screen.c - tmux - Rivoreo Source Code Repositories

 /* $OpenBSD$ */

 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
  *
  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */

 #include <sys/types.h>

 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>

 #include "tmux.h"

 struct screen_title_entry {
 	char				*text;

 	TAILQ_ENTRY(screen_title_entry)	 entry;
 };
 TAILQ_HEAD(screen_titles, screen_title_entry);

 static void	screen_resize_x(struct screen *, u_int);
 static void	screen_resize_y(struct screen *, u_int);

 static void	screen_reflow(struct screen *, u_int);

 /* Free titles stack. */
 static void
 screen_free_titles(struct screen *s)
 {
 	struct screen_title_entry	*title_entry;

 	if (s->titles == NULL)
 		return;

 	while ((title_entry = TAILQ_FIRST(s->titles)) != NULL) {
 		TAILQ_REMOVE(s->titles, title_entry, entry);
 		free(title_entry->text);
 		free(title_entry);
 	}

 	free(s->titles);
 	s->titles = NULL;
 }

 /* Create a new screen. */
 void
 screen_init(struct screen *s, u_int sx, u_int sy, u_int hlimit)
 {
 	s->grid = grid_create(sx, sy, hlimit);
 	s->title = xstrdup("");
 	s->titles = NULL;

 	s->cstyle = 0;
 	s->ccolour = xstrdup("");
 	s->tabs = NULL;

 	screen_reinit(s);
 }

 /* Reinitialise screen. */
 void
 screen_reinit(struct screen *s)
 {
 	s->cx = 0;
 	s->cy = 0;

 	s->rupper = 0;
 	s->rlower = screen_size_y(s) - 1;

 	s->mode = MODE_CURSOR | MODE_WRAP;

 	screen_reset_tabs(s);

 	grid_clear_lines(s->grid, s->grid->hsize, s->grid->sy, 8);

 	screen_clear_selection(s);
 	screen_free_titles(s);
 }

 /* Destroy a screen. */
 void
 screen_free(struct screen *s)
 {
 	free(s->tabs);
 	free(s->title);
 	free(s->ccolour);

 	grid_destroy(s->grid);

 	screen_free_titles(s);
 }

 /* Reset tabs to default, eight spaces apart. */
 void
 screen_reset_tabs(struct screen *s)
 {
 	u_int	i;

 	free(s->tabs);

 	if ((s->tabs = bit_alloc(screen_size_x(s))) == NULL)
 		fatal("bit_alloc failed");
 	for (i = 8; i < screen_size_x(s); i += 8)
 		bit_set(s->tabs, i);
 }

 /* Set screen cursor style. */
 void
 screen_set_cursor_style(struct screen *s, u_int style)
 {
 	if (style <= 6)
 		s->cstyle = style;
 }

 /* Set screen cursor colour. */
 void
 screen_set_cursor_colour(struct screen *s, const char *colour)
 {
 	free(s->ccolour);
 	s->ccolour = xstrdup(colour);
 }

 /* Set screen title. */
 void
 screen_set_title(struct screen *s, const char *title)
 {
 	free(s->title);
 	utf8_stravis(&s->title, title, VIS_OCTAL|VIS_CSTYLE|VIS_TAB|VIS_NL);
 }

 /* Push the current title onto the stack. */
 void
 screen_push_title(struct screen *s)
 {
 	struct screen_title_entry *title_entry;

 	if (s->titles == NULL) {
 		s->titles = xmalloc(sizeof *s->titles);
 		TAILQ_INIT(s->titles);
 	}
 	title_entry = xmalloc(sizeof *title_entry);
 	title_entry->text = xstrdup(s->title);
 	TAILQ_INSERT_HEAD(s->titles, title_entry, entry);
 }

 /*
  * Pop a title from the stack and set it as the screen title. If the stack is
  * empty, do nothing.
  */
 void
 screen_pop_title(struct screen *s)
 {
 	struct screen_title_entry *title_entry;

 	if (s->titles == NULL)
 		return;

 	title_entry = TAILQ_FIRST(s->titles);
 	if (title_entry != NULL) {
 		screen_set_title(s, title_entry->text);

 		TAILQ_REMOVE(s->titles, title_entry, entry);
 		free(title_entry->text);
 		free(title_entry);
 	}
 }

