emacs/src/frame.h

/* Define frame-object for GNU Emacs.
   Copyright (C) 1993, 1994, 1999, 2000, 2001 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 2, 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; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

/* Don't multiply include: dispextern.h includes macterm.h which
   includes frame.h some emacs source includes both dispextern.h and
   frame.h */

#ifndef EMACS_FRAME_H
#define EMACS_FRAME_H


/* Miscellanea.  */

/* Nonzero means don't assume anything about current contents of
   actual terminal frame */

extern int frame_garbaged;

/* Nonzero means FRAME_MESSAGE_BUF (selected_frame) is being used by
   print.  */

extern int message_buf_print;


/* The structure representing a frame.  */

enum output_method
{
  output_termcap,
  output_x_window,
  output_msdos_raw,
  output_w32,
  output_mac
};

enum vertical_scroll_bar_type
{
  vertical_scroll_bar_none,
  vertical_scroll_bar_left,
  vertical_scroll_bar_right
};

#if !defined(MSDOS) && !defined(WINDOWSNT) && !defined(macintosh)

#if !defined(HAVE_X_WINDOWS)

#define PIX_TYPE int

/* A (mostly empty) x_output structure definition for building Emacs
   on Unix and GNU/Linux without X support.  */
struct x_output
{
  PIX_TYPE background_pixel;
  PIX_TYPE foreground_pixel;
};

#define FRAME_INTERNAL_BORDER_WIDTH(f) 0

#endif /* ! HAVE_X_WINDOWS */


#define FRAME_FOREGROUND_PIXEL(f) ((f)->output_data.x->foreground_pixel)
#define FRAME_BACKGROUND_PIXEL(f) ((f)->output_data.x->background_pixel)

/* A structure describing a termcap frame display.  */
extern struct x_output tty_display;

#endif /* ! MSDOS && ! WINDOWSNT && ! macintosh */

struct frame
{
  EMACS_INT size;
  struct Lisp_Vector *next;

  /* All Lisp_Object components must come first.
     Only EMACS_INT values can be intermixed with them.
     That ensures they are all aligned normally.  */

  /* Name of this frame: a Lisp string.  It is used for looking up resources,
     as well as for the title in some cases.  */
  Lisp_Object name;

  /* The name to use for the icon, the last time
     it was refreshed.  nil means not explicitly specified.  */
  Lisp_Object icon_name;

  /* This is the frame title specified explicitly, if any.
     Usually it is nil.  */
  Lisp_Object title;

  /* The frame which should receive keystrokes that occur in this
     frame, or nil if they should go to the frame itself.  This is
     usually nil, but if the frame is minibufferless, we can use this
     to redirect keystrokes to a surrogate minibuffer frame when
     needed.

     Note that a value of nil is different than having the field point
     to the frame itself.  Whenever the Fselect_frame function is used
     to shift from one frame to the other, any redirections to the
     original frame are shifted to the newly selected frame; if
     focus_frame is nil, Fselect_frame will leave it alone.  */
  Lisp_Object focus_frame;

  /* This frame's root window.  Every frame has one.
     If the frame has only a minibuffer window, this is it.
     Otherwise, if the frame has a minibuffer window, this is its sibling.  */
  Lisp_Object root_window;

  /* This frame's selected window.
     Each frame has its own window hierarchy
     and one of the windows in it is selected within the frame.
     The selected window of the selected frame is Emacs's selected window.  */
  Lisp_Object selected_window;

  /* This frame's minibuffer window.
     Most frames have their own minibuffer windows,
     but only the selected frame's minibuffer window
     can actually appear to exist.  */
  Lisp_Object minibuffer_window;

  /* Parameter alist of this frame.
     These are the parameters specified when creating the frame
     or modified with modify-frame-parameters.  */
  Lisp_Object param_alist;

  /* List of scroll bars on this frame.  
     Actually, we don't specify exactly what is stored here at all; the
     scroll bar implementation code can use it to store anything it likes.
     This field is marked by the garbage collector.  It is here
     instead of in the `display' structure so that the garbage
     collector doesn't need to look inside the window-system-dependent
     structure.  */
  Lisp_Object scroll_bars;
  Lisp_Object condemned_scroll_bars;

