docs: Add missing documentation on Windows

The gtk_print_run_page_setup_dialog() function, and its asynchronous
variant, are declared in the common gtkprintoperation.h header, but
implemented in different source files depending on the platform.

diff --git a/gtk/gtkprintoperation-win32.c b/gtk/gtkprintoperation-win32.c
index 13937ad9bd54b78b88c227010581512d89c7dbb2..8fb2ac6c071fafae8ef3f50d728bfae1777e96ff 100644 (file)
--- a/gtk/gtkprintoperation-win32.c
+++ b/gtk/gtkprintoperation-win32.c
@@ -2064,6 +2064,23 @@ _gtk_print_operation_platform_backend_resize_preview_surface (GtkPrintOperation
   /* TODO: Implement */
 }
 
+/**
+ * gtk_print_run_page_setup_dialog:
+ * @parent: (nullable): transient parent
+ * @page_setup: (nullable): an existing `GtkPageSetup`
+ * @settings: a `GtkPrintSettings`
+ *
+ * Runs a page setup dialog, letting the user modify the values from
+ * @page_setup. If the user cancels the dialog, the returned `GtkPageSetup`
+ * is identical to the passed in @page_setup, otherwise it contains the
+ * modifications done in the dialog.
+ *
+ * Note that this function may use a recursive mainloop to show the page
+ * setup dialog. See gtk_print_run_page_setup_dialog_async() if this is
+ * a problem.
+ *
+ * Returns: (transfer full): a new `GtkPageSetup`
+ */
 GtkPageSetup *
 gtk_print_run_page_setup_dialog (GtkWindow        *parent,
                                 GtkPageSetup     *page_setup,
@@ -2196,6 +2213,21 @@ gtk_print_run_page_setup_dialog (GtkWindow        *parent,
   return page_setup;
 }
 
+/**
+ * gtk_print_run_page_setup_dialog_async:
+ * @parent: (nullable): transient parent
+ * @page_setup: (nullable): an existing `GtkPageSetup`
+ * @settings: a `GtkPrintSettings`
+ * @done_cb: (scope async): a function to call when the user saves
+ *    the modified page setup
+ * @data: user data to pass to @done_cb
+ *
+ * Runs a page setup dialog, letting the user modify the values from @page_setup.
+ *
+ * In contrast to gtk_print_run_page_setup_dialog(), this function  returns after
+ * showing the page setup dialog on platforms that support this, and calls @done_cb
+ * from a signal handler for the ::response signal of the dialog.
+ */
 void
 gtk_print_run_page_setup_dialog_async (GtkWindow            *parent,
                                       GtkPageSetup         *page_setup,