root/win8/delegate_execute/command_execute_impl.cc

DEFINITIONS

1. GetUrlFromShellItem
2. LaunchChromeBrowserProcess
3. integrity_level_
4. SetKeyState
5. SetParameters
6. SetPosition
7. SetShowWindow
8. SetNoShowUI
9. SetDirectory
10. GetValue
11. Initialize
12. SetSelection
13. GetSelection
14. AllowForegroundTransfer
15. FindChromeExe
16. GetLaunchScheme
17. LaunchDesktopChrome
18. GetLaunchMode

// 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.
// Implementation of the CommandExecuteImpl class which implements the
// IExecuteCommand and related interfaces for handling ShellExecute based
// launches of the Chrome browser.

#include "win8/delegate_execute/command_execute_impl.h"

#include <shlguid.h>

#include "base/file_util.h"
#include "base/path_service.h"
#include "base/process/launch.h"
#include "base/process/process_handle.h"
#include "base/strings/utf_string_conversions.h"
#include "base/win/message_window.h"
#include "base/win/registry.h"
#include "base/win/scoped_co_mem.h"
#include "base/win/scoped_handle.h"
#include "base/win/scoped_process_information.h"
#include "base/win/win_util.h"
#include "chrome/common/chrome_constants.h"
#include "chrome/common/chrome_paths.h"
#include "chrome/common/chrome_switches.h"
#include "chrome/installer/util/browser_distribution.h"
#include "chrome/installer/util/install_util.h"
#include "chrome/installer/util/shell_util.h"
#include "chrome/installer/util/util_constants.h"
#include "ui/base/clipboard/clipboard_util_win.h"
#include "win8/delegate_execute/chrome_util.h"
#include "win8/delegate_execute/delegate_execute_util.h"
#include "win8/viewer/metro_viewer_constants.h"

namespace {
// Helper function to retrieve the url from IShellItem interface passed in.
// Returns S_OK on success.
HRESULT GetUrlFromShellItem(IShellItem* shell_item, base::string16* url) {
  DCHECK(shell_item);
  DCHECK(url);
  // First attempt to get the url from the underlying IDataObject if any. This
  // ensures that we get the full url, i.e. including the anchor.
  // If we fail to get the underlying IDataObject we retrieve the url via the
  // IShellItem::GetDisplayName function.
  CComPtr<IDataObject> object;
  HRESULT hr = shell_item->BindToHandler(NULL,
                                         BHID_DataObject,
                                         IID_IDataObject,
                                         reinterpret_cast<void**>(&object));
  if (SUCCEEDED(hr)) {
    DCHECK(object);
    if (ui::ClipboardUtil::GetPlainText(object, url))
      return S_OK;
  }

  base::win::ScopedCoMem<wchar_t> name;
  hr = shell_item->GetDisplayName(SIGDN_URL, &name);
  if (hr != S_OK) {
    AtlTrace("Failed to get display name\n");
    return hr;
  }

  *url = static_cast<const wchar_t*>(name);
  AtlTrace("Retrieved url from display name %ls\n", url->c_str());
  return S_OK;
}

bool LaunchChromeBrowserProcess() {
  base::FilePath delegate_exe_path;
  if (!PathService::Get(base::FILE_EXE, &delegate_exe_path))
    return false;

  // First try and go up a level to find chrome.exe.
  base::FilePath chrome_exe_path =
      delegate_exe_path.DirName()
                       .DirName()
                       .Append(chrome::kBrowserProcessExecutableName);
  if (!base::PathExists(chrome_exe_path)) {
    // Try looking in the current directory if we couldn't find it one up in
    // order to support developer installs.
    chrome_exe_path =
        delegate_exe_path.DirName()
                         .Append(chrome::kBrowserProcessExecutableName);
  }

  if (!base::PathExists(chrome_exe_path)) {
    AtlTrace("Could not locate chrome.exe at: %ls\n",
             chrome_exe_path.value().c_str());
    return false;
  }

  CommandLine cl(chrome_exe_path);

  // Prevent a Chrome window from showing up on the desktop.
  cl.AppendSwitch(switches::kSilentLaunch);

