window.c

/* Window creation, deletion and examination for GNU Emacs.
   Does not include redisplay.
   Copyright (C) 1985-1987, 1993-1998, 2000-2015 Free Software
   Foundation, Inc.

This file is part of GNU Emacs.

GNU Emacs is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */

#include <config.h>

#include <stdio.h>

#include "lisp.h"
#include "character.h"
#include "buffer.h"
#include "keyboard.h"
#include "keymap.h"
#include "menu.h"
#include "frame.h"
#include "window.h"
#include "commands.h"
#include "indent.h"
#include "termchar.h"
#include "disptab.h"
#include "dispextern.h"
#include "blockinput.h"
#include "intervals.h"
#include "termhooks.h"		/* For FRAME_TERMINAL.  */
#ifdef HAVE_WINDOW_SYSTEM
#include TERM_HEADER
#endif /* HAVE_WINDOW_SYSTEM */
#ifdef MSDOS
#include "msdos.h"
#endif

static int displayed_window_lines (struct window *);
static int count_windows (struct window *);
static int get_leaf_windows (struct window *, struct window **, int);
static void window_scroll (Lisp_Object, EMACS_INT, bool, int);
static void window_scroll_pixel_based (Lisp_Object, int, bool, int);
static void window_scroll_line_based (Lisp_Object, int, bool, int);
static int add_window_to_list (struct window *, void *);
static Lisp_Object next_window (Lisp_Object, Lisp_Object,
                                Lisp_Object, int);
static void decode_next_window_args (Lisp_Object *, Lisp_Object *,
                                     Lisp_Object *);
static void foreach_window (struct frame *,
				 int (* fn) (struct window *, void *),
                            void *);
static int foreach_window_1 (struct window *,
                             int (* fn) (struct window *, void *),
                             void *);
static Lisp_Object window_list_1 (Lisp_Object, Lisp_Object, Lisp_Object);
static int window_resize_check (struct window *, bool);
static void window_resize_apply (struct window *, bool);
static void window_resize_apply_total (struct window *, bool);
static Lisp_Object select_window (Lisp_Object, Lisp_Object, int);
static void select_window_1 (Lisp_Object, bool);

static struct window *set_window_fringes (struct window *, Lisp_Object,
					  Lisp_Object, Lisp_Object);
static struct window *set_window_margins (struct window *, Lisp_Object,
					  Lisp_Object);
static struct window *set_window_scroll_bars (struct window *, Lisp_Object,
					      Lisp_Object, Lisp_Object, Lisp_Object);
static void apply_window_adjustment (struct window *);

/* This is the window in which the terminal's cursor should
   be left when nothing is being done with it.  This must
   always be a leaf window, and its buffer is selected by
   the top level editing loop at the end of each command.

   This value is always the same as
   FRAME_SELECTED_WINDOW (selected_frame).  */
Lisp_Object selected_window;

/* A list of all windows for use by next_window and Fwindow_list.
   Functions creating or deleting windows should invalidate this cache
   by setting it to nil.  */
Lisp_Object Vwindow_list;

/* The mini-buffer window of the selected frame.
   Note that you cannot test for mini-bufferness of an arbitrary window
   by comparing against this; but you can test for mini-bufferness of
   the selected window.  */
Lisp_Object minibuf_window;

/* Non-nil means it is the window whose mode line should be
   shown as the selected window when the minibuffer is selected.  */
Lisp_Object minibuf_selected_window;

/* Incremented for each window created.  */
static int sequence_number;

/* Used by the function window_scroll_pixel_based.  */
static int window_scroll_pixel_based_preserve_x;
static int window_scroll_pixel_based_preserve_y;

/* Same for window_scroll_line_based.  */
static EMACS_INT window_scroll_preserve_hpos;
static EMACS_INT window_scroll_preserve_vpos;

static void
CHECK_WINDOW_CONFIGURATION (Lisp_Object x)
{
  CHECK_TYPE (WINDOW_CONFIGURATIONP (x), Qwindow_configuration_p, x);
}

/* These setters are used only in this file, so they can be private.  */
static void
wset_combination_limit (struct window *w, Lisp_Object val)
{
  w->combination_limit = val;
}

static void
wset_dedicated (struct window *w, Lisp_Object val)
{
  w->dedicated = val;
}

static void
wset_display_table (struct window *w, Lisp_Object val)
{
  w->display_table = val;
}

static void
wset_new_normal (struct window *w, Lisp_Object val)
{
  w->new_normal = val;
}

static void
wset_new_total (struct window *w, Lisp_Object val)
{
  w->new_total = val;
}

static void
wset_normal_cols (struct window *w, Lisp_Object val)
{
  w->normal_cols = val;
}

static void
wset_normal_lines (struct window *w, Lisp_Object val)
{
  w->normal_lines = val;
}

static void
wset_parent (struct window *w, Lisp_Object val)
{
  w->parent = val;
}

