fix GetTextExtent with non-null font argument, fixes #13750

[wxWidgets.git] / interface / wx / utils.h

/////////////////////////////////////////////////////////////////////////////
// Name:        utils.h
// Purpose:     interface of various utility classes and functions
// Author:      wxWidgets team
// RCS-ID:      $Id$
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

/**
    @class wxWindowDisabler

    This class disables all windows of the application (may be with the
    exception of one of them) in its constructor and enables them back in its
    destructor.

    This is useful when you want to indicate to the user that the application
    is currently busy and cannot respond to user input.

    @library{wxcore}
    @category{misc}

    @see wxBusyCursor
*/
class wxWindowDisabler
{
public:
    /**
        Disables all top level windows of the applications.

        If @a disable is @c false nothing is done. This can be convenient if
        the windows should be disabled depending on some condition.

        @since 2.9.0
    */
    wxWindowDisabler(bool disable = true);

    /**
        Disables all top level windows of the applications with the exception
        of @a winToSkip if it is not @NULL.

        Notice that under MSW if @a winToSkip appears in the taskbar, the user
        will be able to close the entire application (even though its main
        window is disabled) by right clicking on the taskbar icon and selecting
        the appropriate "Close" command from the context menu. To prevent this
        from happening you may want to use wxFRAME_TOOL_WINDOW, if applicable,
        or wxFRAME_NO_TASKBAR style when creating the window that will remain
        enabled.
    */
    wxWindowDisabler(wxWindow* winToSkip);

    /**
        Reenables the windows disabled by the constructor.
    */
    ~wxWindowDisabler();
};



/**
    @class wxBusyCursor

    This class makes it easy to tell your user that the program is temporarily
    busy. Just create a wxBusyCursor object on the stack, and within the
    current scope, the hourglass will be shown.

    For example:

    @code
    wxBusyCursor wait;

    for (int i = 0; i < 100000; i++)
        DoACalculation();
    @endcode

    It works by calling wxBeginBusyCursor() in the constructor, and
    wxEndBusyCursor() in the destructor.

    @library{wxcore}
    @category{misc}

    @see wxBeginBusyCursor(), wxEndBusyCursor(), wxWindowDisabler
*/
class wxBusyCursor
{
public:
    /**
        Constructs a busy cursor object, calling wxBeginBusyCursor().
    */
    wxBusyCursor(const wxCursor* cursor = wxHOURGLASS_CURSOR);

    /**
        Destroys the busy cursor object, calling wxEndBusyCursor().
    */
    ~wxBusyCursor();
};



// ============================================================================
// Global functions/macros
// ============================================================================


/** @addtogroup group_funcmacro_dialog */
//@{

/**
    Changes the cursor to the given cursor for all windows in the application.
    Use wxEndBusyCursor() to revert the cursor back to its previous state.
    These two calls can be nested, and a counter ensures that only the outer
    calls take effect.

    @see wxIsBusy(), wxBusyCursor

    @header{wx/utils.h}
*/
void wxBeginBusyCursor(const wxCursor* cursor = wxHOURGLASS_CURSOR);

/**
    Changes the cursor back to the original cursor, for all windows in the
    application. Use with wxBeginBusyCursor().

    @see wxIsBusy(), wxBusyCursor

    @header{wx/utils.h}
*/
void wxEndBusyCursor();

/**
    Returns @true if between two wxBeginBusyCursor() and wxEndBusyCursor()
    calls.

    @see wxBusyCursor.

    @header{wx/utils.h}
*/
bool wxIsBusy();

/**
    Ring the system bell.

    @note This function is categorized as a GUI one and so is not thread-safe.

    @header{wx/utils.h}
*/
void wxBell();

/**
    Shows a message box with the information about the wxWidgets build used,
    including its version, most important build parameters and the version of
    the underlying GUI toolkit. This is mainly used for diagnostic purposes
    and can be invoked by Ctrl-Alt-middle clicking on any wxWindow which
    doesn't otherwise handle this event.

    @since 2.9.0
    @see wxGetLibraryVersionInfo()
    @header{wx/utils.h}
*/
void wxInfoMessageBox(wxWindow* parent);

//@}

/** @addtogroup group_funcmacro_version */
//@{

/**
    Get wxWidgets version information.

    @since 2.9.2
    @see wxVersionInfo
    @header{wx/utils.h}
    @library{wxcore}
*/
wxVersionInfo wxGetLibraryVersionInfo();

//@}



/** @addtogroup group_funcmacro_env */
//@{

/**
    A map type containing environment variables names and values.

    This type is used with wxGetEnvMap() function and wxExecuteEnv structure
    optionally passed to wxExecute().

