eel-canvas.h 17 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
/*
 * Copyright (C) 1997, 1998, 1999, 2000 Free Software Foundation
 * All rights reserved.
 *
 * This file is part of the Gnome Library.
 *
 * The Gnome Library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * The Gnome Library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with the Gnome Library; see the file COPYING.LIB.  If not,
19
 * see <http://www.gnu.org/licenses/>.
20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
 */
/*
  @NOTATION@
 */
/* EelCanvas widget - Tk-like canvas widget for Gnome
 *
 * EelCanvas is basically a port of the Tk toolkit's most excellent canvas
 * widget.  Tk is copyrighted by the Regents of the University of California,
 * Sun Microsystems, and other parties.
 *
 *
 * Authors: Federico Mena <federico@nuclecu.unam.mx>
 *          Raph Levien <raph@gimp.org>
 */

35
#pragma once
36

37
#include <gtk/gtk.h>
38
#include <gtk/gtk-a11y.h>
39
#include <gdk/gdk.h>
40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101
#include <stdarg.h>

G_BEGIN_DECLS


/* "Small" value used by canvas stuff */
#define EEL_CANVAS_EPSILON 1e-10


/* Macros for building colors that fit in a 32-bit integer.  The values are in
 * [0, 255].
 */

#define EEL_CANVAS_COLOR(r, g, b) ((((int) (r) & 0xff) << 24)	\
				     | (((int) (g) & 0xff) << 16)	\
				     | (((int) (b) & 0xff) << 8)	\
				     | 0xff)

#define EEL_CANVAS_COLOR_A(r, g, b, a) ((((int) (r) & 0xff) << 24)	\
					  | (((int) (g) & 0xff) << 16)	\
					  | (((int) (b) & 0xff) << 8)	\
					  | ((int) (a) & 0xff))


typedef struct _EelCanvas           EelCanvas;
typedef struct _EelCanvasClass      EelCanvasClass;
typedef struct _EelCanvasItem       EelCanvasItem;
typedef struct _EelCanvasItemClass  EelCanvasItemClass;
typedef struct _EelCanvasGroup      EelCanvasGroup;
typedef struct _EelCanvasGroupClass EelCanvasGroupClass;


/* EelCanvasItem - base item class for canvas items
 *
 * All canvas items are derived from EelCanvasItem.  The only information a
 * EelCanvasItem contains is its parent canvas, its parent canvas item group,
 * and its bounding box in world coordinates.
 *
 * Items inside a canvas are organized in a tree of EelCanvasItemGroup nodes
 * and EelCanvasItem leaves.  Each canvas has a single root group, which can
 * be obtained with the eel_canvas_get_root() function.
 *
 * The abstract EelCanvasItem class does not have any configurable or
 * queryable attributes.
 */

/* Object flags for items */
enum {
	EEL_CANVAS_ITEM_REALIZED         = 1 << 4,
	EEL_CANVAS_ITEM_MAPPED           = 1 << 5,
	EEL_CANVAS_ITEM_ALWAYS_REDRAW    = 1 << 6,
	EEL_CANVAS_ITEM_VISIBLE          = 1 << 7,
	EEL_CANVAS_ITEM_NEED_UPDATE      = 1 << 8,
	EEL_CANVAS_ITEM_NEED_DEEP_UPDATE = 1 << 9
};

/* Update flags for items */
enum {
	EEL_CANVAS_UPDATE_REQUESTED  = 1 << 0,
	EEL_CANVAS_UPDATE_DEEP       = 1 << 1
};

102 103 104 105 106 107 108
#define EEL_TYPE_CANVAS_ITEM            (eel_canvas_item_get_type ())
#define EEL_CANVAS_ITEM(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), EEL_TYPE_CANVAS_ITEM, EelCanvasItem))
#define EEL_CANVAS_ITEM_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), EEL_TYPE_CANVAS_ITEM, EelCanvasItemClass))
#define EEL_IS_CANVAS_ITEM(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), EEL_TYPE_CANVAS_ITEM))
#define EEL_IS_CANVAS_ITEM_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), EEL_TYPE_CANVAS_ITEM))
#define EEL_CANVAS_ITEM_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), EEL_TYPE_CANVAS_ITEM, EelCanvasItemClass))

109 110

struct _EelCanvasItem {
111
	GInitiallyUnowned object;
112 113 114 115 116 117 118 119 120

	/* Parent canvas for this item */
	EelCanvas *canvas;

	/* Parent canvas group for this item (a EelCanvasGroup) */
	EelCanvasItem *parent;

	/* Bounding box for this item (in canvas coordinates) */
	double x1, y1, x2, y2;
Bastien Nocera's avatar
Bastien Nocera committed
121 122 123