  /* Vector describing the items to display in the menu bar.
     Each item has four elements in this vector.
     They are KEY, STRING, SUBMAP, and HPOS.
     (HPOS is not used in when the X toolkit is in use.)
     There are four additional elements of nil at the end, to terminate.  */
  Lisp_Object menu_bar_items;

  /* Alist of elements (FACE-NAME . FACE-VECTOR-DATA).  */
  Lisp_Object face_alist;

  /* A vector that records the entire structure of this frame's menu bar.
     For the format of the data, see extensive comments in xmenu.c.
     Only the X toolkit version uses this.  */
  Lisp_Object menu_bar_vector;
  /* Number of elements in the vector that have meaningful data.  */
  EMACS_INT menu_bar_items_used;

  /* Predicate for selecting buffers for other-buffer.  */
  Lisp_Object buffer_predicate;

  /* List of buffers viewed in this frame, for other-buffer.  */
  Lisp_Object buffer_list;

  /* A dummy window used to display menu bars under X when no X
     toolkit support is available.  */
  Lisp_Object menu_bar_window;

  /* A window used to display the tool-bar of a frame.  */
  Lisp_Object tool_bar_window;

  /* Desired and current tool-bar items.  */
  Lisp_Object tool_bar_items;

  /* Desired and current contents displayed in tool_bar_window.  */
  Lisp_Object desired_tool_bar_string, current_tool_bar_string;

  /* beyond here, there should be no more Lisp_Object components.  */

  /* Cache of realized faces.  */
  struct face_cache *face_cache;

  /* A buffer to hold the frame's name.  We can't use the Lisp
     string's pointer (`name', above) because it might get relocated.  */
  char *namebuf;

  /* Glyph pool and matrix. */
  struct glyph_pool *current_pool;
  struct glyph_pool *desired_pool;
  struct glyph_matrix *desired_matrix;
  struct glyph_matrix *current_matrix;

  /* 1 means that glyphs on this frame have been initialized so it can
     be used for output.  */
  unsigned glyphs_initialized_p : 1;

  /* Margin at the top of the frame.  Used to display the tool-bar.  */
  int tool_bar_lines;

  int n_tool_bar_items;
  
  /* A buffer for decode_mode_line. */
  char *decode_mode_spec_buffer;

  /* See do_line_insertion_deletion_costs for info on these arrays. */
  /* Cost of inserting 1 line on this frame */
  int *insert_line_cost;
  /* Cost of deleting 1 line on this frame */
  int *delete_line_cost;
  /* Cost of inserting n lines on this frame */
  int *insert_n_lines_cost;
  /* Cost of deleting n lines on this frame */
  int *delete_n_lines_cost;

  /* Size of this frame, in units of characters.  */
  EMACS_INT height;
  EMACS_INT width;
  EMACS_INT window_width;
  EMACS_INT window_height;

  /* New height and width for pending size change.  0 if no change pending.  */
  int new_height, new_width;

  /* The output method says how the contents of this frame
     are displayed.  It could be using termcap, or using an X window.  */
  enum output_method output_method;

  /* A structure of auxiliary data used for displaying the contents.
     struct x_output is used for X window frames;
     it is defined in xterm.h.  
     struct w32_output is used for W32 window frames;
     it is defined in w32term.h.  */
  union output_data
  {
    struct x_output *x;
    struct w32_output *w32;
    struct mac_output *mac;
    EMACS_INT nothing;
  }
  output_data;

#ifdef MULTI_KBOARD
  /* A pointer to the kboard structure associated with this frame.
     For termcap frames, this points to initial_kboard.  For X frames,
     it will be the same as display.x->display_info->kboard.  */
  struct kboard *kboard;
#endif

  /* Number of lines of menu bar.  */
  int menu_bar_lines;

#if defined (USE_X_TOOLKIT) || defined (HAVE_NTGUI) || defined (macintosh)
  /* Nonzero means using a menu bar that comes from the X toolkit.  */
  int external_menu_bar;
#endif

  /* Nonzero if last attempt at redisplay on this frame was preempted.  */
  char display_preempted;

  /* visible is nonzero if the frame is currently displayed; we check
     it to see if we should bother updating the frame's contents.
     DON'T SET IT DIRECTLY; instead, use FRAME_SET_VISIBLE.

