src/hid.h

   1 #ifndef _HID_H_
   2 #define _HID_H_
   3
   4 #include <stdarg.h>
   5
   6 /* Human Interface Device */
   7
   8 /*
   9
  10 The way the HID layer works is that you instantiate a HID device
  11 structure, and invoke functions through its members.  Code in the
  12 common part of PCB may *not* rely on *anything* other than what's
  13 defined in this file.  Code in the HID layers *may* rely on data and
  14 functions in the common code (like, board size and such) but it's
  15 considered bad form to do so when not needed.
  16
  17 Coordinates are ALWAYS in pcb's default resolution (1/100 mil at the
  18 moment).  Positive X is right, positive Y is down.  Angles are
  19 degrees, with 0 being right (positive X) and 90 being up (negative Y).
  20 All zoom, scaling, panning, and conversions are hidden inside the HID
  21 layers.
  22
  23 The main structure is at the end of this file.
  24
  25 Data structures passed to the HIDs will be copied if the HID needs to
  26 save them.  Data structures retured from the HIDs must not be freed,
  27 and may be changed by the HID in response to new information.
  28
  29 */
  30
  31 #if defined(__cplusplus) && __cplusplus
  32 extern "C"
  33 {
  34 #endif
  35
  36 /* Like end cap styles.  The cap *always* extends beyond the
  37    coordinates given, by half the width of the line.  Beveled ends can
  38    used to make octagonal pads by giving the same x,y coordinate
  39    twice.  */
  40   typedef enum
  41   {
  42     Trace_Cap,                  /* This means we're drawing a trace, which has round caps.  */
  43     Square_Cap,                 /* Square pins or pads. */
  44     Round_Cap,                  /* Round pins or round-ended pads, thermals.  */
  45     Beveled_Cap                 /* Octagon pins or bevel-cornered pads.  */
  46   } EndCapStyle;
  47
  48 /* The HID may need something more than an "int" for colors, timers,
  49    etc.  So it passes/returns one of these, which is castable to a
  50    variety of things.  */
  51   typedef union
  52   {
  53     long lval;
  54     void *ptr;
  55   } hidval;
  56
  57 /* This graphics context is an opaque pointer defined by the HID.  GCs
  58    are HID-specific; attempts to use one HID's GC for a different HID
  59    will result in a fatal error.  */
  60   typedef struct hid_gc_struct *hidGC;
  61
  62 #define HIDCONCAT(a,b) a##b
  63
  64 /* This is used to register the action callbacks (for menus and
  65    whatnot).  HID assumes the following actions are available for its
  66    use:
  67         SaveAs(filename);
  68         Quit();
  69 */
  70   typedef struct
  71   {
  72     /* This is matched against action names in the GUI configuration */
  73     char *name;
  74     /* If this string is non-NULL, the action needs to know the X,Y
  75        coordinates to act on, and this string may be used to prompt
  76        the user to select a coordinate.  If NULL, the coordinates may
  77        be 0,0 if none are known.  */
  78     const char *need_coord_msg;
  79     /* Called when the action is triggered.  If this function returns
  80        non-zero, no further actions will be invoked for this key/mouse
  81        event.  */
  82     int (*trigger_cb) (int argc, char **argv, int x, int y);
  83     /* Short description that sometimes accompanies the name.  */
  84     const char *description;
  85     /* Full allowed syntax; use \n to separate lines.  */
  86     const char *syntax;
  87   } HID_Action;
  88
  89   /* This global variable is always set to the action context, before
  90      an action callback is called. Action context can be specified
  91      when registering an action with hid_register_action() Intended
  92      for plugins with hub action callbacks. */
  93   extern void *hid_action_context;
  94
  95   /* Register a singe action associated with an action context. Makes
  96      a copy of HID_Action.  Intended for plugins to register actions
  97      with a hub callback. */
  98   extern void hid_register_action(const HID_Action *, void *);
  99
 100   /* Deregister an action registered using hid_register_action().
