From fd87bca102321e5804fef74dac8a6d267ae46732 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Sat, 13 Feb 2021 12:31:55 +0100
Subject: [PATCH] =?UTF-8?q?grid:=20enable=20rows=20to=20have=20=E2=80=98ex?=
 =?UTF-8?q?tra=E2=80=99=20data=20associated=20with=20them?=
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This patch adds an ‘extra’ member to the row struct. It is a pointer
to a struct containing extra data to be associated with this row.

Initially, this struct contains a list of URL ranges. These
define (OSC-8) URLs on this row.

The ‘extra’ data is allocated on-demand. I.e. the pointer is NULL by
default; it is *not* allocated by grid_row_alloc().
---
 grid.c     |  9 +++++++++
 terminal.c | 28 ++++++++++++++++++++++++----
 terminal.h | 11 +++++++++++
 3 files changed, 44 insertions(+), 4 deletions(-)

diff --git a/grid.c b/grid.c
index 6d6b6b3c..2f0033ec 100644
--- a/grid.c
+++ b/grid.c
@@ -33,6 +33,7 @@ grid_row_alloc(int cols, bool initialize)
     struct row *row = xmalloc(sizeof(*row));
     row->dirty = false;
     row->linebreak = false;
+    row->extra = NULL;
 
     if (initialize) {
         row->cells = xcalloc(cols, sizeof(row->cells[0]));
@@ -50,6 +51,14 @@ grid_row_free(struct row *row)
     if (row == NULL)
         return;
 
+    if (row->extra != NULL) {
+        tll_foreach(row->extra->uri_ranges, it) {
+            free(it->item.uri);
+            tll_remove(row->extra->uri_ranges, it);
+        }
+    }
+
+    free(row->extra);
     free(row->cells);
     free(row);
 }
diff --git a/terminal.c b/terminal.c
index 0051ca6d..17b985a8 100644
--- a/terminal.c
+++ b/terminal.c
@@ -2154,8 +2154,18 @@ term_scroll_partial(struct terminal *term, struct scroll_region region, int rows
         grid_swap_row(term->grid, i - rows, i);
 
     /* Erase scrolled in lines */
-    for (int r = region.end - rows; r < region.end; r++)
-        erase_line(term, grid_row_and_alloc(term->grid, r));
+    for (int r = region.end - rows; r < region.end; r++) {
+        struct row *row = grid_row_and_alloc(term->grid, r);
+        if (unlikely(row->extra != NULL)) {
+            tll_foreach(row->extra->uri_ranges, it) {
+                free(it->item.uri);
+                tll_remove(row->extra->uri_ranges, it);
+            }
+            free(row->extra);
+            row->extra = NULL;
+        }
+        erase_line(term, row);
+    }
 
     term_damage_scroll(term, DAMAGE_SCROLL, region, rows);
     term->grid->cur_row = grid_row(term->grid, term->grid->cursor.point.row);
@@ -2222,8 +2232,18 @@ term_scroll_reverse_partial(struct terminal *term,
         grid_swap_row(term->grid, i, i - rows);
 
     /* Erase scrolled in lines */
-    for (int r = region.start; r < region.start + rows; r++)
-        erase_line(term, grid_row_and_alloc(term->grid, r));
+    for (int r = region.start; r < region.start + rows; r++) {
+        struct row *row = grid_row_and_alloc(term->grid, r);
+        if (unlikely(row->extra != NULL)) {
+            tll_foreach(row->extra->uri_ranges, it) {
+                free(it->item.uri);
+                tll_remove(row->extra->uri_ranges, it);
+            }
+            free(row->extra);
+            row->extra = NULL;
+        }
+        erase_line(term, row);
+    }
 
     term_damage_scroll(term, DAMAGE_SCROLL_REVERSE, region, rows);
     term->grid->cur_row = grid_row(term->grid, term->grid->cursor.point.row);
diff --git a/terminal.h b/terminal.h
index 39d02859..7df92efc 100644
--- a/terminal.h
+++ b/terminal.h
@@ -86,10 +86,21 @@ struct composed {
     uint8_t count;
 };
 
+struct row_uri_range {
+    int start;
+    int end;
+    char *uri;
+};
+
+struct row_data {
+    tll(struct row_uri_range) uri_ranges;
+};
+
 struct row {
     struct cell *cells;
     bool dirty;
     bool linebreak;
+    struct row_data *extra;
 };
 
 struct sixel {