Make MetaSelection, MetaSelectionSource and MetaMemorySelectionSource public

This exposes the base so that we can reimplement StClipboard on top. Some
gtk-docs have been added for documentation and introspection purposes.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/320

src/core/meta-selection.c

@@ -21,7 +21,7 @@
 
 #include "config.h"
 
-#include "core/meta-selection.h"
+#include "meta/meta-selection.h"
 
 typedef struct TransferRequest TransferRequest;
 
@@ -76,6 +76,15 @@ meta_selection_new (MetaDisplay *display)
                        NULL);
 }
 
+/**
+ * meta_selection_set_owner:
+ * @selection: The selection manager
+ * @selection_type: Selection type
+ * @owner: New selection owner
+ *
+ * Sets @owner as the owner of the selection given by @selection_type,
+ * unsets any previous owner there was.
+ **/
 void
 meta_selection_set_owner (MetaSelection       *selection,
                           MetaSelectionType    selection_type,
@@ -95,6 +104,15 @@ meta_selection_set_owner (MetaSelection       *selection,
   g_signal_emit (selection, signals[OWNER_CHANGED], 0, selection_type, owner);
 }
 
+/**
+ * meta_selection_unset_owner:
+ * @selection: The selection manager
+ * @selection_type: Selection type
+ * @owner: Owner to unset
+ *
+ * Unsets @owner as the owner the selection given by @selection_type. If
+ * @owner does not own the selection, nothing is done.
+ **/
 void
 meta_selection_unset_owner (MetaSelection       *selection,
                             MetaSelectionType    selection_type,
@@ -112,6 +130,15 @@ meta_selection_unset_owner (MetaSelection       *selection,
     }
 }
 
+/**
+ * meta_selection_get_mimetypes:
+ * @selection: The selection manager
+ * @selection_type: Selection to query
+ *
+ * Returns the list of supported mimetypes for the given selection type.
+ *
+ * Returns: (element-type utf8) (transfer full): The supported mimetypes
+ */
 GList *
 meta_selection_get_mimetypes (MetaSelection     *selection,
                               MetaSelectionType  selection_type)
@@ -253,6 +280,20 @@ source_read_cb (MetaSelectionSource *source,
     }
 }
 
+/**
+ * meta_selection_transfer_async:
+ * @selection: The selection manager
+ * @selection_type: Selection type
+ * @mimetype: Mimetype to transfer
+ * @size: Maximum size to transfer, -1 for unlimited
+ * @output: Output stream to write contents to
+ * @cancellable: Cancellable
+ * @callback: User callback
+ * @user_data: User data
+ *
+ * Requests a transfer of @mimetype on the selection given by
+ * @selection_type.
+ **/
 void
 meta_selection_transfer_async (MetaSelection        *selection,
                                MetaSelectionType     selection_type,
@@ -283,6 +324,16 @@ meta_selection_transfer_async (MetaSelection        *selection,
                                     task);
 }
 
+/**
+ * meta_selection_transfer_finish:
+ * @selection: The selection manager
+ * @result: The async result
+ * @error: Location for returned error, or %NULL
+ *
+ * Finishes the transfer of a queried mimetype.
+ *
+ * Returns: #TRUE if the transfer was successful.
+ **/
 gboolean
 meta_selection_transfer_finish (MetaSelection  *selection,
                                 GAsyncResult   *result,