static void
wset_pointm (struct window *w, Lisp_Object val)
{
  w->pointm = val;
}

static void
wset_old_pointm (struct window *w, Lisp_Object val)
{
  w->old_pointm = val;
}

static void
wset_start (struct window *w, Lisp_Object val)
{
  w->start = val;
}

static void
wset_temslot (struct window *w, Lisp_Object val)
{
  w->temslot = val;
}

static void
wset_vertical_scroll_bar_type (struct window *w, Lisp_Object val)
{
  w->vertical_scroll_bar_type = val;
}

static void
wset_window_parameters (struct window *w, Lisp_Object val)
{
  w->window_parameters = val;
}

static void
wset_combination (struct window *w, bool horflag, Lisp_Object val)
{
  /* Since leaf windows never becomes non-leaf, there should
     be no buffer and markers in start and pointm fields of W.  */
  eassert (!BUFFERP (w->contents) && NILP (w->start) && NILP (w->pointm));
  w->contents = val;
  /* When an internal window is deleted and VAL is nil, HORFLAG
     is meaningless.  */
  if (!NILP (val))
    w->horizontal = horflag;
}

/* Nonzero if leaf window W doesn't reflect the actual state
   of displayed buffer due to its text or overlays change.  */

bool
window_outdated (struct window *w)
{
  struct buffer *b = XBUFFER (w->contents);
  return (w->last_modified < BUF_MODIFF (b)
	  || w->last_overlay_modified < BUF_OVERLAY_MODIFF (b));
}

struct window *
decode_live_window (register Lisp_Object window)
{
  if (NILP (window))
    return XWINDOW (selected_window);

  CHECK_LIVE_WINDOW (window);
  return XWINDOW (window);
}

struct window *
decode_any_window (register Lisp_Object window)
{
  struct window *w;

  if (NILP (window))
    return XWINDOW (selected_window);

  CHECK_WINDOW (window);
  w = XWINDOW (window);
  return w;
}

static struct window *
decode_valid_window (register Lisp_Object window)
{
  struct window *w;

  if (NILP (window))
    return XWINDOW (selected_window);

  CHECK_VALID_WINDOW (window);
  w = XWINDOW (window);
  return w;
}

/* Called when W's buffer slot is changed.  ARG -1 means that W is about to
   cease its buffer, and 1 means that W is about to set up the new one.  */

static void
adjust_window_count (struct window *w, int arg)
{
  eassert (eabs (arg) == 1);
  if (BUFFERP (w->contents))
    {
      struct buffer *b = XBUFFER (w->contents);

      if (b->base_buffer)
	b = b->base_buffer;
      b->window_count += arg;
      eassert (b->window_count >= 0);
      /* These should be recalculated by redisplay code.  */
      w->window_end_valid = 0;
      w->base_line_pos = 0;
    }
}

/* Set W's buffer slot to VAL and recompute number
   of windows showing VAL if it is a buffer.  */

void
wset_buffer (struct window *w, Lisp_Object val)
{
  adjust_window_count (w, -1);
  if (BUFFERP (val))
    /* Make sure that we do not assign the buffer
       to an internal window.  */
    eassert (MARKERP (w->start) && MARKERP (w->pointm));
  w->contents = val;
  adjust_window_count (w, 1);
}

DEFUN ("windowp", Fwindowp, Swindowp, 1, 1, 0,
       doc: /* Return t if OBJECT is a window and nil otherwise.  */)
  (Lisp_Object object)
{
  return WINDOWP (object) ? Qt : Qnil;
}

DEFUN ("window-valid-p", Fwindow_valid_p, Swindow_valid_p, 1, 1, 0,
       doc: /* Return t if OBJECT is a valid window and nil otherwise.
A valid window is either a window that displays a buffer or an internal
window.  Windows that have been deleted are not valid.  */)
  (Lisp_Object object)
{
  return WINDOW_VALID_P (object) ? Qt : Qnil;
}

DEFUN ("window-live-p", Fwindow_live_p, Swindow_live_p, 1, 1, 0,
       doc: /* Return t if OBJECT is a live window and nil otherwise.
A live window is a window that displays a buffer.
Internal windows and deleted windows are not live.  */)
  (Lisp_Object object)
{
  return WINDOW_LIVE_P (object) ? Qt : Qnil;
}

/* Frames and windows.  */
DEFUN ("window-frame", Fwindow_frame, Swindow_frame, 0, 1, 0,
       doc: /* Return the frame that window WINDOW is on.
WINDOW must be a valid window and defaults to the selected one.  */)
  (Lisp_Object window)
{
  return decode_valid_window (window)->frame;
}

