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<!-- ##### SECTION Title ##### -->
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<!-- ##### SECTION Short_Description ##### -->
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Library initialization and miscellaneous functions
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<!-- ##### SECTION Long_Description ##### -->
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This section describes the GDK initialization functions and miscellaneous
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<!-- ##### SECTION See_Also ##### -->
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<!-- ##### SECTION Stability_Level ##### -->
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<!-- ##### SECTION Image ##### -->
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<!-- ##### FUNCTION gdk_init ##### -->
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Initializes the GDK library and connects to the X server.
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If initialization fails, a warning message is output and the application
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terminates with a call to <literal>exit(1)</literal>.
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Any arguments used by GDK are removed from the array and @argc and @argv are
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GTK+ initializes GDK in gtk_init() and so this function is not usually needed
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@argc: the number of command line arguments.
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@argv: the array of command line arguments.
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<!-- ##### FUNCTION gdk_init_check ##### -->
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Initializes the GDK library and connects to the X server, returning %TRUE on
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Any arguments used by GDK are removed from the array and @argc and @argv are
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GTK+ initializes GDK in gtk_init() and so this function is not usually needed
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@argc: the number of command line arguments.
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@argv: the array of command line arguments.
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@Returns: %TRUE if initialization succeeded.
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<!-- ##### FUNCTION gdk_parse_args ##### -->
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<!-- ##### FUNCTION gdk_get_display_arg_name ##### -->
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<!-- ##### FUNCTION gdk_set_locale ##### -->
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Initializes the support for internationalization by calling the <function>setlocale()</function>
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system call. This function is called by gtk_set_locale() and so GTK+
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applications should use that instead.
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The locale to use is determined by the <envar>LANG</envar> environment variable,
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so to run an application in a certain locale you can do something like this:
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... run application ...
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If the locale is not supported by X then it is reset to the standard "C"
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@Returns: the resulting locale.
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@Deprecated: 2.24: Use setlocale() directly
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<!-- ##### FUNCTION gdk_set_sm_client_id ##### -->
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<!-- ##### FUNCTION gdk_exit ##### -->
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Exits the application using the <function>exit()</function> system call.
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This routine is provided mainly for backwards compatibility, since it used to
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perform tasks necessary to exit the application cleanly. Those tasks are now
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performed in a function which is automatically called on exit (via the use
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@error_code: the error code to pass to the <function>exit()</function> call.
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<!-- ##### FUNCTION gdk_notify_startup_complete ##### -->
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<!-- ##### FUNCTION gdk_notify_startup_complete_with_id ##### -->
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<!-- ##### FUNCTION gdk_get_program_class ##### -->
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Gets the program class. Unless the program class has explicitly
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been set with gdk_set_program_class() or with the <option>--class</option>
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commandline option, the default value is the program name (determined
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with g_get_prgname()) with the first character converted to uppercase.
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@Returns: the program class.
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<!-- ##### FUNCTION gdk_set_program_class ##### -->
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Sets the program class. The X11 backend uses the program class to set
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the class name part of the <literal>WM_CLASS</literal> property on
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toplevel windows; see the ICCCM.
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@program_class: a string.
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<!-- ##### FUNCTION gdk_get_display ##### -->
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Gets the name of the display, which usually comes from the <envar>DISPLAY</envar>
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environment variable or the <option>--display</option> command line option.
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@Returns: the name of the display.
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<!-- ##### FUNCTION gdk_flush ##### -->
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Flushes the X output buffer and waits until all requests have been processed
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by the server. This is rarely needed by applications. It's main use is for
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trapping X errors with gdk_error_trap_push() and gdk_error_trap_pop().
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<!-- ##### FUNCTION gdk_screen_width ##### -->
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<!-- ##### FUNCTION gdk_screen_height ##### -->
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<!-- ##### FUNCTION gdk_screen_width_mm ##### -->
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<!-- ##### FUNCTION gdk_screen_height_mm ##### -->
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<!-- ##### FUNCTION gdk_pointer_grab ##### -->
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Grabs the pointer (usually a mouse) so that all events are passed to this
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application until the pointer is ungrabbed with gdk_pointer_ungrab(), or
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the grab window becomes unviewable.
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This overrides any previous pointer grab by this client.
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Pointer grabs are used for operations which need complete control over mouse
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events, even if the mouse leaves the application.
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For example in GTK+ it is used for Drag and Drop, for dragging the handle in
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the #GtkHPaned and #GtkVPaned widgets, and for resizing columns in #GtkCList
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Note that if the event mask of an X window has selected both button press and
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button release events, then a button press event will cause an automatic
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pointer grab until the button is released.
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X does this automatically since most applications expect to receive button
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press and release events in pairs.
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It is equivalent to a pointer grab on the window with @owner_events set to
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If you set up anything at the time you take the grab that needs to be cleaned
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up when the grab ends, you should handle the #GdkEventGrabBroken events that
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are emitted when the grab ends unvoluntarily.
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@window: the #GdkWindow which will own the grab (the grab window).