 101      Action context pointer is copied in the 2nd argument if it's not
 102      NULL.  Intended for plugins to deregister custom actions. */
 103   extern void hid_deregister_action(const char *, void **);
 104
 105   /* Register a list of static actions without action context */
 106   extern void hid_register_actions (HID_Action *, int);
 107
 108 #define REGISTER_ACTIONS(a) HIDCONCAT(void register_,a) ()\
 109 { hid_register_actions(a, sizeof(a)/sizeof(a[0])); }
 110
 111   /* Note that PCB expects the gui to provide the following actions:
 112
 113      PCBChanged();
 114      RouteStylesChanged()
 115      NetlistChanged()  (but core should call "void NetlistChanged(int);" in netlist.c)
 116      LayersChanged()
 117      LibraryChanged()
 118      Busy()
 119    */
 120
 121   extern const char pcbchanged_help[];
 122   extern const char pcbchanged_syntax[];
 123   extern const char routestyleschanged_help[];
 124   extern const char routestyleschanged_syntax[];
 125   extern const char netlistchanged_help[];
 126   extern const char netlistchanged_syntax[];
 127   extern const char layerschanged_help[];
 128   extern const char layerschanged_syntax[];
 129   extern const char librarychanged_help[];
 130   extern const char librarychanged_syntax[];
 131
 132   int hid_action (const char *action_);
 133   int hid_actionl (const char *action_, ...);   /* NULL terminated */
 134   int hid_actionv (const char *action_, int argc_, char **argv_);
 135   void hid_save_settings (int);
 136   void hid_load_settings (void);
 137
 138 /* Parse the given string into action calls, and call `f' for each
 139    action found.  Returns nonzero if the action handler(s) return
 140    nonzero.  If f is NULL, hid_actionv is called.  */
 141   int hid_parse_actions (const char *str_,
 142                          int (*_f) (const char *, int, char **));
 143
 144   typedef struct
 145   {
 146     /* Name of the flag */
 147     char *name;
 148     /* Function to call to get the value of the flag.  */
 149     int (*function) (int);
 150     /* Additional parameter to pass to that function.  */
 151     int parm;
 152   } HID_Flag;
 153
 154   extern void hid_register_flags (HID_Flag *, int);
 155 #define REGISTER_FLAGS(a) HIDCONCAT(void register_,a) ()\
 156 { hid_register_flags(a, sizeof(a)/sizeof(a[0])); }
 157
 158 /* Looks up one of the flags registered above.  If the flag is
 159    unknown, returns zero.  */
 160   int hid_get_flag (const char *name_);
 161
 162 /* Used for HID attributes (exporting and printing, mostly).
 163    HA_boolean uses int_value, HA_enum sets int_value to the index and
 164    str_value to the enumeration string.  HID_Label just shows the
 165    default str_value.  HID_Mixed is a real_value followed by an enum,
 166    like 0.5in or 100mm. */
 167   typedef struct
 168   {
 169     int int_value;
 170     char *str_value;
 171     double real_value;
 172   } HID_Attr_Val;
 173
 174   typedef struct
 175   {
 176     char *name;
 177     /* If the help_text is this, usage() won't show this option */
 178 #define ATTR_UNDOCUMENTED ((char *)(1))
 179     char *help_text;
 180     enum
 181     { HID_Label, HID_Integer, HID_Real, HID_String,
 182       HID_Boolean, HID_Enum, HID_Mixed, HID_Path
 183     } type;
 184     int min_val, max_val;       /* for integer and real */
 185     HID_Attr_Val default_val;   /* Also actual value for global attributes.  */
 186     const char **enumerations;
 187     /* If set, this is used for global attributes (i.e. those set
 188        statically with REGISTER_ATTRIBUTES below) instead of changing
 189        the default_val.  Note that a HID_Mixed attribute must specify a
 190        pointer to HID_Attr_Val here, and HID_Boolean assumes this is
 191        "char *" so the value should be initialized to zero, and may be
 192        set to non-zero (not always one).  */
 193     void *value;
 194     int hash; /* for detecting changes. */
 195   } HID_Attribute;
 196
 197   extern void hid_register_attributes (HID_Attribute *, int);
 198 #define REGISTER_ATTRIBUTES(a) HIDCONCAT(void register_,a) ()\
 199 { hid_register_attributes(a, sizeof(a)/sizeof(a[0])); }
