mutter/src/include/boxes.h

/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */

/* Simple box operations */

/* 
 * Copyright (C) 2005, 2006 Elijah Newren
 * 
 * This program 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 of the
 * License, or (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 */

#ifndef META_BOXES_H
#define META_BOXES_H

#include <glib.h>
#include "common.h"

typedef struct _MetaRectangle MetaRectangle;
struct _MetaRectangle
{
  int x;
  int y;
  int width;
  int height;
};

typedef struct _MetaStrut MetaStrut;
struct _MetaStrut
{
  MetaRectangle rect;
  MetaDirection side;
};

#define BOX_LEFT(box)    ((box).x)                /* Leftmost pixel of rect */
#define BOX_RIGHT(box)   ((box).x + (box).width)  /* One pixel past right   */
#define BOX_TOP(box)     ((box).y)                /* Topmost pixel of rect  */
#define BOX_BOTTOM(box)  ((box).y + (box).height) /* One pixel past bottom  */

typedef enum
{
  FIXED_DIRECTION_NONE = 0,
  FIXED_DIRECTION_X    = 1 << 0,
  FIXED_DIRECTION_Y    = 1 << 1,
} FixedDirections;

typedef enum
{
  META_EDGE_WINDOW,
  META_EDGE_XINERAMA,
  META_EDGE_SCREEN
} MetaEdgeType;

typedef struct _MetaEdge MetaEdge;
struct _MetaEdge
{
  MetaRectangle rect;      /* width or height should be 1 */
  MetaDirection side_type; /* should only have 1 of the 4 directions set */
  MetaEdgeType  edge_type;
};

/* Output functions -- note that the output buffer had better be big enough:
 *   rect_to_string:   RECT_LENGTH
 *   region_to_string: (RECT_LENGTH+strlen(separator_string)) *
 *                     g_list_length (region)
 *   edge_to_string:   EDGE_LENGTH
 *   edge_list_to_...: (EDGE_LENGTH+strlen(separator_string)) * 
 *                     g_list_length (edge_list)
 */
#define RECT_LENGTH 27
#define EDGE_LENGTH 37
char* meta_rectangle_to_string        (const MetaRectangle *rect,
                                       char                *output);
char* meta_rectangle_region_to_string (GList               *region,
                                       const char          *separator_string,
                                       char                *output);
char* meta_rectangle_edge_to_string   (const MetaEdge      *edge,
                                       char                *output);
char* meta_rectangle_edge_list_to_string (
                                       GList               *edge_list,
                                       const char          *separator_string,
                                       char                *output);

/* Function to make initializing a rect with a single line of code easy */
MetaRectangle                 meta_rect (int x, int y, int width, int height);

/* Basic comparison functions */
int      meta_rectangle_area            (const MetaRectangle *rect);
gboolean meta_rectangle_intersect       (const MetaRectangle *src1,
                                         const MetaRectangle *src2,
                                         MetaRectangle       *dest);
gboolean meta_rectangle_equal           (const MetaRectangle *src1,
                                         const MetaRectangle *src2);

/* overlap is similar to intersect but doesn't provide location of
 * intersection information.
 */
gboolean meta_rectangle_overlap         (const MetaRectangle *rect1,
                                         const MetaRectangle *rect2);

/* vert_overlap means ignore the horizontal location and ask if the
 * vertical parts overlap.  An alternate way to think of it is "Does there
 * exist a way to shift either rect horizontally so that the two rects
 * overlap?"  horiz_overlap is similar.
 */
gboolean meta_rectangle_vert_overlap    (const MetaRectangle *rect1,
                                         const MetaRectangle *rect2);
gboolean meta_rectangle_horiz_overlap   (const MetaRectangle *rect1,
                                         const MetaRectangle *rect2);

/* could_fit_rect determines whether "outer_rect" is big enough to contain
 * inner_rect.  contains_rect checks whether it actually contains it.
 */
gboolean meta_rectangle_could_fit_rect  (const MetaRectangle *outer_rect,
                                         const MetaRectangle *inner_rect);
gboolean meta_rectangle_contains_rect   (const MetaRectangle *outer_rect,
                                         const MetaRectangle *inner_rect);

/* Resize old_rect to the given new_width and new_height, but store the
 * result in rect.  NOTE THAT THIS IS RESIZE ONLY SO IT CANNOT BE USED FOR
 * A MOVERESIZE OPERATION (that simplies the routine a little bit as it
 * means there's no difference between NorthWestGravity and StaticGravity.
 * Also, I lied a little bit--technically, you could use it in a MoveResize
 * operation if you muck with old_rect just right).
 */
void meta_rectangle_resize_with_gravity (const MetaRectangle *old_rect,
                                         MetaRectangle       *rect,
                                         int                  gravity,
                                         int                  new_width,
                                         int                  new_height);