    @since 2.9.2

    @header{wx/utils.h}
*/
typedef wxStringToStringHashMap wxEnvVariableHashMap;

/**
    This is a macro defined as @c getenv() or its wide char version in Unicode
    mode.

    Note that under Win32 it may not return correct value for the variables set
    with wxSetEnv(), use wxGetEnv() function instead.

    @header{wx/utils.h}
*/
wxChar* wxGetenv(const wxString& var);

/**
    Returns the current value of the environment variable @a var in @a value.

    @a value may be @NULL if you just want to know if the variable exists and
    are not interested in its value.

    Returns @true if the variable exists, @false otherwise.

    @header{wx/utils.h}
*/
bool wxGetEnv(const wxString& var, wxString* value);

/**
    Sets the value of the environment variable @a var (adding it if necessary)
    to @a value.

    Notice that under Windows platforms the program may have two different
    environment blocks: the first one is that of a Windows process and is
    always present, but the CRT may maintain its own independent copy of the
    environment. wxSetEnv() will always update the first copy, which means that
    wxGetEnv(), which uses it directly, will always return the expected value
    after this call. But wxSetEnv() only updates the second copy for some
    compilers/CRT implementations (currently only MSVC and MinGW which uses the
    same MSVC CRT) and so using wxGetenv() (notice the difference in case) may
    not return the updated value.

    @param var
        The environment variable to be set, must not contain @c '=' character.
    @param value
        New value of the variable.
    @return
        @true on success or @false if changing the value failed.

    @see wxUnsetEnv()

    @header{wx/utils.h}
*/
bool wxSetEnv(const wxString& var, const wxString& value);

/**
    Removes the variable @a var from the environment.

    wxGetEnv() will return @NULL after the call to this function.

    Returns @true on success.

    @header{wx/utils.h}
*/
bool wxUnsetEnv(const wxString& var);

/**
    Fill a map with the complete content of current environment.

    The map will contain the environment variable names as keys and their
    values as values.

    @param map
        The environment map to fill, must be non-@NULL.
    @return
        @true if environment was successfully retrieved or @false otherwise.

    @header{wx/utils.h}

    @since 2.9.2
*/
bool wxGetEnvMap(wxEnvVariableHashMap *map);
//@}



/** @addtogroup group_funcmacro_misc */
//@{

/**
    Returns battery state as one of @c wxBATTERY_NORMAL_STATE,
    @c wxBATTERY_LOW_STATE, @c wxBATTERY_CRITICAL_STATE,
    @c wxBATTERY_SHUTDOWN_STATE or @c wxBATTERY_UNKNOWN_STATE.
    @c wxBATTERY_UNKNOWN_STATE is also the default on platforms where this
    feature is not implemented (currently everywhere but MS Windows).

    @header{wx/utils.h}
*/
wxBatteryState wxGetBatteryState();

/**
    Returns the type of power source as one of @c wxPOWER_SOCKET,
    @c wxPOWER_BATTERY or @c wxPOWER_UNKNOWN. @c wxPOWER_UNKNOWN is also the
    default on platforms where this feature is not implemented (currently
    everywhere but MS Windows).

    @header{wx/utils.h}
*/
wxPowerType wxGetPowerType();

/**
    Under X only, returns the current display name.

    @see wxSetDisplayName()

    @header{wx/utils.h}
*/
wxString wxGetDisplayName();

/**
    For normal keys, returns @true if the specified key is currently down.

    For togglable keys (Caps Lock, Num Lock and Scroll Lock), returns @true if
    the key is toggled such that its LED indicator is lit. There is currently
    no way to test whether togglable keys are up or down.

    Even though there are virtual key codes defined for mouse buttons, they
    cannot be used with this function currently.

    @header{wx/utils.h}
*/
bool wxGetKeyState(wxKeyCode key);

/**
    Returns the mouse position in screen coordinates.

    @header{wx/utils.h}
*/
wxPoint wxGetMousePosition();

/**
    Returns the current state of the mouse.  Returns a wxMouseState instance
    that contains the current position of the mouse pointer in screen
    coordinates, as well as boolean values indicating the up/down status of the
    mouse buttons and the modifier keys.

    @header{wx/utils.h}
*/
wxMouseState wxGetMouseState();

/**
    This function enables or disables all top level windows. It is used by
    wxSafeYield().

    @header{wx/utils.h}
*/
void wxEnableTopLevelWindows(bool enable = true);

/**
    Find the deepest window at the given mouse position in screen coordinates,
    returning the window if found, or @NULL if not.

    @header{wx/utils.h}
*/
wxWindow* wxFindWindowAtPoint(const wxPoint& pt);

/**
    @deprecated Replaced by wxWindow::FindWindowByLabel().

