+/* Get information about special display element WHAT in an
+ environment described by IT. WHAT is one of IT_TRUNCATION or
+ IT_CONTINUATION. Maybe produce glyphs for WHAT if IT has a
+ non-null glyph_row member. This function ensures that fields like
+ face_id, c, len of IT are left untouched. */
+
+static void
+produce_special_glyphs (struct it *it, enum display_element_type what)
+{
+ struct it temp_it;
+ Lisp_Object gc;
+ GLYPH glyph;
+
+ temp_it = *it;
+ temp_it.object = make_number (0);
+ memset (&temp_it.current, 0, sizeof temp_it.current);
+
+ if (what == IT_CONTINUATION)
+ {
+ /* Continuation glyph. For R2L lines, we mirror it by hand. */
+ if (it->bidi_it.paragraph_dir == R2L)
+ SET_GLYPH_FROM_CHAR (glyph, '/');
+ else
+ SET_GLYPH_FROM_CHAR (glyph, '\\');
+ if (it->dp
+ && (gc = DISP_CONTINUE_GLYPH (it->dp), GLYPH_CODE_P (gc)))
+ {
+ /* FIXME: Should we mirror GC for R2L lines? */
+ SET_GLYPH_FROM_GLYPH_CODE (glyph, gc);
+ spec_glyph_lookup_face (XWINDOW (it->window), &glyph);
+ }
+ }
+ else if (what == IT_TRUNCATION)
+ {
+ /* Truncation glyph. */
+ SET_GLYPH_FROM_CHAR (glyph, '$');
+ if (it->dp
+ && (gc = DISP_TRUNC_GLYPH (it->dp), GLYPH_CODE_P (gc)))
+ {
+ /* FIXME: Should we mirror GC for R2L lines? */
+ SET_GLYPH_FROM_GLYPH_CODE (glyph, gc);
+ spec_glyph_lookup_face (XWINDOW (it->window), &glyph);
+ }
+ }
+ else
+ abort ();
+
+#ifdef HAVE_WINDOW_SYSTEM
+ /* On a GUI frame, when the right fringe (left fringe for R2L rows)
+ is turned off, we precede the truncation/continuation glyphs by a
+ stretch glyph whose width is computed such that these special
+ glyphs are aligned at the window margin, even when very different
+ fonts are used in different glyph rows. */
+ if (FRAME_WINDOW_P (temp_it.f)
+ /* init_iterator calls this with it->glyph_row == NULL, and it
+ wants only the pixel width of the truncation/continuation
+ glyphs. */
+ && temp_it.glyph_row
+ /* insert_left_trunc_glyphs calls us at the beginning of the
+ row, and it has its own calculation of the stretch glyph
+ width. */
+ && temp_it.glyph_row->used[TEXT_AREA] > 0
+ && (temp_it.glyph_row->reversed_p
+ ? WINDOW_LEFT_FRINGE_WIDTH (temp_it.w)
+ : WINDOW_RIGHT_FRINGE_WIDTH (temp_it.w)) == 0)
+ {
+ int stretch_width = temp_it.last_visible_x - temp_it.current_x;
+
+ if (stretch_width > 0)
+ {
+ struct face *face = FACE_FROM_ID (temp_it.f, temp_it.face_id);
+ struct font *font =
+ face->font ? face->font : FRAME_FONT (temp_it.f);
+ int stretch_ascent =
+ (((temp_it.ascent + temp_it.descent)
+ * FONT_BASE (font)) / FONT_HEIGHT (font));
+
+ append_stretch_glyph (&temp_it, make_number (0), stretch_width,
+ temp_it.ascent + temp_it.descent,
+ stretch_ascent);
+ }
+ }
+#endif
+
+ temp_it.dp = NULL;
+ temp_it.what = IT_CHARACTER;
+ temp_it.len = 1;
+ temp_it.c = temp_it.char_to_display = GLYPH_CHAR (glyph);
+ temp_it.face_id = GLYPH_FACE (glyph);
+ temp_it.len = CHAR_BYTES (temp_it.c);
+
+ PRODUCE_GLYPHS (&temp_it);
+ it->pixel_width = temp_it.pixel_width;
+ it->nglyphs = temp_it.pixel_width;
+}
+