     Note that, since invisible frames aren't updated, whenever a
     frame becomes visible again, it must be marked as garbaged.  The
     FRAME_SAMPLE_VISIBILITY macro takes care of this.

     On Windows NT/9X, to avoid wasting effort updating visible frames
     that are actually completely obscured by other windows on the
     display, we bend the meaning of visible slightly: if greater than
     1, then the frame is obscured - we still consider it to be
     "visible" as seen from lisp, but we don't bother updating it.  We
     must take care to garbage the frame when it ceaces to be obscured
     though.  Note that these semantics are only used on NT/9X.

     iconified is nonzero if the frame is currently iconified.

     Asynchronous input handlers should NOT change these directly;
     instead, they should change async_visible or async_iconified, and
     let the FRAME_SAMPLE_VISIBILITY macro set visible and iconified
     at the next redisplay.

     These should probably be considered read-only by everyone except
     FRAME_SAMPLE_VISIBILITY.

     These two are mutually exclusive.  They might both be zero, if the
     frame has been made invisible without an icon.  */
  char visible, iconified;

  /* Asynchronous input handlers change these, and
     FRAME_SAMPLE_VISIBILITY copies them into visible and iconified.
     See FRAME_SAMPLE_VISIBILITY, below.  */
  volatile char async_visible, async_iconified;

  /* Nonzero if this frame should be redrawn.  */
  volatile char garbaged;

  /* True if frame actually has a minibuffer window on it.
     0 if using a minibuffer window that isn't on this frame.  */
  char has_minibuffer;
     
  /* 0 means, if this frame has just one window,
     show no modeline for that window.  */
  char wants_modeline;

  /* Non-zero if the hardware device this frame is displaying on can
     support scroll bars.  */
  char can_have_scroll_bars;

  /* If can_have_scroll_bars is non-zero, this is non-zero if we should
     actually display them on this frame.  */
  enum vertical_scroll_bar_type vertical_scroll_bar_type;

  /* Non-0 means raise this frame to the top of the heap when selected.  */
  char auto_raise;

  /* Non-0 means lower this frame to the bottom of the stack when left.  */
  char auto_lower;

  /* True if frame's root window can't be split.  */
  char no_split;

  /* If this is set, then Emacs won't change the frame name to indicate
     the current buffer, etcetera.  If the user explicitly sets the frame
     name, this gets set.  If the user sets the name to Qnil, this is
     cleared.  */
  char explicit_name;

  /* Nonzero if size of some window on this frame has changed.  */
  char window_sizes_changed;

  /* Storage for messages to this frame. */
  char *message_buf;

  /* Nonnegative if current redisplay should not do scroll computation
     for lines beyond a certain vpos.  This is the vpos.  */
  int scroll_bottom_vpos;

  /* Width of the scroll bar, in pixels and in characters.
     scroll_bar_cols tracks scroll_bar_pixel_width if the latter is positive;
     a zero value in scroll_bar_pixel_width means to compute the actual width
     on the fly, using scroll_bar_cols and the current font width.  */
  int scroll_bar_pixel_width;
  int scroll_bar_cols;

  /* The baud rate that was used to calculate costs for this frame.  */
  int cost_calculation_baud_rate;

  /* Nonzero if the mouse has moved on this display
     since the last time we checked.  */
  char mouse_moved;

  /* Exponent for gamma correction of colors.  1/(VIEWING_GAMMA *
     SCREEN_GAMMA) where viewing_gamma is 0.4545 and SCREEN_GAMMA is a
     frame parameter.  0 means don't do gamma correction.  */
  double gamma;

