vis: promote selections to first class primitives

This unifies cursors and selections. The cursor are now represendted
as singleton selections.

6 files changed, 86 insertions, 229 deletions

diff --git a/main.c b/main.c
index 11ec217..350f00d 100644
--- a/main.c
+++ b/main.c
@@ -1309,12 +1309,8 @@ static const char *cursors_align_indent(Vis *vis, const char *keys, const Arg *a
 	for (int i = 0; i < columns; i++) {
 		int mincol = INT_MAX, maxcol = 0;
 		for (Cursor *c = view_cursors_column(view, i); c; c = view_cursors_column_next(c, i)) {
-			size_t pos;
 			Filerange sel = view_cursors_selection_get(c);
-			if (text_range_valid(&sel))
-				pos = left_align ? sel.start : sel.end;
-			else
-				pos = view_cursors_pos(c);
+			size_t pos = left_align ? sel.start : sel.end;
 			int col = text_line_width_get(txt, pos);
 			if (col < mincol)
 				mincol = col;
@@ -1329,15 +1325,9 @@ static const char *cursors_align_indent(Vis *vis, const char *keys, const Arg *a
 		memset(buf, ' ', len);
 
 		for (Cursor *c = view_cursors_column(view, i); c; c = view_cursors_column_next(c, i)) {
-			size_t pos, ipos;
 			Filerange sel = view_cursors_selection_get(c);
-			if (text_range_valid(&sel)) {
-				pos = left_align ? sel.start : sel.end;
-				ipos = sel.start;
-			} else {
-				pos = view_cursors_pos(c);
-				ipos = pos;
-			}
+			size_t pos = left_align ? sel.start : sel.end;
+			size_t ipos = sel.start;
 			int col = text_line_width_get(txt, pos);
 			if (col < maxcol) {
 				size_t off = maxcol - col;
@@ -1366,12 +1356,9 @@ static const char *cursors_select(Vis *vis, const char *keys, const Arg *arg) {
 	Text *txt = vis_text(vis);
 	View *view = vis_view(vis);
 	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)) {
+		if (text_range_valid(&word))
 			view_cursors_selection_set(cursor, &word);
-			view_cursors_to(cursor, text_char_prev(txt, word.end));
-		}
 	}
 	vis_mode_switch(vis, VIS_MODE_VISUAL);
 	return keys;
@@ -1476,12 +1463,8 @@ static const char *cursors_remove_column_except(Vis *vis, const char *keys, cons
 
