browser: first cut at horizontal split.

When in 'merge' mode we display the patch in a bottom window when on a
conflict or wiggle, so full context can be see.

This is a bit rough at the moment - the image jumps more than I would
like and it is hard to visually follow what is happening.

Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/vpatch.c b/vpatch.c
index 68f8a47c07dda2035eb8ec86b9ddfd4df7c1eb67..f7ae935823314e5932fec03b7129ced31ea22ca3 100644 (file)
--- a/vpatch.c
+++ b/vpatch.c
@@ -912,11 +912,22 @@ int mcontains(struct mpos pos,
  *  d   diff     - show just the patch, both before and after
  *  m   merge    - show the full merge with -+ sections for changes.
  *                 If point is in a wiggled or conflicted section the
- *                 window is split  horizontally and the diff is shown
+ *                 window is split horizontally and the diff is shown
  *                 in the bottom window
  *  | sidebyside - two panes, left and right.  Left holds the merge,
  *                 right holds the diff.  In the case of a conflict,
  *                 left holds orig/after, right holds before/after
+ *
+ * The horizontal split for 'merge' mode is managed as follows.
+ * - The window is split when we first visit a line that contains
+ *   a wiggle or a conflict, and the second pane is removed when
+ *   we next visit a line that contains no changes (is fully Unchanged).
+ * - to display the second pane, we go do the previous mline for that
+ *   alternate mode (BEFORE|AFTER) same point is not visible.  Then
+ *   we centre that line
+ * - We need to rewind to an unchanged section, and wind forward again
+ *   to make sure that 'lo' and 'hi' are set properly.
+ * - every time we move, we redraw the second pane (see how that goes).
  */
 
 
@@ -1114,6 +1125,8 @@ void merge_window(struct plist *p, FILE *f, int reverse)
        int ch;
        int refresh = 2;
        int rows = 0, cols = 0;
+       int splitrow = -1;
+       int lastrow = 0;
        int i, c;
        int mode = ORIG|RESULT | BEFORE|AFTER;
        char *modename = "sidebyside";
@@ -1172,23 +1185,47 @@ void merge_window(struct plist *p, FILE *f, int reverse)
                        (void)attrset(A_NORMAL);
                        refresh = 1;
                }
-               if (row < 1 || row >= rows)
+               if (row < 1 || row >= lastrow)
                        refresh = 1;
 
 
+
+               if (mode == (ORIG|RESULT)) {
+                       int cmode = check_line(pos, fm,fb,fa,ci.merger, mode);
+                       if (splitrow < 0 && (cmode & (WIGGLED|CONFLICTED))) {
+                               splitrow = (rows+1)/2;
+                               lastrow = splitrow - 1;
+                               refresh = 1;
+                       }
+                       if (splitrow >= 0 && !(cmode & CHANGES)) {
+                               splitrow = -1;
+                               lastrow = rows-1;
+                               refresh = 1;
+                       }
+               } else if (splitrow >= 0) {
+                       splitrow = -1;
+                       lastrow = rows-1;
+                       refresh = 1;
+               }
+
                if (refresh) {
                        getmaxyx(stdscr, rows, cols);
                        rows--; /* keep last row clear */
+                       if (splitrow >= 0) {
+                               splitrow = (rows+1)/2;
+                               lastrow = splitrow - 1;
+                       } else
+                               lastrow =  rows - 1;
+
                        if (row < -3)
-                               row = (rows-1)/2+1;
+                               row = lastrow/2+1;
                        if (row < 1)
                                row = 1;
-                       if (row > rows+3)
-                               row = (rows-1)/2+1;
-                       if (row >= rows)
-                               row = rows-1;
+                       if (row > lastrow+3)
+                               row = lastrow/2+1;
+                       if (row >= lastrow)
+                               row = lastrow-1;
                }
-
                if (getenv("WIGGLE_VTRACE")) {
                        char b[100];
                        char *e, e2[7];
@@ -1259,15 +1296,49 @@ void merge_window(struct plist *p, FILE *f, int reverse)
                        while (i >= 1)
                                blank(i--, 0, cols, a_void);
                        tpos = pos;
-                       for (i=row; i<rows && ci.merger[tpos.p.m].type != End; ) {
+                       for (i=row; i<= lastrow && ci.merger[tpos.p.m].type != End; ) {
                                draw_mline(mode, i++, start, cols, fm,fb,fa,ci.merger,
                                           tpos, 0, NULL);
                                next_mline(&tpos, fm,fb,fa,ci.merger, mode);
                        }
                        botpos = tpos; botrow = i;
-                       while (i<rows)
+                       while (i<=lastrow)
                                blank(i++, 0, cols, a_void);
-               } else {
+               }
+               
+               if (splitrow >= 0) {
+                       struct mpos spos = pos;
+                       int smode = BEFORE|AFTER;
+                       int srow = (rows + splitrow)/2;
+                       if (visible(smode, ci.merger[spos.p.m].type,
+                                   spos.p.s) < 0)
+                               prev_mline(&spos, fm,fb,fa,ci.merger, smode);
+                       /* Now hi/lo might be wrong, so lets fix it. */
+                       tpos = spos;
+                       while (spos.p.m >= 0 && spos.state != 0)
+                               prev_mline(&spos, fm,fb,fa,ci.merger, smode);
+                       while (!same_mpos(spos, tpos))
+                               next_mline(&spos, fm,fb,fa,ci.merger, smode);
+                       
+
+                       (void)attrset(a_sep);
+                       for (i=0; i<cols; i++)
+                               mvaddstr(splitrow, i, "-");
+
+                       tpos = spos;
+                       for (i=srow-1; i>splitrow; i-- ) {
+                               prev_mline(&tpos, fm,fb,fa,ci.merger, smode);
+                               draw_mline(smode, i, start, cols, fm,fb,fa,ci.merger,
+                                          tpos, 0, NULL);
+                       }
+                       while (i > splitrow)
+                               blank(i--, 0, cols, a_void);
+                       tpos = spos;
+                       for (i=srow; i<rows && ci.merger[tpos.p.m].type != End; i++) {
+                               draw_mline(smode, i, start, cols, fm, fb,fa,ci.merger,
+                                          tpos, 0, NULL);
+                               next_mline(&tpos, fm,fb,fa,ci.merger, smode);
+                       }
                }
 #define META(c) ((c)|0x1000)
 #define        SEARCH(c) ((c)|0x2000)
@@ -1312,8 +1383,8 @@ void merge_window(struct plist *p, FILE *f, int reverse)
                                pos = tpos; row++;
                                next_mline(&tpos, fm,fb,fa,ci.merger,mode);
                        } while (ci.merger[tpos.p.m].type != End);
-                       if (row >= rows)
-                               row = rows;
+                       if (row >= lastrow)
+                               row = lastrow;
                        break;
                case '0' ... '9':
                        if (tnum < 0) tnum = 0;
@@ -1407,12 +1478,12 @@ void merge_window(struct plist *p, FILE *f, int reverse)
                        break;
                case 'L'-64:
                        refresh = 2;
-                       row = rows / 2;
+                       row = lastrow / 2;
                        break;
 
                case 'V'-64: /* page down */
                        pos = botpos;
-                       if (botrow < rows)
+                       if (botrow <= lastrow)
                                row = botrow;
                        else
                                row = 2;
@@ -1420,7 +1491,7 @@ void merge_window(struct plist *p, FILE *f, int reverse)
                        break;
                case META('v'): /* page up */
                        pos = toppos;
-                       row = rows-2;
+                       row = lastrow-1;
                        refresh = 1;
                        break;