render-lines: factor out code in revalidate_start()

revalidate start considers 3 cases when the point is on the line.  Each
of these checks if the point is on the line.
Factor out that test and other code so that 3 (or 4) cases can focus on
their particular issue.

Signed-off-by: NeilBrown <neil@brown.name>

diff --git a/render-lines.c b/render-lines.c
index 50dcbc225855d9b2d553ecbac4ed8c7e6e991564..65e90854cff096cc84b05b8b83247bdca6f8bc0e 100644 (file)
--- a/render-lines.c
+++ b/render-lines.c
@@ -1130,63 +1130,49 @@ static int revalidate_start(struct rl_data *rl safe,
                }
                y += hp->h;
                m2 = vmark_next(m);
-               if (pm && m == start && rl->skip_height > 0 && m2 &&
-                   mark_ordered_not_same(pm, m2)) {
-                       /* Point might be in this line, but off top
-                        * of the screen
-                        */
+               /* The doc_prior handles case when EOF is at the end
+                * of a non-empty line.
+                */
+               if (pm && m2 && mark_ordered_or_same(m, pm) &&
+                   (mark_ordered_not_same(pm, m2) ||
+                    (mark_same(pm, m2) && !is_eol(doc_prior(focus,m2))))) {
+
+                       /* Cursor is on this line */
                        int offset = call_render_line_to_point(focus,
                                                               pm, m);
+                       int lh = attr_find_int(hp->attrs,
+                                              "line-height");
+                       int cy = y - hp->h + hp->cy;
+                       if (lh < 1)
+                               lh = 1;
                        measure_line(p, focus, m, offset);
-                       if (hp->cy >= rl->skip_height + rl->margin)
-                               /* Cursor is visible on this line
-                                * and after margin from top.
+                       if (m == start && rl->skip_height > 0) {
+                               /* Point might be in this line, but off top
+                                * of the screen
                                 */
+                               if (hp->cy >= rl->skip_height + rl->margin)
+                                       /* Cursor is visible on this line
+                                        * and after margin from top.
+                                        */
+                                       on_screen = True;
+                               else if (start_of_file && rl->skip_height == 0)
+                                       /* Cannot make more margin space */
+                                       on_screen = True;
+                       } else if (y >= p->h) {
+                               /* point might be in this line, but off end
+                                * of the screen
+                                */
+                               if (hp->cy >= 0 &&
+                                   y - hp->h + hp->cy <= p->h - lh - rl->margin) {
+                                       /* Cursor is on screen */
+                                       on_screen = True;
+                               }
+                       } else if (rl->margin == 0)
                                on_screen = True;
-                       else if (start_of_file && rl->skip_height == 0)
-                               /* Cannot make more margin space */
-                               on_screen = True;
-               } else if (pm && m2 && y >= p->h && m->seq < pm->seq &&
-                          mark_ordered_not_same(pm, m2)) {
-                       /* point might be in this line, but off end
-                        * of the screen
-                        */
-                       int offset = call_render_line_to_point(focus,
-                                                              pm, m);
-                       int lh;
-                       measure_line(p, focus, m, offset);
-                       lh = attr_find_int(hp->attrs,
-                                          "line-height");
-                       if (lh <= 0)
-                               lh = 1;
-                       if (hp->cy >= 0 &&
-                           y - hp->h + hp->cy <= p->h - lh - rl->margin) {
-                               /* Cursor is on screen */
-                               on_screen = True;
-                       }
-               } else if (pm && mark_ordered_or_same(m, pm) && m2 &&
-                          (mark_ordered_not_same(pm, m2) ||
-                           (mark_same(pm, m2) && !is_eol(doc_prior(focus,m2))))
-                          ) {
-                       /* Above doc_prior handles case when EOF is at the end
-                        * of a non-empty line.
-                        */
-                       if (rl->margin == 0)
+                       else if (cy >= rl->margin &&
+                                cy <= p->h - rl->margin - lh)
+                               /* Cursor at least margin from edge */
                                on_screen = True;
-                       else {
-                               int offset = call_render_line_to_point(
-                                       focus, pm, m);
-                               int lh;
-                               int cy;
-                               measure_line(p, focus, m, offset);
-                               lh = attr_find_int(hp->attrs,
-                                                  "line-height");
-                               cy = y - hp->h + hp->cy;
-                               if (cy >= rl->margin &&
-                                   cy <= p->h - rl->margin - lh)
-                                       /* Cursor at least margin from edge */
-                                       on_screen = True;
-                       }
                }
        }
        if (y >= p->h)