 static const char *cursors_navigate(Vis *vis, const char *keys, const Arg *arg) {
 	View *view = vis_view(vis);
-	if (!view_cursors_multiple(view)) {
-		Filerange sel = view_selection_get(view);
-		if (!text_range_valid(&sel))
-			return wscroll(vis, keys, arg);
-		return keys;
-	}
+	if (!view_cursors_multiple(view))
+		return wscroll(vis, keys, arg);
 	Cursor *c = view_cursors_primary_get(view);
 	VisCountIterator it = vis_count_iterator_get(vis, 1);
 	while (vis_count_iterator_next(&it)) {
@@ -1558,7 +1541,6 @@ static const char *selections_rotate(Vis *vis, const char *keys, const Arg *arg)
 					continue;
 				newsel.end = newsel.start + oldrot->len;
 				view_cursors_selection_set(newrot->cursor, &newsel);
-				view_cursors_selection_sync(newrot->cursor);
 				free(oldrot->data);
 			}
 			array_clear(&arr);
@@ -1585,7 +1567,6 @@ static const char *selections_trim(Vis *vis, const char *keys, const Arg *arg) {
 			&& isspace((unsigned char)b); sel.start++);
 		if (sel.start < sel.end) {
 			view_cursors_selection_set(c, &sel);
-			view_cursors_selection_sync(c);
 		} else if (!view_cursors_dispose(c)) {
 			vis_mode_switch(vis, VIS_MODE_NORMAL);
 		}
diff --git a/sam.c b/sam.c
index d04c230..815940f 100644
--- a/sam.c
+++ b/sam.c
@@ -1213,7 +1213,7 @@ enum SamError sam_cmd(Vis *vis, const char *s) {
 				if (c->cursor) {
 					if (visual) {
 						view_cursors_selection_set(c->cursor, &sel);
-						view_cursors_selection_sync(c->cursor);
+						view_cursors_selection_start(c->cursor);
 					} else {
 						if (memchr(c->data, '\n', c->len))
 							view_cursors_to(c->cursor, sel.start);
@@ -1224,7 +1224,7 @@ enum SamError sam_cmd(Vis *vis, const char *s) {
 					Cursor *cursor = view_cursors_new(c->win->view, sel.start);
 					if (cursor) {
 						view_cursors_selection_set(cursor, &sel);
-						view_cursors_selection_sync(cursor);
+						view_cursors_selection_start(cursor);
 					}
 				}
 			}
@@ -1239,8 +1239,7 @@ enum SamError sam_cmd(Vis *vis, const char *s) {
 		view_cursors_primary_set(view_cursors(vis->win->view));
 		bool completed = true;
 		for (Cursor *c = view_cursors(vis->win->view); c; c = view_cursors_next(c)) {
-			Filerange sel = view_cursors_selection_get(c);
-			if (text_range_valid(&sel)) {
+			if (view_selection_anchored(c)) {
 				completed = false;
 				break;
 			}
@@ -1504,10 +1503,12 @@ static bool cmd_print(Vis *vis, Win *win, Command *cmd, const char *argv[], Curs
 	else
 		cur = view_cursors_new_force(view, pos);
 	if (cur) {
-		if (range->start != range->end)
+		if (range->start != range->end) {
 			view_cursors_selection_set(cur, range);
-		else
+			view_cursors_selection_start(cur);
+		} else {
 			view_cursors_selection_clear(cur);
+		}
 	}
 	return cur != NULL;
 }
@@ -1559,17 +1560,16 @@ static bool cmd_write(Vis *vis, Win *win, Command *cmd, const char *argv[], Curs
 			return false;
 		}
 
+		bool visual = vis->mode->visual;
+
 		for (Cursor *c = view_cursors(win->view); c; c = view_cursors_next(c)) {
-			Filerange range = view_cursors_selection_get(c);
-			bool invalid_range = !text_range_valid(&range);
-			if (invalid_range)
-				range = *r;
+			Filerange range = visual ? view_cursors_selection_get(c) : *r;
 			ssize_t written = text_write_range(text, &range, file->fd);
 			if (written == -1 || (size_t)written != text_range_size(&range)) {
 				vis_info_show(vis, "Can not write to stdout");
 				return false;
 			}
-			if (invalid_range)
+			if (!visual)
 				break;
 		}
 
@@ -1612,13 +1612,10 @@ static bool cmd_write(Vis *vis, Win *win, Command *cmd, const char *argv[], Curs
 		}
 
 		bool failure = false;
+		bool visual = vis->mode->visual;
 
 		for (Cursor *c = view_cursors(win->view); c; c = view_cursors_next(c)) {
-			Filerange range = view_cursors_selection_get(c);
-			bool invalid_range = !text_range_valid(&range);
-			if (invalid_range)
-				range = *r;
-
+			Filerange range = visual ? view_cursors_selection_get(c) : *r;
 			ssize_t written = text_save_write_range(ctx, &range);
 			failure = (written == -1 || (size_t)written != text_range_size(&range));
 			if (failure) {
@@ -1626,7 +1623,7 @@ static bool cmd_write(Vis *vis, Win *win, Command *cmd, const char *argv[], Curs
 				break;
 			}
 