DEFUN ("frame-root-window", Fframe_root_window, Sframe_root_window, 0, 1, 0,
       doc: /* Return the root window of FRAME-OR-WINDOW.
If omitted, FRAME-OR-WINDOW defaults to the currently selected frame.
With a frame argument, return that frame's root window.
With a window argument, return the root window of that window's frame.  */)
  (Lisp_Object frame_or_window)
{
  Lisp_Object window;

  if (NILP (frame_or_window))
    window = SELECTED_FRAME ()->root_window;
  else if (WINDOW_VALID_P (frame_or_window))
      window = XFRAME (XWINDOW (frame_or_window)->frame)->root_window;
  else
    {
      CHECK_LIVE_FRAME (frame_or_window);
      window = XFRAME (frame_or_window)->root_window;
    }

  return window;
}

DEFUN ("minibuffer-window", Fminibuffer_window, Sminibuffer_window, 0, 1, 0,
       doc: /* Return the minibuffer window for frame FRAME.
If FRAME is omitted or nil, it defaults to the selected frame.  */)
  (Lisp_Object frame)
{
  return FRAME_MINIBUF_WINDOW (decode_live_frame (frame));
}

DEFUN ("window-minibuffer-p", Fwindow_minibuffer_p,
       Swindow_minibuffer_p, 0, 1, 0,
       doc: /* Return non-nil if WINDOW is a minibuffer window.
WINDOW must be a valid window and defaults to the selected one.  */)
  (Lisp_Object window)
{
  return MINI_WINDOW_P (decode_valid_window (window)) ? Qt : Qnil;
}

/* Don't move this to window.el - this must be a safe routine.  */
DEFUN ("frame-first-window", Fframe_first_window, Sframe_first_window, 0, 1, 0,
       doc: /* Return the topmost, leftmost live window on FRAME-OR-WINDOW.
If omitted, FRAME-OR-WINDOW defaults to the currently selected frame.
Else if FRAME-OR-WINDOW denotes a valid window, return the first window
of that window's frame.  If FRAME-OR-WINDOW denotes a live frame, return
the first window of that frame.  */)
  (Lisp_Object frame_or_window)
{
  Lisp_Object window;

  if (NILP (frame_or_window))
    window = SELECTED_FRAME ()->root_window;
  else if (WINDOW_VALID_P (frame_or_window))
    window = XFRAME (WINDOW_FRAME (XWINDOW (frame_or_window)))->root_window;
  else
    {
      CHECK_LIVE_FRAME (frame_or_window);
      window = XFRAME (frame_or_window)->root_window;
    }

  while (WINDOWP (XWINDOW (window)->contents))
    window = XWINDOW (window)->contents;

  return window;
}

DEFUN ("frame-selected-window", Fframe_selected_window,
       Sframe_selected_window, 0, 1, 0,
       doc: /* Return the selected window of FRAME-OR-WINDOW.
If omitted, FRAME-OR-WINDOW defaults to the currently selected frame.
Else if FRAME-OR-WINDOW denotes a valid window, return the selected
window of that window's frame.  If FRAME-OR-WINDOW denotes a live frame,
return the selected window of that frame.  */)
  (Lisp_Object frame_or_window)
{
  Lisp_Object window;

  if (NILP (frame_or_window))
    window = SELECTED_FRAME ()->selected_window;
  else if (WINDOW_VALID_P (frame_or_window))
    window = XFRAME (WINDOW_FRAME (XWINDOW (frame_or_window)))->selected_window;
  else
    {
      CHECK_LIVE_FRAME (frame_or_window);
      window = XFRAME (frame_or_window)->selected_window;
    }

  return window;
}

DEFUN ("set-frame-selected-window", Fset_frame_selected_window,
       Sset_frame_selected_window, 2, 3, 0,
       doc: /* Set selected window of FRAME to WINDOW.
FRAME must be a live frame and defaults to the selected one.  If FRAME
is the selected frame, this makes WINDOW the selected window.  Optional
argument NORECORD non-nil means to neither change the order of recently
selected windows nor the buffer list.  WINDOW must denote a live window.
Return WINDOW.  */)
  (Lisp_Object frame, Lisp_Object window, Lisp_Object norecord)
{
  if (NILP (frame))
    frame = selected_frame;

  CHECK_LIVE_FRAME (frame);
  CHECK_LIVE_WINDOW (window);

  if (! EQ (frame, WINDOW_FRAME (XWINDOW (window))))
    error ("In `set-frame-selected-window', WINDOW is not on FRAME");

  if (EQ (frame, selected_frame))
    return Fselect_window (window, norecord);
  else
    {
      fset_selected_window (XFRAME (frame), window);
      return window;
    }
}

DEFUN ("selected-window", Fselected_window, Sselected_window, 0, 0, 0,
       doc: /* Return the selected window.
The selected window is the window in which the standard cursor for
selected windows appears and to which many commands apply.  */)
  (void)
{
  return selected_window;
}

int window_select_count;

/* If select_window is called with inhibit_point_swap non-zero it will
   not store point of the old selected window's buffer back into that
   window's pointm slot.  This is needed by Fset_window_configuration to
   avoid that the display routine is called with selected_window set to
   Qnil causing a subsequent crash.  */
static Lisp_Object
select_window (Lisp_Object window, Lisp_Object norecord, int inhibit_point_swap)
{
  register struct window *w;
  struct frame *sf;

