child_rect->right() > parent_rect.right())
    child_rect->set_x(parent_rect.right() - child_rect->width() - padding);
}

void SetChildBounds(HWND child_window, HWND parent_window,
                    HWND insert_after_window, const gfx::Rect& bounds,
                    int padding, unsigned long flags) {
  DCHECK(IsWindow(child_window));

  // First figure out the bounds of the parent.
  RECT parent_rect = {0};
  if (parent_window) {
    GetClientRect(parent_window, &parent_rect);
  } else {
    // If there is no parent, we consider the bounds of the monitor the window
    // is on to be the parent bounds.

    // If the child_window isn't visible yet and we've been given a valid,
    // visible insert after window, use that window to locate the correct
    // monitor instead.
    HWND window = child_window;
    if (!IsWindowVisible(window) && IsWindow(insert_after_window) &&
        IsWindowVisible(insert_after_window))
      window = insert_after_window;

    POINT window_point = { bounds.x(), bounds.y() };
    HMONITOR monitor = MonitorFromPoint(window_point,
                                        MONITOR_DEFAULTTONEAREST);
    if (monitor) {
      MONITORINFO mi = {0};
      mi.cbSize = sizeof(mi);
      GetMonitorInfo(monitor, &mi);
      parent_rect = mi.rcWork;
    } else {
      NOTREACHED() << "Unable to get default monitor";
    }
  }

  gfx::Rect actual_bounds = bounds;
  EnsureRectIsVisibleInRect(gfx::Rect(parent_rect), &actual_bounds, padding);

  SetWindowPos(child_window, insert_after_window, actual_bounds.x(),
               actual_bounds.y(), actual_bounds.width(),
               actual_bounds.height(), flags);
}

gfx::Rect GetMonitorBoundsForRect(const gfx::Rect& rect) {
  RECT p_rect = rect.ToRECT();
  HMONITOR monitor = MonitorFromRect(&p_rect, MONITOR_DEFAULTTONEAREST);
  if (monitor) {
    MONITORINFO mi = {0};
    mi.cbSize = sizeof(mi);
    GetMonitorInfo(monitor, &mi);
    return gfx::Rect(mi.rcWork);
  }
  NOTREACHED();
  return gfx::Rect();
}

bool IsNumPadDigit(int key_code, bool extended_key) {
  if (key_code >= VK_NUMPAD0 && key_code <= VK_NUMPAD9)
    return true;

  // Check for num pad keys without NumLock.
  // Note: there is no easy way to know if a the key that was pressed comes from
  //       the num pad or the rest of the keyboard.  Investigating how
  //       TranslateMessage() generates the WM_KEYCHAR from an
  //       ALT + <NumPad sequences> it appears it looks at the extended key flag
  //       (which is on if the key pressed comes from one of the 3 clusters to
  //       the left of the numeric keypad).  So we use it as well.
  return !extended_key &&
            ((key_code >= VK_PRIOR && key_code <= VK_DOWN) ||  // All keys but 5
                                                               // and 0.
            (key_code == VK_CLEAR) ||  // Key 5.
            (key_code == VK_INSERT));  // Key 0.
}

void GrabWindowSnapshot(HWND window_handle,
                        std::vector<unsigned char>* png_representation) {
  // Create a memory DC that's compatible with the window.
  CWindowDC window_hdc(window_handle);
  CDC mem_hdc(::CreateCompatibleDC(window_hdc));

  // Create a DIB that's the same size as the window.
  RECT content_rect = {0, 0, 0, 0};
  ::GetWindowRect(window_handle, &content_rect);
  content_rect.right++;  // Match what PrintWindow wants.
  int width = content_rect.right - content_rect.left;
  int height = content_rect.bottom - content_rect.top;
  BITMAPINFOHEADER hdr;
  gfx::CreateBitmapHeader(width, height, &hdr);
  unsigned char *bit_ptr = NULL;
  CBitmap bitmap(::CreateDIBSection(mem_hdc,
                                    reinterpret_cast<BITMAPINFO*>(&hdr),
                                    DIB_RGB_COLORS,
                                    reinterpret_cast<void **>(&bit_ptr),
                                    NULL, 0));

  mem_hdc.SelectBitmap(bitmap);
  // Clear the bitmap to white (so that rounded corners on windows
  // show up on a white background, and strangely-shaped windows
  // look reasonable). Not capturing an alpha mask saves a
  // bit of space.
  mem_hdc.PatBlt(0, 0, width, height, WHITENESS);
  // Grab a copy of the window
  // First, see if PrintWindow is defined (it's not in Windows 2000).
  typedef BOOL (WINAPI *PrintWindowPointer)(HWND, HDC, UINT);
  PrintWindowPointer print_window =
      reinterpret_cast<PrintWindowPointer>(
          GetProcAddress(GetModuleHandle(L"User32.dll"), "PrintWindow"));