-			if (invalid_range)
+			if (!visual)
 				break;
 		}
 
diff --git a/view.c b/view.c
index 76410aa..2106b0e 100644
--- a/view.c
+++ b/view.c
@@ -37,26 +37,23 @@ enum {
  * The view_selections_{get,set} functions take care of adding/removing
  * the necessary offset for the last character.
  */
-struct Selection {
-	Mark anchor;             /* position where the selection was created */
-	Mark cursor;             /* other selection endpoint where it changes */
-	View *view;              /* associated view to which this selection belongs */
-	Cursor *cur;             /* cursor whose movement will affect this selection */
-	Selection *prev, *next;  /* previsous/next selections in no particular order */
-};
+
+typedef struct {
+	Mark anchor;
+	Mark cursor;
+} SelectionRegion;
 
 struct Cursor {             /* cursor position */
+	Mark cursor;        /* other selection endpoint where it changes */
+	Mark anchor;        /* position where the selection was created */
+	bool anchored;      /* whether anchor remains fixed */
 	size_t pos;         /* in bytes from the start of the file */
 	int row, col;       /* in terms of zero based screen coordinates */
 	int lastcol;        /* remembered column used when moving across lines */
 	Line *line;         /* screen line on which cursor currently resides */
-	Mark mark;          /* mark used to keep track of current cursor position */
-	Mark mark_old;      /* previous value of the mark, used to recover cursor position */
-	Selection *sel;     /* selection (if any) which folows the cursor upon movement */
-	Mark lastsel_anchor;/* previously used selection data, */
-	Mark lastsel_cursor;/* used to restore it */
 	int generation;     /* used to filter out newly created cursors during iteration */
 	int number;         /* how many cursors are located before this one */
+	SelectionRegion region; /* saved selection region */
 	View *view;         /* associated view to which this cursor belongs */
 	Cursor *prev, *next;/* previous/next cursors ordered by location at creation time */
 };
@@ -86,7 +83,6 @@ struct View {
 	const SyntaxSymbol *symbols[SYNTAX_SYMBOL_LAST]; /* symbols to use for white spaces etc */
 	int tabwidth;       /* how many spaces should be used to display a tab character */
 	Cursor *cursors;    /* all cursors currently active */
-	Selection *selections; /* all selected regions */
 	int cursor_generation; /* used to filter out newly created cursors during iteration */
 	bool need_update;   /* whether view has been redrawn */
 	bool large_file;    /* optimize for displaying large files */
@@ -261,13 +257,12 @@ static bool view_addch(View *view, Cell *cell) {
 
 static void cursor_to(Cursor *c, size_t pos) {
 	Text *txt = c->view->text;
-	c->mark_old = c->mark;
-	c->mark = text_mark_set(txt, pos);
+	c->cursor = text_mark_set(txt, pos);
+	if (!c->anchored)
+		c->anchor = c->cursor;
 	if (pos != c->pos)
 		c->lastcol = 0;
 	c->pos = pos;
-	if (c->sel)
-		c->sel->cursor = text_mark_set(txt, pos);
 	if (!view_coord_get(c->view, pos, &c->line, &c->row, &c->col)) {
 		if (c->view->cursor == c) {
 			c->line = c->view->topline;
@@ -484,8 +479,6 @@ void view_free(View *view) {
 		return;
 	while (view->cursors)
 		view_cursors_free(view->cursors);
-	while (view->selections)
-		view_selections_free(view->selections);
 	free(view->lines);
 	free(view);
 }
@@ -1028,7 +1021,6 @@ bool view_cursors_dispose(Cursor *c) {
 	View *view = c->view;
 	if (!view->cursors || !view->cursors->next)
 		return false;
-	view_selections_free(c->sel);
 	view_cursors_free(c);
 	view_cursors_primary_set(view->cursor);
 	return true;
@@ -1064,11 +1056,7 @@ Cursor *view_cursors_primary_get(View *view) {
 void view_cursors_primary_set(Cursor *c) {
 	if (!c)
 		return;
-	View *view = c->view;
-	view->cursor = c;
-	Filerange sel = view_cursors_selection_get(c);
-	view_cursors_to(c, view_cursors_pos(c));
-	view_cursors_selection_set(c, &sel);
+	c->view->cursor = c;
 }
 
