Add support for keys to jump between matching brackets - C-M-f and C-M-b

in emacs, % in vi. Suggested by and help from Chris Barber in GitHub
issue 1666.

1 files changed, 222 insertions, 1 deletions

diff --git a/window-copy.c b/window-copy.c
index 741e2bfd..82b4765c 100644
--- a/window-copy.c
+++ b/window-copy.c
@@ -223,7 +223,7 @@ struct window_copy_mode_data {
 
 	int		 searchtype;
 	char		*searchstr;
-	bitstr_t        *searchmark;
+	bitstr_t	*searchmark;
 	u_int		 searchcount;
 	int		 searchthis;
 	int		 searchx;
@@ -995,6 +995,218 @@ window_copy_cmd_middle_line(struct window_copy_cmd_state *cs)
 }
 
 static enum window_copy_cmd_action
+window_copy_cmd_previous_matching_bracket(struct window_copy_cmd_state *cs)
+{
+	struct window_mode_entry	*wme = cs->wme;
+	u_int				 np = wme->prefix;
+	struct window_copy_mode_data	*data = wme->data;
+	struct screen			*s = data->backing;
+	char				 open[] = "{[(", close[] = "}])";
+	char				 tried, found, start, *cp;
+	u_int				 px, py, xx, yy, n;
+	struct grid_cell		 gc;
+	int				 failed;
+
+	for (; np != 0; np--) {
+		/* Get cursor position and line length. */
+		px = data->cx;
+		py = screen_hsize(s) + data->cy - data->oy;
+		xx = window_copy_find_length(wme, py);
+		yy = screen_hsize(s) + screen_size_y(s) - 1;
+		if (xx == 0)
+			break;
+
+		/*
+		 * Get the current character. If not on a bracket, try the
+		 * previous. If still not, then behave like previous-word.
+		 */
+		tried = 0;
+	retry:
+		grid_get_cell(s->grid, px, py, &gc);
+		if (gc.data.size != 1 || (gc.flags & GRID_FLAG_PADDING))
+			cp = NULL;
+		else {
+			found = *gc.data.data;
+			cp = strchr(close, found);
+		}
+		if (cp == NULL) {
+			if (data->modekeys == MODEKEY_EMACS) {
+				if (!tried && px > 0) {
+					px--;
+					tried = 1;
+					goto retry;
+				}
+				window_copy_cursor_previous_word(wme, "}]) ");
+				px = data->cx;
+				continue;
+			}
+			continue;
+		}
+		start = open[cp - close];
+
+		/* Walk backward until the matching bracket is reached. */
+		n = 1;
+		failed = 0;
+		do {
+			if (px == 0) {
+				if (py == 0) {
+					failed = 1;
+					break;
+				}
+				do {
+					py--;
+					xx = window_copy_find_length(wme, py);
+				} while (xx == 0 && py > 0);
+				if (xx == 0 && py == 0) {
+					failed = 1;
+					break;
+				}
+				px = xx - 1;
+			} else
+				px--;
+
+			grid_get_cell(s->grid, px, py, &gc);
+			if (gc.data.size == 1 &&
+			    (~gc.flags & GRID_FLAG_PADDING)) {
+				if (*gc.data.data == found)
+					n++;
+				else if (*gc.data.data == start)
+					n--;
+			}
+		} while (n != 0);
+
+		/* Move the cursor to the found location if any. */
+		if (!failed)
+			window_copy_scroll_to(wme, px, py);
+	}
+
+	return (WINDOW_COPY_CMD_NOTHING);
+}
+
+
+static enum window_copy_cmd_action
+window_copy_cmd_next_matching_bracket(struct window_copy_cmd_state *cs)
+{
+	struct window_mode_entry	*wme = cs->wme;
+	u_int				 np = wme->prefix;
+	struct window_copy_mode_data	*data = wme->data;
+	struct screen			*s = data->backing;
+	char				 open[] = "{[(", close[] = "}])";
+	char				 tried, found, end, *cp;
+	u_int				 px, py, xx, yy, sx, sy, n;
+	struct grid_cell		 gc;
+	int				 failed;
+	struct grid_line		*gl;
+
+	for (; np != 0; np--) {
+		/* Get cursor position and line length. */
+		px = data->cx;
+		py = screen_hsize(s) + data->cy - data->oy;
+		xx = window_copy_find_length(wme, py);
+		yy = screen_hsize(s) + screen_size_y(s) - 1;
+		if (xx == 0)
+			break;
+
+		/*