    Find a window by its label. Depending on the type of window, the label may
    be a window title or panel item label. If @a parent is @NULL, the search
    will start from all top-level frames and dialog boxes; if non-@NULL, the
    search will be limited to the given window hierarchy. The search is
    recursive in both cases.

    @header{wx/utils.h}
*/
wxWindow* wxFindWindowByLabel(const wxString& label,
                              wxWindow* parent = NULL);

/**
    @deprecated Replaced by wxWindow::FindWindowByName().

    Find a window by its name (as given in a window constructor or @e Create
    function call). If @a parent is @NULL, the search will start from all
    top-level frames and dialog boxes; if non-@NULL, the search will be limited
    to the given window hierarchy. The search is recursive in both cases.

    If no such named window is found, wxFindWindowByLabel() is called.

    @header{wx/utils.h}
*/
wxWindow* wxFindWindowByName(const wxString& name, wxWindow* parent = NULL);

/**
    Find a menu item identifier associated with the given frame's menu bar.

    @header{wx/utils.h}
*/
int wxFindMenuItemId(wxFrame* frame, const wxString& menuString,
                     const wxString& itemString);

/**
    @deprecated Ids generated by it can conflict with the Ids defined by the
                user code, use @c wxID_ANY to assign ids which are guaranteed
                to not conflict with the user-defined ids for the controls and
                menu items you create instead of using this function.

    Generates an integer identifier unique to this run of the program.

    @header{wx/utils.h}
*/
long wxNewId();

/**
    Ensures that Ids subsequently generated by wxNewId() do not clash with the
    given @a id.

    @header{wx/utils.h}
*/
void wxRegisterId(long id);

/**
    Opens the @a document in the application associated with the files of this
    type.

    The @a flags parameter is currently not used

    Returns @true if the application was successfully launched.

    @see wxLaunchDefaultBrowser(), wxExecute()

    @header{wx/utils.h}
*/
bool wxLaunchDefaultApplication(const wxString& document, int flags = 0);

/**
    Opens the @a url in user's default browser.

    If the @a flags parameter contains @c wxBROWSER_NEW_WINDOW flag, a new
    window is opened for the URL (currently this is only supported under
    Windows).

    And unless the @a flags parameter contains @c wxBROWSER_NOBUSYCURSOR flag,
    a busy cursor is shown while the browser is being launched (using
    wxBusyCursor).

    The parameter @a url is interpreted as follows:
    - if it has a valid scheme (e.g. @c "file:", @c "http:" or @c "mailto:")
      it is passed to the appropriate browser configured in the user system.
    - if it has no valid scheme (e.g. it's a local file path without the @c "file:"
      prefix), then ::wxFileExists and ::wxDirExists are used to test if it's a
      local file/directory; if it is, then the browser is called with the
      @a url parameter eventually prefixed by @c "file:".
    - if it has no valid scheme and it's not a local file/directory, then @c "http:"
      is prepended and the browser is called.

    Returns @true if the application was successfully launched.

    @note For some configurations of the running user, the application which is
          launched to open the given URL may be URL-dependent (e.g. a browser
          may be used for local URLs while another one may be used for remote
          URLs).

    @see wxLaunchDefaultApplication(), wxExecute()

    @header{wx/utils.h}
*/
bool wxLaunchDefaultBrowser(const wxString& url, int flags = 0);

/**
    Loads a user-defined Windows resource as a string. If the resource is
    found, the function creates a new character array and copies the data into
    it. A pointer to this data is returned. If unsuccessful, @NULL is returned.

    The resource must be defined in the @c .rc file using the following syntax:

    @code
    myResource TEXT file.ext
    @endcode

    Where @c file.ext is a file that the resource compiler can find.

    This function is available under Windows only.

    @header{wx/utils.h}
*/
wxString wxLoadUserResource(const wxString& resourceName,
                            const wxString& resourceType = "TEXT");

/**
    @deprecated Replaced by wxWindow::Close(). See the
                @ref overview_windowdeletion "window deletion overview".

    Tells the system to delete the specified object when all other events have
    been processed. In some environments, it is necessary to use this instead
    of deleting a frame directly with the delete operator, because some GUIs
    will still send events to a deleted window.

    @header{wx/utils.h}
*/
void wxPostDelete(wxObject* object);


/**
    Compare function type for use with wxQsort()

    @header{wx/utils.h}
*/
typedef int (*wxSortCallback)(const void* pItem1, const void* pItem2, const void* user_data);

/**
    Function implementing quick sort algorithm.