 Cursor *view_cursors_prev(Cursor *c) {
@@ -1092,8 +1080,7 @@ Cursor *view_cursors_next(Cursor *c) {
 }
 
 size_t view_cursors_pos(Cursor *c) {
-	size_t pos = text_mark_get(c->view->text, c->mark);
-	return pos != EPOS ? pos : text_mark_get(c->view->text, c->mark_old);
+	return text_mark_get(c->view->text, c->cursor);
 }
 
 size_t view_cursors_line(Cursor *c) {
@@ -1171,147 +1158,46 @@ void view_cursors_place(Cursor *c, size_t line, size_t col) {
 }
 
 void view_cursors_selection_start(Cursor *c) {
-	if (c->sel)
-		return;
-	size_t pos = view_cursors_pos(c);
-	if (pos == EPOS || !(c->sel = view_selections_new(c->view, c)))
-		return;
-	Text *txt = c->view->text;
-	c->sel->anchor = text_mark_set(txt, pos);
-	c->sel->cursor = c->sel->anchor;
-	c->view->need_update = true;
-}
-
-void view_cursors_selection_restore(Cursor *c) {
-	Text *txt = c->view->text;
-	if (c->sel)
-		return;
-	Filerange sel = text_range_new(
-		text_mark_get(txt, c->lastsel_anchor),
-		text_mark_get(txt, c->lastsel_cursor)
-	);
-	if (!text_range_valid(&sel))
-		return;
-	view_cursors_to(c, sel.end);
-	sel.end = text_char_next(txt, sel.end);
-	if (!(c->sel = view_selections_new(c->view, c)))
-		return;
-	view_selections_set(c->sel, &sel);
-}
-
-void view_cursors_selection_stop(Cursor *c) {
-	c->sel = NULL;
+	c->anchored = true;
 }
 
 void view_cursors_selection_clear(Cursor *c) {
-	view_selections_free(c->sel);
+	c->anchored = false;
+	c->anchor = c->cursor;
 	c->view->need_update = true;
 }
 
-void view_cursors_selection_swap(Cursor *c) {
-	if (!c->sel)
-		return;
-	view_selections_swap(c->sel);
-	view_cursors_selection_sync(c);
-}
-
-void view_cursors_selection_sync(Cursor *c) {
-	if (!c->sel)
-		return;
-	Text *txt = c->view->text;
-	size_t pos = text_mark_get(txt, c->sel->cursor);
-	view_cursors_to(c, pos);
-}
-
-Filerange view_cursors_selection_get(Cursor *c) {
-	return view_selections_get(c->sel);
-}
-
-void view_cursors_selection_set(Cursor *c, const Filerange *r) {
-	if (!text_range_valid(r))
-		return;
-	bool new = !c->sel;
-	if (new && !(c->sel = view_selections_new(c->view, c)))
-		return;
-	view_selections_set(c->sel, r);
-	if (!new) {
-		size_t pos = view_cursors_pos(c);
-		if (!text_range_contains(r, pos))
-			view_cursors_selection_sync(c);
-	}
-}
-
-Selection *view_selections_new(View *view, Cursor *c) {
-	Selection *s = calloc(1, sizeof(*s));
-	if (!s)
-		return NULL;
-	s->view = view;
-	s->next = view->selections;
-	if (view->selections)
-		view->selections->prev = s;
-	view->selections = s;
-	s->cur = c;
-	return s;
+void view_cursors_selection_swap(Cursor *s) {
+	Mark temp = s->anchor;
+	s->anchor = s->cursor;
+	s->cursor = temp;
+	view_cursors_to(s, text_mark_get(s->view->text, s->cursor));
 }
 