  /* Additional space to put between text lines on this frame.  */
  int extra_line_spacing;

  /* Set to non-zero in change_frame_size when size of frame changed
     Clear the frame in clear_garbaged_frames if set.  */
  unsigned resized_p : 1;
};

#ifdef MULTI_KBOARD
#define FRAME_KBOARD(f) ((f)->kboard)
#else
#define FRAME_KBOARD(f) (&the_only_kboard)
#endif

typedef struct frame *FRAME_PTR;

#define XFRAME(p) (eassert (GC_FRAMEP(p)),(struct frame *) XPNTR (p))
#define XSETFRAME(a, b) (XSETPSEUDOVECTOR (a, b, PVEC_FRAME))

/* Given a window, return its frame as a Lisp_Object.  */
#define WINDOW_FRAME(w) (w)->frame

/* Test a frame for particular kinds of display methods.  */
#define FRAME_TERMCAP_P(f) ((f)->output_method == output_termcap)
#define FRAME_X_P(f) ((f)->output_method == output_x_window)
#define FRAME_W32_P(f) ((f)->output_method == output_w32)
#define FRAME_MSDOS_P(f) ((f)->output_method == output_msdos_raw)
#define FRAME_MAC_P(f) ((f)->output_method == output_mac)

/* FRAME_WINDOW_P tests whether the frame is a window, and is
   defined to be the predicate for the window system being used.  */

#ifdef HAVE_X_WINDOWS
#define FRAME_WINDOW_P(f) FRAME_X_P (f)
#endif
#ifdef HAVE_NTGUI
#define FRAME_WINDOW_P(f) FRAME_W32_P (f)
#endif
#ifdef macintosh
#define FRAME_WINDOW_P(f) FRAME_MAC_P (f)
#endif
#ifndef FRAME_WINDOW_P
#define FRAME_WINDOW_P(f) (0)
#endif

/* Nonzero if frame F is still alive (not deleted).  */
#define FRAME_LIVE_P(f) ((f)->output_data.nothing != 0)

/* Nonzero if frame F is a minibuffer-only frame.  */
#define FRAME_MINIBUF_ONLY_P(f) \
  EQ (FRAME_ROOT_WINDOW (f), FRAME_MINIBUF_WINDOW (f))

/* Nonzero if frame F contains a minibuffer window.
   (If this is 0, F must use some other minibuffer window.)  */
#define FRAME_HAS_MINIBUF_P(f) ((f)->has_minibuffer)
#define FRAME_HEIGHT(f) (f)->height

/* Width of frame F, measured in character columns,
   not including scroll bars if any.  */
#define FRAME_WIDTH(f) (f)->width

/* Number of lines of frame F used for menu bar.
   This is relevant on terminal frames and on
   X Windows when not using the X toolkit.
   These lines are counted in FRAME_HEIGHT.  */
#define FRAME_MENU_BAR_LINES(f) (f)->menu_bar_lines

/* Number of lines of frame F used for the tool-bar.  */

#define FRAME_TOOL_BAR_LINES(f) (f)->tool_bar_lines

/* Lines above the top-most window in frame F.  */

#define FRAME_TOP_MARGIN(F) \
     (FRAME_MENU_BAR_LINES (F) + FRAME_TOOL_BAR_LINES (F))

/* Nonzero if this frame should display a menu bar
   in a way that does not use any text lines.  */
#if defined (USE_X_TOOLKIT) || defined (HAVE_NTGUI) || defined (macintosh)
#define FRAME_EXTERNAL_MENU_BAR(f) (f)->external_menu_bar
#else
#define FRAME_EXTERNAL_MENU_BAR(f) 0
#endif
#define FRAME_VISIBLE_P(f) ((f)->visible != 0)

/* Nonzero if frame F is currently visible but hidden.  */
#define FRAME_OBSCURED_P(f) ((f)->visible > 1)

/* Nonzero if frame F is currently iconified.  */
#define FRAME_ICONIFIED_P(f) (f)->iconified