 /* Resize screen. */
 void
 screen_resize(struct screen *s, u_int sx, u_int sy, int reflow)
 {
 	if (sx < 1)
 		sx = 1;
 	if (sy < 1)
 		sy = 1;

 	if (sx != screen_size_x(s)) {
 		screen_resize_x(s, sx);

 		/*
 		 * It is unclear what should happen to tabs on resize. xterm
 		 * seems to try and maintain them, rxvt resets them. Resetting
 		 * is simpler and more reliable so let's do that.
 		 */
 		screen_reset_tabs(s);
 	} else
 		reflow = 0;

 	if (sy != screen_size_y(s))
 		screen_resize_y(s, sy);

 	if (reflow)
 		screen_reflow(s, sx);
 }

 static void
 screen_resize_x(struct screen *s, u_int sx)
 {
 	struct grid		*gd = s->grid;

 	if (sx == 0)
 		fatalx("zero size");

 	/*
 	 * Treat resizing horizontally simply: just ensure the cursor is
 	 * on-screen and change the size. Don't bother to truncate any lines -
 	 * then the data should be accessible if the size is then increased.
 	 *
 	 * The only potential wrinkle is if UTF-8 double-width characters are
 	 * left in the last column, but UTF-8 terminals should deal with this
 	 * sanely.
 	 */
 	if (s->cx >= sx)
 		s->cx = sx - 1;
 	gd->sx = sx;
 }

 static void
 screen_resize_y(struct screen *s, u_int sy)
 {
 	struct grid	*gd = s->grid;
 	u_int		 needed, available, oldy, i;

 	if (sy == 0)
 		fatalx("zero size");
 	oldy = screen_size_y(s);

 	/*
 	 * When resizing:
 	 *
 	 * If the height is decreasing, delete lines from the bottom until
 	 * hitting the cursor, then push lines from the top into the history.
 	 *
 	 * When increasing, pull as many lines as possible from scrolled
 	 * history (not explicitly cleared from view) to the top, then fill the
 	 * remaining with blanks at the bottom.
 	 */

 	/* Size decreasing. */
 	if (sy < oldy) {
 		needed = oldy - sy;

 		/* Delete as many lines as possible from the bottom. */
 		available = oldy - 1 - s->cy;
 		if (available > 0) {
 			if (available > needed)
 				available = needed;
 			grid_view_delete_lines(gd, oldy - available, available,
 			    8);
 		}
 		needed -= available;

 		/*
 		 * Now just increase the history size, if possible, to take
 		 * over the lines which are left. If history is off, delete
 		 * lines from the top.
 		 */
 		available = s->cy;
 		if (gd->flags & GRID_HISTORY) {
 			gd->hscrolled += needed;
 			gd->hsize += needed;
 		} else if (needed > 0 && available > 0) {
 			if (available > needed)
 				available = needed;
 			grid_view_delete_lines(gd, 0, available, 8);
 		}
 		s->cy -= needed;
 	}

 	/* Resize line arrays. */
 	gd->linedata = xreallocarray(gd->linedata, gd->hsize + sy,
 	    sizeof *gd->linedata);

 	/* Size increasing. */
 	if (sy > oldy) {
 		needed = sy - oldy;

 		/*
 		 * Try to pull as much as possible out of scrolled history, if
 		 * is is enabled.
 		 */
 		available = gd->hscrolled;
 		if (gd->flags & GRID_HISTORY && available > 0) {
 			if (available > needed)
 				available = needed;
 			gd->hscrolled -= available;
 			gd->hsize -= available;
 			s->cy += available;
 		} else
 			available = 0;
 		needed -= available;

 		/* Then fill the rest in with blanks. */
 		for (i = gd->hsize + sy - needed; i < gd->hsize + sy; i++)
 			memset(&gd->linedata[i], 0, sizeof gd->linedata[i]);
 	}

 	/* Set the new size, and reset the scroll region. */
 	gd->sy = sy;
 	s->rupper = 0;
 	s->rlower = screen_size_y(s) - 1;
 }