-void view_selections_free(Selection *s) {
-	if (!s)
-		return;
-	if (s->prev)
-		s->prev->next = s->next;
-	if (s->next)
-		s->next->prev = s->prev;
-	if (s->view->selections == s)
-		s->view->selections = s->next;
-	Cursor *c = s->cur;
-	if (c) {
-		c->lastsel_anchor = s->anchor;
-		c->lastsel_cursor = s->cursor;
-		c->sel = NULL;
-	}
-	free(s);
+bool view_selection_anchored(Selection *s) {
+	return s->anchored;
 }
 
 void view_selections_clear(View *view) {
-	while (view->selections)
-		view_selections_free(view->selections);
+	for (Cursor *c = view->cursors; c; c = c->next)
+		view_cursors_selection_clear(c);
 	view_draw(view);
 }
 
 void view_cursors_clear(View *view) {
 	for (Cursor *c = view->cursors, *next; c; c = next) {
 		next = c->next;
-		if (c != view->cursor) {
-			view_selections_free(c->sel);
+		if (c != view->cursor)
 			view_cursors_free(c);
-		}
 	}
 	view_draw(view);
 }
 
-void view_selections_swap(Selection *s) {
-	Mark temp = s->anchor;
-	s->anchor = s->cursor;
-	s->cursor = temp;
-}
-
-Selection *view_selections(View *view) {
-	return view->selections;
-}
-
-Selection *view_selections_prev(Selection *s) {
-	return s->prev;
-}
-
-Selection *view_selections_next(Selection *s) {
-	return s->next;
-}
-
 Filerange view_selection_get(View *view) {
-	return view_selections_get(view->cursor->sel);
+	return view_cursors_selection_get(view->cursor);
 }
 
-Filerange view_selections_get(Selection *s) {
+Filerange view_cursors_selection_get(Selection *s) {
 	if (!s)
 		return text_range_empty();
 	Text *txt = s->view->text;
@@ -1323,7 +1209,7 @@ Filerange view_selections_get(Selection *s) {
 	return sel;
 }
 
-void view_selections_set(Selection *s, const Filerange *r) {
+void view_cursors_selection_set(Selection *s, const Filerange *r) {
 	if (!text_range_valid(r))
 		return;
 	Text *txt = s->view->text;
@@ -1340,7 +1226,27 @@ void view_selections_set(Selection *s, const Filerange *r) {
 		s->anchor = text_mark_set(txt, r->start);
 		s->cursor = text_mark_set(txt, end);
 	}
-	s->view->need_update = true;
+	s->anchored = true;
+	view_cursors_to(s, text_mark_get(s->view->text, s->cursor));
+}
+
+void view_cursors_selection_save(Selection *s) {
+	s->region.cursor = s->cursor;
+	s->region.anchor = s->anchor;
+}
+
+bool view_cursors_selection_restore(Selection *s) {
+	Text *txt = s->view->text;
+	size_t pos = text_mark_get(txt, s->region.cursor);
+	if (pos == EPOS)
+		return false;
+	if (s->region.anchor != s->region.cursor && text_mark_get(txt, s->region.anchor) == EPOS)
+		return false;
+	s->cursor = s->region.cursor;
+	s->anchor = s->region.anchor;
+	s->anchored = true;
+	view_cursors_to(s, pos);
+	return true;
 }
 
 Text *view_text(View *view) {
diff --git a/view.h b/view.h
index a6d455e..833252a 100644
--- a/view.h
+++ b/view.h
@@ -6,7 +6,7 @@
 
 typedef struct View View;
 typedef struct Cursor Cursor;
-typedef struct Selection Selection;
+typedef Cursor Selection;
 
 #include "text.h"
 #include "ui.h"
@@ -162,30 +162,20 @@ void view_cursors_place(Cursor*, size_t line, size_t col);
 /* start selected area at current cursor position. further cursor movements
  * will affect the selected region. */
 void view_cursors_selection_start(Cursor*);
-/* detach cursor from selection, further cursor movements will not affect
- * the selected region. */
-void view_cursors_selection_stop(Cursor*);
 /* clear selection associated with this cursor (if any) */
 void view_cursors_selection_clear(Cursor*);
 /* move cursor position from one end of the selection to the other */
 void view_cursors_selection_swap(Cursor*);
-/* move cursor to the end/boundary of the associated selection */
-void view_cursors_selection_sync(Cursor*);
-/* restore previous used selection of this cursor */
-void view_cursors_selection_restore(Cursor*);
 /* get/set the selected region associated with this cursor */
 Filerange view_cursors_selection_get(Cursor*);
 void view_cursors_selection_set(Cursor*, const Filerange*);
 