  // Tell Chrome to connect to the Metro viewer process.
  cl.AppendSwitch(switches::kViewerConnect);

  base::LaunchOptions launch_options;
  launch_options.start_hidden = true;

  return base::LaunchProcess(cl, launch_options, NULL);
}

}  // namespace

bool CommandExecuteImpl::path_provider_initialized_ = false;

// CommandExecuteImpl is resposible for activating chrome in Windows 8. The
// flow is complicated and this tries to highlight the important events.
// The current approach is to have a single instance of chrome either
// running in desktop or metro mode. If there is no current instance then
// the desktop shortcut launches desktop chrome and the metro tile or search
// charm launches metro chrome.
// If chrome is running then focus/activation is given to the existing one
// regarless of what launch point the user used.
//
// The general flow for activation is as follows:
//
// 1- User interacts with launch point (icon, tile, search, shellexec, etc)
// 2- Windows finds the appid for launch item and resolves it to chrome
// 3- Windows activates CommandExecuteImpl inside a surrogate process
// 4- Windows calls the following sequence of entry points:
//    CommandExecuteImpl::SetShowWindow
//    CommandExecuteImpl::SetPosition
//    CommandExecuteImpl::SetDirectory
//    CommandExecuteImpl::SetParameter
//    CommandExecuteImpl::SetNoShowUI
//    CommandExecuteImpl::SetSelection
//    CommandExecuteImpl::Initialize
//    Up to this point the code basically just gathers values passed in, like
//    the launch scheme (or url) and the activation verb.
// 5- Windows calls CommandExecuteImpl::Getvalue()
//    Here we need to return AHE_IMMERSIVE or AHE_DESKTOP. That depends on:
//    a) if run in high-integrity return AHE_DESKTOP.
//    b) else we return what GetLaunchMode() tells us, which is:
//       i) if chrome is not the default browser, return AHE_DESKTOP
//       ii) if the command line --force-xxx is present return that
//       iii) if the registry 'launch_mode' exists return that
//       iv) else return AHE_DESKTOP
// 6- If we returned AHE_IMMERSIVE in step 5 windows might not call us back
//    and simply activate chrome in metro by itself, however in some cases
//    it might proceed at step 7.
//    As far as we know if we return AHE_DESKTOP then step 7 always happens.
// 7- Windows calls CommandExecuteImpl::Execute()
//    Here we call GetLaunchMode() which returns the cached answer
//    computed at step 5c. which can be:
//    a) ECHUIM_DESKTOP then we call LaunchDesktopChrome() that calls
//       ::CreateProcess and we exit at this point even on failure.
//    b) else we call one of the IApplicationActivationManager activation
//       functions depending on the parameters passed in step 4.
//    c) If the activation returns E_APPLICATION_NOT_REGISTERED, then we fall
//       back to launching chrome on the desktop via LaunchDestopChrome().  Note
//       that this case can lead to strange behavior, because at this point we
//       have pre-launched the browser with --silent-launch --viewer-connect.
//       E_APPLICATION_NOT_REGISTERED is always returned if Chrome is not the
//       default browser (this case will have already been checked for by
//       GetLaunchMode() and AHE_DESKTOP returned), but we don't know if it can
//       be returned for other reasons.
//
// Note that if a command line --force-xxx is present we write that launch mode
// in the registry so next time the logic reaches 5c-ii it will use the same
// mode again.
//
CommandExecuteImpl::CommandExecuteImpl()
    : parameters_(CommandLine::NO_PROGRAM),
      launch_scheme_(INTERNET_SCHEME_DEFAULT),
      integrity_level_(base::INTEGRITY_UNKNOWN) {
  memset(&start_info_, 0, sizeof(start_info_));
  start_info_.cb = sizeof(start_info_);

  // We need to query the user data dir of chrome so we need chrome's
  // path provider. We can be created multiplie times in a single instance
  // however so make sure we do this only once.
  if (!path_provider_initialized_) {
    chrome::RegisterPathProvider();
    path_provider_initialized_ = true;
  }
}

// CommandExecuteImpl
STDMETHODIMP CommandExecuteImpl::SetKeyState(DWORD key_state) {
  return S_OK;
}

