Support R2L lines in tool-tip text.

 xfns.c (Fx_show_tip): If any of the tool-tip text lines is R2L,
 adjust width of tool-tip frame to the width of text, excluding the
 stretch glyph at the beginning of R2L glyph rows.
 w32fns.c (Fx_show_tip): Likewise.

3 files changed, 140 insertions, 18 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 142cfeb57d7..81e9eb8215e 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,11 @@
+2010-11-06  Eli Zaretskii  <eliz@gnu.org>
+
+        * xfns.c (Fx_show_tip): If any of the tool-tip text lines is R2L,
+        adjust width of tool-tip frame to the width of text, excluding the
+        stretch glyph at the beginning of R2L glyph rows.
+
+        * w32fns.c (Fx_show_tip): Likewise.
+
 2010-11-06  Jan Djärv  <jan.h.d@swipnet.se>
 
         * nsfont.m: Include termchar for new mouse-highlight.
diff --git a/src/w32fns.c b/src/w32fns.c
index 15dbb404737..5a4f1354993 100644
--- a/src/w32fns.c
+++ b/src/w32fns.c
@@ -5657,7 +5657,7 @@ Text larger than the specified size is clipped.  */)
   int root_x, root_y;
   struct buffer *old_buffer;
   struct text_pos pos;
-  int i, width, height;
+  int i, width, height, seen_reversed_p;
   struct gcpro gcpro1, gcpro2, gcpro3, gcpro4;
   int old_windows_or_buffers_changed = windows_or_buffers_changed;
   int count = SPECPDL_INDEX ();
@@ -5787,7 +5787,7 @@ Text larger than the specified size is clipped.  */)
   try_window (FRAME_ROOT_WINDOW (f), pos, 0);
 
   /* Compute width and height of the tooltip.  */
-  width = height = 0;
+  width = height = seen_reversed_p = 0;
   for (i = 0; i < w->desired_matrix->nrows; ++i)
     {
       struct glyph_row *row = &w->desired_matrix->rows[i];
@@ -5801,24 +5801,83 @@ Text larger than the specified size is clipped.  */)
       /* Let the row go over the full width of the frame.  */
       row->full_width_p = 1;
 
-#ifdef TODO /* Investigate why some fonts need more width than is
-               calculated for some tooltips.  */
-      /* There's a glyph at the end of rows that is use to place
-         the cursor there.  Don't include the width of this glyph.  */
+      row_width = row->pixel_width;
       if (row->used[TEXT_AREA])
         {
-          last = &row->glyphs[TEXT_AREA][row->used[TEXT_AREA] - 1];
-          row_width = row->pixel_width - last->pixel_width;
-        }
-      else
+          if (!row->reversed_p)
+            {
+#ifdef TODO   /* Investigate why some fonts need more width than is
+                 calculated for some tooltips.  */
+
+              /* There's a glyph at the end of rows that is used to
+                 place the cursor there.  Don't include the width of
+                 this glyph.  */
+              last = &row->glyphs[TEXT_AREA][row->used[TEXT_AREA] - 1];
+              if (INTEGERP (last->object))
+                row_width -= last->pixel_width;
 #endif
-        row_width = row->pixel_width;
+            }
+          else
+            {
+              /* There could be a stretch glyph at the beginning of R2L
+                 rows that is produced by extend_face_to_end_of_line.
+                 Don't count that glyph.  */
+              struct glyph *g = row->glyphs[TEXT_AREA];
+
+              if (g->type == STRETCH_GLYPH && INTEGERP (g->object))
+                {
+                  row_width -= g->pixel_width;
+                  seen_reversed_p = 1;
+                }
+            }
+        }
 
       /* TODO: find why tips do not draw along baseline as instructed.  */
       height += row->height;
       width = max (width, row_width);
     }
 