  CHECK_LIVE_WINDOW (window);

  w = XWINDOW (window);

  /* Make the selected window's buffer current.  */
  Fset_buffer (w->contents);

  if (EQ (window, selected_window) && !inhibit_point_swap)
    /* `switch-to-buffer' uses (select-window (selected-window)) as a "clever"
       way to call record_buffer from Elisp, so it's important that we call
       record_buffer before returning here.  */
    goto record_and_return;

  if (NILP (norecord))
    { /* Mark the window for redisplay since the selected-window has
	 a different mode-line.  */
      wset_redisplay (XWINDOW (selected_window));
      wset_redisplay (w);
    }
  else
    redisplay_other_windows ();

  sf = SELECTED_FRAME ();
  if (XFRAME (WINDOW_FRAME (w)) != sf)
    {
      fset_selected_window (XFRAME (WINDOW_FRAME (w)), window);
      /* Use this rather than Fhandle_switch_frame
	 so that FRAME_FOCUS_FRAME is moved appropriately as we
	 move around in the state where a minibuffer in a separate
	 frame is active.  */
      Fselect_frame (WINDOW_FRAME (w), norecord);
      /* Fselect_frame called us back so we've done all the work already.  */
      eassert (EQ (window, selected_window));
      return window;
    }
  else
    fset_selected_window (sf, window);

  select_window_1 (window, inhibit_point_swap);
  bset_last_selected_window (XBUFFER (w->contents), window);

 record_and_return:
  /* record_buffer can run QUIT, so make sure it is run only after we have
     re-established the invariant between selected_window and selected_frame,
     otherwise the temporary broken invariant might "escape" (bug#14161).  */
  if (NILP (norecord))
    {
      w->use_time = ++window_select_count;
      record_buffer (w->contents);
    }

  return window;
}

/* Select window with a minimum of fuss, i.e. don't record the change anywhere
   (not even for redisplay's benefit), and assume that the window's frame is
   already selected.  */
static void
select_window_1 (Lisp_Object window, bool inhibit_point_swap)
{
  /* Store the old selected window's buffer's point in pointm of the old
     selected window.  It belongs to that window, and when the window is
     not selected, must be in the window.  */
  if (!inhibit_point_swap)
    {
      struct window *ow = XWINDOW (selected_window);
      if (BUFFERP (ow->contents))
	set_marker_both (ow->pointm, ow->contents,
			 BUF_PT (XBUFFER (ow->contents)),
			 BUF_PT_BYTE (XBUFFER (ow->contents)));
    }

  selected_window = window;

  /* Go to the point recorded in the window.
     This is important when the buffer is in more
     than one window.  It also matters when
     redisplay_window has altered point after scrolling,
     because it makes the change only in the window.  */
  set_point_from_marker (XWINDOW (window)->pointm);
}

DEFUN ("select-window", Fselect_window, Sselect_window, 1, 2, 0,
       doc: /* Select WINDOW which must be a live window.
Also make WINDOW's frame the selected frame and WINDOW that frame's
selected window.  In addition, make WINDOW's buffer current and set its
buffer's value of `point' to the value of WINDOW's `window-point'.
Return WINDOW.

Optional second arg NORECORD non-nil means do not put this buffer at the
front of the buffer list and do not make this window the most recently
selected one.

Run `buffer-list-update-hook' unless NORECORD is non-nil.  Note that
applications and internal routines often select a window temporarily for
various purposes; mostly, to simplify coding.  As a rule, such
selections should be not recorded and therefore will not pollute
`buffer-list-update-hook'.  Selections that "really count" are those
causing a visible change in the next redisplay of WINDOW's frame and
should be always recorded.  So if you think of running a function each
time a window gets selected put it on `buffer-list-update-hook'.

Also note that the main editor command loop sets the current buffer to
the buffer of the selected window before each command.  */)
  (register Lisp_Object window, Lisp_Object norecord)
{
  return select_window (window, norecord, 0);
}

DEFUN ("window-buffer", Fwindow_buffer, Swindow_buffer, 0, 1, 0,
       doc: /* Return the buffer displayed in window WINDOW.
If WINDOW is omitted or nil, it defaults to the selected window.
Return nil for an internal window or a deleted window.  */)
  (Lisp_Object window)
{
  struct window *w = decode_any_window (window);
  return WINDOW_LEAF_P (w) ? w->contents : Qnil;
}

DEFUN ("window-parent", Fwindow_parent, Swindow_parent, 0, 1, 0,
       doc: /* Return the parent window of window WINDOW.
WINDOW must be a valid window and defaults to the selected one.
Return nil for a window with no parent (e.g. a root window).  */)
  (Lisp_Object window)
{
  return decode_valid_window (window)->parent;
}