+		 * Get the current character. If not on a bracket, try the
+		 * next. If still not, then behave like next-word.
+		 */
+		tried = 0;
+	retry:
+		grid_get_cell(s->grid, px, py, &gc);
+		if (gc.data.size != 1 || (gc.flags & GRID_FLAG_PADDING))
+			cp = NULL;
+		else {
+			found = *gc.data.data;
+
+			/*
+			 * In vi mode, attempt to move to previous bracket if a
+			 * closing bracket is found first. If this fails,
+			 * return to the original cursor position.
+			 */
+			cp = strchr(close, found);
+			if (cp != NULL && data->modekeys == MODEKEY_VI) {
+				sx = data->cx;
+				sy = screen_hsize(s) + data->cy - data->oy;
+
+				window_copy_scroll_to(wme, px, py);
+				window_copy_cmd_previous_matching_bracket(cs);
+
+				px = data->cx;
+				py = screen_hsize(s) + data->cy - data->oy;
+				grid_get_cell(s->grid, px, py, &gc);
+				if (gc.data.size != 1 ||
+				    (gc.flags & GRID_FLAG_PADDING) ||
+				    strchr(close, *gc.data.data) == NULL)
+					window_copy_scroll_to(wme, sx, sy);
+				break;
+			}
+
+			cp = strchr(open, found);
+		}
+		if (cp == NULL) {
+			if (data->modekeys == MODEKEY_EMACS) {
+				if (!tried && px <= xx) {
+					px++;
+					tried = 1;
+					goto retry;
+				}
+				window_copy_cursor_next_word_end(wme, "{[( ");
+				px = data->cx;
+				continue;
+			}
+			/* For vi, continue searching for bracket until EOL. */
+			if (px > xx) {
+				if (py == yy)
+					continue;
+				gl = grid_get_line(s->grid, py);
+				if (~gl->flags & GRID_LINE_WRAPPED)
+					continue;
+				if (gl->cellsize > s->grid->sx)
+					continue;
+				px = 0;
+				py++;
+				xx = window_copy_find_length(wme, py);
+			} else
+				px++;
+			goto retry;
+		}
+		end = close[cp - open];
+
+		/* Walk forward until the matching bracket is reached. */
+		n = 1;
+		failed = 0;
+		do {
+			if (px > xx) {
+				if (py == yy) {
+					failed = 1;
+					break;
+				}
+				px = 0;
+				py++;
+				xx = window_copy_find_length(wme, py);
+			} else
+				px++;
+
+			grid_get_cell(s->grid, px, py, &gc);
+			if (gc.data.size == 1 &&
+			    (~gc.flags & GRID_FLAG_PADDING)) {
+				if (*gc.data.data == found)
+					n++;
+				else if (*gc.data.data == end)
+					n--;
+			}
+		} while (n != 0);
+
+		/* Move the cursor to the found location if any. */
+		if (!failed)
+			window_copy_scroll_to(wme, px, py);
+	}
+
+	return (WINDOW_COPY_CMD_NOTHING);
+}
+
+static enum window_copy_cmd_action
 window_copy_cmd_next_paragraph(struct window_copy_cmd_state *cs)
 {
 	struct window_mode_entry	*wme = cs->wme;
@@ -1613,6 +1825,8 @@ static const struct {
 	  window_copy_cmd_jump_to_forward },
 	{ "middle-line", 0, 0,
 	  window_copy_cmd_middle_line },
+	{ "next-matching-bracket", 0, 0,
+	  window_copy_cmd_next_matching_bracket },
 	{ "next-paragraph", 0, 0,
 	  window_copy_cmd_next_paragraph },
 	{ "next-space", 0, 0,
@@ -1631,6 +1845,8 @@ static const struct {
 	  window_copy_cmd_page_down_and_cancel },
 	{ "page-up", 0, 0,
 	  window_copy_cmd_page_up },
+	{ "previous-matching-bracket", 0, 0,
+	  window_copy_cmd_previous_matching_bracket },
 	{ "previous-paragraph", 0, 0,
 	  window_copy_cmd_previous_paragraph },
 	{ "previous-space", 0, 0,
@@ -3147,6 +3363,11 @@ window_copy_cursor_previous_word(struct window_mode_entry *wme,
 
 			py = screen_hsize(data->backing) + data->cy - data->oy;
 			px = window_copy_find_length(wme, py);
+
+			/* Stop if separator at EOL. */
+			if (px > 0 &&
+			    window_copy_in_set(wme, px - 1, py, separators))
+				break;
 		}
 	}