STDMETHODIMP CommandExecuteImpl::SetParameters(LPCWSTR params) {
  parameters_ = delegate_execute::CommandLineFromParameters(params);
  return S_OK;
}

STDMETHODIMP CommandExecuteImpl::SetPosition(POINT pt) {
  return S_OK;
}

STDMETHODIMP CommandExecuteImpl::SetShowWindow(int show) {
  start_info_.wShowWindow = show;
  start_info_.dwFlags |= STARTF_USESHOWWINDOW;
  return S_OK;
}

STDMETHODIMP CommandExecuteImpl::SetNoShowUI(BOOL no_show_ui) {
  return S_OK;
}

STDMETHODIMP CommandExecuteImpl::SetDirectory(LPCWSTR directory) {
  return S_OK;
}

STDMETHODIMP CommandExecuteImpl::GetValue(enum AHE_TYPE* pahe) {
  if (!GetLaunchScheme(&display_name_, &launch_scheme_)) {
    AtlTrace("Failed to get scheme, E_FAIL\n");
    return E_FAIL;
  }

  EC_HOST_UI_MODE mode = GetLaunchMode();
  *pahe = (mode == ECHUIM_DESKTOP) ? AHE_DESKTOP : AHE_IMMERSIVE;

  // If we're going to return AHE_IMMERSIVE, then both the browser process and
  // the metro viewer need to launch and connect before the user can start
  // browsing.  However we must not launch the metro viewer until we get a
  // call to CommandExecuteImpl::Execute().  If we wait until then to launch
  // the browser process as well, it will appear laggy while they connect to
  // each other, so we pre-launch the browser process now.
  if (*pahe == AHE_IMMERSIVE && verb_ != win8::kMetroViewerConnectVerb)
    LaunchChromeBrowserProcess();
  return S_OK;
}

STDMETHODIMP CommandExecuteImpl::Execute() {
  AtlTrace("In %hs\n", __FUNCTION__);

  if (integrity_level_ == base::HIGH_INTEGRITY)
    return LaunchDesktopChrome();

  EC_HOST_UI_MODE mode = GetLaunchMode();
  if (mode == ECHUIM_DESKTOP)
    return LaunchDesktopChrome();

  HRESULT hr = E_FAIL;
  CComPtr<IApplicationActivationManager> activation_manager;
  hr = activation_manager.CoCreateInstance(CLSID_ApplicationActivationManager);
  if (!activation_manager) {
    AtlTrace("Failed to get the activation manager, error 0x%x\n", hr);
    return S_OK;
  }

  BrowserDistribution* distribution = BrowserDistribution::GetDistribution();
  bool is_per_user_install = InstallUtil::IsPerUserInstall(
      chrome_exe_.value().c_str());
  base::string16 app_id = ShellUtil::GetBrowserModelId(
      distribution, is_per_user_install);

  DWORD pid = 0;
  if (launch_scheme_ == INTERNET_SCHEME_FILE &&
      display_name_.find(installer::kChromeExe) != base::string16::npos) {
    AtlTrace("Activating for file\n");
    hr = activation_manager->ActivateApplication(app_id.c_str(),
                                                 verb_.c_str(),
                                                 AO_NONE,
                                                 &pid);
  } else {
    AtlTrace("Activating for protocol\n");
    hr = activation_manager->ActivateForProtocol(app_id.c_str(),
                                                 item_array_,
                                                 &pid);
  }
  if (hr == E_APPLICATION_NOT_REGISTERED) {
    AtlTrace("Metro chrome is not registered, launching in desktop\n");
    return LaunchDesktopChrome();
  }
  AtlTrace("Metro Chrome launch, pid=%d, returned 0x%x\n", pid, hr);
  return S_OK;
}

STDMETHODIMP CommandExecuteImpl::Initialize(LPCWSTR name,
                                            IPropertyBag* bag) {
  if (!FindChromeExe(&chrome_exe_))
    return E_FAIL;
  delegate_execute::UpdateChromeIfNeeded(chrome_exe_);

  if (name) {
    AtlTrace("Verb is %S\n", name);
    verb_ = name;
  }

  base::GetProcessIntegrityLevel(base::GetCurrentProcessHandle(),
                                 &integrity_level_);
  return S_OK;
}

