tmux/layout.c
Nicholas Marriott 6036bdd06c Improved layout code.
Each window now has a tree of layout cells associated with it. In this tree,
each node is either a horizontal or vertical cell containing a list of other
cells running from left-to-right or top-to-bottom, or a leaf cell which is
associated with a pane.

The major functional changes are:

- panes may now be split arbitrarily both horizontally (splitw -h, C-b %) and
  vertically (splitw -v, C-b ");
- panes may be resized both horizontally and vertically (resizep -L/-R/-U/-D,
  bound to C-b left/right/up/down and C-b M-left/right/up/down);
- layouts are now applied and then may be modified by resizing or splitting
  panes, rather than being fixed and reapplied when the window is resized or
  panes are added;
- manual-vertical layout is no longer necessary, and active-only layout is gone
  (but may return in future);
- the main-pane layouts now reduce the size of the main pane to fit all panes
  if possible.

Thanks to all who tested.
2009-07-19 13:21:40 +00:00

650 lines
16 KiB
C

/* $OpenBSD$ */
/*
* Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
*
* 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 "tmux.h"
/*
* The window layout is a tree of cells each of which can be one of: a
* left-right container for a list of cells, a top-bottom container for a list
* of cells, or a container for a window pane.
*
* Each window has a pointer to the root of its layout tree (containing its
* panes), every pane has a pointer back to the cell containing it, and each
* cell a pointer to its parent cell.
*/
int layout_resize_pane_grow(struct layout_cell *, enum layout_type, int);
int layout_resize_pane_shrink(struct layout_cell *, enum layout_type, int);
struct layout_cell *
layout_create_cell(struct layout_cell *lcparent)
{
struct layout_cell *lc;
lc = xmalloc(sizeof *lc);
lc->type = LAYOUT_WINDOWPANE;
lc->parent = lcparent;
TAILQ_INIT(&lc->cells);
lc->sx = UINT_MAX;
lc->sy = UINT_MAX;
lc->xoff = UINT_MAX;
lc->yoff = UINT_MAX;
lc->wp = NULL;
return (lc);
}
void
layout_free_cell(struct layout_cell *lc)
{
struct layout_cell *lcchild;
switch (lc->type) {
case LAYOUT_LEFTRIGHT:
case LAYOUT_TOPBOTTOM:
while (!TAILQ_EMPTY(&lc->cells)) {
lcchild = TAILQ_FIRST(&lc->cells);
TAILQ_REMOVE(&lc->cells, lcchild, entry);
layout_free_cell(lcchild);
}
break;
case LAYOUT_WINDOWPANE:
if (lc->wp != NULL)
lc->wp->layout_cell = NULL;
break;
}
xfree(lc);
}
void
layout_print_cell(struct layout_cell *lc, const char *hdr, u_int n)
{
struct layout_cell *lcchild;
log_debug(
"%s:%*s%p type %u [parent %p] wp=%p [%u,%u %ux%u]", hdr, n, " ", lc,
lc->type, lc->parent, lc->wp, lc->xoff, lc->yoff, lc->sx, lc->sy);
switch (lc->type) {
case LAYOUT_LEFTRIGHT:
case LAYOUT_TOPBOTTOM:
TAILQ_FOREACH(lcchild, &lc->cells, entry)
layout_print_cell(lcchild, hdr, n + 1);
break;
case LAYOUT_WINDOWPANE:
break;
}
}
void
layout_set_size(
struct layout_cell *lc, u_int sx, u_int sy, u_int xoff, u_int yoff)
{
lc->sx = sx;
lc->sy = sy;
lc->xoff = xoff;
lc->yoff = yoff;
}
void
layout_make_leaf(struct layout_cell *lc, struct window_pane *wp)
{
lc->type = LAYOUT_WINDOWPANE;
TAILQ_INIT(&lc->cells);
wp->layout_cell = lc;
lc->wp = wp;
}
void
layout_make_node(struct layout_cell *lc, enum layout_type type)
{
if (type == LAYOUT_WINDOWPANE)
fatalx("bad layout type");
lc->type = type;
TAILQ_INIT(&lc->cells);
if (lc->wp != NULL)
lc->wp->layout_cell = NULL;
lc->wp = NULL;
}
/* Fix cell offsets based on their sizes. */
void
layout_fix_offsets(struct layout_cell *lc)
{
struct layout_cell *lcchild;
u_int xoff, yoff;
if (lc->type == LAYOUT_LEFTRIGHT) {
xoff = lc->xoff;
TAILQ_FOREACH(lcchild, &lc->cells, entry) {
lcchild->xoff = xoff;
lcchild->yoff = lc->yoff;
if (lcchild->type != LAYOUT_WINDOWPANE)
layout_fix_offsets(lcchild);
xoff += lcchild->sx + 1;
}
} else {
yoff = lc->yoff;
TAILQ_FOREACH(lcchild, &lc->cells, entry) {
lcchild->xoff = lc->xoff;
lcchild->yoff = yoff;
if (lcchild->type != LAYOUT_WINDOWPANE)
layout_fix_offsets(lcchild);
yoff += lcchild->sy + 1;
}
}
}
/* Update pane offsets and sizes based on their cells. */
void
layout_fix_panes(struct window *w, u_int wsx, u_int wsy)
{
struct window_pane *wp;
struct layout_cell *lc;
u_int sx, sy;
TAILQ_FOREACH(wp, &w->panes, entry) {
if ((lc = wp->layout_cell) == NULL)
continue;
wp->xoff = lc->xoff;
wp->yoff = lc->yoff;
/*
* Layout cells are limited by the smallest size of other cells
* within the same row or column; if this isn't the case
* resizing becomes difficult.