    This function sorts @a total_elems objects of size @a size located at @a
    pbase. It uses @a cmp function for comparing them and passes @a user_data
    pointer to the comparison function each time it's called.

    @header{wx/utils.h}
*/
void wxQsort(void* pbase, size_t total_elems,
             size_t size, wxSortCallback cmp, const void* user_data);


/**
    Under X only, sets the current display name. This is the X host and display
    name such as "colonsay:0.0", and the function indicates which display
    should be used for creating windows from this point on. Setting the display
    within an application allows multiple displays to be used.

    @see wxGetDisplayName()

    @header{wx/utils.h}
*/
void wxSetDisplayName(const wxString& displayName);

/**
    Strips any menu codes from @a str and returns the result.

    By default, the functions strips both the mnemonics character (@c '&')
    which is used to indicate a keyboard shortkey, and the accelerators, which
    are used only in the menu items and are separated from the main text by the
    @c \\t (TAB) character. By using @a flags of @c wxStrip_Mnemonics or
    @c wxStrip_Accel to strip only the former or the latter part, respectively.

    Notice that in most cases wxMenuItem::GetLabelFromText() or
    wxControl::GetLabelText() can be used instead.

    @header{wx/utils.h}
*/
wxString wxStripMenuCodes(const wxString& str, int flags = wxStrip_All);

//@}



/** @addtogroup group_funcmacro_networkuseros */
//@{

/**
    Copies the user's email address into the supplied buffer, by concatenating
    the values returned by wxGetFullHostName() and wxGetUserId().

    @return @true if successful, @false otherwise.

    @header{wx/utils.h}
*/
wxString wxGetEmailAddress();

/**
    @deprecated Use wxGetEmailAddress() instead.

    @param buf Buffer to store the email address in.
    @param sz  Size of the buffer.

    @return @true if successful, @false otherwise.

    @header{wx/utils.h}
*/
bool wxGetEmailAddress(char* buf, int sz);

/**
    Returns the amount of free memory in bytes under environments which support
    it, and -1 if not supported or failed to perform measurement.

    @header{wx/utils.h}
*/
wxMemorySize wxGetFreeMemory();

/**
    Return the (current) user's home directory.

    @see wxGetUserHome(), wxStandardPaths

    @header{wx/utils.h}
*/
wxString wxGetHomeDir();

/**
    Copies the current host machine's name into the supplied buffer. Please
    note that the returned name is @e not fully qualified, i.e. it does not
    include the domain name.

    Under Windows or NT, this function first looks in the environment variable
    SYSTEM_NAME; if this is not found, the entry @b HostName in the wxWidgets
    section of the WIN.INI file is tried.

    @return The hostname if successful or an empty string otherwise.

    @see wxGetFullHostName()

    @header{wx/utils.h}
*/
wxString wxGetHostName();

/**
    @deprecated Use wxGetHostName() instead.

    @param buf Buffer to store the host name in.
    @param sz  Size of the buffer.

    @return @true if successful, @false otherwise.

    @header{wx/utils.h}
*/
bool wxGetHostName(char* buf, int sz);

/**
    Returns the FQDN (fully qualified domain host name) or an empty string on
    error.

    @see wxGetHostName()

    @header{wx/utils.h}
*/
wxString wxGetFullHostName();

/**
    Returns the home directory for the given user. If the @a user is empty
    (default value), this function behaves like wxGetHomeDir() (i.e. returns
    the current user home directory).

    If the home directory couldn't be determined, an empty string is returned.

    @header{wx/utils.h}
*/
wxString wxGetUserHome(const wxString& user = wxEmptyString);

/**
    This function returns the "user id" also known as "login name" under Unix
    (i.e. something like "jsmith"). It uniquely identifies the current user (on
    this system).  Under Windows or NT, this function first looks in the
    environment variables USER and LOGNAME; if neither of these is found, the
    entry @b UserId in the @b wxWidgets section of the WIN.INI file is tried.

    @return The login name if successful or an empty string otherwise.

    @see wxGetUserName()

    @header{wx/utils.h}
*/
wxString wxGetUserId();

/**
    @deprecated Use wxGetUserId() instead.

    @param buf Buffer to store the login name in.
    @param sz  Size of the buffer.

    @return @true if successful, @false otherwise.

    @header{wx/utils.h}
*/
bool wxGetUserId(char* buf, int sz);

/**
    This function returns the full user name (something like "Mr. John Smith").

    Under Windows or NT, this function looks for the entry UserName in the
    wxWidgets section of the WIN.INI file. If PenWindows is running, the entry
    Current in the section User of the PENWIN.INI file is used.

    @return The full user name if successful or an empty string otherwise.