STDMETHODIMP CommandExecuteImpl::SetSelection(IShellItemArray* item_array) {
  item_array_ = item_array;
  return S_OK;
}

STDMETHODIMP CommandExecuteImpl::GetSelection(REFIID riid, void** selection) {
  return S_OK;
}

STDMETHODIMP CommandExecuteImpl::AllowForegroundTransfer(void* reserved) {
  return S_OK;
}

// Returns false if chrome.exe cannot be found.
// static
bool CommandExecuteImpl::FindChromeExe(base::FilePath* chrome_exe) {
  // Look for chrome.exe one folder above delegate_execute.exe (as expected in
  // Chrome installs). Failing that, look for it alonside delegate_execute.exe.
  base::FilePath dir_exe;
  if (!PathService::Get(base::DIR_EXE, &dir_exe)) {
    AtlTrace("Failed to get current exe path\n");
    return false;
  }

  *chrome_exe = dir_exe.DirName().Append(chrome::kBrowserProcessExecutableName);
  if (!base::PathExists(*chrome_exe)) {
    *chrome_exe = dir_exe.Append(chrome::kBrowserProcessExecutableName);
    if (!base::PathExists(*chrome_exe)) {
      AtlTrace("Failed to find chrome exe file\n");
      return false;
    }
  }
  return true;
}

bool CommandExecuteImpl::GetLaunchScheme(
    base::string16* display_name, INTERNET_SCHEME* scheme) {
  if (!item_array_)
    return false;

  ATLASSERT(display_name);
  ATLASSERT(scheme);

  DWORD count = 0;
  item_array_->GetCount(&count);

  if (count != 1) {
    AtlTrace("Cannot handle %d elements in the IShellItemArray\n", count);
    return false;
  }

  CComPtr<IEnumShellItems> items;
  item_array_->EnumItems(&items);
  CComPtr<IShellItem> shell_item;
  HRESULT hr = items->Next(1, &shell_item, &count);
  if (hr != S_OK) {
    AtlTrace("Failed to read element from the IShellItemsArray\n");
    return false;
  }

  hr = GetUrlFromShellItem(shell_item, display_name);
  if (FAILED(hr)) {
    AtlTrace("Failed to get url. Error 0x%x\n", hr);
    return false;
  }

  wchar_t scheme_name[16];
  URL_COMPONENTS components = {0};
  components.lpszScheme = scheme_name;
  components.dwSchemeLength = sizeof(scheme_name)/sizeof(scheme_name[0]);

  components.dwStructSize = sizeof(components);
  if (!InternetCrackUrlW(display_name->c_str(), 0, 0, &components)) {
    AtlTrace("Failed to crack url %ls\n", display_name->c_str());
    return false;
  }

  AtlTrace("Launch scheme is [%ls] (%d)\n", scheme_name, components.nScheme);
  *scheme = components.nScheme;
  return true;
}

HRESULT CommandExecuteImpl::LaunchDesktopChrome() {
  base::string16 display_name = display_name_;

  switch (launch_scheme_) {
    case INTERNET_SCHEME_FILE:
      // If anything other than chrome.exe is passed in the display name we
      // should honor it. For e.g. If the user clicks on a html file when
      // chrome is the default we should treat it as a parameter to be passed
      // to chrome.
      if (display_name.find(installer::kChromeExe) != base::string16::npos)
        display_name.clear();
      break;

    default:
      break;
  }

  CommandLine chrome(
      delegate_execute::MakeChromeCommandLine(chrome_exe_, parameters_,
                                              display_name));
  base::string16 command_line(chrome.GetCommandLineString());

  AtlTrace("Formatted command line is %ls\n", command_line.c_str());