 200
 201 /* These three are set by hid_parse_command_line().  */
 202   extern char *program_name;
 203   extern char *program_directory;
 204   extern char *program_basename;
 205
 206 #define SL_0_SIDE       0x0000
 207 #define SL_TOP_SIDE     0x0001
 208 #define SL_BOTTOM_SIDE  0x0002
 209 #define SL_SILK         0x0010
 210 #define SL_MASK         0x0020
 211 #define SL_PDRILL       0x0030
 212 #define SL_UDRILL       0x0040
 213 #define SL_PASTE        0x0050
 214 #define SL_INVISIBLE    0x0060
 215 #define SL_FAB          0x0070
 216 #define SL_ASSY         0x0080
 217 #define SL_RATS         0x0090
 218 /* Callers should use this.  */
 219 #define SL(type,side) (~0xfff | SL_##type | SL_##side##_SIDE)
 220
 221 /* File Watch flags */
 222 /* Based upon those in dbus/dbus-connection.h */
 223 typedef enum
 224 {
 225   PCB_WATCH_READABLE = 1 << 0, /**< As in POLLIN */
 226   PCB_WATCH_WRITABLE = 1 << 1, /**< As in POLLOUT */
 227   PCB_WATCH_ERROR    = 1 << 2, /**< As in POLLERR */
 228   PCB_WATCH_HANGUP   = 1 << 3  /**< As in POLLHUP */
 229 } PCBWatchFlags;
 230
 231 /* DRC GUI Hooks */
 232   typedef struct
 233   {
 234     int log_drc_overview;
 235     int log_drc_violations;
 236     void (*reset_drc_dialog_message) (void);
 237     void (*append_drc_violation) (DrcViolationType *violation);
 238     int (*throw_drc_dialog) (void);
 239   } HID_DRC_GUI;
 240
 241
 242 /* This is the main HID structure.  */
 243   typedef struct
 244   {
 245     /* The size of this structure.  We use this as a compatibility
 246        check; a HID built with a different hid.h than we're expecting
 247        should have a different size here.  */
 248     int struct_size;
 249
 250     /* The name of this HID.  This should be suitable for
 251        command line options, multi-selection menus, file names,
 252        etc. */
 253     const char *name;
 254
 255     /* Likewise, but allowed to be longer and more descriptive.  */
 256     const char *description;
 257
 258     /* If set, this is the GUI HID.  Exactly one of these three flags
 259        must be set; setting "gui" lets the expose callback optimize and
 260        coordinate itself.  */
 261     char gui:1;
 262
 263     /* If set, this is the printer-class HID.  The common part of PCB
 264        may use this to do command-line printing, without having
 265        instantiated any GUI HIDs.  Only one printer HID is normally
 266        defined at a time.  */
 267     char printer:1;
 268
 269     /* If set, this HID provides an export option, and should be used as
 270        part of the File->Export menu option.  Examples are PNG, Gerber,
 271        and EPS exporters.  */
 272     char exporter:1;
 273
 274     /* If set, the redraw code will draw polygons before erasing the
 275        clearances.  */
 276     char poly_before:1;
 277
 278     /* If set, the redraw code will draw polygons after erasing the
 279        clearances.  Note that HIDs may set both of these, in which case
 280        polygons will be drawn twice.  */
 281     char poly_after:1;
 282
 283     /* If set, the redraw code will dice the polygons, so that there
 284        are no clearances in any polygons.  */
 285     char poly_dicer:1;
 286
 287     /* Returns a set of resources describing options the export or print
 288        HID supports.  In GUI mode, the print/export dialogs use this to
 289        set up the selectable options.  In command line mode, these are
 290        used to interpret command line options.  If n_ret is non-NULL,
 291        the number of attributes is stored there.  */
 292     HID_Attribute *(*get_export_options) (int *n_ret_);
 293
 294     /* Export (or print) the current PCB.  The options given represent
 295        the choices made from the options returned from
 296        get_export_options.  Call with options == NULL to start the
 297        primary GUI (create a main window, print, export, etc)  */
 298     void (*do_export) (HID_Attr_Val * options_);
 299
 300     /* Parse the command line.  Call this early for whatever HID will be
 301        the primary HID, as it will set all the registered attributes.
