// Copyright (c) 2011 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.
#ifndef CHROME_FRAME_CHROME_ACTIVE_DOCUMENT_H_
#define CHROME_FRAME_CHROME_ACTIVE_DOCUMENT_H_
#include <atlbase.h>
#include <atlcom.h>
#include <atlctl.h>
#include <htiframe.h>
#include <mshtmcid.h>
#include <perhist.h>
#include <map>
#include <string>
#include "base/memory/scoped_ptr.h"
#include "base/threading/thread.h"
#include "base/win/scoped_comptr.h"
#include "chrome_frame/chrome_frame_activex_base.h"
#include "chrome_frame/com_type_info_holder.h"
#include "chrome_frame/extra_system_apis.h"
#include "chrome_frame/find_dialog.h"
#include "chrome_frame/html_private_window_impl.h"
#include "chrome_frame/html_window_impl.h"
#include "chrome_frame/resource.h"
#include "chrome_frame/utils.h"
#include "third_party/active_doc/in_place_menu.h"
#include "third_party/active_doc/ole_document_impl.h"
class TabProxy;
class ChromeActiveDocument;
// A call to IOleCommandTarget::Exec on the webbrowser with this command id
// and a command group of CGID_EXPLORER causes IE to finalize the current
// travel log entry and move to a new location (pruning any forward entries
// if needed)
#define INTERNAL_CMDID_FINALIZE_TRAVEL_LOG (38)
// To set the lock icon status call IOleCommandTarget::Exec on site with
// this command id and a command group of CGID_EXPLORER The in arg is one of
// the values: SECURELOCK_SET_UNSECURE, SECURELOCK_SET_MIXED,
// SECURELOCK_SET_SECURE128BIT etc declared in shdeprecated.h
#define INTERNAL_CMDID_SET_SSL_LOCK (37)
// A call to IOleCommandTarget::Exec on the webbrowser with this command id
// and a command group of CGID_EXPLORER causes IE to replace the URL in the
// current travel log entry
#define INTERNAL_CMDID_REPLACE_CURRENT_TRAVEL_LOG_ENTRY_URL (40)
// The following macro is to define the mapping of IE encoding menu item to
// corresponding available encoding name in Chrome. For each encoding
// definition, there are three fields.
// The first one is the definition name of encoding menu item in IE.
// The second one is execution id of the encoding menu item in IE, starting
// from 3609(IDM_MIMECSET__FIRST__) to 3699(IDM_MIMECSET__LAST__) end. For
// the details, please refer to mshtmcid.h.
// The last one is the available encoding name of the IE encoding menu item
// in Chrome. If the encoding menu item does not have corresponding encoding
// in Chrome, it will be "unknown".
// So far we don't support the encoding auto detect since we can not control
// the status of encoding menu, such as toggle status of encoding auto detect
// item on the encoding menu.
#define INTERNAL_IE_ENCODINGMENU_IDS(V) \
V(INTERNAL_IE_ENCODINGMENU_ARABIC_ASMO708, 3609, "unknown") \
V(INTERNAL_IE_ENCODINGMENU_ARABIC_DOS, 3610, "unknown") \
V(INTERNAL_IE_ENCODINGMENU_ARABIC_ISO, 3611, "ISO-8859-6") \
V(INTERNAL_IE_ENCODINGMENU_ARABIC_WINDOWS, 3612, "windows-1256") \
V(INTERNAL_IE_ENCODINGMENU_BALTIC_ISO, 3614, "ISO-8859-4") \
V(INTERNAL_IE_ENCODINGMENU_BALTIC_WINDOWS, 3615, "windows-1257") \
