vis: use multiple cursor/selection infrastructure

This commits introduces the following keybindings, in normal mode:

 CTRL-N   select word the cursor is currently over, switch to visual mode
 CTRL-P   remove least recently added cursor
 ESC      if a selection is active, clear it.
          Otherwise dispose all but the primary cursor.

In visual mode:

 CTRL-N   create new cursor and select next word matching current selection
 CTRL-X   clear (skip) current selection, but select next matching word
 CTRL-P   remove least recently added cursor

4 files changed, 81 insertions, 1 deletions

diff --git a/config.def.h b/config.def.h
index 4402cd0..859b3db 100644
--- a/config.def.h
+++ b/config.def.h
@@ -363,6 +363,8 @@ static KeyBinding vis_mode_normal[] = {
 	{ { CONTROL('K')            }, cursors_new,    { .i = -1                   } },
 	{ { CONTROL('J')            }, cursors_new,    { .i = +1                   } },
 	{ { CONTROL('A')            }, cursors_align,  {                           } },
+	{ { CONTROL('N')            }, cursors_select, {                           } },
+	{ { CONTROL('P')            }, cursors_remove, {                           } },
 	{ { CONTROL('w'), NONE('n') }, cmd,            { .s = "open"               } },
 	{ { CONTROL('w'), NONE('c') }, cmd,            { .s = "q"                  } },
 	{ { CONTROL('w'), NONE('s') }, cmd,            { .s = "split"              } },
@@ -423,6 +425,9 @@ static KeyBinding vis_mode_normal[] = {
 };
 
 static KeyBinding vis_mode_visual[] = {
+	{ { CONTROL('N')            }, cursors_select_next, {                      } },
+	{ { CONTROL('X')            }, cursors_select_skip, {                      } },
+	{ { CONTROL('P')            }, cursors_remove, {                           } },
 	{ { KEY(BACKSPACE)          }, operator,       { .i = OP_DELETE            } },
 	{ { KEY(DELETE)             }, operator,       { .i = OP_DELETE            } },
 	{ { CONTROL('O')            }, operator,       { .i = OP_CURSOR            } },
diff --git a/view.c b/view.c
index 4af93f8..ff3ab42 100644
--- a/view.c
+++ b/view.c
@@ -912,6 +912,17 @@ void view_cursors_free(Cursor *c) {
 	free(c);
 }
 
+void view_cursors_dispose(Cursor *c) {
+	if (!c)
+		return;
+	View *view = c->view;
+	if (view->cursors && view->cursors->next) {
+		view_selections_free(c->sel);
+		view_cursors_free(c);
+		view_draw(view);
+	}
+}
+
 Cursor *view_cursors(View *view) {
 	return view->cursors;
 }
diff --git a/view.h b/view.h
index 4e750c0..d0e7070 100644
--- a/view.h
+++ b/view.h
@@ -117,7 +117,10 @@ void view_cursor_to(View*, size_t pos);
 Cursor *view_cursors_new(View*);
 /* get number of active cursors */
 int view_cursors_count(View*);
-/* dispose an existing cursor */
+/* dispose an existing cursor with its associated selection (if any),
+ * not applicaple for the last existing cursor */
+void view_cursors_dispose(Cursor*);
+/* dispose an existing cursor, no matter what */
 void view_cursors_free(Cursor*);
 /* only keep the main cursor, release all others together with their
  * selections (if any) */
diff --git a/vis.c b/vis.c
index b10f798..b385135 100644
--- a/vis.c
+++ b/vis.c
@@ -326,6 +326,14 @@ static void cursors_new(const Arg *arg);
 static void cursors_align(const Arg *arg);
 /* remove all but the primary cursor and their selections */
 static void cursors_clear(const Arg *arg);
+/* remove the least recently added cursor */
+static void cursors_remove(const Arg *arg);
+/* select the word the cursor is currently over */
+static void cursors_select(const Arg *arg);
+/* select the next region matching the current selection */
+static void cursors_select_next(const Arg *arg);
+/* clear current selection but select next match */
+static void cursors_select_skip(const Arg *arg);
 /* adjust action.count by arg->i */
 static void count(const Arg *arg);
 /* move to the action.count-th line or if not given either to the first (arg->i < 0)
@@ -869,6 +877,59 @@ static void cursors_clear(const Arg *arg) {
 		view_cursors_selection_clear(view_cursor(view));
 }
 
+static void cursors_select(const Arg *arg) {
+	Text *txt = vis->win->file->text;
+	View *view = vis->win->view;
+	for (Cursor *cursor = view_cursors(view); cursor; cursor = view_cursors_next(cursor)) {
+		Filerange sel = view_cursors_selection_get(cursor);
+		Filerange word = text_object_word(txt, view_cursors_pos(cursor));
+		if (!text_range_valid(&sel) && text_range_valid(&word)) {
+			view_cursors_selection_set(cursor, &word);
+			view_cursors_to(cursor, text_char_prev(txt, word.end));
+		}
+	}
+	switchmode(&(const Arg){ .i = VIS_MODE_VISUAL });
+}
+
+static void cursors_select_next(const Arg *arg) {
+	Text *txt = vis->win->file->text;
+	View *view = vis->win->view;
+	Cursor *cursor = view_cursor(view);
+	Filerange sel = view_cursors_selection_get(cursor);
+	if (!text_range_valid(&sel))
+		return;
+
+	size_t len = text_range_size(&sel);
+	char *buf = malloc(len+1);
+	if (!buf)
+		return;
+	len = text_bytes_get(txt, sel.start, len, buf);
+	buf[len] = '\0';
+	Filerange word = text_object_word_find_next(txt, sel.end, buf);
+	free(buf);
+
+	if (text_range_valid(&word)) {
+		cursor = view_cursors_new(view);
+		if (!cursor)
+			return;
+		view_cursors_selection_set(cursor, &word);
+		view_cursors_to(cursor, text_char_prev(txt, word.end));
+	}
+}
+
+static void cursors_select_skip(const Arg *arg) {
+	View *view = vis->win->view;
+	Cursor *cursor = view_cursor(view);
+	cursors_select_next(arg);
+	if (cursor != view_cursor(view))
+		view_cursors_dispose(cursor);
+}
+
+static void cursors_remove(const Arg *arg) {
+	View *view = vis->win->view;
+	view_cursors_dispose(view_cursor(view));
+}
+
 static void replace(const Arg *arg) {
 	Key k = getkey();
 	if (!k.str[0])