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@owner_events: if %FALSE then all pointer events are reported with respect to
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@window and are only reported if selected by @event_mask. If %TRUE then pointer
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events for this application are reported as normal, but pointer events outside
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this application are reported with respect to @window and only if selected by
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@event_mask. In either mode, unreported events are discarded.
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@event_mask: specifies the event mask, which is used in accordance with
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@owner_events. Note that only pointer events (i.e. button and motion events)
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@confine_to: If non-%NULL, the pointer will be confined to this
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window during the grab. If the pointer is outside @confine_to, it will
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automatically be moved to the closest edge of @confine_to and enter
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and leave events will be generated as necessary.
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@cursor: the cursor to display while the grab is active. If this is %NULL then
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the normal cursors are used for @window and its descendants, and the cursor
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for @window is used for all other windows.
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@time_: the timestamp of the event which led to this pointer grab. This usually
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comes from a #GdkEventButton struct, though %GDK_CURRENT_TIME can be used if
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the time isn't known.
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@Returns: %GDK_GRAB_SUCCESS if the grab was successful.
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<!-- ##### ENUM GdkGrabStatus ##### -->
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Returned by gdk_pointer_grab() and gdk_keyboard_grab() to indicate
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success or the reason for the failure of the grab attempt.
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@GDK_GRAB_SUCCESS: the resource was successfully grabbed.
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@GDK_GRAB_ALREADY_GRABBED: the resource is actively grabbed by another client.
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@GDK_GRAB_INVALID_TIME: the resource was grabbed more recently than the
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@GDK_GRAB_NOT_VIEWABLE: the grab window or the @confine_to window are not
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@GDK_GRAB_FROZEN: the resource is frozen by an active grab of another client.
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<!-- ##### FUNCTION gdk_pointer_ungrab ##### -->
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<!-- ##### FUNCTION gdk_pointer_is_grabbed ##### -->
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<!-- ##### FUNCTION gdk_set_double_click_time ##### -->
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<!-- ##### FUNCTION gdk_keyboard_grab ##### -->
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Grabs the keyboard so that all events are passed to this
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application until the keyboard is ungrabbed with gdk_keyboard_ungrab().
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This overrides any previous keyboard grab by this client.
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If you set up anything at the time you take the grab that needs to be cleaned
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up when the grab ends, you should handle the #GdkEventGrabBroken events that
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are emitted when the grab ends unvoluntarily.
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@window: the #GdkWindow which will own the grab (the grab window).
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@owner_events: if %FALSE then all keyboard events are reported with respect to
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@window. If %TRUE then keyboard events for this application are reported as
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normal, but keyboard events outside this application are reported with respect
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to @window. Both key press and key release events are always reported,
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independant of the event mask set by the application.
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@time_: a timestamp from a #GdkEvent, or %GDK_CURRENT_TIME if no timestamp is
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@Returns: %GDK_GRAB_SUCCESS if the grab was successful.
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<!-- ##### FUNCTION gdk_keyboard_ungrab ##### -->
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<!-- ##### FUNCTION gdk_beep ##### -->
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<!-- ##### FUNCTION gdk_get_use_xshm ##### -->
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Returns %TRUE if GDK will attempt to use the MIT-SHM shared memory extension.
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The shared memory extension is used for #GdkImage, and consequently for
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<link linkend="gdk-GdkRGB">GdkRGB</link>.
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It enables much faster drawing by communicating with the X server through
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SYSV shared memory calls. However, it can only be used if the X client and
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server are on the same machine and the server supports it.
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@Returns: %TRUE if use of the MIT shared memory extension will be attempted.
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<!-- ##### FUNCTION gdk_set_use_xshm ##### -->
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Sets whether the use of the MIT shared memory extension should be attempted.
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This function is mainly for internal use. It is only safe for an application
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to set this to %FALSE, since if it is set to %TRUE and the server does not
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support the extension it may cause warning messages to be output.
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@use_xshm: %TRUE if use of the MIT shared memory extension should be attempted.
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<!-- ##### FUNCTION gdk_error_trap_push ##### -->
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This function allows X errors to be trapped instead of the normal behavior
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of exiting the application. It should only be used if it is not possible to
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avoid the X error in any other way.
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<title>Trapping an X error</title>
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gdk_error_trap_push (<!-- -->);
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/* ... Call the X function which may cause an error here ... */
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/* Flush the X queue to catch errors now. */
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gdk_flush (<!-- -->);
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if (gdk_error_trap_pop (<!-- -->))
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/* ... Handle the error here ... */
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<!-- ##### FUNCTION gdk_error_trap_pop ##### -->
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Removes the X error trap installed with gdk_error_trap_push().
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@Returns: the X error code, or 0 if no error occurred.
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<!-- ##### MACRO GDK_WINDOWING_X11 ##### -->
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This macro is defined if GDK is configured to use the X11 backend.
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<!-- ##### MACRO GDK_WINDOWING_WIN32 ##### -->
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This macro is defined if GDK is configured to use the Win32 backend.