    @see wxGetUserId()

    @header{wx/utils.h}
*/
wxString wxGetUserName();

/**
    @deprecated Use wxGetUserName() instead.

    @param buf Buffer to store the full user name in.
    @param sz  Size of the buffer.

    @return @true if successful, @false otherwise.

    @header{wx/utils.h}
*/
bool wxGetUserName(char* buf, int sz);

/**
    Returns the string containing the description of the current platform in a
    user-readable form. For example, this function may return strings like
    "Windows NT Version 4.0" or "Linux 2.2.2 i386".

    @see wxGetOsVersion()

    @header{wx/utils.h}
*/
wxString wxGetOsDescription();

/**
    Gets the version and the operating system ID for currently running OS. 
    The returned wxOperatingSystemId value can be used for a basic categorization
    of the OS family; the major and minor version numbers allows to detect a specific
    system.
    
    For Unix-like systems (@c wxOS_UNIX) the major and minor version integers will 
    contain the kernel major and minor version numbers (as returned by the
    'uname -r' command); e.g. "2" and "6" if the machine is using kernel 2.6.19.

    For Mac OS X systems (@c wxOS_MAC) the major and minor version integers are the
    natural version numbers associated with the OS; e.g. "10" and "6" if the machine
    is using Mac OS X Snow Leopard.    
    
    For Windows-like systems (@c wxOS_WINDOWS) the major and minor version integers will 
    contain the following values:
    @beginTable
    @row3col{<b>Windows OS name</b>, <b>Major version</b>, <b>Minor version</b>}
    @row3col{Windows 7,                 6, 1}
    @row3col{Windows Server 2008 R2,    6, 1}
    @row3col{Windows Server 2008,       6, 0}
    @row3col{Windows Vista,             6, 0}
    @row3col{Windows Server 2003 R2,    5, 2}
    @row3col{Windows Server 2003,       5, 2}
    @row3col{Windows XP,                5, 1}
    @row3col{Windows 2000,              5, 0}
    @endDefList
    See the <a href="http://msdn.microsoft.com/en-us/library/ms724832(VS.85).aspx">MSDN</a>
    for more info about the values above.

    @see wxGetOsDescription(), wxPlatformInfo

    @header{wx/utils.h}
*/
wxOperatingSystemId wxGetOsVersion(int* major = NULL, int* minor = NULL);

/**
    Returns @true if the operating system the program is running under is 64
    bit. The check is performed at run-time and may differ from the value
    available at compile-time (at compile-time you can just check if
    <tt>sizeof(void*) == 8</tt>) since the program could be running in
    emulation mode or in a mixed 32/64 bit system (bi-architecture operating
    system).

    @note This function is not 100% reliable on some systems given the fact
          that there isn't always a standard way to do a reliable check on the
          OS architecture.

    @header{wx/utils.h}
*/
bool wxIsPlatform64Bit();

/**
    Returns @true if the current platform is little endian (instead of big
    endian). The check is performed at run-time.

    @see @ref group_funcmacro_byteorder "Byte Order Functions and Macros"

    @header{wx/utils.h}
*/
bool wxIsPlatformLittleEndian();

/**
    Returns a structure containing informations about the currently running
    Linux distribution.
    
    This function uses the @c lsb_release utility which is part of the 
    <tt>Linux Standard Base Core</tt> specification 
    (see http://refspecs.linux-foundation.org/lsb.shtml) since the very first LSB 
    release 1.0 (released in 2001).
    The @c lsb_release utility is very common on modern Linux distributions but in
    case it's not available, then this function will return a ::wxLinuxDistributionInfo
    structure containing empty strings.
    
    This function is Linux-specific and is only available when the @c __LINUX__
    symbol is defined.
*/
wxLinuxDistributionInfo wxGetLinuxDistributionInfo();

//@}



/** @addtogroup group_funcmacro_procctrl */
//@{

/**
    @struct wxExecuteEnv

    This structure can optionally be passed to wxExecute() to specify
    additional options to use for the child process.

    @since 2.9.2

    @header{wx/utils.h}
*/
struct wxExecuteEnv
{
    /**
        The initial working directory for the new process.

        If this field is empty, the current working directory of this process
        is used.
    */
    wxString cwd;

    /**
        The environment variable map.

        If the map is empty, the environment variables of the current process
        are also used for the child one, otherwise only the variables defined
        in this map are used.
    */
    wxEnvVariableHashMap env;
};

/**
    Bit flags that can be used with wxExecute().
 */
enum
{
    /**
        Execute the process asynchronously.

        Notice that, due to its value, this is the default.
     */
    wxEXEC_ASYNC    = 0,

    /**
        Execute the process synchronously.
     */
    wxEXEC_SYNC     = 1,

    /**
        Always show the child process console under MSW.