DEFUN ("window-top-child", Fwindow_top_child, Swindow_top_child, 0, 1, 0,
       doc: /* Return the topmost child window of window WINDOW.
WINDOW must be a valid window and defaults to the selected one.
Return nil if WINDOW is a live window (live windows have no children).
Return nil if WINDOW is an internal window whose children form a
horizontal combination.  */)
  (Lisp_Object window)
{
  struct window *w = decode_valid_window (window);
  return WINDOW_VERTICAL_COMBINATION_P (w) ? w->contents : Qnil;
}

DEFUN ("window-left-child", Fwindow_left_child, Swindow_left_child, 0, 1, 0,
       doc: /* Return the leftmost child window of window WINDOW.
WINDOW must be a valid window and defaults to the selected one.
Return nil if WINDOW is a live window (live windows have no children).
Return nil if WINDOW is an internal window whose children form a
vertical combination.  */)
  (Lisp_Object window)
{
  struct window *w = decode_valid_window (window);
  return WINDOW_HORIZONTAL_COMBINATION_P (w) ? w->contents : Qnil;
}

DEFUN ("window-next-sibling", Fwindow_next_sibling, Swindow_next_sibling, 0, 1, 0,
       doc: /* Return the next sibling window of window WINDOW.
WINDOW must be a valid window and defaults to the selected one.
Return nil if WINDOW has no next sibling.  */)
  (Lisp_Object window)
{
  return decode_valid_window (window)->next;
}

DEFUN ("window-prev-sibling", Fwindow_prev_sibling, Swindow_prev_sibling, 0, 1, 0,
       doc: /* Return the previous sibling window of window WINDOW.
WINDOW must be a valid window and defaults to the selected one.
Return nil if WINDOW has no previous sibling.  */)
  (Lisp_Object window)
{
  return decode_valid_window (window)->prev;
}

DEFUN ("window-combination-limit", Fwindow_combination_limit, Swindow_combination_limit, 1, 1, 0,
       doc: /* Return combination limit of window WINDOW.
WINDOW must be a valid window used in horizontal or vertical combination.
If the return value is nil, child windows of WINDOW can be recombined with
WINDOW's siblings.  A return value of t means that child windows of
WINDOW are never \(re-)combined with WINDOW's siblings.  */)
  (Lisp_Object window)
{
  struct window *w;

  CHECK_VALID_WINDOW (window);
  w = XWINDOW (window);
  if (WINDOW_LEAF_P (w))
    error ("Combination limit is meaningful for internal windows only");
  return w->combination_limit;
}

DEFUN ("set-window-combination-limit", Fset_window_combination_limit, Sset_window_combination_limit, 2, 2, 0,
       doc: /* Set combination limit of window WINDOW to LIMIT; return LIMIT.
WINDOW must be a valid window used in horizontal or vertical combination.
If LIMIT is nil, child windows of WINDOW can be recombined with WINDOW's
siblings.  LIMIT t means that child windows of WINDOW are never
\(re-)combined with WINDOW's siblings.  Other values are reserved for
future use.  */)
  (Lisp_Object window, Lisp_Object limit)
{
  struct window *w;

  CHECK_VALID_WINDOW (window);
  w = XWINDOW (window);
  if (WINDOW_LEAF_P (w))
    error ("Combination limit is meaningful for internal windows only");
  wset_combination_limit (w, limit);
  return limit;
}

DEFUN ("window-use-time", Fwindow_use_time, Swindow_use_time, 0, 1, 0,
       doc: /* Return the use time of window WINDOW.
WINDOW must be a live window and defaults to the selected one.
The window with the highest use time is the most recently selected
one.  The window with the lowest use time is the least recently
selected one.  */)
  (Lisp_Object window)
{
  return make_number (decode_live_window (window)->use_time);
}

DEFUN ("window-pixel-width", Fwindow_pixel_width, Swindow_pixel_width, 0, 1, 0,
       doc: /* Return the width of window WINDOW in pixels.
WINDOW must be a valid window and defaults to the selected one.

The return value includes the fringes and margins of WINDOW as well as
any vertical dividers or scroll bars belonging to WINDOW.  If WINDOW is
an internal window, its pixel width is the width of the screen areas
spanned by its children.  */)
     (Lisp_Object window)
{
  return make_number (decode_valid_window (window)->pixel_width);
}

DEFUN ("window-pixel-height", Fwindow_pixel_height, Swindow_pixel_height, 0, 1, 0,
       doc: /* Return the height of window WINDOW in pixels.
WINDOW must be a valid window and defaults to the selected one.

The return value includes the mode line and header line and the bottom
divider, if any.  If WINDOW is an internal window, its pixel height is
the height of the screen areas spanned by its children.  */)
  (Lisp_Object window)
{
  return make_number (decode_valid_window (window)->pixel_height);
}

DEFUN ("window-total-height", Fwindow_total_height, Swindow_total_height, 0, 2, 0,
       doc: /* Return the height of window WINDOW in lines.
WINDOW must be a valid window and defaults to the selected one.