*
* However, panes do not have to take up their entire cell, so
* they can be cropped to the window edge if the layout
* overflows and they are partly visible.
*
* This stops cells being hidden unnecessarily.
*/
/*
* Work out the horizontal size. If the pane is actually
* outside the window or the entire pane is already visible,
* don't crop.
*/
if (lc->xoff >= wsx || lc->xoff + lc->sx < wsx)
sx = lc->sx;
else {
sx = wsx - lc->xoff;
if (sx < 1)
sx = lc->sx;
}
/*
* Similarly for the vertical size; the minimum vertical size
* is two because scroll regions cannot be one line.
*/
if (lc->yoff >= wsy || lc->yoff + lc->sy < wsy)
sy = lc->sy;
else {
sy = wsy - lc->yoff;
if (sy < 2)
sy = lc->sy;
}
window_pane_resize(wp, sx, sy);
}
}
/* Calculate how much size is available to be removed from a cell. */
u_int
layout_resize_check(struct layout_cell *lc, enum layout_type type)
{
struct layout_cell *lcchild;
u_int available, minimum;
if (lc->type == LAYOUT_WINDOWPANE) {
/* Space available in this cell only. */
if (type == LAYOUT_LEFTRIGHT)
available = lc->sx;
else
available = lc->sy;
if (available > PANE_MINIMUM)
available -= PANE_MINIMUM;
else
available = 0;
} else if (lc->type == type) {
/* Same type: total of available space in all child cells. */
available = 0;
TAILQ_FOREACH(lcchild, &lc->cells, entry)
available += layout_resize_check(lcchild, type);
} else {
/* Different type: minimum of available space in child cells. */
minimum = UINT_MAX;
TAILQ_FOREACH(lcchild, &lc->cells, entry) {
available = layout_resize_check(lcchild, type);
if (available < minimum)
minimum = available;
}
available = minimum;
}
return (available);
}
/*
* Adjust cell size evenly, including altering its children. This function
* expects the change to have already been bounded to the space available.
*/
void
layout_resize_adjust(struct layout_cell *lc, enum layout_type type, int change)
{
struct layout_cell *lcchild;
/* Adjust the cell size. */
if (type == LAYOUT_LEFTRIGHT)
lc->sx += change;
else
lc->sy += change;
/* If this is a leaf cell, that is all that is necessary. */
if (type == LAYOUT_WINDOWPANE)
return;
/* Child cell runs in a different direction. */
if (lc->type != type) {
TAILQ_FOREACH(lcchild, &lc->cells, entry)
layout_resize_adjust(lcchild, type, change);
return;
}
/*
* Child cell runs in the same direction. Adjust each child equally
* until no further change is possible.
*/
while (change != 0) {
TAILQ_FOREACH(lcchild, &lc->cells, entry) {
if (change == 0)
break;
if (change > 0) {
layout_resize_adjust(lcchild, type, 1);
change--;
continue;
}
if (layout_resize_check(lcchild, type) > 0) {
layout_resize_adjust(lcchild, type, -1);
change++;
}
}
}
}
void
layout_init(struct window *w)
{
struct layout_cell *lc;
lc = w->layout_root = layout_create_cell(NULL);
layout_set_size(lc, w->sx, w->sy, 0, 0);
layout_make_leaf(lc, TAILQ_FIRST(&w->panes));
layout_fix_panes(w, w->sx, w->sy);
}
void
layout_free(struct window *w)
{
layout_free_cell(w->layout_root);
}
/* Resize the entire layout after window resize. */
void
layout_resize(struct window *w, u_int sx, u_int sy)
{
struct layout_cell *lc = w->layout_root;
int xlimit, ylimit, xchange, ychange;
/*
* Adjust horizontally. Do not attempt to reduce the layout lower than
* the minimum (more than the amount returned by layout_resize_check).