	/* Object flags */
	guint flags;
124 125 126
};

struct _EelCanvasItemClass {
127 128 129
	GInitiallyUnownedClass parent_class;

	void (* destroy) (EelCanvasItem *item);
130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153

	/* Tell the item to update itself.  The flags are from the update flags
	 * defined above.  The item should update its internal state from its
	 * queued state, and recompute and request its repaint area. The
	 * update method also recomputes the bounding box of the item.
	 */
	void (* update) (EelCanvasItem *item, double i2w_dx, double i2w_dy, int flags);

	/* Realize an item -- create GCs, etc. */
	void (* realize) (EelCanvasItem *item);

	/* Unrealize an item */
	void (* unrealize) (EelCanvasItem *item);

	/* Map an item - normally only need by items with their own GdkWindows */
	void (* map) (EelCanvasItem *item);

	/* Unmap an item */
	void (* unmap) (EelCanvasItem *item);

	/* Draw an item of this type.  (x, y) are the upper-left canvas pixel
	 * coordinates of the drawable, a temporary pixmap, where things get
	 * drawn.  (width, height) are the dimensions of the drawable.
	 */
154
	void (* draw) (EelCanvasItem *item, cairo_t *cr, cairo_region_t *region);
155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191

	/* Calculate the distance from an item to the specified point.  It also
         * returns a canvas item which is the item itself in the case of the
         * object being an actual leaf item, or a child in case of the object
         * being a canvas group.  (cx, cy) are the canvas pixel coordinates that
         * correspond to the item-relative coordinates (x, y).
	 */
	double (* point) (EelCanvasItem *item, double x, double y, int cx, int cy,
			  EelCanvasItem **actual_item);

	void (* translate) (EelCanvasItem *item, double dx, double dy);
	
	/* Fetch the item's bounding box (need not be exactly tight).  This
	 * should be in item-relative coordinates.
	 */
	void (* bounds) (EelCanvasItem *item, double *x1, double *y1, double *x2, double *y2);

	/* Signal: an event ocurred for an item of this type.  The (x, y)
	 * coordinates are in the canvas world coordinate system.
	 */
	gboolean (* event)                (EelCanvasItem *item, GdkEvent *event);

	/* Reserved for future expansion */
	gpointer spare_vmethods [4];
};


/* Standard Gtk function */
GType eel_canvas_item_get_type (void) G_GNUC_CONST;

/* Create a canvas item using the standard Gtk argument mechanism.  The item is
 * automatically inserted at the top of the specified canvas group.  The last
 * argument must be a NULL pointer.
 */
EelCanvasItem *eel_canvas_item_new (EelCanvasGroup *parent, GType type,
				    const gchar *first_arg_name, ...);

192 193
void eel_canvas_item_destroy (EelCanvasItem *item);

194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232
/* Configure an item using the standard Gtk argument mechanism.  The last
 * argument must be a NULL pointer.
 */
void eel_canvas_item_set (EelCanvasItem *item, const gchar *first_arg_name, ...);

/* Move an item by the specified amount */
void eel_canvas_item_move (EelCanvasItem *item, double dx, double dy);

/* Raise an item in the z-order of its parent group by the specified number of
 * positions.
 */
void eel_canvas_item_raise (EelCanvasItem *item, int positions);

/* Lower an item in the z-order of its parent group by the specified number of
 * positions.
 */
void eel_canvas_item_lower (EelCanvasItem *item, int positions);

/* Raise an item to the top of its parent group's z-order. */
void eel_canvas_item_raise_to_top (EelCanvasItem *item);

/* Lower an item to the bottom of its parent group's z-order */
void eel_canvas_item_lower_to_bottom (EelCanvasItem *item);

/* Send an item behind another item */
void eel_canvas_item_send_behind (EelCanvasItem *item,
				  EelCanvasItem *behind_item);


/* Show an item (make it visible).  If the item is already shown, it has no
 * effect.
 */
void eel_canvas_item_show (EelCanvasItem *item);

/* Hide an item (make it invisible).  If the item is already invisible, it has
 * no effect.
 */
void eel_canvas_item_hide (EelCanvasItem *item);

233 234 235
/* Grab the seat for the specified item.  Only the events in event_mask will be
 * reported. If cursor is non-NULL, it will be used during the duration of the
 * grab. event is the event, triggering the grab. Returns the same values as gdk_seat_grab().
236
 */
237 238 239
GdkGrabStatus eel_canvas_item_grab (EelCanvasItem *item,
				    GdkEventMask event_mask,
				    GdkCursor *cursor,
240
				    const GdkEvent* event);
241

242 243
/* Ungrabs the seat -- the specified item must be the same that was passed to
 * eel_canvas_item_grab().
244
 */
245
void eel_canvas_item_ungrab (EelCanvasItem *item);
246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287