 /* Set selection. */
 void
 screen_set_selection(struct screen *s, u_int sx, u_int sy,
     u_int ex, u_int ey, u_int rectflag, struct grid_cell *gc)
 {
 	struct screen_sel	*sel = &s->sel;

 	memcpy(&sel->cell, gc, sizeof sel->cell);
 	sel->flag = 1;
 	sel->hidden = 0;

 	sel->rectflag = rectflag;

 	sel->sx = sx; sel->sy = sy;
 	sel->ex = ex; sel->ey = ey;
 }

 /* Clear selection. */
 void
 screen_clear_selection(struct screen *s)
 {
 	struct screen_sel	*sel = &s->sel;

 	sel->flag = 0;
 	sel->hidden = 0;
 	sel->lineflag = LINE_SEL_NONE;
 }

 /* Hide selection. */
 void
 screen_hide_selection(struct screen *s)
 {
 	struct screen_sel	*sel = &s->sel;

 	sel->hidden = 1;
 }

 /* Check if cell in selection. */
 int
 screen_check_selection(struct screen *s, u_int px, u_int py)
 {
 	struct screen_sel	*sel = &s->sel;
 	u_int			 xx;

 	if (!sel->flag || sel->hidden)
 		return (0);

 	if (sel->rectflag) {
 		if (sel->sy < sel->ey) {
 			/* start line < end line -- downward selection. */
 			if (py < sel->sy || py > sel->ey)
 				return (0);
 		} else if (sel->sy > sel->ey) {
 			/* start line > end line -- upward selection. */
 			if (py > sel->sy || py < sel->ey)
 				return (0);
 		} else {
 			/* starting line == ending line. */
 			if (py != sel->sy)
 				return (0);
 		}

 		/*
 		 * Need to include the selection start row, but not the cursor
 		 * row, which means the selection changes depending on which
 		 * one is on the left.
 		 */
 		if (sel->ex < sel->sx) {
 			/* Cursor (ex) is on the left. */
 			if (px < sel->ex)
 				return (0);

 			if (px > sel->sx)
 				return (0);
 		} else {
 			/* Selection start (sx) is on the left. */
 			if (px < sel->sx)
 				return (0);

 			if (px > sel->ex)
 				return (0);
 		}
 	} else {
 		/*
 		 * Like emacs, keep the top-left-most character, and drop the
 		 * bottom-right-most, regardless of copy direction.
 		 */
 		if (sel->sy < sel->ey) {
 			/* starting line < ending line -- downward selection. */
 			if (py < sel->sy || py > sel->ey)
 				return (0);

 			if (py == sel->sy && px < sel->sx)
 				return (0);

 			if (py == sel->ey && px > sel->ex)
 				return (0);
 		} else if (sel->sy > sel->ey) {
 			/* starting line > ending line -- upward selection. */
 			if (py > sel->sy || py < sel->ey)
 				return (0);

 			if (py == sel->ey && px < sel->ex)
 				return (0);

 			if (sel->modekeys == MODEKEY_EMACS)
 				xx = sel->sx - 1;
 			else
 				xx = sel->sx;
 			if (py == sel->sy && (sel->sx == 0 || px > xx))
 				return (0);
 		} else {
 			/* starting line == ending line. */
 			if (py != sel->sy)
 				return (0);

 			if (sel->ex < sel->sx) {
 				/* cursor (ex) is on the left */
 				if (sel->modekeys == MODEKEY_EMACS)
 					xx = sel->sx - 1;
 				else
 					xx = sel->sx;
 				if (px > xx || px < sel->ex)
 					return (0);
 			} else {
 				/* selection start (sx) is on the left */
 				if (px < sel->sx || px > sel->ex)
 					return (0);
 			}
 		}
 	}

 	return (1);
 }

 /* Get selected grid cell. */
 void
 screen_select_cell(struct screen *s, struct grid_cell *dst,
     const struct grid_cell *src)
 {
 	if (!s->sel.flag || s->sel.hidden)
 		return;

 	memcpy(dst, &s->sel.cell, sizeof *dst);

 	utf8_copy(&dst->data, &src->data);
 	dst->attr = dst->attr & ~GRID_ATTR_CHARSET;
 	dst->attr |= src->attr & GRID_ATTR_CHARSET;
 	dst->flags = src->flags;
 }