+  /* If we've seen partial-length R2L rows, we need to re-adjust the
+     tool-tip frame width and redisplay it again, to avoid over-wide
+     tips due to the stretch glyph that extends R2L lines to full
+     width of the frame.  */
+  if (seen_reversed_p)
+    {
+      /* w->total_cols and FRAME_TOTAL_COLS want the width in columns,
+         not in pixels.  */
+      width /= WINDOW_FRAME_COLUMN_WIDTH (w);
+      w->total_cols = make_number (width);
+      FRAME_TOTAL_COLS (f) = width;
+      adjust_glyphs (f);
+      clear_glyph_matrix (w->desired_matrix);
+      clear_glyph_matrix (w->current_matrix);
+      try_window (FRAME_ROOT_WINDOW (f), pos, 0);
+      width = height = 0;
+      /* Recompute width and height of the tooltip.  */
+      for (i = 0; i < w->desired_matrix->nrows; ++i)
+        {
+          struct glyph_row *row = &w->desired_matrix->rows[i];
+          struct glyph *last;
+          int row_width;
+
+          if (!row->enabled_p || !row->displays_text_p)
+            break;
+          row->full_width_p = 1;
+          row_width = row->pixel_width;
+#ifdef TODO /* See above.  */
+          if (row->used[TEXT_AREA] && !row->reversed_p)
+            {
+              last = &row->glyphs[TEXT_AREA][row->used[TEXT_AREA] - 1];
+              if (INTEGERP (last->object))
+                row_width -= last->pixel_width;
+            }
+#endif
+
+          height += row->height;
+          width = max (width, row_width);
+        }
+    }
+
   /* Add the frame's internal border to the width and height the X
      window should have.  */
   height += 2 * FRAME_INTERNAL_BORDER_WIDTH (f);
diff --git a/src/xfns.c b/src/xfns.c
index 6492bbd8a23..8ef9c92523e 100644
--- a/src/xfns.c
+++ b/src/xfns.c
@@ -5017,7 +5017,7 @@ Text larger than the specified size is clipped.  */)
   int root_x, root_y;
   struct buffer *old_buffer;
   struct text_pos pos;
-  int i, width, height;
+  int i, width, height, seen_reversed_p;
   struct gcpro gcpro1, gcpro2, gcpro3, gcpro4;
   int old_windows_or_buffers_changed = windows_or_buffers_changed;
   int count = SPECPDL_INDEX ();
@@ -5158,7 +5158,7 @@ Text larger than the specified size is clipped.  */)
   try_window (FRAME_ROOT_WINDOW (f), pos, TRY_WINDOW_IGNORE_FONTS_CHANGE);
 
   /* Compute width and height of the tooltip.  */
-  width = height = 0;
+  width = height = seen_reversed_p = 0;
   for (i = 0; i < w->desired_matrix->nrows; ++i)
     {
       struct glyph_row *row = &w->desired_matrix->rows[i];
@@ -5173,19 +5173,74 @@ Text larger than the specified size is clipped.  */)
       row->full_width_p = 1;
 
       row_width = row->pixel_width;
-      /* There's a glyph at the end of rows that is used to place
-         the cursor there.  Don't include the width of this glyph.  */
       if (row->used[TEXT_AREA])
         {
-          last = &row->glyphs[TEXT_AREA][row->used[TEXT_AREA] - 1];
-          if (INTEGERP (last->object))
-            row_width -= last->pixel_width;
+          /* There's a glyph at the end of rows that is used to place
+             the cursor there.  Don't include the width of this glyph.  */
+          if (!row->reversed_p)
+            {
+              last = &row->glyphs[TEXT_AREA][row->used[TEXT_AREA] - 1];
+              if (INTEGERP (last->object))
+                row_width -= last->pixel_width;
+            }
+          else
+            {
+              /* There could be a stretch glyph at the beginning of R2L
+                 rows that is produced by extend_face_to_end_of_line.
+                 Don't count that glyph.  */
+              struct glyph *g = row->glyphs[TEXT_AREA];
+
+              if (g->type == STRETCH_GLYPH && INTEGERP (g->object))
+                {
+                  row_width -= g->pixel_width;
+                  seen_reversed_p = 1;
+                }
+            }
         }
 
       height += row->height;
       width = max (width, row_width);
     }
 
+  /* If we've seen partial-length R2L rows, we need to re-adjust the
+     tool-tip frame width and redisplay it again, to avoid over-wide
+     tips due to the stretch glyph that extends R2L lines to full
+     width of the frame.  */
+  if (seen_reversed_p)
+    {
+      /* w->total_cols and FRAME_TOTAL_COLS want the width in columns,
+         not in pixels.  */
+      width /= WINDOW_FRAME_COLUMN_WIDTH (w);
+      w->total_cols = make_number (width);
+      FRAME_TOTAL_COLS (f) = width;
+      adjust_glyphs (f);
+      clear_glyph_matrix (w->desired_matrix);
+      clear_glyph_matrix (w->current_matrix);
+      try_window (FRAME_ROOT_WINDOW (f), pos, 0);
+      width = height = 0;
+      /* Recompute width and height of the tooltip.  */
+      for (i = 0; i < w->desired_matrix->nrows; ++i)
+        {
+          struct glyph_row *row = &w->desired_matrix->rows[i];
+          struct glyph *last;
+          int row_width;
+
+          if (!row->enabled_p || !row->displays_text_p)
+            break;
+          row->full_width_p = 1;
+          row_width = row->pixel_width;
+          if (row->used[TEXT_AREA] && !row->reversed_p)
+            {
+              last = &row->glyphs[TEXT_AREA][row->used[TEXT_AREA] - 1];
+              if (INTEGERP (last->object))
+                row_width -= last->pixel_width;
+            }
+
+          height += row->height;
+          width = max (width, row_width);
+        }
+    }
+
   /* Add the frame's internal border to the width and height the X
      window should have.  */
   height += 2 * FRAME_INTERNAL_BORDER_WIDTH (f);