/* These functions convert from a coordinate system to another.  "w" is world
 * coordinates and "i" is item coordinates.
 */
void eel_canvas_item_i2w (EelCanvasItem *item, double *x, double *y);

/* Fetch the bounding box of the item.  The bounding box may not be exactly
 * tight, but the canvas items will do the best they can.  The returned bounding
 * box is in the coordinate system of the item's parent.
 */
void eel_canvas_item_get_bounds (EelCanvasItem *item,
				 double *x1, double *y1, double *x2, double *y2);

/* Request that the update method eventually get called.  This should be used
 * only by item implementations.
 */
void eel_canvas_item_request_update (EelCanvasItem *item);

/* Request a redraw of the bounding box of the canvas item */
void eel_canvas_item_request_redraw (EelCanvasItem *item);

/* EelCanvasGroup - a group of canvas items
 *
 * A group is a node in the hierarchical tree of groups/items inside a canvas.
 * Groups serve to give a logical structure to the items.
 *
 * Consider a circuit editor application that uses the canvas for its schematic
 * display.  Hierarchically, there would be canvas groups that contain all the
 * components needed for an "adder", for example -- this includes some logic
 * gates as well as wires.  You can move stuff around in a convenient way by
 * doing a eel_canvas_item_move() of the hierarchical groups -- to move an
 * adder, simply move the group that represents the adder.
 *
 * The following arguments are available:
 *
 * name		type		read/write	description
 * --------------------------------------------------------------------------------
 * x		double		RW		X coordinate of group's origin
 * y		double		RW		Y coordinate of group's origin
 */


288 289 290 291 292 293 294
#define EEL_TYPE_CANVAS_GROUP            (eel_canvas_group_get_type ())
#define EEL_CANVAS_GROUP(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), EEL_TYPE_CANVAS_GROUP, EelCanvasGroup))
#define EEL_CANVAS_GROUP_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), EEL_TYPE_CANVAS_GROUP, EelCanvasGroupClass))
#define EEL_IS_CANVAS_GROUP(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), EEL_TYPE_CANVAS_GROUP))
#define EEL_IS_CANVAS_GROUP_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), EEL_TYPE_CANVAS_GROUP))
#define EEL_CANVAS_GROUP_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), EEL_TYPE_CANVAS_GROUP, EelCanvasGroupClass))

295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316

struct _EelCanvasGroup {
	EelCanvasItem item;

	double xpos, ypos;
	
	/* Children of the group */
	GList *item_list;
	GList *item_list_end;
};

struct _EelCanvasGroupClass {
	EelCanvasItemClass parent_class;
};


/* Standard Gtk function */
GType eel_canvas_group_get_type (void) G_GNUC_CONST;


/*** EelCanvas ***/

317 318 319 320 321 322 323 324

#define EEL_TYPE_CANVAS            (eel_canvas_get_type ())
#define EEL_CANVAS(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), EEL_TYPE_CANVAS, EelCanvas))
#define EEL_CANVAS_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), EEL_TYPE_CANVAS, EelCanvasClass))
#define EEL_IS_CANVAS(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), EEL_TYPE_CANVAS))
#define EEL_IS_CANVAS_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), EEL_TYPE_CANVAS))
#define EEL_CANVAS_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), EEL_TYPE_CANVAS, EelCanvasClass))

325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467

struct _EelCanvas {
	GtkLayout layout;

	/* Root canvas group */
	EelCanvasItem *root;

	/* The item containing the mouse pointer, or NULL if none */
	EelCanvasItem *current_item;

	/* Item that is about to become current (used to track deletions and such) */
	EelCanvasItem *new_current_item;

	/* Item that holds a pointer grab, or NULL if none */
	EelCanvasItem *grabbed_item;

	/* If non-NULL, the currently focused item */
	EelCanvasItem *focused_item;

	/* Event on which selection of current item is based */
	GdkEvent pick_event;

	/* Scrolling region */
	double scroll_x1, scroll_y1;
	double scroll_x2, scroll_y2;

	/* Scaling factor to be used for display */
	double pixels_per_unit;

	/* Idle handler ID */
	guint idle_id;

	/* Signal handler ID for destruction of the root item */
	guint root_destroy_id;

	/* Internal pixel offsets when zoomed out */
	int zoom_xofs, zoom_yofs;

	/* Last known modifier state, for deferred repick when a button is down */
	int state;

	/* Event mask specified when grabbing an item */
	guint grabbed_event_mask;

	/* Tolerance distance for picking items */
	int close_enough;

	/* Whether the canvas should center the canvas in the middle of
	 * the window if the scroll region is smaller than the window */
	unsigned int center_scroll_region : 1;