V(INTERNAL_IE_ENCODINGMENU_CENTRAL_EUROPEAN_DOS, 3616, "unknown") \
V(INTERNAL_IE_ENCODINGMENU_CENTRAL_EUROPEAN_ISO, 3617, "ISO-8859-2") \
V(INTERNAL_IE_ENCODINGMENU_CENTRAL_EUROPEAN_WINDOWS, 3618, "windows-1250") \
V(INTERNAL_IE_ENCODINGMENU_CHINESE_SIMP_GB18030, 3619, "gb18030") \
V(INTERNAL_IE_ENCODINGMENU_CHINESE_SIMP_GB2312, 3620, "GBK") \
V(INTERNAL_IE_ENCODINGMENU_CHINESE_SIMP_HZ, 3621, "unknown") \
V(INTERNAL_IE_ENCODINGMENU_CHINESE_TRAD_BIG5, 3622, "Big5") \
V(INTERNAL_IE_ENCODINGMENU_CYRILLIC_DOS, 3623, "unknown") \
V(INTERNAL_IE_ENCODINGMENU_CYRILLIC_ISO, 3624, "ISO-8859-5") \
V(INTERNAL_IE_ENCODINGMENU_CYRILLIC_KOI8R, 3625, "KOI8-R") \
V(INTERNAL_IE_ENCODINGMENU_CYRILLIC_KOI8U, 3626, "KOI8-U") \
V(INTERNAL_IE_ENCODINGMENU_CYRILLIC_WINDOWS, 3627, "windows-1251") \
V(INTERNAL_IE_ENCODINGMENU_GREEK_ISO, 3628, "ISO-8859-7") \
V(INTERNAL_IE_ENCODINGMENU_GREEK_WINDOWS, 3629, "windows-1253") \
V(INTERNAL_IE_ENCODINGMENU_HEBREW_DOS, 3630, "unknown") \
V(INTERNAL_IE_ENCODINGMENU_HEBREW_ISO_LOGICAL, 3631, "ISO-8859-8-I") \
V(INTERNAL_IE_ENCODINGMENU_HEBREW_ISO_VISUAL, 3632, "ISO-8859-8") \
V(INTERNAL_IE_ENCODINGMENU_HEBREW_WINDOWS, 3633, "windows-1255") \
V(INTERNAL_IE_ENCODINGMENU_JAPAN_AUTOSELECT, 3634, "ISO-2022-JP") \
V(INTERNAL_IE_ENCODINGMENU_JAPAN_EUC, 3635, "EUC-JP") \
V(INTERNAL_IE_ENCODINGMENU_JAPAN_SHIFT_JIS, 3636, "Shift_JIS") \
V(INTERNAL_IE_ENCODINGMENU_KOREA, 3637, "EUC-KR") \
V(INTERNAL_IE_ENCODINGMENU_THAI, 3638, "windows-874") \
V(INTERNAL_IE_ENCODINGMENU_TURKISH_ISO, 3639, "windows-1254") \
V(INTERNAL_IE_ENCODINGMENU_TURKISH_WINDOWS, 3640, "windows-1254") \
V(INTERNAL_IE_ENCODINGMENU_UTF8, 3641, "UTF-8") \
V(INTERNAL_IE_ENCODINGMENU_USERDEFINED, 3642, "windows-1252") \
V(INTERNAL_IE_ENCODINGMENU_VIETNAMESE, 3643, "windows-1258") \
V(INTERNAL_IE_ENCODINGMENU_WEST_EUROPEAN_ISO8859_1, 3644, "ISO-8859-1") \
V(INTERNAL_IE_ENCODINGMENU_WEST_EUROPEAN_WINDOWS, 3645, "windows-1252") \
V(INTERNAL_IE_ENCODINGMENU_AUTODETECT, 3699, "unknown")
#define DEFINE_ENCODING_ID(encoding_name, id, chrome_name) \
const DWORD encoding_name = id;
INTERNAL_IE_ENCODINGMENU_IDS(DEFINE_ENCODING_ID)
#undef DEFINE_ENCODING_ID
extern const DWORD kIEEncodingIdArray[];
#ifndef SBCMDID_MIXEDZONE
// This command is sent by the frame to allow the document to return the URL
// security zone for display.
// Please refer to http://msdn.microsoft.com/en-us/library/aa770042(VS.85).aspx
// for more information.
#define SBCMDID_MIXEDZONE 39
#endif // SBCMDID_MIXEDZONE
// From MSDN:
// Controlling Navigation: The fact that a document can navigate on its own
// implies that it will also take care of updating the navigation history.
// In Internet Explorer 6 and later, the DocObject can indicate to the client
// site that it can navigate using CGID_DocHostCmdPriv (a privately defined
// command group GUID) and the DOCHOST_DOCCANNAVIGATE command. A pointer to
// the object that implements the IHTMLWindow2 interface is passed with the
// command in the VARIANTARG* parameter pvaIn. (Set pvaIn to NULL if the
// document cannot perform its own navigation.)