The return value includes the heights of WINDOW's mode and header line
and its bottom divider, if any.  If WINDOW is an internal window, the
total height is the height of the screen areas spanned by its children.

If WINDOW's pixel height is not an integral multiple of its frame's
character height, the number of lines occupied by WINDOW is rounded
internally.  This is done in a way such that, if WINDOW is a parent
window, the sum of the total heights of all its children internally
equals the total height of WINDOW.

If the optional argument ROUND is `ceiling', return the smallest integer
larger than WINDOW's pixel height divided by the character height of
WINDOW's frame.  ROUND `floor' means to return the largest integer
smaller than WINDOW's pixel height divided by the character height of
WINDOW's frame.  Any other value of ROUND means to return the internal
total height of WINDOW.  */)
  (Lisp_Object window, Lisp_Object round)
{
  struct window *w = decode_valid_window (window);

  if (! EQ (round, Qfloor) && ! EQ (round, Qceiling))
    return make_number (w->total_lines);
  else
    {
      int unit = FRAME_LINE_HEIGHT (WINDOW_XFRAME (w));

      return make_number (EQ (round, Qceiling)
			  ? ((w->pixel_height + unit - 1) /unit)
			  : (w->pixel_height / unit));
    }
}

DEFUN ("window-total-width", Fwindow_total_width, Swindow_total_width, 0, 2, 0,
       doc: /* Return the total width of window WINDOW in columns.
WINDOW must be a valid window and defaults to the selected one.

The return value includes the widths of WINDOW's fringes, margins,
scroll bars and its right divider, if any.  If WINDOW is an internal
window, the total width is the width of the screen areas spanned by its
children.

If WINDOW's pixel width is not an integral multiple of its frame's
character width, the number of lines occupied by WINDOW is rounded
internally.  This is done in a way such that, if WINDOW is a parent
window, the sum of the total widths of all its children internally
equals the total width of WINDOW.

If the optional argument ROUND is `ceiling', return the smallest integer
larger than WINDOW's pixel width divided by the character width of
WINDOW's frame.  ROUND `floor' means to return the largest integer
smaller than WINDOW's pixel width divided by the character width of
WINDOW's frame.  Any other value of ROUND means to return the internal
total width of WINDOW.  */)
  (Lisp_Object window, Lisp_Object round)
{
  struct window *w = decode_valid_window (window);

  if (! EQ (round, Qfloor) && ! EQ (round, Qceiling))
    return make_number (w->total_cols);
  else
    {
      int unit = FRAME_COLUMN_WIDTH (WINDOW_XFRAME (w));

      return make_number (EQ (round, Qceiling)
			  ? ((w->pixel_width + unit - 1) /unit)
			  : (w->pixel_width / unit));
    }
}

DEFUN ("window-new-total", Fwindow_new_total, Swindow_new_total, 0, 1, 0,
       doc: /* Return the new total size of window WINDOW.
WINDOW must be a valid window and defaults to the selected one.

The new total size of WINDOW is the value set by the last call of
`set-window-new-total' for WINDOW.  If it is valid, it will be shortly
installed as WINDOW's total height (see `window-total-height') or total
width (see `window-total-width').  */)
  (Lisp_Object window)
{
  return decode_valid_window (window)->new_total;
}

DEFUN ("window-normal-size", Fwindow_normal_size, Swindow_normal_size, 0, 2, 0,
       doc: /* Return the normal height of window WINDOW.
WINDOW must be a valid window and defaults to the selected one.
If HORIZONTAL is non-nil, return the normal width of WINDOW.

The normal height of a frame's root window or a window that is
horizontally combined (a window that has a left or right sibling) is
1.0.  The normal height of a window that is vertically combined (has a
sibling above or below) is the fraction of the window's height with
respect to its parent.  The sum of the normal heights of all windows in a
vertical combination equals 1.0.

Similarly, the normal width of a frame's root window or a window that is
vertically combined equals 1.0.  The normal width of a window that is
horizontally combined is the fraction of the window's width with respect
to its parent.  The sum of the normal widths of all windows in a
horizontal combination equals 1.0.

The normal sizes of windows are used to restore the proportional sizes
of windows after they have been shrunk to their minimum sizes; for
example when a frame is temporarily made very small and afterwards gets
re-enlarged to its previous size.  */)
  (Lisp_Object window, Lisp_Object horizontal)
{
  struct window *w = decode_valid_window (window);

  return NILP (horizontal) ? w->normal_lines : w->normal_cols;
}

DEFUN ("window-new-normal", Fwindow_new_normal, Swindow_new_normal, 0, 1, 0,
       doc: /* Return new normal size of window WINDOW.
WINDOW must be a valid window and defaults to the selected one.