	/* Whether items need update at next idle loop iteration */
	unsigned int need_update : 1;

	/* Are we in the midst of an update */
	unsigned int doing_update : 1;

	/* Whether the canvas needs redrawing at the next idle loop iteration */
	unsigned int need_redraw : 1;

	/* Whether current item will be repicked at next idle loop iteration */
	unsigned int need_repick : 1;

	/* For use by internal pick_current_item() function */
	unsigned int left_grabbed_item : 1;

	/* For use by internal pick_current_item() function */
	unsigned int in_repick : 1;
};

struct _EelCanvasClass {
	GtkLayoutClass parent_class;

	/* Private Virtual methods for groping the canvas inside bonobo */
	void (* request_update) (EelCanvas *canvas);

	/* Reserved for future expansion */
	gpointer spare_vmethods [4];
};


/* Standard Gtk function */
GType eel_canvas_get_type (void) G_GNUC_CONST;

/* Creates a new canvas.  You should check that the canvas is created with the
 * proper visual and colormap.  Any visual will do unless you intend to insert
 * gdk_imlib images into it, in which case you should use the gdk_imlib visual.
 *
 * You should call eel_canvas_set_scroll_region() soon after calling this
 * function to set the desired scrolling limits for the canvas.
 */
GtkWidget *eel_canvas_new (void);

/* Returns the root canvas item group of the canvas */
EelCanvasGroup *eel_canvas_root (EelCanvas *canvas);

/* Sets the limits of the scrolling region, in world coordinates */
void eel_canvas_set_scroll_region (EelCanvas *canvas,
				   double x1, double y1, double x2, double y2);

/* Gets the limits of the scrolling region, in world coordinates */
void eel_canvas_get_scroll_region (EelCanvas *canvas,
				   double *x1, double *y1, double *x2, double *y2);

/* Sets the number of pixels that correspond to one unit in world coordinates */
void eel_canvas_set_pixels_per_unit (EelCanvas *canvas, double n);

/* Returns the scroll offsets of the canvas in canvas pixel coordinates.  You
 * can specify NULL for any of the values, in which case that value will not be
 * queried.
 */
void eel_canvas_get_scroll_offsets (EelCanvas *canvas, int *cx, int *cy);

/* For use only by item type implementations.  Request that the canvas
 * eventually redraw the specified region, specified in canvas pixel
 * coordinates.  The region contains (x1, y1) but not (x2, y2).
 */
void eel_canvas_request_redraw (EelCanvas *canvas, int x1, int y1, int x2, int y2);

/* These functions convert from a coordinate system to another.  "w" is world
 * coordinates, "c" is canvas pixel coordinates (pixel coordinates that are
 * (0,0) for the upper-left scrolling limit and something else for the
 * lower-left scrolling limit).
 */
void eel_canvas_w2c_rect_d (EelCanvas *canvas,
			    double *x1, double *y1,
			    double *x2, double *y2);
void eel_canvas_w2c (EelCanvas *canvas, double wx, double wy, int *cx, int *cy);
void eel_canvas_w2c_d (EelCanvas *canvas, double wx, double wy, double *cx, double *cy);
void eel_canvas_c2w (EelCanvas *canvas, int cx, int cy, double *wx, double *wy);

/* This function takes in coordinates relative to the GTK_LAYOUT
 * (canvas)->bin_window and converts them to world coordinates.
 * These days canvas coordinates and window coordinates are the same, but
 * these are left for backwards compat reasons.
 */
void eel_canvas_window_to_world (EelCanvas *canvas,
				 double winx, double winy, double *worldx, double *worldy);

/* This is the inverse of eel_canvas_window_to_world() */
void eel_canvas_world_to_window (EelCanvas *canvas,
				 double worldx, double worldy, double *winx, double *winy);

468
/* Accessible implementation */
469
GType eel_canvas_accessible_get_type (void);
470 471 472 473

typedef struct _EelCanvasAccessible EelCanvasAccessible;
struct _EelCanvasAccessible
{
474
	GtkContainerAccessible parent;
475 476 477 478 479
};

typedef struct _EelCanvasAccessibleClass EelCanvasAccessibleClass;
struct _EelCanvasAccessibleClass
{
480
	GtkContainerAccessibleClass parent_class;
481 482
};

483 484 485 486 487 488 489 490 491 492 493 494 495 496
GType eel_canvas_item_accessible_get_type (void);

typedef struct _EelCanvasItemAccessible EelCanvasItemAccessible;
struct _EelCanvasItemAccessible
{
	GtkAccessible parent;
};

typedef struct _EelCanvasItemAccessibleClass EelCanvasItemAccessibleClass;
struct _EelCanvasItemAccessibleClass
{
	GtkAccessibleClass parent_class;
};

497
G_END_DECLS