#define FRAME_SET_VISIBLE(f,p) \
  ((f)->async_visible = (p), FRAME_SAMPLE_VISIBILITY (f))
#define SET_FRAME_GARBAGED(f) (frame_garbaged = 1, f->garbaged = 1)
#define FRAME_GARBAGED_P(f) (f)->garbaged

/* Nonzero means do not allow splitting this frame's window.  */
#define FRAME_NO_SPLIT_P(f) (f)->no_split

/* Not really implemented.  */
#define FRAME_WANTS_MODELINE_P(f) (f)->wants_modeline

/* Nonzero if a size change has been requested for frame F
   but not yet really put into effect.  This can be true temporarily
   when an X event comes in at a bad time.  */
#define FRAME_WINDOW_SIZES_CHANGED(f) (f)->window_sizes_changed
/* When a size change is pending, these are the requested new sizes.  */
#define FRAME_NEW_HEIGHT(f) (f)->new_height
#define FRAME_NEW_WIDTH(f) (f)->new_width

/* The minibuffer window of frame F, if it has one; otherwise nil.  */
#define FRAME_MINIBUF_WINDOW(f) (f)->minibuffer_window

/* The root window of the window tree of frame F.  */
#define FRAME_ROOT_WINDOW(f) (f)->root_window

/* The currently selected window of the window tree of frame F.  */
#define FRAME_SELECTED_WINDOW(f) (f)->selected_window

#define FRAME_INSERT_COST(f) (f)->insert_line_cost    
#define FRAME_DELETE_COST(f) (f)->delete_line_cost    
#define FRAME_INSERTN_COST(f) (f)->insert_n_lines_cost
#define FRAME_DELETEN_COST(f) (f)->delete_n_lines_cost
#define FRAME_MESSAGE_BUF(f) (f)->message_buf
#define FRAME_SCROLL_BOTTOM_VPOS(f) (f)->scroll_bottom_vpos
#define FRAME_FOCUS_FRAME(f) (f)->focus_frame

/* Nonzero if frame F supports scroll bars.
   If this is zero, then it is impossible to enable scroll bars
   on frame F.  */
#define FRAME_CAN_HAVE_SCROLL_BARS(f) ((f)->can_have_scroll_bars)

/* This frame slot says whether scroll bars are currently enabled for frame F,
   and which side they are on.  */
#define FRAME_VERTICAL_SCROLL_BAR_TYPE(f) ((f)->vertical_scroll_bar_type)
#define FRAME_HAS_VERTICAL_SCROLL_BARS(f) \
     ((f)->vertical_scroll_bar_type != vertical_scroll_bar_none)
#define FRAME_HAS_VERTICAL_SCROLL_BARS_ON_LEFT(f) \
     ((f)->vertical_scroll_bar_type == vertical_scroll_bar_left)
#define FRAME_HAS_VERTICAL_SCROLL_BARS_ON_RIGHT(f) \
     ((f)->vertical_scroll_bar_type == vertical_scroll_bar_right)

/* Width that a scroll bar in frame F should have, if there is one.
   Measured in pixels.
   If scroll bars are turned off, this is still nonzero.  */
#define FRAME_SCROLL_BAR_PIXEL_WIDTH(f) ((f)->scroll_bar_pixel_width)

/* Width that a scroll bar in frame F should have, if there is one.
   Measured in columns (characters).
   If scroll bars are turned off, this is still nonzero.  */
#define FRAME_SCROLL_BAR_COLS(f) ((f)->scroll_bar_cols)

/* Width of a scroll bar in frame F, measured in columns (characters),
   but only if scroll bars are on the left.  If scroll bars are on
   the right in this frame, or there are no scroll bars, value is 0.  */

#define FRAME_LEFT_SCROLL_BAR_WIDTH(f)			\
     (FRAME_HAS_VERTICAL_SCROLL_BARS_ON_LEFT (f)	\
      ? FRAME_SCROLL_BAR_COLS (f)			\
      : 0)