 302        The HID should remove all arguments, leaving any possible file
 303        names behind.  */
 304     void (*parse_arguments) (int *argc_, char ***argv_);
 305
 306     /* This may be called to ask the GUI to force a redraw of a given area */
 307     void (*invalidate_lr) (int left_, int right_, int top_, int bottom_);
 308     void (*invalidate_all) (void);
 309
 310     /* During redraw or print/export cycles, this is called once per
 311        layer (or layer group, for copper layers).  If it returns false
 312        (zero), the HID does not want that layer, and none of the drawing
 313        functions should be called.  If it returns true (nonzero), the
 314        items in that layer [group] should be drawn using the various
 315        drawing functions.  In addition to the MAX_LAYERS copper layer
 316        groups, you may select layers indicated by the macros SL_*
 317        defined above, or any others with an index of -1.  For copper
 318        layer groups, you may pass NULL for name to have a name fetched
 319        from the PCB struct.  The EMPTY argument is a hint - if set, the
 320        layer is empty, if zero it may be non-empty.  */
 321     int (*set_layer) (const char *name_, int group_, int _empty);
 322
 323     /* Drawing Functions.  Coordinates and distances are ALWAYS in PCB's
 324        default coordinates (1/100 mil at the time this comment was
 325        written).  Angles are always in degrees, with 0 being "right"
 326        (positive X) and 90 being "up" (positive Y).  */
 327
 328     /* Make an empty graphics context.  */
 329       hidGC (*make_gc) (void);
 330     void (*destroy_gc) (hidGC gc_);
 331
 332     /* Special note about the "erase" color: To use this color, you must
 333        use this function to tell the HID when you're using it.  At the
 334        beginning of a layer redraw cycle (i.e. after set_layer), call
 335        use_mask() to redirect output to a buffer.  Draw to the buffer
 336        (using regular HID calls) using regular and "erase" colors.  Then
 337        call use_mask(HID_MASK_OFF) to flush the buffer to the HID.  If
 338        you use the "erase" color when use_mask is disabled, it simply
 339        draws in the background color.  */
 340     void (*use_mask) (int use_it_);
 341     /* Flush the buffer and return to non-mask operation.  */
 342 #define HID_MASK_OFF 0
 343     /* Polygons being drawn before clears.  */
 344 #define HID_MASK_BEFORE 1
 345     /* Clearances being drawn.  */
 346 #define HID_MASK_CLEAR 2
 347     /* Polygons being drawn after clears.  */
 348 #define HID_MASK_AFTER 3
 349     /* Set to do live drawing on the screen   */
 350 #define HID_LIVE_DRAWING 4
 351     /* stop live drawing on the screen   */
 352 #define HID_LIVE_DRAWING_OFF 5
 353     /* flush any queued drawing   */
 354 #define HID_FLUSH_DRAW_Q 6
 355
 356     /* Set a color.  Names can be like "red" or "#rrggbb" or special
 357        names like "erase".  *Always* use the "erase" color for removing
 358        ink (like polygon reliefs or thermals), as you cannot rely on
 359        knowing the background color or special needs of the HID.  Always
 360        use the "drill" color to draw holes.  You may assume this is
 361        cheap enough to call inside the redraw callback, but not cheap
 362        enough to call for each item drawn. */
 363     void (*set_color) (hidGC gc_, const char *name_);
 364
 365     /* Set the line style.  While calling this is cheap, calling it with
 366        different values each time may be expensive, so grouping items by
 367        line style is helpful.  */
 368     void (*set_line_cap) (hidGC gc_, EndCapStyle style_);