*
* This can mean that the window size is smaller than the total layout
* size: redrawing this is handled at a higher level, but it does leave
* a problem with growing the window size here: if the current size is
* < the minimum, growing proportionately by adding to each pane is
* wrong as it would keep the layout size larger than the window size.
* Instead, spread the difference between the minimum and the new size
* out proportionately - this should leave the layout fitting the new
* window size.
*/
xchange = sx - w->sx;
xlimit = layout_resize_check(lc, LAYOUT_LEFTRIGHT);
if (xchange < 0 && xchange < -xlimit)
xchange = -xlimit;
if (xlimit == 0) {
if (sx <= lc->sx) /* lc->sx is minimum possible */
xchange = 0;
else
xchange = sx - lc->sx;
}
if (xchange != 0)
layout_resize_adjust(lc, LAYOUT_LEFTRIGHT, xchange);
/* Adjust vertically in a similar fashion. */
ychange = sy - w->sy;
ylimit = layout_resize_check(lc, LAYOUT_TOPBOTTOM);
if (ychange < 0 && ychange < -ylimit)
ychange = -ylimit;
if (ylimit == 0) {
if (sy <= lc->sy) /* lc->sy is minimum possible */
ychange = 0;
else
ychange = sy - lc->sy;
}
if (ychange != 0)
layout_resize_adjust(lc, LAYOUT_TOPBOTTOM, ychange);
/* Fix cell offsets. */
layout_fix_offsets(lc);
layout_fix_panes(w, sx, sy);
}
/* Resize a single pane within the layout. */
void
layout_resize_pane(struct window_pane *wp, enum layout_type type, int change)
{
struct layout_cell *lc, *lcparent;
int needed, size;
lc = wp->layout_cell;
/* Find next parent of the same type. */
lcparent = lc->parent;
while (lcparent != NULL && lcparent->type != type) {
lc = lcparent;
lcparent = lc->parent;
}
if (lcparent == NULL)
return;
/* If this is the last cell, move back one. */
if (lc == TAILQ_LAST(&lcparent->cells, layout_cells))
lc = TAILQ_PREV(lc, layout_cells, entry);
/* Grow or shrink the cell. */
needed = change;
while (needed != 0) {
if (change > 0) {
size = layout_resize_pane_grow(lc, type, needed);
needed -= size;
} else {
size = layout_resize_pane_shrink(lc, type, needed);
needed += size;
}
if (size == 0) /* no more change possible */
break;
}
/* Fix cell offsets. */
layout_fix_offsets(wp->window->layout_root);
layout_fix_panes(wp->window, wp->window->sx, wp->window->sy);
}
int
layout_resize_pane_grow(
struct layout_cell *lc, enum layout_type type, int needed)
{
struct layout_cell *lcadd, *lcremove;
u_int size;
/* Growing. Always add to the current cell. */
lcadd = lc;
/* Look towards the tail for a suitable cell for reduction. */
lcremove = TAILQ_NEXT(lc, entry);
while (lcremove != NULL) {
size = layout_resize_check(lcremove, type);
if (size > 0)
break;
lcremove = TAILQ_NEXT(lcremove, entry);
}
/* If none found, look towards the head. */
if (lcremove == NULL) {
lcremove = TAILQ_PREV(lc, layout_cells, entry);
while (lcremove != NULL) {
size = layout_resize_check(lcremove, type);
if (size > 0)
break;
lcremove = TAILQ_PREV(lcremove, layout_cells, entry);
}
if (lcremove == NULL)
return (0);
}
/* Change the cells. */
if (size > (u_int) needed)
size = needed;
layout_resize_adjust(lcadd, type, size);
layout_resize_adjust(lcremove, type, -size);
return (size);
}
int
layout_resize_pane_shrink(
struct layout_cell *lc, enum layout_type type, int needed)
{
struct layout_cell *lcadd, *lcremove;
u_int size;
/* Shrinking. Find cell to remove from by walking towards head. */
lcremove = lc;
do {
size = layout_resize_check(lcremove, type);
if (size != 0)
break;
lcremove = TAILQ_PREV(lcremove, layout_cells, entry);
} while (lcremove != NULL);
if (lcremove == NULL)
return (0);
/* And add onto the next cell (from the original cell). */
lcadd = TAILQ_NEXT(lc, entry);
if (lcadd == NULL)
return (0);
/* Change the cells. */
if (size > (u_int) -needed)
size = -needed;
layout_resize_adjust(lcadd, type, size);
layout_resize_adjust(lcremove, type, -size);
return (size);
}
/* Split a pane into two. size is a hint, or -1 for default half/half split. */
int
layout_split_pane(struct window_pane *wp,
enum layout_type type, int size, struct window_pane *new_wp)
{
struct layout_cell *lc, *lcparent, *lcnew;
u_int sx, sy, xoff, yoff, size1, size2;
lc = wp->layout_cell;
/* Copy the old cell size. */
sx = lc->sx;
sy = lc->sy;
xoff = lc->xoff;
yoff = lc->yoff;
/* Check there is enough space for the two new panes. */
switch (type) {
case LAYOUT_LEFTRIGHT:
if (sx < PANE_MINIMUM * 2 + 1)
return (-1);
break;
case LAYOUT_TOPBOTTOM:
if (sy < PANE_MINIMUM * 2 + 1)
return (-1);
break;
default:
fatalx("bad layout type");
}
if (lc->parent != NULL && lc->parent->type == type) {
/*
* If the parent exists and is of the same type as the split,
* create a new cell and insert it after this one.
