backends: Add meta_cursor_get_legacy_name()

To aid loading of legacy cursor themes.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3718>

src/backends/meta-cursor-sprite-xcursor.c

@@ -95,6 +95,57 @@ meta_cursor_get_name (MetaCursor cursor)
   return NULL;
 }
 
+const char *
+meta_cursor_get_legacy_name (MetaCursor cursor)
+{
+  switch (cursor)
+    {
+    case META_CURSOR_DEFAULT:
+      return "left_ptr";
+    case META_CURSOR_NORTH_RESIZE:
+      return "top_side";
+    case META_CURSOR_SOUTH_RESIZE:
+      return "bottom_side";
+    case META_CURSOR_WEST_RESIZE:
+      return "left_side";
+    case META_CURSOR_EAST_RESIZE:
+      return "right_side";
+    case META_CURSOR_SE_RESIZE:
+      return "bottom_right_corner";
+    case META_CURSOR_SW_RESIZE:
+      return "bottom_left_corner";
+    case META_CURSOR_NE_RESIZE:
+      return "top_right_corner";
+    case META_CURSOR_NW_RESIZE:
+      return "top_left_corner";
+    case META_CURSOR_MOVE_OR_RESIZE_WINDOW:
+      return "fleur";
+    case META_CURSOR_BUSY:
+      return "watch";
+    case META_CURSOR_DND_IN_DRAG:
+      return "dnd-none";
+    case META_CURSOR_DND_MOVE:
+      return "dnd-move";
+    case META_CURSOR_DND_COPY:
+      return "dnd-copy";
+    case META_CURSOR_DND_UNSUPPORTED_TARGET:
+      return "dnd-none";
+    case META_CURSOR_POINTING_HAND:
+      return "hand2";
+    case META_CURSOR_CROSSHAIR:
+      return "crosshair";
+    case META_CURSOR_IBEAM:
+      return "xterm";
+    case META_CURSOR_BLANK:
+    case META_CURSOR_NONE:
+    case META_CURSOR_LAST:
+      break;
+    }
+
+  g_assert_not_reached ();
+  return NULL;
+}
+
 static XcursorImages *
 create_blank_cursor_images (void)
 {

src/backends/meta-cursor-sprite-xcursor.h

@@ -39,3 +39,5 @@ MetaCursor meta_cursor_sprite_xcursor_get_cursor (MetaCursorSpriteXcursor *sprit
 XcursorImage * meta_cursor_sprite_xcursor_get_current_image (MetaCursorSpriteXcursor *sprite_xcursor);
 
 const char * meta_cursor_get_name (MetaCursor cursor);
+
+const char * meta_cursor_get_legacy_name (MetaCursor cursor);