  // If PrintWindow is defined, use it.  It will work on partially
  // obscured windows, and works better for out of process sub-windows.
  // Otherwise grab the bits we can get with BitBlt; it's better
  // than nothing and will work fine in the average case (window is
  // completely on screen).
  if (print_window)
    (*print_window)(window_handle, mem_hdc, 0);
  else
    mem_hdc.BitBlt(0, 0, width, height, window_hdc, 0, 0, SRCCOPY);

  // We now have a copy of the window contents in a DIB, so
  // encode it into a useful format for posting to the bug report
  // server.
  PNGEncoder::Encode(bit_ptr, PNGEncoder::FORMAT_BGRA,
                     width, height, width * 4, true,
                     png_representation);
}

bool IsWindowActive(HWND hwnd) {
  WINDOWINFO info;
  return ::GetWindowInfo(hwnd, &info) &&
         ((info.dwWindowStatus & WS_ACTIVECAPTION) != 0);
}

bool IsReservedName(const std::wstring& filename) {
  // This list is taken from the MSDN article "Naming a file"
  // http://msdn2.microsoft.com/en-us/library/aa365247(VS.85).aspx
  // I also added clock$ because GetSaveFileName seems to consider it as a
  // reserved name too.
  static const wchar_t* const known_devices[] = {
    L"con", L"prn", L"aux", L"nul", L"com1", L"com2", L"com3", L"com4", L"com5",
    L"com6", L"com7", L"com8", L"com9", L"lpt1", L"lpt2", L"lpt3", L"lpt4",
    L"lpt5", L"lpt6", L"lpt7", L"lpt8", L"lpt9", L"clock$"
  };
  std::wstring filename_lower = StringToLowerASCII(filename);

  for (int i = 0; i < arraysize(known_devices); ++i) {
    // Exact match.
    if (filename_lower == known_devices[i])
      return true;
    // Starts with "DEVICE.".
    if (filename_lower.find(std::wstring(known_devices[i]) + L".") == 0)
      return true;
  }

  static const wchar_t* const magic_names[] = {
    // These file names are used by the "Customize folder" feature of the shell.
    L"desktop.ini",
    L"thumbs.db",
  };

  for (int i = 0; i < arraysize(magic_names); ++i) {
    if (filename_lower == magic_names[i])
      return true;
  }

  return false;
}

bool IsShellIntegratedExtension(const std::wstring& extension) {
  std::wstring extension_lower = StringToLowerASCII(extension);

  static const wchar_t* const integrated_extensions[] = {
    // See <http://msdn.microsoft.com/en-us/library/ms811694.aspx>.
    L"local",
    // Right-clicking on shortcuts can be magical.
    L"lnk",
  };

  for (int i = 0; i < arraysize(integrated_extensions); ++i) {
    if (extension_lower == integrated_extensions[i])
      return true;
  }

  // See <http://www.juniper.net/security/auto/vulnerabilities/vuln2612.html>.
  // That vulnerability report is not exactly on point, but files become magical
  // if their end in a CLSID.  Here we block extensions that look like CLSIDs.
  if (extension_lower.size() > 0 && extension_lower.at(0) == L'{' &&
      extension_lower.at(extension_lower.length() - 1) == L'}')
    return true;

  return false;
}

// In addition to passing the RTL flags to ::MessageBox if we are running in an
// RTL locale, we need to make sure that LTR strings are rendered correctly by
// adding the appropriate Unicode directionality marks.
int MessageBox(HWND hwnd,
               const std::wstring& text,
               const std::wstring& caption,
               UINT flags) {
  UINT actual_flags = flags;
  if (l10n_util::GetTextDirection() == l10n_util::RIGHT_TO_LEFT)
    actual_flags |= MB_RIGHT | MB_RTLREADING;

  std::wstring localized_text;
  const wchar_t* text_ptr = text.c_str();
  if (l10n_util::AdjustStringForLocaleDirection(text, &localized_text))
    text_ptr = localized_text.c_str();

  std::wstring localized_caption;
  const wchar_t* caption_ptr = caption.c_str();
  if (l10n_util::AdjustStringForLocaleDirection(caption, &localized_caption))
    caption_ptr = localized_caption.c_str();

  return ::MessageBox(hwnd, text_ptr, caption_ptr, actual_flags);
}

ChromeFont GetWindowTitleFont() {
  NONCLIENTMETRICS ncm;
  win_util::GetNonClientMetrics(&ncm);
  ScopedHFONT caption_font(CreateFontIndirect(&(ncm.lfCaptionFont)));
  return ChromeFont::CreateFont(caption_font);
}

}  // namespace win_util