#define DOCHOST_DOCCANNAVIGATE (0)
#define DOCHOST_DISPLAY_PRIVACY (75)
// This macro should be defined in the public section of the class.
#define BEGIN_EXEC_COMMAND_MAP(theClass) \
public: \
HRESULT ProcessExecCommand(const GUID* cmd_group_guid, DWORD command_id, \
DWORD cmd_exec_opt, VARIANT* in_args, \
VARIANT* out_args) { \
HRESULT hr = OLECMDERR_E_NOTSUPPORTED; \
do {
#define EXEC_COMMAND_HANDLER(group, id, handler) \
if ((id == command_id) && ((group != NULL && cmd_group_guid != NULL && \
IsEqualGUID(*reinterpret_cast<const GUID*>(group), *cmd_group_guid)) || \
(group == NULL && cmd_group_guid == NULL))) { \
hr = S_OK; \
handler(cmd_group_guid, command_id, cmd_exec_opt, in_args, out_args); \
break; \
}
#define EXEC_COMMAND_HANDLER_NO_ARGS(group, id, handler) \
if ((id == command_id) && ((group != NULL && cmd_group_guid != NULL && \
IsEqualGUID(*reinterpret_cast<const GUID*>(group), *cmd_group_guid)) || \
(group == NULL && cmd_group_guid == NULL))) { \
hr = S_OK; \
handler(); \
break; \
}
#define EXEC_COMMAND_HANDLER_GENERIC(group, id, code) \
if ((id == command_id) && ((group != NULL && cmd_group_guid != NULL && \
IsEqualGUID(*reinterpret_cast<const GUID*>(group), *cmd_group_guid)) || \
(group == NULL && cmd_group_guid == NULL))) { \
hr = S_OK; \
code; \
break; \
}
#define EXEC_GROUP_COMMANDS_HANDLER(group, group_commands, handler) \
do { \
const DWORD* commands = group_commands; \
bool id_in_group_commands = false; \
while (*commands) { \
if (*commands == command_id) { \
id_in_group_commands = true; \
break; \
} \
commands++; \
} \
if (id_in_group_commands && ((group != NULL && cmd_group_guid != NULL && \
IsEqualGUID(*reinterpret_cast<const GUID*>(group), \
*cmd_group_guid)) || \
(group == NULL && cmd_group_guid == NULL))) { \
hr = S_OK; \
handler(cmd_group_guid, command_id, cmd_exec_opt, in_args, out_args); \
break; \
} \
} while (0);
#define END_EXEC_COMMAND_MAP() \
} while (0); \
return hr; \
}
// ChromeActiveDocument: Implementation of the Active Document object that is
// responsible for rendering pages in Chrome. This object delegates to
// Chrome.exe (via the Chrome IPC-based automation mechanism) for the actual
// rendering
class ATL_NO_VTABLE ChromeActiveDocument
: public ChromeFrameActivexBase<ChromeActiveDocument,
CLSID_ChromeActiveDocument>,
public IOleDocumentImpl<ChromeActiveDocument>,
public IOleDocumentViewImpl<ChromeActiveDocument>,
public IPersistMoniker,
public IOleCommandTarget,
public InPlaceMenu<ChromeActiveDocument>,
public IWebBrowserEventsUrlService,
public IPersistHistory,
public IEnumPrivacyRecords,
public HTMLWindowImpl<IHTMLWindow2>,
public HTMLPrivateWindowImpl<IHTMLPrivateWindow> {
public:
typedef ChromeFrameActivexBase<ChromeActiveDocument,