 369     void (*set_line_width) (hidGC gc_, int width_);
 370     void (*set_draw_xor) (hidGC gc_, int xor_);
 371     /* Blends 20% or so color with 80% background.  Only used for
 372        assembly drawings so far. */
 373     void (*set_draw_faded) (hidGC gc_, int faded_);
 374
 375     /* When you pass the same x,y twice to draw_line, the end caps are
 376        drawn as if the "line" were parallel to the line defined by these
 377        coordinates.  Use this for rotating non-round pads.  */
 378     void (*set_line_cap_angle) (hidGC gc_, int x1_, int y1_, int x2_, int y2_);
 379
 380     /* The usual drawing functions.  "draw" means to use segments of the
 381        given width, whereas "fill" means to fill to a zero-width
 382        outline.  */
 383     void (*draw_line) (hidGC gc_, int x1_, int y1_, int x2_, int y2_);
 384     void (*draw_arc) (hidGC gc_, int cx_, int cy_, int xradius_, int yradius_,
 385                       int start_angle_, int delta_angle_);
 386     void (*draw_rect) (hidGC gc_, int x1_, int y1_, int x2_, int y2_);
 387     void (*fill_circle) (hidGC gc_, int cx_, int cy_, int radius_);
 388     void (*fill_polygon) (hidGC gc_, int n_coords_, int *x_, int *y_);
 389     void (*fill_pcb_polygon) (hidGC gc_, PolygonType *poly,
 390                               const BoxType *clip_box);
 391     void (*thindraw_pcb_polygon) (hidGC gc_, PolygonType *poly,
 392                                   const BoxType *clip_box);
 393     void (*fill_rect) (hidGC gc_, int x1_, int y1_, int x2_, int y2_);
 394
 395
 396     /* This is for the printer.  If you call this for the GUI, xval and
 397        yval are ignored, and a dialog pops up to lead you through the
 398        calibration procedure.  For the printer, if xval and yval are
 399        zero, a calibration page is printed with instructions for
 400        calibrating your printer.  After calibrating, nonzero xval and
 401        yval are passed according to the instructions.  Metric is nonzero
 402        if the user prefers metric units, else inches are used. */
 403     void (*calibrate) (double xval_, double yval_);
 404
 405
 406     /* GUI layout functions.  Not used or defined for print/export
 407        HIDs.  */
 408
 409     /* Temporary */
 410     int (*shift_is_pressed) (void);
 411     int (*control_is_pressed) (void);
 412         int (*mod1_is_pressed) (void);
 413     void (*get_coords) (const char *msg_, int *x_, int *y_);
 414
 415     /* Sets the crosshair, which may differ from the pointer depending
 416        on grid and pad snap.  Note that the HID is responsible for
 417        hiding, showing, redrawing, etc.  The core just tells it what
 418        coordinates it's actually using.  Note that this routine may
 419        need to know what "pcb units" are so it can display them in mm
 420        or mils accordingly.  If cursor_action is set, the cursor or
 421        screen may be adjusted so that the cursor and the crosshair are
 422        at the same point on the screen.  */
 423     void (*set_crosshair) (int x_, int y_, int cursor_action_);
 424 #define HID_SC_DO_NOTHING       0
 425 #define HID_SC_WARP_POINTER     1
 426 #define HID_SC_PAN_VIEWPORT     2
 427
 428     /* Causes func to be called at some point in the future.  Timers are
 429        only good for *one* call; if you want it to repeat, add another
 430        timer during the callback for the first.  user_data can be
 431        anything, it's just passed to func.  Times are not guaranteed to
 432        be accurate.  */
 433       hidval (*add_timer) (void (*func) (hidval user_data_),
 434                            unsigned long milliseconds_, hidval user_data_);