/* Width of a scroll bar in frame F, measured in columns (characters),
   but only if scroll bars are on the right.  If scroll bars are on
   the left in this frame, or there are no scroll bars, value is 0.  */

#define FRAME_RIGHT_SCROLL_BAR_WIDTH(f)			\
     (FRAME_HAS_VERTICAL_SCROLL_BARS_ON_RIGHT (f)	\
      ? FRAME_SCROLL_BAR_COLS (f)			\
      : 0)

/* Width of a scroll bar in frame F, measured in columns (characters).  */
#define FRAME_SCROLL_BAR_WIDTH(f) \
     (FRAME_HAS_VERTICAL_SCROLL_BARS (f) \
      ? FRAME_SCROLL_BAR_COLS (f) \
      : 0)

/* Total width of frame F, in columns (characters),
   including the width used by scroll bars if any.  */
#define FRAME_WINDOW_WIDTH(f) ((f)->window_width)

/* Set the width of frame F to VAL.
   VAL is the width of a full-frame window,
   not including scroll bars.  */
#define SET_FRAME_WIDTH(f, val)						\
     ((f)->width = (val),						\
      (f)->window_width = FRAME_WINDOW_WIDTH_ARG (f, (f)->width))

/* Given a value WIDTH for frame F's nominal width,
   return the value that FRAME_WINDOW_WIDTH should have.  */
#define FRAME_WINDOW_WIDTH_ARG(f, width)	\
     ((width)					\
      + FRAME_SCROLL_BAR_WIDTH (f)		\
      + FRAME_FRINGE_COLS (f))

/* Maximum + 1 legitimate value for FRAME_CURSOR_X.  */
#define FRAME_CURSOR_X_LIMIT(f) \
     (FRAME_WIDTH (f) + FRAME_LEFT_SCROLL_BAR_WIDTH (f))

/* Nonzero if frame F has scroll bars.  */
#define FRAME_SCROLL_BARS(f) ((f)->scroll_bars)

#define FRAME_CONDEMNED_SCROLL_BARS(f) ((f)->condemned_scroll_bars)
#define FRAME_MENU_BAR_ITEMS(f) ((f)->menu_bar_items)
#define FRAME_COST_BAUD_RATE(f) ((f)->cost_calculation_baud_rate)

/* Return a pointer to the face cache of frame F.  */

#define FRAME_FACE_CACHE(F)	(F)->face_cache

/* Return the size of message_buf of the frame F.  We multiply the
   width of the frame by 4 because multi-byte form may require at most
   4-byte for a character.  */
     
#define FRAME_MESSAGE_BUF_SIZE(f) (((int) (f)->width) * 4)

/* Emacs's redisplay code could become confused if a frame's
   visibility changes at arbitrary times.  For example, if a frame is
   visible while the desired glyphs are being built, but becomes
   invisible before they are updated, then some rows of the
   desired_glyphs will be left marked as enabled after redisplay is
   complete, which should never happen.  The next time the frame
   becomes visible, redisplay will probably barf.

   Currently, there are no similar situations involving iconified, but
   the principle is the same.

   So instead of having asynchronous input handlers directly set and
   clear the frame's visibility and iconification flags, they just set
   the async_visible and async_iconified flags; the redisplay code
   calls the FRAME_SAMPLE_VISIBILITY macro before doing any redisplay,
   which sets visible and iconified from their asynchronous
   counterparts.

   Synchronous code must use the FRAME_SET_VISIBLE macro.