 /* Reflow wrapped lines. */
 static void
 screen_reflow(struct screen *s, u_int new_x)
 {
 	struct grid	*old = s->grid;
 	u_int		 change;

 	s->grid = grid_create(old->sx, old->sy, old->hlimit);

 	change = grid_reflow(s->grid, old, new_x);
 	if (change < s->cy)
 		s->cy -= change;
 	else
 		s->cy = 0;
 }
	/* $OpenBSD$ */

	/*
	* Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
	*
	* Permission to use, copy, modify, and distribute this software for any
	* purpose with or without fee is hereby granted, provided that the above
	* copyright notice and this permission notice appear in all copies.
	*
	* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
	* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
	* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	* WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
	* IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
	* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
	*/

	#include <sys/types.h>

	#include <stdlib.h>
	#include <string.h>
	#include <unistd.h>

	#include "tmux.h"

	struct screen_title_entry {
	char *text;

	TAILQ_ENTRY(screen_title_entry) entry;
	};
	TAILQ_HEAD(screen_titles, screen_title_entry);

	static void screen_resize_x(struct screen *, u_int);
	static void screen_resize_y(struct screen *, u_int);

	static void screen_reflow(struct screen *, u_int);

	/* Free titles stack. */
	static void
	screen_free_titles(struct screen *s)
	{
	struct screen_title_entry *title_entry;

	if (s->titles == NULL)
	return;

	while ((title_entry = TAILQ_FIRST(s->titles)) != NULL) {
	TAILQ_REMOVE(s->titles, title_entry, entry);
	free(title_entry->text);
	free(title_entry);
	}

	free(s->titles);
	s->titles = NULL;
	}

	/* Create a new screen. */
	void
	screen_init(struct screen *s, u_int sx, u_int sy, u_int hlimit)
	{
	s->grid = grid_create(sx, sy, hlimit);
	s->title = xstrdup("");
	s->titles = NULL;

	s->cstyle = 0;
	s->ccolour = xstrdup("");
	s->tabs = NULL;

	screen_reinit(s);
	}

	/* Reinitialise screen. */
	void
	screen_reinit(struct screen *s)
	{
	s->cx = 0;
	s->cy = 0;

	s->rupper = 0;
	s->rlower = screen_size_y(s) - 1;

	s->mode = MODE_CURSOR \| MODE_WRAP;

	screen_reset_tabs(s);

	grid_clear_lines(s->grid, s->grid->hsize, s->grid->sy, 8);

	screen_clear_selection(s);
	screen_free_titles(s);
	}

	/* Destroy a screen. */
	void
	screen_free(struct screen *s)
	{
	free(s->tabs);
	free(s->title);
	free(s->ccolour);

	grid_destroy(s->grid);

	screen_free_titles(s);
	}

	/* Reset tabs to default, eight spaces apart. */
	void
	screen_reset_tabs(struct screen *s)
	{
	u_int i;

	free(s->tabs);

	if ((s->tabs = bit_alloc(screen_size_x(s))) == NULL)
	fatal("bit_alloc failed");
	for (i = 8; i < screen_size_x(s); i += 8)
	bit_set(s->tabs, i);
	}

	/* Set screen cursor style. */
	void
	screen_set_cursor_style(struct screen *s, u_int style)
	{
	if (style <= 6)
	s->cstyle = style;
	}

	/* Set screen cursor colour. */
	void
	screen_set_cursor_colour(struct screen s, const char colour)
	{
	free(s->ccolour);
	s->ccolour = xstrdup(colour);
	}

	/* Set screen title. */
	void
	screen_set_title(struct screen s, const char title)
	{
	free(s->title);
	utf8_stravis(&s->title, title, VIS_OCTAL\|VIS_CSTYLE\|VIS_TAB\|VIS_NL);
	}

	/* Push the current title onto the stack. */
	void
	screen_push_title(struct screen *s)
	{
	struct screen_title_entry *title_entry;

	if (s->titles == NULL) {
	s->titles = xmalloc(sizeof *s->titles);
	TAILQ_INIT(s->titles);
	}
	title_entry = xmalloc(sizeof *title_entry);
	title_entry->text = xstrdup(s->title);
	TAILQ_INSERT_HEAD(s->titles, title_entry, entry);
	}