The new normal size of WINDOW is the value set by the last call of
`set-window-new-normal' for WINDOW.  If valid, it will be shortly
installed as WINDOW's normal size (see `window-normal-size').  */)
  (Lisp_Object window)
{
  return decode_valid_window (window)->new_normal;
}

DEFUN ("window-new-pixel", Fwindow_new_pixel, Swindow_new_pixel, 0, 1, 0,
       doc: /* Return new pixel size of window WINDOW.
WINDOW must be a valid window and defaults to the selected one.

The new pixel size of WINDOW is the value set by the last call of
`set-window-new-pixel' for WINDOW.  If it is valid, it will be shortly
installed as WINDOW's pixel height (see `window-pixel-height') or pixel
width (see `window-pixel-width').  */)
  (Lisp_Object window)
{
  return decode_valid_window (window)->new_pixel;
}

DEFUN ("window-pixel-left", Fwindow_pixel_left, Swindow_pixel_left, 0, 1, 0,
       doc: /* Return left pixel edge of window WINDOW.
WINDOW must be a valid window and defaults to the selected one.  */)
  (Lisp_Object window)
{
  return make_number (decode_valid_window (window)->pixel_left);
}

DEFUN ("window-pixel-top", Fwindow_pixel_top, Swindow_pixel_top, 0, 1, 0,
       doc: /* Return top pixel edge of window WINDOW.
WINDOW must be a valid window and defaults to the selected one.  */)
  (Lisp_Object window)
{
  return make_number (decode_valid_window (window)->pixel_top);
}

DEFUN ("window-left-column", Fwindow_left_column, Swindow_left_column, 0, 1, 0,
       doc: /* Return left column of window WINDOW.
This is the distance, in columns, between the left edge of WINDOW and
the left edge of the frame's window area.  For instance, the return
value is 0 if there is no window to the left of WINDOW.

WINDOW must be a valid window and defaults to the selected one.  */)
  (Lisp_Object window)
{
  return make_number (decode_valid_window (window)->left_col);
}

DEFUN ("window-top-line", Fwindow_top_line, Swindow_top_line, 0, 1, 0,
       doc: /* Return top line of window WINDOW.
This is the distance, in lines, between the top of WINDOW and the top
of the frame's window area.  For instance, the return value is 0 if
there is no window above WINDOW.

WINDOW must be a valid window and defaults to the selected one.  */)
  (Lisp_Object window)
{
  return make_number (decode_valid_window (window)->top_line);
}

/* Return the number of lines/pixels of W's body.  Don't count any mode
   or header line or horizontal divider of W.  Rounds down to nearest
   integer when not working pixelwise. */
static int
window_body_height (struct window *w, bool pixelwise)
{
  int height = (w->pixel_height
		- WINDOW_HEADER_LINE_HEIGHT (w)
		- (WINDOW_HAS_HORIZONTAL_SCROLL_BAR (w)
		   ? WINDOW_SCROLL_BAR_AREA_HEIGHT (w)
		   : 0)
		- WINDOW_MODE_LINE_HEIGHT (w)
		- WINDOW_BOTTOM_DIVIDER_WIDTH (w));

  /* Don't return a negative value.  */
  return max (pixelwise
	      ? height
	      : height / FRAME_LINE_HEIGHT (WINDOW_XFRAME (w)),
	      0);
}

/* Return the number of columns/pixels of W's body.  Don't count columns
   occupied by the scroll bar or the divider/vertical bar separating W
   from its right sibling or margins.  On window-systems don't count
   fringes either.  Round down to nearest integer when not working
   pixelwise.  */
int
window_body_width (struct window *w, bool pixelwise)
{
  struct frame *f = XFRAME (WINDOW_FRAME (w));

  int width = (w->pixel_width
	       - WINDOW_RIGHT_DIVIDER_WIDTH (w)
	       - (WINDOW_HAS_VERTICAL_SCROLL_BAR (w)
		  ? WINDOW_SCROLL_BAR_AREA_WIDTH (w)
		  : ((!FRAME_WINDOW_P (f)
		      && !WINDOW_RIGHTMOST_P (w)
		      && !WINDOW_RIGHT_DIVIDER_WIDTH (w))
		     /* A vertical bar is either 1 or 0.  */
		     ? 1 : 0))
		- WINDOW_MARGINS_WIDTH (w)
		- (FRAME_WINDOW_P (f)
		   ? WINDOW_FRINGES_WIDTH (w)
		   : 0));

  /* Don't return a negative value.  */
  return max (pixelwise
	      ? width
	      : width / FRAME_COLUMN_WIDTH (WINDOW_XFRAME (w)),
	      0);
}

DEFUN ("window-body-height", Fwindow_body_height, Swindow_body_height, 0, 2, 0,
       doc: /* Return the height of WINDOW's text area.
WINDOW must be a live window and defaults to the selected one.  Optional
argument PIXELWISE non-nil means return the height of WINDOW's text area
in pixels.  The return value does not include the mode line or header
line or any horizontal divider.