-Selection *view_selections_new(View*, Cursor*);
-void view_selections_free(Selection*);
+void view_cursors_selection_save(Selection*);
+bool view_cursors_selection_restore(Selection*);
+
+bool view_selection_anchored(Cursor*);
+
 void view_selections_clear(View*);
-void view_selections_swap(Selection*);
-Selection *view_selections(View*);
-Selection *view_selections_prev(Selection*);
-Selection *view_selections_next(Selection*);
-Filerange view_selections_get(Selection*);
-void view_selections_set(Selection*, const Filerange*);
 Text *view_text(View*);
 
 /* get number of columns, that is maximal number of cursors on a line */
diff --git a/vis-prompt.c b/vis-prompt.c
index a08a19f..c37f093 100644
--- a/vis-prompt.c
+++ b/vis-prompt.c
@@ -55,7 +55,7 @@ static const char *prompt_enter(Vis *vis, const char *keys, const Arg *arg) {
 	char *cmd = NULL;
 
 	Filerange range = view_selection_get(view);
-	if (!text_range_valid(&range)) {
+	if (!vis->mode->visual) {
 		const char *pattern = NULL;
 		Regex *regex = text_regex_new();
 		size_t pos = view_cursor_get(view);
diff --git a/vis.c b/vis.c
index b689e6f..2455a59 100644
--- a/vis.c
+++ b/vis.c
@@ -245,10 +245,15 @@ void vis_window_status(Win *win, const char *status) {
 }
 
 void window_selection_save(Win *win) {
+	Vis *vis = win->vis;
 	File *file = win->file;
 	Filerange sel = view_cursors_selection_get(view_cursors(win->view));
 	file->marks[VIS_MARK_SELECTION_START] = text_mark_set(file->text, sel.start);
 	file->marks[VIS_MARK_SELECTION_END] = text_mark_set(file->text, sel.end);
+	if (!vis->action.op) {
+		for (Selection *s = view_cursors(win->view); s; s = view_cursors_next(s))
+			view_cursors_selection_save(s);
+	}
 }
 
 static void window_free(Win *win) {
@@ -966,39 +971,17 @@ void vis_do(Vis *vis) {
 
 		if (linewise && vis->mode != &vis_modes[VIS_MODE_VISUAL])
 			c.range = text_range_linewise(txt, &c.range);
-		if (vis->mode->visual) {
+		if (vis->mode->visual)
 			view_cursors_selection_set(cursor, &c.range);
-			if (vis->mode == &vis_modes[VIS_MODE_VISUAL] || a->textobj)
-				view_cursors_selection_sync(cursor);
-		}
 
 		if (a->op) {
 			size_t pos = a->op->func(vis, txt, &c);
 			if (pos == EPOS) {
 				view_cursors_dispose(cursor);
 			} else if (pos <= text_size(txt)) {
-				/* moving the cursor will affect the selection.
-				 * because we want to be able to later restore
-				 * the old selection we update it again before
-				 * leaving visual mode.
-				 */
-				Filerange sel = view_cursors_selection_get(cursor);
+				if (vis->mode->visual)
+					view_cursors_selection_save(cursor);
 				view_cursors_to(cursor, pos);
-				if (vis->mode->visual) {
-					if (sel.start == EPOS && sel.end == EPOS)
-						sel = c.range;
-					else if (sel.start == EPOS)
-						sel = text_range_new(c.range.start, sel.end);
-					else if (sel.end == EPOS)
-						sel = text_range_new(c.range.start, sel.start);
-					if (vis->mode == &vis_modes[VIS_MODE_VISUAL_LINE])
-						sel = text_range_linewise(txt, &sel);
-					if (!text_range_contains(&sel, pos)) {
-						Filerange cur = text_range_new(pos, pos);
-						sel = text_range_union(&sel, &cur);
-					}
-					view_cursors_selection_set(cursor, &sel);
-				}
 			}
 		}
 	}