CLSID_ChromeActiveDocument> BaseActiveX;
ChromeActiveDocument();
~ChromeActiveDocument();
DECLARE_REGISTRY_RESOURCEID(IDR_CHROMEACTIVEDOCUMENT)
BEGIN_COM_MAP(ChromeActiveDocument)
COM_INTERFACE_ENTRY(IOleDocument)
COM_INTERFACE_ENTRY(IOleDocumentView)
COM_INTERFACE_ENTRY(IPersistMoniker)
COM_INTERFACE_ENTRY(IOleCommandTarget)
COM_INTERFACE_ENTRY(IWebBrowserEventsUrlService)
COM_INTERFACE_ENTRY(IPersist)
COM_INTERFACE_ENTRY(IPersistHistory)
COM_INTERFACE_ENTRY(IHTMLFramesCollection2)
COM_INTERFACE_ENTRY(IHTMLWindow2)
COM_INTERFACE_ENTRY(IHTMLPrivateWindow)
COM_INTERFACE_ENTRY(IEnumPrivacyRecords)
COM_INTERFACE_ENTRY_CHAIN(BaseActiveX)
END_COM_MAP()
BEGIN_MSG_MAP(ChromeActiveDocument)
MESSAGE_HANDLER(WM_FIRE_PRIVACY_CHANGE_NOTIFICATION, OnFirePrivacyChange)
COMMAND_ID_HANDLER(IDC_CHROMEFRAME_FORWARD, OnForward)
COMMAND_ID_HANDLER(IDC_CHROMEFRAME_BACK, OnBack)
MESSAGE_HANDLER(WM_SHOWWINDOW, OnShowWindow)
MESSAGE_HANDLER(WM_SETFOCUS, OnSetFocus)
CHAIN_MSG_MAP(BaseActiveX)
END_MSG_MAP()
HRESULT FinalConstruct();
#define FORWARD_TAB_COMMAND(group, id, command) \
EXEC_COMMAND_HANDLER_GENERIC(group, id, GetTabProxy() ? \
GetTabProxy()->command() : 1)
BEGIN_EXEC_COMMAND_MAP(ChromeActiveDocument)
EXEC_COMMAND_HANDLER_GENERIC(NULL, OLECMDID_PRINT,
automation_client_->PrintTab())
EXEC_COMMAND_HANDLER_NO_ARGS(NULL, OLECMDID_FIND, OnFindInPage)
EXEC_COMMAND_HANDLER_NO_ARGS(&CGID_MSHTML, IDM_FIND, OnFindInPage)
EXEC_COMMAND_HANDLER_NO_ARGS(&CGID_MSHTML, IDM_VIEWSOURCE, OnViewSource)
FORWARD_TAB_COMMAND(NULL, OLECMDID_SELECTALL, SelectAll)
FORWARD_TAB_COMMAND(NULL, OLECMDID_CUT, Cut)
FORWARD_TAB_COMMAND(NULL, OLECMDID_COPY, Copy)
FORWARD_TAB_COMMAND(NULL, OLECMDID_PASTE, Paste)
FORWARD_TAB_COMMAND(NULL, OLECMDID_STOP, StopAsync)
FORWARD_TAB_COMMAND(NULL, OLECMDID_SAVEAS, SaveAsAsync)
EXEC_COMMAND_HANDLER(NULL, OLECMDID_REFRESH, OnRefreshPage)
EXEC_COMMAND_HANDLER(&CGID_Explorer, SBCMDID_MIXEDZONE,
OnDetermineSecurityZone)
EXEC_COMMAND_HANDLER(&CGID_MSHTML, IDM_BASELINEFONT1, SetPageFontSize)
EXEC_COMMAND_HANDLER(&CGID_MSHTML, IDM_BASELINEFONT2, SetPageFontSize)
EXEC_COMMAND_HANDLER(&CGID_MSHTML, IDM_BASELINEFONT3, SetPageFontSize)
EXEC_COMMAND_HANDLER(&CGID_MSHTML, IDM_BASELINEFONT4, SetPageFontSize)
EXEC_COMMAND_HANDLER(&CGID_MSHTML, IDM_BASELINEFONT5, SetPageFontSize)
EXEC_GROUP_COMMANDS_HANDLER(&CGID_MSHTML, kIEEncodingIdArray,
OnEncodingChange)
EXEC_COMMAND_HANDLER_NO_ARGS(&CGID_ShellDocView, DOCHOST_DISPLAY_PRIVACY,
OnDisplayPrivacyInfo)
EXEC_COMMAND_HANDLER(NULL, OLECMDID_OPTICAL_GETZOOMRANGE, OnGetZoomRange)
EXEC_COMMAND_HANDLER(NULL, OLECMDID_OPTICAL_ZOOM, OnSetZoomRange)
EXEC_COMMAND_HANDLER(NULL, OLECMDID_ONUNLOAD, OnUnload)
END_EXEC_COMMAND_MAP()
// IPCs from automation server.