        The child console is hidden by default if the child IO is redirected,
        this flag allows to change this and show it nevertheless.

        This flag is ignored under the other platforms.
     */
    wxEXEC_SHOW_CONSOLE   = 2,

    /**
        Make the new process a group leader.

        Under Unix, if the process is the group leader then passing
        wxKILL_CHILDREN to wxKill() kills all children as well as pid.

        This flag is currently ignored under MSW.
     */
    wxEXEC_MAKE_GROUP_LEADER = 4,

    /**
        Don't disable the program UI while running the child synchronously.

        By default synchronous execution disables all program windows to avoid
        that the user interacts with the program while the child process is
        running, you can use this flag to prevent this from happening.

        This flag can only be used with ::wxEXEC_SYNC.
     */
    wxEXEC_NODISABLE = 8,

    /**
        Don't dispatch events while the child process is executed.

        By default, the event loop is run while waiting for synchronous
        execution to complete and this flag can be used to simply block the
        main process until the child process finishes

        This flag can only be used with ::wxEXEC_SYNC.
     */
    wxEXEC_NOEVENTS = 16,

    /**
        Hide child process console under MSW.

        Under MSW, hide the console of the child process if it has one,
        even if its IO is not redirected.

        This flag is ignored under the other platforms.
     */
    wxEXEC_HIDE_CONSOLE = 32,

    /**
        Convenient synonym for flags given system()-like behaviour.
     */
    wxEXEC_BLOCK = wxEXEC_SYNC | wxEXEC_NOEVENTS
};
/**
    Executes another program in Unix or Windows.

    In the overloaded versions of this function, if @a flags parameter contains
    @c wxEXEC_ASYNC flag (the default), flow of control immediately returns. If
    it contains @c wxEXEC_SYNC, the current application waits until the other
    program has terminated.

    In the case of synchronous execution, the return value is the exit code of
    the process (which terminates by the moment the function returns) and will
    be -1 if the process couldn't be started and typically 0 if the process
    terminated successfully. Also, while waiting for the process to terminate,
    wxExecute() will call wxYield(). Because of this, by default this function
    disables all application windows to avoid unexpected reentrancies which
    could result from the users interaction with the program while the child
    process is running. If you are sure that it is safe to not disable the
    program windows, you may pass @c wxEXEC_NODISABLE flag to prevent this
    automatic disabling from happening.

    For asynchronous execution, however, the return value is the process id and
    zero value indicates that the command could not be executed. As an added
    complication, the return value of -1 in this case indicates that we didn't
    launch a new process, but connected to the running one (this can only
    happen when using DDE under Windows for command execution). In particular,
    in this case only, the calling code will not get the notification about
    process termination.

    If @a callback isn't @NULL and if execution is asynchronous,
    wxProcess::OnTerminate() will be called when the process finishes.
    Specifying this parameter also allows you to redirect the standard input
    and/or output of the process being launched by calling
    wxProcess::Redirect().

    Under Windows, when launching a console process its console is shown by
    default but hidden if its IO is redirected. Both of these default
    behaviours may be overridden: if ::wxEXEC_HIDE_CONSOLE is specified, the
    console will never be shown. If ::wxEXEC_SHOW_CONSOLE is used, the console
    will be shown even if the child process IO is redirected. Neither of these
    flags affect non-console Windows applications or does anything under the
    other systems.

    Under Unix the flag @c wxEXEC_MAKE_GROUP_LEADER may be used to ensure that
    the new process is a group leader (this will create a new session if
    needed). Calling wxKill() passing wxKILL_CHILDREN will kill this process as
    well as all of its children (except those which have started their own
    session).

    The @c wxEXEC_NOEVENTS flag prevents processing of any events from taking
    place while the child process is running. It should be only used for very
    short-lived processes as otherwise the application windows risk becoming
    unresponsive from the users point of view. As this flag only makes sense
    with @c wxEXEC_SYNC, @c wxEXEC_BLOCK equal to the sum of both of these
    flags is provided as a convenience.

    @note Currently wxExecute() can only be used from the main thread, calling
          this function from another thread will result in an assert failure in
          debug build and won't work.

    @param command
        The command to execute and any parameters to pass to it as a single
        string, i.e. "emacs file.txt".
    @param flags
        Must include either wxEXEC_ASYNC or wxEXEC_SYNC and can also include
        wxEXEC_SHOW_CONSOLE, wxEXEC_HIDE_CONSOLE, wxEXEC_MAKE_GROUP_LEADER (in
        either case) or wxEXEC_NODISABLE and wxEXEC_NOEVENTS or wxEXEC_BLOCK,
        which is equal to their combination, in wxEXEC_SYNC case.
    @param callback
        An optional pointer to wxProcess.
    @param env
        An optional pointer to additional parameters for the child process,
        such as its initial working directory and environment variables. This
        parameter is available in wxWidgets 2.9.2 and later only.