   Also, if a frame used to be invisible, but has just become visible,
   it must be marked as garbaged, since redisplay hasn't been keeping
   up its contents.  */
     
#define FRAME_SAMPLE_VISIBILITY(f) \
  (((f)->async_visible && (f)->visible != (f)->async_visible) ? \
   SET_FRAME_GARBAGED (f) : 0, \
   (f)->visible = (f)->async_visible, \
   (f)->iconified = (f)->async_iconified)

#define CHECK_FRAME(x)					\
     do {						\
       if (! FRAMEP (x))				\
         x = wrong_type_argument (Qframep, (x));	\
     } while (0)

#define CHECK_LIVE_FRAME(x)				\
     do {						\
       if (! FRAMEP (x)					\
	   || ! FRAME_LIVE_P (XFRAME (x)))		\
         x = wrong_type_argument (Qframe_live_p, (x));	\
     } while (0)

/* FOR_EACH_FRAME (LIST_VAR, FRAME_VAR) followed by a statement is a
   `for' loop which iterates over the elements of Vframe_list.  The
   loop will set FRAME_VAR, a Lisp_Object, to each frame in
   Vframe_list in succession and execute the statement.  LIST_VAR
   should be a Lisp_Object too; it is used to iterate through the
   Vframe_list.  

   This macro is a holdover from a time when multiple frames weren't always
   supported.  An alternate definition of the macro would expand to
   something which executes the statement once.  */

#define FOR_EACH_FRAME(list_var, frame_var)			\
  for ((list_var) = Vframe_list;				\
       (CONSP (list_var)					\
	&& (frame_var = XCAR (list_var), 1));		\
       list_var = XCDR (list_var))


extern Lisp_Object Qframep, Qframe_live_p, Qicon;
extern Lisp_Object Qleft_fringe, Qright_fringe;

extern struct frame *last_nonminibuf_frame;

extern struct frame *make_terminal_frame P_ ((void));
extern struct frame *make_frame P_ ((int));
#ifdef HAVE_WINDOW_SYSTEM
extern struct frame *make_minibuffer_frame P_ ((void));
extern struct frame *make_frame_without_minibuffer P_ ((Lisp_Object,
							struct kboard *,
							Lisp_Object));
#endif /* HAVE_WINDOW_SYSTEM */
extern int other_visible_frames P_ ((struct frame *));

extern Lisp_Object Vframe_list;
extern Lisp_Object Vdefault_frame_alist;

extern Lisp_Object Vterminal_frame;

extern Lisp_Object Vmouse_highlight;

/* Device-independent scroll bar stuff.  */

/* Return the starting column (zero-based) of the vertical scroll bar
   for window W.  The column before this one is the last column we can
   use for text.  If the window touches the right edge of the frame,
   we have extra space allocated for it.  Otherwise, the scroll bar
   takes over the window's rightmost columns.  */

#define WINDOW_VERTICAL_SCROLL_BAR_COLUMN(w) \
  (FRAME_HAS_VERTICAL_SCROLL_BARS_ON_RIGHT (XFRAME (WINDOW_FRAME (w))) ? \
    (((XINT ((w)->left) + XINT ((w)->width)) \
      < FRAME_WIDTH (XFRAME (WINDOW_FRAME (w)))) \
     ? (XINT ((w)->left) + XINT ((w)->width) \
       - FRAME_SCROLL_BAR_COLS (XFRAME (WINDOW_FRAME (w)))) \
     : FRAME_WIDTH (XFRAME (WINDOW_FRAME (w)))) \
  : XINT ((w)->left))

/* Return the height in lines of the vertical scroll bar in w.  If the
   window has a mode line, don't make the scroll bar extend that far.  */
     
#define WINDOW_VERTICAL_SCROLL_BAR_HEIGHT(w) (window_internal_height (w))

/* The currently selected frame.  */

extern Lisp_Object selected_frame;

/* Value is a pointer to the selected frame.  If the selected frame
   isn't live, abort.  */

#define SELECTED_FRAME()				\
     ((FRAMEP (selected_frame)				\
       && FRAME_LIVE_P (XFRAME (selected_frame)))	\
      ? XFRAME (selected_frame)				\
      : (abort (), (struct frame *) 0))


/***********************************************************************
			Display-related Macros
 ***********************************************************************/

/* Canonical y-unit on frame F.  This value currently equals the line
   height of the frame.  Terminal specific header files are expected
   to define the macro FRAME_LINE_HEIGHT.  */