virtual void OnNavigationStateChanged(
int flags, const NavigationInfo& nav_info);
virtual void OnUpdateTargetUrl(const std::wstring& new_target_url);
virtual void OnAcceleratorPressed(const MSG& accel_message);
virtual void OnTabbedOut(bool reverse);
virtual void OnDidNavigate(const NavigationInfo& nav_info);
virtual void OnCloseTab();
// Override DoVerb
STDMETHOD(DoVerb)(LONG verb,
LPMSG msg,
IOleClientSite* active_site,
LONG index,
HWND parent_window,
LPCRECT pos);
// Override IOleInPlaceActiveObjectImpl::OnDocWindowActivate
STDMETHOD(OnDocWindowActivate)(BOOL activate);
STDMETHOD(TranslateAccelerator)(MSG* msg);
// IPersistMoniker methods
STDMETHOD(GetClassID)(CLSID* class_id);
STDMETHOD(IsDirty)();
STDMETHOD(GetCurMoniker)(IMoniker** moniker_name);
STDMETHOD(Load)(BOOL fully_avalable,
IMoniker* moniker_name,
LPBC bind_context,
DWORD mode);
STDMETHOD(Save)(IMoniker* moniker_name,
LPBC bind_context,
BOOL remember);
STDMETHOD(SaveCompleted)(IMoniker* moniker_name,
LPBC bind_context);
// IOleCommandTarget methods
STDMETHOD(QueryStatus)(const GUID* cmd_group_guid,
ULONG number_of_commands,
OLECMD commands[],
OLECMDTEXT* command_text);
STDMETHOD(Exec)(const GUID* cmd_group_guid, DWORD command_id,
DWORD cmd_exec_opt,
VARIANT* in_args,
VARIANT* out_args);
// IPersistHistory
STDMETHOD(LoadHistory)(IStream* stream, IBindCtx* bind_context);
STDMETHOD(SaveHistory)(IStream* stream);
STDMETHOD(SetPositionCookie)(DWORD position_cookie);
STDMETHOD(GetPositionCookie)(DWORD* position_cookie);
// IWebBrowserEventsUrlService methods
STDMETHOD(GetUrlForEvents)(BSTR* url);
// IHTMLPrivateWindow methods
STDMETHOD(GetAddressBarUrl)(BSTR* url);
// ChromeFrameActivexBase overrides
HRESULT IOleObject_SetClientSite(IOleClientSite* client_site);
HRESULT ActiveXDocActivate(LONG verb);
// Callbacks from ChromeFramePlugin<T>
bool PreProcessContextMenu(HMENU menu);
bool HandleContextMenuCommand(UINT cmd, const MiniContextMenuParams& params);
// ChromeFramePlugin overrides.
virtual void OnAutomationServerReady();
// IEnumPrivacyRecords
STDMETHOD(Reset)();
STDMETHOD(GetSize)(ULONG* size);
STDMETHOD(GetPrivacyImpacted)(BOOL* privacy_impacted);
STDMETHOD(Next)(BSTR* url, BSTR* policy, LONG* reserved, DWORD* flags);
// NavigationConstraints overrides.
bool IsSchemeAllowed(const GURL& url);
// Accessor for InPlaceMenu. Returns S_OK if set, S_FALSE if NULL.
HRESULT GetInPlaceFrame(IOleInPlaceFrame** in_place_frame);
protected:
// ChromeFrameActivexBase overrides
virtual void OnAttachExternalTab(const AttachExternalTabParams& params);
virtual void OnGoToHistoryEntryOffset(int offset);
virtual void OnMoveWindow(const gfx::Rect& dimensions);
// A helper method that updates our internal navigation state
// as well as IE's navigation state (viz Title and current URL).