    @see wxShell(), wxProcess, @ref page_samples_exec,
         wxLaunchDefaultApplication(), wxLaunchDefaultBrowser()

    @header{wx/utils.h}

    @beginWxPerlOnly
    In wxPerl this function is called @c Wx::ExecuteCommand.
    @endWxPerlOnly
*/
long wxExecute(const wxString& command, int flags = wxEXEC_ASYNC,
                wxProcess* callback = NULL,
                const wxExecuteEnv* env = NULL);
//@}

/** @addtogroup group_funcmacro_procctrl */
//@{
/**
    This is an overloaded version of wxExecute(const wxString&,int,wxProcess*),
    please see its documentation for general information.

    This version takes an array of values: a command, any number of arguments,
    terminated by @NULL.

    @param argv
        The command to execute should be the first element of this array, any
        additional ones are the command parameters and the array must be
        terminated with a @NULL pointer.
    @param flags
        Same as for wxExecute(const wxString&,int,wxProcess*) overload.
    @param callback
        An optional pointer to wxProcess.
    @param env
        An optional pointer to additional parameters for the child process,
        such as its initial working directory and environment variables. This
        parameter is available in wxWidgets 2.9.2 and later only.

    @see wxShell(), wxProcess, @ref page_samples_exec,
         wxLaunchDefaultApplication(), wxLaunchDefaultBrowser()

    @header{wx/utils.h}

    @beginWxPerlOnly
    In wxPerl this function is called @c Wx::ExecuteArgs.
    @endWxPerlOnly
*/
long wxExecute(char** argv, int flags = wxEXEC_ASYNC,
                wxProcess* callback = NULL,
                const wxExecuteEnv *env = NULL);
long wxExecute(wchar_t** argv, int flags = wxEXEC_ASYNC,
                wxProcess* callback = NULL,
                const wxExecuteEnv *env = NULL);
//@}

/** @addtogroup group_funcmacro_procctrl */
//@{

/**
    This is an overloaded version of wxExecute(const wxString&,int,wxProcess*),
    please see its documentation for general information.

    This version can be used to execute a process (always synchronously, the
    contents of @a flags is or'd with @c wxEXEC_SYNC) and capture its output in
    the array @e output.

    @param command
        The command to execute and any parameters to pass to it as a single
        string.
    @param output
        The string array where the stdout of the executed process is saved.
    @param flags
        Combination of flags to which ::wxEXEC_SYNC is always implicitly added.
    @param env
        An optional pointer to additional parameters for the child process,
        such as its initial working directory and environment variables. This
        parameter is available in wxWidgets 2.9.2 and later only.

    @see wxShell(), wxProcess, @ref page_samples_exec,
         wxLaunchDefaultApplication(), wxLaunchDefaultBrowser()

    @header{wx/utils.h}

    @beginWxPerlOnly
    This function is called @c Wx::ExecuteStdout: it only takes the
    @a command argument, and returns a 2-element list (@c status, @c output),
    where @c output in an array reference.
    @endWxPerlOnly
*/
long wxExecute(const wxString& command, wxArrayString& output, int flags = 0,
                const wxExecuteEnv *env = NULL);

/**
    This is an overloaded version of wxExecute(const wxString&,int,wxProcess*),
    please see its documentation for general information.

    This version adds the possibility to additionally capture the messages from
    standard error output in the @a errors array. As with the above overload
    capturing standard output only, execution is always synchronous.

    @param command
        The command to execute and any parameters to pass to it as a single
        string.
    @param output
        The string array where the stdout of the executed process is saved.
    @param errors
        The string array where the stderr of the executed process is saved.
    @param flags
        Combination of flags to which ::wxEXEC_SYNC is always implicitly added.
    @param env
        An optional pointer to additional parameters for the child process,
        such as its initial working directory and environment variables. This
        parameter is available in wxWidgets 2.9.2 and later only.

    @see wxShell(), wxProcess, @ref page_samples_exec,
         wxLaunchDefaultApplication(), wxLaunchDefaultBrowser()

    @header{wx/utils.h}

    @beginWxPerlOnly
    This function is called @c Wx::ExecuteStdoutStderr: it only takes the
    @a command argument, and returns a 3-element list (@c status, @c output,
    @c errors), where @c output and @c errors are array references.
    @endWxPerlOnly
*/
long wxExecute(const wxString& command, wxArrayString& output,
                wxArrayString& errors, int flags = 0,
                const wxExecuteEnv *env = NULL);

/**
    Returns the number uniquely identifying the current process in the system.
    If an error occurs, 0 is returned.