#define CANON_Y_UNIT(F) \
     (FRAME_WINDOW_P (F) ? FRAME_LINE_HEIGHT (F) : 1)

/* Canonical x-unit on frame F.  This is currently equal to the width
   of the default font of F.  Terminal specific headers are expected
   to define the macro FRAME_DEFAULT_FONT_WIDTH.  */

#define CANON_X_UNIT(F) \
     (FRAME_WINDOW_P (F) ? FRAME_DEFAULT_FONT_WIDTH (F) : 1)

/* Pixel width of areas used to display truncation marks, continuation
   marks, overlay arrows.  This is 0 for terminal frames.  */

#ifdef HAVE_WINDOW_SYSTEM

#define FRAME_FRINGE_COLS(F) \
     (FRAME_WINDOW_P (F) ? FRAME_X_FRINGE_COLS (F) : 0)
#define FRAME_FRINGE_WIDTH(F) \
     (FRAME_WINDOW_P (F) ? FRAME_X_FRINGE_WIDTH (F) : 0)
#define FRAME_LEFT_FRINGE_WIDTH(F) \
     (FRAME_WINDOW_P (F) ? FRAME_X_LEFT_FRINGE_WIDTH (F) : 0)
#define FRAME_RIGHT_FRINGE_WIDTH(F) \
     (FRAME_WINDOW_P (F) ? FRAME_X_RIGHT_FRINGE_WIDTH (F) : 0)
     
#else /* not HAVE_WINDOW_SYSTEM */

#define FRAME_FRINGE_WIDTH(F)	0
#define FRAME_FRINGE_COLS(F)	0
#define FRAME_LEFT_FRINGE_WIDTH(F)  0
#define FRAME_RIGHT_FRINGE_WIDTH(F) 0

#endif /* not HAVE_WINDOW_SYSTEM */
     



/***********************************************************************
	    Conversion between canonical units and pixels
 ***********************************************************************/

/* Canonical x-values are fractions of CANON_X_UNIT, canonical y-unit
   are fractions of CANON_Y_UNIT of a frame.  Both are represented as
   Lisp numbers, i.e. integers or floats.  */

/* Convert canonical value X to pixels.  F is the frame whose
   canonical char width is to be used.  X must be a Lisp integer or
   float.  Value is a C integer.  */
     
#define PIXEL_X_FROM_CANON_X(F, X)			\
     (INTEGERP (X)					\
      ? XINT (X) * CANON_X_UNIT (F)			\
      : (int) (XFLOAT_DATA (X) * CANON_X_UNIT (F)))
      
/* Convert canonical value Y to pixels.  F is the frame whose
   canonical character height is to be used.  X must be a Lisp integer
   or float.  Value is a C integer.  */
     
#define PIXEL_Y_FROM_CANON_Y(F, Y)			\
     (INTEGERP (Y)					\
      ? XINT (Y) * CANON_Y_UNIT (F)			\
      : (int) (XFLOAT_DATA (Y) * CANON_Y_UNIT (F)))

/* Convert pixel-value X to canonical units.  F is the frame whose
   canonical character width is to be used.  X is a C integer.  Result
   is a Lisp float if X is not a multiple of the canon width,
   otherwise it's a Lisp integer.  */

#define CANON_X_FROM_PIXEL_X(F, X)			\
     ((X) % CANON_X_UNIT (F) != 0			\
      ? make_float ((double) (X) / CANON_X_UNIT (F))	\
      : make_number ((X) / CANON_X_UNIT (F)))

/* Convert pixel-value Y to canonical units.  F is the frame whose
   canonical character height is to be used.  Y is a C integer.
   Result is a Lisp float if Y is not a multiple of the canon width,
   otherwise it's a Lisp integer.  */

#define CANON_Y_FROM_PIXEL_Y(F, Y)			\
     ((Y) % CANON_Y_UNIT (F) 				\
      ? make_float ((double) (Y) / CANON_Y_UNIT (F))	\
      : make_number ((Y) / CANON_Y_UNIT (F)))	
			     
#endif /* not EMACS_FRAME_H */