	/*
	* Pop a title from the stack and set it as the screen title. If the stack is
	* empty, do nothing.
	*/
	void
	screen_pop_title(struct screen *s)
	{
	struct screen_title_entry *title_entry;

	if (s->titles == NULL)
	return;

	title_entry = TAILQ_FIRST(s->titles);
	if (title_entry != NULL) {
	screen_set_title(s, title_entry->text);

	TAILQ_REMOVE(s->titles, title_entry, entry);
	free(title_entry->text);
	free(title_entry);
	}
	}

	/* Resize screen. */
	void
	screen_resize(struct screen *s, u_int sx, u_int sy, int reflow)
	{
	if (sx < 1)
	sx = 1;
	if (sy < 1)
	sy = 1;

	if (sx != screen_size_x(s)) {
	screen_resize_x(s, sx);

	/*
	* It is unclear what should happen to tabs on resize. xterm
	* seems to try and maintain them, rxvt resets them. Resetting
	* is simpler and more reliable so let's do that.
	*/
	screen_reset_tabs(s);
	} else
	reflow = 0;

	if (sy != screen_size_y(s))
	screen_resize_y(s, sy);

	if (reflow)
	screen_reflow(s, sx);
	}

	static void
	screen_resize_x(struct screen *s, u_int sx)
	{
	struct grid *gd = s->grid;

	if (sx == 0)
	fatalx("zero size");

	/*
	* Treat resizing horizontally simply: just ensure the cursor is
	* on-screen and change the size. Don't bother to truncate any lines -
	* then the data should be accessible if the size is then increased.
	*
	* The only potential wrinkle is if UTF-8 double-width characters are
	* left in the last column, but UTF-8 terminals should deal with this
	* sanely.
	*/
	if (s->cx >= sx)
	s->cx = sx - 1;
	gd->sx = sx;
	}

	static void
	screen_resize_y(struct screen *s, u_int sy)
	{
	struct grid *gd = s->grid;
	u_int needed, available, oldy, i;

	if (sy == 0)
	fatalx("zero size");
	oldy = screen_size_y(s);

	/*
	* When resizing:
	*
	* If the height is decreasing, delete lines from the bottom until
	* hitting the cursor, then push lines from the top into the history.
	*
	* When increasing, pull as many lines as possible from scrolled
	* history (not explicitly cleared from view) to the top, then fill the
	* remaining with blanks at the bottom.
	*/

	/* Size decreasing. */
	if (sy < oldy) {
	needed = oldy - sy;

	/* Delete as many lines as possible from the bottom. */
	available = oldy - 1 - s->cy;
	if (available > 0) {
	if (available > needed)
	available = needed;
	grid_view_delete_lines(gd, oldy - available, available,
	8);
	}
	needed -= available;

	/*
	* Now just increase the history size, if possible, to take
	* over the lines which are left. If history is off, delete
	* lines from the top.
	*/
	available = s->cy;
	if (gd->flags & GRID_HISTORY) {
	gd->hscrolled += needed;
	gd->hsize += needed;
	} else if (needed > 0 && available > 0) {
	if (available > needed)
	available = needed;
	grid_view_delete_lines(gd, 0, available, 8);
	}
	s->cy -= needed;
	}

	/* Resize line arrays. */
	gd->linedata = xreallocarray(gd->linedata, gd->hsize + sy,
	sizeof *gd->linedata);

	/* Size increasing. */
	if (sy > oldy) {
	needed = sy - oldy;

	/*
	* Try to pull as much as possible out of scrolled history, if
	* is is enabled.
	*/
	available = gd->hscrolled;
	if (gd->flags & GRID_HISTORY && available > 0) {
	if (available > needed)
	available = needed;
	gd->hscrolled -= available;
	gd->hsize -= available;
	s->cy += available;
	} else
	available = 0;
	needed -= available;

	/* Then fill the rest in with blanks. */
	for (i = gd->hsize + sy - needed; i < gd->hsize + sy; i++)
	memset(&gd->linedata[i], 0, sizeof gd->linedata[i]);
	}

	/* Set the new size, and reset the scroll region. */
	gd->sy = sy;
	s->rupper = 0;
	s->rlower = screen_size_y(s) - 1;
	}