    @header{wx/utils.h}
*/
unsigned long wxGetProcessId();

/**
    Equivalent to the Unix kill function: send the given signal @a sig to the
    process with PID @a pid.

    The valid signal values are:

    @code
    enum wxSignal
    {
        wxSIGNONE = 0, // verify if the process exists under Unix
        wxSIGHUP,
        wxSIGINT,
        wxSIGQUIT,
        wxSIGILL,
        wxSIGTRAP,
        wxSIGABRT,
        wxSIGEMT,
        wxSIGFPE,
        wxSIGKILL,     // forcefully kill, dangerous!
        wxSIGBUS,
        wxSIGSEGV,
        wxSIGSYS,
        wxSIGPIPE,
        wxSIGALRM,
        wxSIGTERM      // terminate the process gently
    };
    @endcode

    @c wxSIGNONE, @c wxSIGKILL and @c wxSIGTERM have the same meaning under
    both Unix and Windows but all the other signals are equivalent to
    @c wxSIGTERM under Windows.

    Returns 0 on success, -1 on failure. If the @a rc parameter is not @NULL,
    it will be filled with a value from the @c wxKillError enum:

    @code
    enum wxKillError
    {
        wxKILL_OK,            // no error
        wxKILL_BAD_SIGNAL,    // no such signal
        wxKILL_ACCESS_DENIED, // permission denied
        wxKILL_NO_PROCESS,    // no such process
        wxKILL_ERROR          // another, unspecified error
    };
    @endcode

    The @a flags parameter can be wxKILL_NOCHILDREN (the default), or
    wxKILL_CHILDREN, in which case the child processes of this process will be
    killed too. Note that under Unix, for wxKILL_CHILDREN to work you should
    have created the process by passing wxEXEC_MAKE_GROUP_LEADER to
    wxExecute().

    @see wxProcess::Kill(), wxProcess::Exists(), @ref page_samples_exec

    @header{wx/utils.h}
*/
int wxKill(long pid, wxSignal sig = wxSIGTERM,
            wxKillError* rc = NULL, int flags = wxKILL_NOCHILDREN);

/**
    Executes a command in an interactive shell window. If no command is
    specified, then just the shell is spawned.

    @see wxExecute(), @ref page_samples_exec

    @header{wx/utils.h}
*/
bool wxShell(const wxString& command = wxEmptyString);

/**
    This function shuts down or reboots the computer depending on the value of
    the @a flags.

    @note Note that performing the shutdown requires the corresponding access
        rights (superuser under Unix, SE_SHUTDOWN privilege under Windows NT)
        and that this function is only implemented under Unix and MSW.

    @param flags
        One of @c wxSHUTDOWN_POWEROFF, @c wxSHUTDOWN_REBOOT or
        @c wxSHUTDOWN_LOGOFF (currently implemented only for MSW) possibly
        combined with @c wxSHUTDOWN_FORCE which forces shutdown under MSW by
        forcefully terminating all the applications. As doing this can result
        in a data loss, this flag shouldn't be used unless really necessary.

    @return @true on success, @false if an error occurred.

    @header{wx/utils.h}
*/
bool wxShutdown(int flags = wxSHUTDOWN_POWEROFF);

//@}



/** @addtogroup group_funcmacro_time */
//@{

/**
    Sleeps for the specified number of microseconds. The microsecond resolution
    may not, in fact, be available on all platforms (currently only Unix
    platforms with nanosleep(2) may provide it) in which case this is the same
    as calling wxMilliSleep() with the argument of @e microseconds/1000.

    @header{wx/utils.h}
*/
void wxMicroSleep(unsigned long microseconds);

/**
    Sleeps for the specified number of milliseconds. Notice that usage of this
    function is encouraged instead of calling usleep(3) directly because the
    standard @e usleep() function is not MT safe.

    @header{wx/utils.h}
*/
void wxMilliSleep(unsigned long milliseconds);

/**
    Returns a string representing the current date and time.

    @header{wx/utils.h}
*/
wxString wxNow();

/**
    Sleeps for the specified number of seconds.

    @header{wx/utils.h}
*/
void wxSleep(int secs);

/**
    @deprecated This function is deprecated because its name is misleading:
                notice that the argument is in milliseconds, not microseconds.
                Please use either wxMilliSleep() or wxMicroSleep() depending on
                the resolution you need.

    Sleeps for the specified number of milliseconds.

    @header{wx/utils.h}
*/
void wxUsleep(unsigned long milliseconds);

//@}