 435     /* Use this to stop a timer that hasn't triggered yet.  */
 436     void (*stop_timer) (hidval timer_);
 437
 438     /* Causes func to be called when some condition occurs on the file
 439        descriptor passed. Conditions include data for reading, writing,
 440        hangup, and errors. user_data can be anything, it's just passed
 441        to func. */
 442       hidval (*watch_file) (int fd_, unsigned int condition_, void (*func_) (hidval watch_, int fd_, unsigned int condition_, hidval user_data_),
 443         hidval user_data);
 444     /* Use this to stop a file watch. */
 445     void (*unwatch_file) (hidval watch_);
 446
 447     /* Causes func to be called in the mainloop prior to blocking */
 448       hidval (*add_block_hook) (void (*func_) (hidval data_), hidval data_);
 449     /* Use this to stop a mainloop block hook. */
 450     void (*stop_block_hook) (hidval block_hook_);
 451
 452     /* Various dialogs */
 453
 454     /* Log a message to the log window.  */
 455     void (*log) (const char *fmt_, ...);
 456     void (*logv) (const char *fmt_, va_list args_);
 457
 458     /* A generic yes/no dialog.  Returns zero if the cancel button is
 459        pressed, one for the ok button.  If you specify alternate labels
 460        for ..., they are used instead of the default OK/Cancel ones, and
 461        the return value is the index of the label chosen.  You MUST pass
 462        NULL as the last parameter to this.  */
 463     int (*confirm_dialog) (char *msg_, ...);
 464
 465     /* A close confirmation dialog for unsaved pages, for example, with
 466        options "Close without saving", "Cancel" and "Save". Returns zero
 467        if the close is cancelled, or one if it should proceed. The HID
 468        is responsible for any "Save" action the user may wish before
 469        confirming the close.
 470        */
 471     int (*close_confirm_dialog) ();
 472 #define HID_CLOSE_CONFIRM_CANCEL 0
 473 #define HID_CLOSE_CONFIRM_OK     1
 474
 475     /* Just prints text.  */
 476     void (*report_dialog) (char *title_, char *msg_);
 477
 478     /* Prompts the user to enter a string, returns the string.  If
 479        default_string isn't NULL, the form is pre-filled with this
 480        value.  "msg" is like "Enter value:".  */
 481     char *(*prompt_for) (char *msg_, char *default_string_);
 482
 483     /* Prompts the user for a filename or directory name.  For GUI
 484        HID's this would mean a file select dialog box.  The 'flags'
 485        argument is the bitwise OR of the following values.  */
 486 #define HID_FILESELECT_READ  0x01
 487
 488     /* The function calling hid->fileselect will deal with the case
 489        where the selected file already exists.  If not given, then the
 490        gui will prompt with an "overwrite?" prompt.  Only used when
 491        writing.
 492     */
 493 #define HID_FILESELECT_MAY_NOT_EXIST 0x02
 494
 495     /* The call is supposed to return a file template (for gerber
 496        output for example) instead of an actual file.  Only used when
 497        writing.
 498     */
 499 #define HID_FILESELECT_IS_TEMPLATE 0x04
 500
 501     /* title may be used as a dialog box title.  Ignored if NULL.
 502      *
 503      * descr is a longer help string.  Ignored if NULL.
 504      *
 505      * default_file is the default file name.  Ignored if NULL.
 506      *
 507      * default_ext is the default file extension, like ".pdf".
 508      * Ignored if NULL.
 509      *
 510      * history_tag may be used by the GUI to keep track of file
 511      * history.  Examples would be "board", "vendor", "renumber",
 512      * etc.  If NULL, no specific history is kept.