/* find a list of rectangles with the property that a window is contained
 * in the given region if and only if it is contained in one of the
 * rectangles in the list.
 *
 * In this case, the region is given by taking basic_rect, removing from
 * it the intersections with all the rectangles in the all_struts list,
 * then expanding all the rectangles in the resulting list by the given
 * amounts on each side.
 *
 * See boxes.c for more details.
 */
GList*   meta_rectangle_get_minimal_spanning_set_for_region (
                                         const MetaRectangle *basic_rect,
                                         const GSList        *all_struts);

/* Expand all rectangles in region by the given amount on each side */
GList*   meta_rectangle_expand_region   (GList               *region,
                                         const int            left_expand,
                                         const int            right_expand,
                                         const int            top_expand,
                                         const int            bottom_expand);
/* Same as for meta_rectangle_expand_region except that rectangles not at
 * least min_x or min_y in size are not expanded in that direction
 */
GList*   meta_rectangle_expand_region_conditionally (
                                         GList                *region,
                                         const int            left_expand,
                                         const int            right_expand,
                                         const int            top_expand,
                                         const int            bottom_expand,
                                         const int            min_x,
                                         const int            min_y);

/* Expand rect in direction to the size of expand_to, and then clip out any
 * overlapping struts oriented orthognal to the expansion direction.  (Think
 * horizontal or vertical maximization)
 */
void     meta_rectangle_expand_to_avoiding_struts (
                                         MetaRectangle       *rect,
                                         const MetaRectangle *expand_to,
                                         const MetaDirection  direction,
                                         const GSList        *all_struts);

/* Free the list created by
 *   meta_rectangle_get_minimal_spanning_set_for_region()
 * or
 *   meta_rectangle_find_onscreen_edges ()
 * or
 *   meta_rectangle_find_nonintersected_xinerama_edges()
 */
void     meta_rectangle_free_list_and_elements (GList *filled_list);

/* could_fit_in_region determines whether one of the spanning_rects is
 * big enough to contain rect.  contained_in_region checks whether one
 * actually contains it.
 */
gboolean meta_rectangle_could_fit_in_region (
                                         const GList         *spanning_rects,
                                         const MetaRectangle *rect);
gboolean meta_rectangle_contained_in_region (
                                         const GList         *spanning_rects,
                                         const MetaRectangle *rect);
gboolean meta_rectangle_overlaps_with_region (
                                         const GList         *spanning_rects,
                                         const MetaRectangle *rect);

/* Make the rectangle small enough to fit into one of the spanning_rects,
 * but make it no smaller than min_size.
 */
void     meta_rectangle_clamp_to_fit_into_region (
                                         const GList         *spanning_rects,
                                         FixedDirections      fixed_directions,
                                         MetaRectangle       *rect,
                                         const MetaRectangle *min_size);

/* Clip the rectangle so that it fits into one of the spanning_rects, assuming
 * it overlaps with at least one of them
 */
void     meta_rectangle_clip_to_region  (const GList         *spanning_rects,
                                         FixedDirections      fixed_directions,
                                         MetaRectangle       *rect);

/* Shove the rectangle into one of the spanning_rects, assuming it fits in
 * one of them.
 */
void     meta_rectangle_shove_into_region(
                                         const GList         *spanning_rects,
                                         FixedDirections      fixed_directions,
                                         MetaRectangle       *rect);

/* Finds the point on the line connecting (x1,y1) to (x2,y2) which is closest
 * to (px, py).  Useful for finding an optimal rectangle size when given a
 * range between two sizes that are all candidates.
 */
void meta_rectangle_find_linepoint_closest_to_point (double x1,    double y1,
                                                     double x2,    double y2,
                                                     double px,    double py,
                                                     double *valx, double *valy);

/***************************************************************************/
/*                                                                         */
/* Switching gears to code for edges instead of just rectangles            */
/*                                                                         */
/***************************************************************************/

/* Return whether an edge overlaps or is adjacent to the rectangle in the
 * nonzero-width dimension of the edge.
 */
gboolean meta_rectangle_edge_aligns (const MetaRectangle *rect, 
                                     const MetaEdge      *edge);

/* Compare two edges, so that sorting functions can put a list of edges in
 * canonical order.
 */
gint   meta_rectangle_edge_cmp (gconstpointer a, gconstpointer b);

/* Compare two edges, so that sorting functions can put a list of edges in
 * order.  This function doesn't separate left edges first, then right edges,
 * etc., but rather compares only upon location.
 */
gint   meta_rectangle_edge_cmp_ignore_type (gconstpointer a, gconstpointer b);

/* Removes an parts of edges in the given list that intersect any box in the
 * given rectangle list.  Returns the result.
 */
GList* meta_rectangle_remove_intersections_with_boxes_from_edges (
                                           GList *edges,
                                           const GSList *rectangles);

/* Finds all the edges of an onscreen region, returning a GList* of
 * MetaEdgeRect's.
 */
GList* meta_rectangle_find_onscreen_edges (const MetaRectangle *basic_rect,
                                           const GSList        *all_struts);

/* Finds edges between adjacent xineramas which are not covered by the given
 * struts.
 */
GList* meta_rectangle_find_nonintersected_xinerama_edges (
                                           const GList         *xinerama_rects,
                                           const GSList        *all_struts);

#endif /* META_BOXES_H */