1 files changed, 109 insertions, 0 deletions
diff --git a/src/textconv.h b/src/textconv.h
new file mode 100644
index 00000000000..f6e7eb7925f
--- /dev/null
+++ b/src/textconv.h
@@ -0,0 +1,109 @@
+/* String conversion support for graphics terminals.
+
+Copyright (C) 2023 Free Software Foundation, Inc.
+
+This file is part of GNU Emacs.
+
+GNU Emacs is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or (at
+your option) any later version.
+
+GNU Emacs is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
+
+#ifndef _TEXTCONV_H_
+
+#include "lisp.h"
+#include "frame.h"
+
+/* The function pointers in this structure should be filled out by
+   each GUI backend interested in supporting text conversion.
+
+   Finally, register_texconv_interface must be called at some point
+   during terminal initialization.  */
+
+struct textconv_interface
+{
+  /* Notice that the text conversion context has changed (which can
+     happen if the window is deleted or switches buffers, or an
+     unexpected buffer change occurs.) */
+  void (*reset) (struct frame *);
+};
+
+
+
+enum textconv_caret_direction
+  {
+    TEXTCONV_FORWARD_CHAR,
+    TEXTCONV_BACKWARD_CHAR,
+    TEXTCONV_FORWARD_WORD,
+    TEXTCONV_BACKWARD_WORD,
+    TEXTCONV_CARET_UP,
+    TEXTCONV_CARET_DOWN,
+    TEXTCONV_NEXT_LINE,
+    TEXTCONV_PREVIOUS_LINE,
+    TEXTCONV_LINE_START,
+    TEXTCONV_LINE_END,
+    TEXTCONV_ABSOLUTE_POSITION,
+  };
+
+enum textconv_operation
+  {
+    TEXTCONV_SUBSTITUTION,
+    TEXTCONV_RETRIEVAL,
+  };
+
+/* Structure describing text in a buffer corresponding to a ``struct
+   textconv_callback_struct''.  */
+
+struct textconv_conversion_text
+{
+  /* Length of the text in characters and bytes.  */
+  size_t length, bytes;
+
+  /* Pointer to the text data.  This must be deallocated by the
+     caller.  */
+  char *text;
+};
+
+/* Structure describing a single query submitted by the input
+   method.  */
+
+struct textconv_callback_struct
+{
+  /* Character position, relative to the current spot location, from
+     where on text should be returned.  */
+  EMACS_INT position;
+
+  /* The type of scanning to perform to determine either the start or
+     the end of the conversion.  */
+  enum textconv_caret_direction direction;
+
+  /* The the number of times for which to repeat the scanning in order
+     to determine the starting position of the text to return.  */
+  unsigned short factor;
+
+  /* The operation to perform upon the current buffer contents.
+
+     If this is TEXTCONV_SUBSTITUTION, then the text that is returned
+     will be deleted from the buffer itself.
+
+     Otherwise, the text is simply returned without modifying the
+     buffer contents.  */
+  enum textconv_operation operation;
+
+  /* Structure that will be filled with a description of the resulting
+     text.  */
+  struct textconv_conversion_text text;
+};
+
+extern int textconv_query (struct frame *, struct textconv_callback_struct *);
+extern void register_texconv_interface (struct textconv_interface *);
+
+#endif /* _TEXTCONV_H_ */