 513      *
 514      * flags are the bitwise or of the HID_FILESELECT defines above
 515      */
 516
 517     char *(*fileselect) (const char *title_, const char *descr_,
 518                          char *default_file_, char *default_ext_,
 519                          const char *history_tag_, int flags_);
 520
 521     /* A generic dialog to ask for a set of attributes.  If n_attrs is
 522        zero, attrs(.name) must be NULL terminated.  Returns non-zero if
 523        an error occurred (usually, this means the user cancelled the
 524        dialog or something). title is the title of the dialog box
 525        descr (if not NULL) can be a longer description of what the
 526        attributes are used for.  The HID may choose to ignore it or it
 527        may use it for a tooltip or text in a dialog box, or a help
 528        string.
 529     */
 530     int (*attribute_dialog) (HID_Attribute * attrs_,
 531                              int n_attrs_, HID_Attr_Val * results_,
 532                              const char * title_, const char * descr_);
 533
 534     /* This causes a second window to display, which only shows the
 535        selected item. The expose callback is called twice; once to size
 536        the extents of the item, and once to draw it.  To pass magic
 537        values, pass the address of a variable created for this
 538        purpose.  */
 539     void (*show_item) (void *item_);
 540
 541     /* Something to alert the user.  */
 542     void (*beep) (void);
 543
 544     /* Used by optimizers and autorouter to show progress to the user.
 545        Pass all zeros to flush display and remove any dialogs.
 546        Returns nonzero if the user wishes to cancel the operation.  */
 547     int (*progress) (int so_far_, int total_, const char *message_);
 548
 549     HID_DRC_GUI *drc_gui;
 550
 551     void (*edit_attributes) (char *owner, AttributeListType *attrlist_);
 552
 553   } HID;
 554
 555 /* Call this as soon as possible from main().  No other HID calls are
 556    valid until this is called.  */
 557   void hid_init (void);
 558
 559 /* When PCB runs in interactive mode, this is called to instantiate
 560    one GUI HID which happens to be the GUI.  This HID is the one that
 561    interacts with the mouse and keyboard.  */
 562   HID *hid_find_gui ();
 563
 564 /* Finds the one printer HID and instantiates it.  */
 565   HID *hid_find_printer (void);
 566
 567 /* Finds the indicated exporter HID and instantiates it.  */
 568   HID *hid_find_exporter (const char *);
 569
 570 /* This returns a NULL-terminated array of available HIDs.  The only
 571    real reason to use this is to locate all the export-style HIDs. */
 572   HID **hid_enumerate (void);
 573
 574 /* This function (in the common code) will be called whenever the GUI
 575    needs to redraw the screen, print the board, or export a layer.  If
 576    item is not NULL, only draw the given item.  Item is only non-NULL
 577    if the HID was created via show_item.
 578
 579    Each time func is called, it should do the following:
 580
 581    * allocate any colors needed, via get_color.
 582
 583    * cycle through the layers, calling set_layer for each layer to be
 584      drawn, and only drawing elements (all or specified) of desired
 585      layers.
 586
 587    Do *not* assume that the hid that is passed is the GUI hid.  This
 588    callback is also used for printing and exporting. */
 589   struct BoxType;
 590   void hid_expose_callback (HID * hid_, struct BoxType *region_, void *item_);
 591
 592 /* This is initially set to a "no-gui" gui, and later reset by
 593    hid_start_gui.  */
 594   extern HID *gui;
 595
 596 /* This is either NULL or points to the current HID that is being called to
 597         do the exporting. The gui HIDs set and unset this var.*/
 598   extern HID *exporter;
 599
 600 /* The GUI may set this to be approximately the PCB size of a pixel,
 601    to allow for near-misses in selection and changes in drawing items
 602    smaller than a screen pixel.  */
 603   extern int pixel_slop;
 604
 605 #if defined(__cplusplus) && __cplusplus
 606 }
 607 #endif
 608
 609 #endif