// The navigation_flags is a TabContents::InvalidateTypes enum
void UpdateNavigationState(const NavigationInfo& nav_info, int flags);
TabProxy* GetTabProxy() const {
if (automation_client_.get())
return automation_client_->tab();
return NULL;
}
// Exec command handlers
void OnFindInPage();
void OnViewSource();
void OnDetermineSecurityZone(const GUID* cmd_group_guid, DWORD command_id,
DWORD cmd_exec_opt, VARIANT* in_args,
VARIANT* out_args);
void OnDisplayPrivacyInfo();
void OnGetZoomRange(const GUID* cmd_group_guid, DWORD command_id,
DWORD cmd_exec_opt, VARIANT* in_args, VARIANT* out_args);
void OnSetZoomRange(const GUID* cmd_group_guid, DWORD command_id,
DWORD cmd_exec_opt, VARIANT* in_args, VARIANT* out_args);
// This function handles the OLECMDID_ONUNLOAD command. It enables Chrome to
// invoke before unload and unload handlers on the page if any, thereby
// enabling a webpage to potentially cancel the operation.
void OnUnload(const GUID* cmd_group_guid, DWORD command_id,
DWORD cmd_exec_opt, VARIANT* in_args, VARIANT* out_args);
// Call exec on our site's command target
HRESULT IEExec(const GUID* cmd_group_guid, DWORD command_id,
DWORD cmd_exec_opt, VARIANT* in_args, VARIANT* out_args);
// Initiates navigation to the URL passed in.
// Returns true on success.
bool LaunchUrl(const ChromeFrameUrl& cf_url, const std::string& referrer);
// Handler to set the page font size in Chrome.
HRESULT SetPageFontSize(const GUID* cmd_group_guid,
DWORD command_id,
DWORD cmd_exec_opt,
VARIANT* in_args,
VARIANT* out_args);
// IOleCommandTarget handler for page refresh command
HRESULT OnRefreshPage(const GUID* cmd_group_guid, DWORD command_id,
DWORD cmd_exec_opt, VARIANT* in_args, VARIANT* out_args);
// Handler to set the page encoding info in Chrome.
HRESULT OnEncodingChange(const GUID* cmd_group_guid, DWORD command_id,
DWORD cmd_exec_opt, VARIANT* in_args,
VARIANT* out_args);
// Get the travel log from the client site
HRESULT GetBrowserServiceAndTravelLog(IBrowserService** browser_service,
ITravelLog** travel_log);
LRESULT OnForward(WORD notify_code, WORD id, HWND control_window,
BOOL& bHandled);
LRESULT OnBack(WORD notify_code, WORD id, HWND control_window,
BOOL& bHandled);
LRESULT OnFirePrivacyChange(UINT message, WPARAM wparam, LPARAM lparam,
BOOL& handled);
LRESULT OnShowWindow(UINT message, WPARAM wparam, LPARAM lparam,
BOOL& handled);
LRESULT OnSetFocus(UINT message, WPARAM wparam, LPARAM lparam,
BOOL& handled);
// Returns true if the NavigationInfo object passed in represents a new
// navigation initiated by the renderer.
bool IsNewNavigation(const NavigationInfo& new_navigation_info,
int flags) const;
// Returns true if the NavigationInfo object passed in represents a first
// page navigation initiated as this active document was being created.
bool IsFirstNavigation(const NavigationInfo& new_navigation_info) const;
protected:
typedef std::map<int, OLECMDF> CommandStatusMap;
scoped_ptr<NavigationInfo> navigation_info_;
bool is_doc_object_;
// This indicates whether this is the first navigation in this
// active document. It is initalize to true and it is set to false
// after we get a navigation notification from Chrome
bool first_navigation_;
// Our find dialog
CFFindDialog find_dialog_;
// These members contain the status of the commands we support.
CommandStatusMap null_group_commands_map_;
CommandStatusMap mshtml_group_commands_map_;
CommandStatusMap explorer_group_commands_map_;
CommandStatusMap shdoc_view_group_commands_map_;
// Set to true if the automation_client_ member is initialized from
// an existing ChromeActiveDocument instance which is going away and
// a new ChromeActiveDocument instance is taking its place.
bool is_automation_client_reused_;
base::win::ScopedComPtr<INewWindowManager> popup_manager_;
bool popup_allowed_;
HACCEL accelerator_table_;
// Contains privacy data retrieved from the UrlmonUrlRequestManager. This
// is used to return privacy data in response to the View->Privacy policy
// command.
UrlmonUrlRequestManager::PrivacyInfo privacy_info_;
UrlmonUrlRequestManager::PrivacyInfo::PrivacyRecords::iterator
next_privacy_record_;
public:
OLEINPLACEFRAMEINFO frame_info_;
};
#endif // CHROME_FRAME_CHROME_ACTIVE_DOCUMENT_H_