If PIXELWISE is nil, return the largest integer smaller than WINDOW's
pixel height divided by the character height of WINDOW's frame.  This
means that if a line at the bottom of the text area is only partially
visible, that line is not counted.  */)
  (Lisp_Object window, Lisp_Object pixelwise)
{
  return make_number (window_body_height (decode_live_window (window),
					  NILP (pixelwise) ? 0 : 1));
}

DEFUN ("window-body-width", Fwindow_body_width, Swindow_body_width, 0, 2, 0,
       doc: /* Return the width of WINDOW's text area.
WINDOW must be a live window and defaults to the selected one.  Optional
argument PIXELWISE non-nil means return the width in pixels.  The return
value does not include any vertical dividers, fringes or marginal areas,
or scroll bars.

If PIXELWISE is nil, return the largest integer smaller than WINDOW's
pixel width divided by the character width of WINDOW's frame.  This
means that if a column at the right of the text area is only partially
visible, that column is not counted.  */)
  (Lisp_Object window, Lisp_Object pixelwise)
{
  return make_number (window_body_width (decode_live_window (window),
					 NILP (pixelwise) ? 0 : 1));
}

DEFUN ("window-mode-line-height", Fwindow_mode_line_height,
       Swindow_mode_line_height, 0, 1, 0,
       doc: /* Return the height in pixels of WINDOW's mode-line.
WINDOW must be a live window and defaults to the selected one.  */)
  (Lisp_Object window)
{
  return (make_number (WINDOW_MODE_LINE_HEIGHT (decode_live_window (window))));
}

DEFUN ("window-header-line-height", Fwindow_header_line_height,
       Swindow_header_line_height, 0, 1, 0,
       doc: /* Return the height in pixels of WINDOW's header-line.
WINDOW must be a live window and defaults to the selected one.  */)
  (Lisp_Object window)
{
  return (make_number (WINDOW_HEADER_LINE_HEIGHT (decode_live_window (window))));
}

DEFUN ("window-right-divider-width", Fwindow_right_divider_width,
       Swindow_right_divider_width, 0, 1, 0,
       doc: /* Return the width in pixels of WINDOW's right divider.
WINDOW must be a live window and defaults to the selected one.  */)
  (Lisp_Object window)
{
  return (make_number (WINDOW_RIGHT_DIVIDER_WIDTH (decode_live_window (window))));
}

DEFUN ("window-bottom-divider-width", Fwindow_bottom_divider_width,
       Swindow_bottom_divider_width, 0, 1, 0,
       doc: /* Return the width in pixels of WINDOW's bottom divider.
WINDOW must be a live window and defaults to the selected one.  */)
  (Lisp_Object window)
{
  return (make_number (WINDOW_BOTTOM_DIVIDER_WIDTH (decode_live_window (window))));
}

DEFUN ("window-scroll-bar-width", Fwindow_scroll_bar_width,
       Swindow_scroll_bar_width, 0, 1, 0,
       doc: /* Return the width in pixels of WINDOW's vertical scrollbar.
WINDOW must be a live window and defaults to the selected one.  */)
  (Lisp_Object window)
{
  return (make_number (WINDOW_SCROLL_BAR_AREA_WIDTH (decode_live_window (window))));
}

DEFUN ("window-scroll-bar-height", Fwindow_scroll_bar_height,
       Swindow_scroll_bar_height, 0, 1, 0,
       doc: /* Return the height in pixels of WINDOW's horizontal scrollbar.
WINDOW must be a live window and defaults to the selected one.  */)
  (Lisp_Object window)
{
  return (make_number (WINDOW_SCROLL_BAR_AREA_HEIGHT (decode_live_window (window))));
}

DEFUN ("window-hscroll", Fwindow_hscroll, Swindow_hscroll, 0, 1, 0,
       doc: /* Return the number of columns by which WINDOW is scrolled from left margin.
WINDOW must be a live window and defaults to the selected one.  */)
  (Lisp_Object window)
{
  return make_number (decode_live_window (window)->hscroll);
}

/* Set W's horizontal scroll amount to HSCROLL clipped to a reasonable
   range, returning the new amount as a fixnum.  */
static Lisp_Object
set_window_hscroll (struct window *w, EMACS_INT hscroll)
{
  /* Horizontal scrolling has problems with large scroll amounts.
     It's too slow with long lines, and even with small lines the
     display can be messed up.  For now, though, impose only the limits
     required by the internal representation: horizontal scrolling must
     fit in fixnum (since it's visible to Elisp) and into ptrdiff_t
     (since it's stored in a ptrdiff_t).  */
  ptrdiff_t hscroll_max = min (MOST_POSITIVE_FIXNUM, PTRDIFF_MAX);
  ptrdiff_t new_hscroll = clip_to_bounds (0, hscroll, hscroll_max);

  /* Prevent redisplay shortcuts when changing the hscroll.  */
  if (w->hscroll != new_hscroll)
    XBUFFER (w->contents)->prevent_redisplay_optimizations_p = 1;