*/
/* Create the new child cell. */
lcnew = layout_create_cell(lc->parent);
TAILQ_INSERT_AFTER(&lc->parent->cells, lc, lcnew, entry);
} else {
/*
* Otherwise create a new parent and insert it.
*/
/* Create and insert the replacement parent. */
lcparent = layout_create_cell(lc->parent);
layout_make_node(lcparent, type);
layout_set_size(lcparent, sx, sy, xoff, yoff);
if (lc->parent == NULL)
wp->window->layout_root = lcparent;
else
TAILQ_REPLACE(&lc->parent->cells, lc, lcparent, entry);
/* Insert the old cell. */
lc->parent = lcparent;
TAILQ_INSERT_HEAD(&lcparent->cells, lc, entry);
/* Create the new child cell. */
lcnew = layout_create_cell(lcparent);
TAILQ_INSERT_TAIL(&lcparent->cells, lcnew, entry);
}
/* Set new cell sizes. size is the target size or -1 for middle split,
* size1 is the size of the top/left and size2 the bottom/right.
*/
switch (type) {
case LAYOUT_LEFTRIGHT:
if (size < 0)
size2 = ((sx + 1) / 2) - 1;
else
size2 = size;
if (size2 < PANE_MINIMUM)
size2 = PANE_MINIMUM;
else if (size2 > sx - 2)
size2 = sx - 2;
size1 = sx - 1 - size2;
layout_set_size(lc, size1, sy, xoff, yoff);
layout_set_size(lcnew, size2, sy, xoff + lc->sx + 1, yoff);
break;
case LAYOUT_TOPBOTTOM:
if (size < 0)
size2 = ((sy + 1) / 2) - 1;
else
size2 = size;
if (size2 < PANE_MINIMUM)
size2 = PANE_MINIMUM;
else if (size2 > sy - 2)
size2 = sy - 2;
size1 = sy - 1 - size2;
layout_set_size(lc, sx, size1, xoff, yoff);
layout_set_size(lcnew, sx, size2, xoff, yoff + lc->sy + 1);
break;
default:
fatalx("bad layout type");
}
/* Assign the panes. */
layout_make_leaf(lc, wp);
layout_make_leaf(lcnew, new_wp);
/* Fix pane offsets and sizes. */
layout_fix_panes(wp->window, wp->window->sx, wp->window->sy);
return (0);
}
/* Destroy the layout associated with a pane and redistribute the space. */
void
layout_close_pane(struct window_pane *wp)
{
struct layout_cell *lc, *lcother, *lcparent;
lc = wp->layout_cell;
lcparent = lc->parent;
/*
* If no parent, this is the last pane so window close is imminent and
* there is no need to resize anything.
*/
if (lcparent == NULL) {
layout_free_cell(lc);
wp->window->layout_root = NULL;
return;
}
/* Merge the space into the previous or next cell. */
if (lc == TAILQ_FIRST(&lcparent->cells))
lcother = TAILQ_NEXT(lc, entry);
else
lcother = TAILQ_PREV(lc, layout_cells, entry);
if (lcparent->type == LAYOUT_LEFTRIGHT)
layout_resize_adjust(lcother, lcparent->type, lc->sx + 1);
else
layout_resize_adjust(lcother, lcparent->type, lc->sy + 1);
/* Remove this from the parent's list. */
TAILQ_REMOVE(&lcparent->cells, lc, entry);
layout_free_cell(lc);
/*
* If the parent now has one cell, remove the parent from the tree and
* replace it by that cell.
*/
lc = TAILQ_FIRST(&lcparent->cells);
if (TAILQ_NEXT(lc, entry) == NULL) {
TAILQ_REMOVE(&lcparent->cells, lc, entry);
lc->parent = lcparent->parent;
if (lc->parent == NULL) {
lc->xoff = 0; lc->yoff = 0;
wp->window->layout_root = lc;
} else
TAILQ_REPLACE(&lc->parent->cells, lcparent, lc, entry);
layout_free_cell(lcparent);
}
/* Fix pane offsets and sizes. */
layout_fix_offsets(wp->window->layout_root);
layout_fix_panes(wp->window, wp->window->sx, wp->window->sy);
}