  PROCESS_INFORMATION temp_process_info = {};
  BOOL ret = CreateProcess(chrome_exe_.value().c_str(),
                           const_cast<LPWSTR>(command_line.c_str()),
                           NULL, NULL, FALSE, 0, NULL, NULL, &start_info_,
                           &temp_process_info);
  if (ret) {
    base::win::ScopedProcessInformation proc_info(temp_process_info);
    AtlTrace("Process id is %d\n", proc_info.process_id());
    AllowSetForegroundWindow(proc_info.process_id());
  } else {
    AtlTrace("Process launch failed, error %d\n", ::GetLastError());
  }

  return S_OK;
}

EC_HOST_UI_MODE CommandExecuteImpl::GetLaunchMode() {
  // See the header file for an explanation of the mode selection logic.
  static bool launch_mode_determined = false;
  static EC_HOST_UI_MODE launch_mode = ECHUIM_DESKTOP;

  const char* modes[] = { "Desktop", "Immersive", "SysLauncher", "??" };

  if (launch_mode_determined)
    return launch_mode;

  if (integrity_level_ == base::HIGH_INTEGRITY) {
    // Metro mode apps don't work in high integrity mode.
    AtlTrace("High integrity: launching in desktop mode\n");
    launch_mode = ECHUIM_DESKTOP;
    launch_mode_determined = true;
    return launch_mode;
  }

  base::FilePath chrome_exe;
  if (!FindChromeExe(&chrome_exe) ||
      ShellUtil::GetChromeDefaultStateFromPath(chrome_exe) !=
          ShellUtil::IS_DEFAULT) {
    AtlTrace("Chrome is not default: launching in desktop mode\n");
    launch_mode = ECHUIM_DESKTOP;
    launch_mode_determined = true;
    return launch_mode;
  }

  if (GetAsyncKeyState(VK_SHIFT) && GetAsyncKeyState(VK_F11)) {
    AtlTrace("Hotkey: launching in immersive mode\n");
    launch_mode = ECHUIM_IMMERSIVE;
    launch_mode_determined = true;
    return launch_mode;
  }

  // From here on, if we can, we will write the outcome
  // of this function to the registry.
  if (parameters_.HasSwitch(switches::kForceImmersive)) {
    launch_mode = ECHUIM_IMMERSIVE;
    launch_mode_determined = true;
    parameters_ = CommandLine(CommandLine::NO_PROGRAM);
  } else if (parameters_.HasSwitch(switches::kForceDesktop)) {
    launch_mode = ECHUIM_DESKTOP;
    launch_mode_determined = true;
    parameters_ = CommandLine(CommandLine::NO_PROGRAM);
  }

  base::win::RegKey reg_key;
  LONG key_result = reg_key.Create(HKEY_CURRENT_USER,
                                   chrome::kMetroRegistryPath,
                                   KEY_ALL_ACCESS);
  if (key_result != ERROR_SUCCESS) {
    AtlTrace("Failed to open HKCU %ls key, error 0x%x\n",
             chrome::kMetroRegistryPath,
             key_result);
    if (!launch_mode_determined) {
      // If we cannot open the key and we don't know the
      // launch mode we default to desktop mode.
      launch_mode = ECHUIM_DESKTOP;
      launch_mode_determined = true;
    }
    return launch_mode;
  }

  if (launch_mode_determined) {
    AtlTrace("Launch mode forced by cmdline to %s\n", modes[launch_mode]);
    reg_key.WriteValue(chrome::kLaunchModeValue,
                       static_cast<DWORD>(launch_mode));
    return launch_mode;
  }

  // Use the previous mode if available. Else launch in desktop mode.
  DWORD reg_value;
  if (reg_key.ReadValueDW(chrome::kLaunchModeValue,
                          &reg_value) != ERROR_SUCCESS) {
    launch_mode = ECHUIM_DESKTOP;
    AtlTrace("Can't read registry, defaulting to %s\n", modes[launch_mode]);
  } else if (reg_value >= ECHUIM_SYSTEM_LAUNCHER) {
    AtlTrace("Invalid registry launch mode value %u\n", reg_value);
    launch_mode = ECHUIM_DESKTOP;
  } else {
    launch_mode = static_cast<EC_HOST_UI_MODE>(reg_value);
    AtlTrace("Launch mode forced by registry to %s\n", modes[launch_mode]);
  }

  launch_mode_determined = true;
  return launch_mode;
}