	/* Set selection. */
	void
	screen_set_selection(struct screen *s, u_int sx, u_int sy,
	u_int ex, u_int ey, u_int rectflag, struct grid_cell *gc)
	{
	struct screen_sel *sel = &s->sel;

	memcpy(&sel->cell, gc, sizeof sel->cell);
	sel->flag = 1;
	sel->hidden = 0;

	sel->rectflag = rectflag;

	sel->sx = sx; sel->sy = sy;
	sel->ex = ex; sel->ey = ey;
	}

	/* Clear selection. */
	void
	screen_clear_selection(struct screen *s)
	{
	struct screen_sel *sel = &s->sel;

	sel->flag = 0;
	sel->hidden = 0;
	sel->lineflag = LINE_SEL_NONE;
	}

	/* Hide selection. */
	void
	screen_hide_selection(struct screen *s)
	{
	struct screen_sel *sel = &s->sel;

	sel->hidden = 1;
	}

	/* Check if cell in selection. */
	int
	screen_check_selection(struct screen *s, u_int px, u_int py)
	{
	struct screen_sel *sel = &s->sel;
	u_int xx;

	if (!sel->flag \|\| sel->hidden)
	return (0);

	if (sel->rectflag) {
	if (sel->sy < sel->ey) {
	/* start line < end line -- downward selection. */
	if (py < sel->sy \|\| py > sel->ey)
	return (0);
	} else if (sel->sy > sel->ey) {
	/* start line > end line -- upward selection. */
	if (py > sel->sy \|\| py < sel->ey)
	return (0);
	} else {
	/* starting line == ending line. */
	if (py != sel->sy)
	return (0);
	}

	/*
	* Need to include the selection start row, but not the cursor
	* row, which means the selection changes depending on which
	* one is on the left.
	*/
	if (sel->ex < sel->sx) {
	/* Cursor (ex) is on the left. */
	if (px < sel->ex)
	return (0);

	if (px > sel->sx)
	return (0);
	} else {
	/* Selection start (sx) is on the left. */
	if (px < sel->sx)
	return (0);

	if (px > sel->ex)
	return (0);
	}
	} else {
	/*
	* Like emacs, keep the top-left-most character, and drop the
	* bottom-right-most, regardless of copy direction.
	*/
	if (sel->sy < sel->ey) {
	/* starting line < ending line -- downward selection. */
	if (py < sel->sy \|\| py > sel->ey)
	return (0);

	if (py == sel->sy && px < sel->sx)
	return (0);

	if (py == sel->ey && px > sel->ex)
	return (0);
	} else if (sel->sy > sel->ey) {
	/* starting line > ending line -- upward selection. */
	if (py > sel->sy \|\| py < sel->ey)
	return (0);

	if (py == sel->ey && px < sel->ex)
	return (0);

	if (sel->modekeys == MODEKEY_EMACS)
	xx = sel->sx - 1;
	else
	xx = sel->sx;
	if (py == sel->sy && (sel->sx == 0 \|\| px > xx))
	return (0);
	} else {
	/* starting line == ending line. */
	if (py != sel->sy)
	return (0);

	if (sel->ex < sel->sx) {
	/* cursor (ex) is on the left */
	if (sel->modekeys == MODEKEY_EMACS)
	xx = sel->sx - 1;
	else
	xx = sel->sx;
	if (px > xx \|\| px < sel->ex)
	return (0);
	} else {
	/* selection start (sx) is on the left */
	if (px < sel->sx \|\| px > sel->ex)
	return (0);
	}
	}
	}

	return (1);
	}

	/* Get selected grid cell. */
	void
	screen_select_cell(struct screen s, struct grid_cell dst,
	const struct grid_cell *src)
	{
	if (!s->sel.flag \|\| s->sel.hidden)
	return;

	memcpy(dst, &s->sel.cell, sizeof *dst);

	utf8_copy(&dst->data, &src->data);
	dst->attr = dst->attr & ~GRID_ATTR_CHARSET;
	dst->attr \|= src->attr & GRID_ATTR_CHARSET;
	dst->flags = src->flags;
	}

	/* Reflow wrapped lines. */
	static void
	screen_reflow(struct screen *s, u_int new_x)
	{
	struct grid *old = s->grid;
	u_int change;

	s->grid = grid_create(old->sx, old->sy, old->hlimit);

	change = grid_reflow(s->grid, old, new_x);
	if (change < s->cy)
	s->cy -= change;
	else
	s->cy = 0;
	}