git.zerfleddert.de Git - micropolis/blob - src/tk/tkcanvas.h

   1 /*
   2  * tkCanvas.h --
   3  *
   4  *      Declarations shared among all the files that implement
   5  *      canvas widgets.
   6  *
   7  * Copyright 1991-1992 Regents of the University of California.
   8  * Permission to use, copy, modify, and distribute this
   9  * software and its documentation for any purpose and without
  10  * fee is hereby granted, provided that the above copyright
  11  * notice appear in all copies.  The University of California
  12  * makes no representations about the suitability of this
  13  * software for any purpose.  It is provided "as is" without
  14  * express or implied warranty.
  15  *
  16  * $Header: /user6/ouster/wish/RCS/tkCanvas.h,v 1.14 92/08/19 08:34:16 ouster Exp $ SPRITE (Berkeley)
  17  */
  18
  19 #ifndef _TKCANVAS
  20 #define _TKCANVAS
  21
  22 #ifndef _TK
  23 #include "tk.h"
  24 #endif
  25
  26 /*
  27  * For each item in a canvas widget there exists one record with
  28  * the following structure.  Each actual item is represented by
  29  * a record with the following stuff at its beginning, plus additional
  30  * type-specific stuff after that.
  31  */
  32
  33 #define TK_TAG_SPACE 3
  34
  35 typedef struct Tk_Item  {
  36     int id;                             /* Unique identifier for this item
  37                                          * (also serves as first tag for
  38                                          * item). */
  39     struct Tk_Item *nextPtr;            /* Next in display list of all
  40                                          * items in this canvas.  Later items
  41                                          * in list are drawn on top of earlier
  42                                          * ones. */
  43     Tk_Uid staticTagSpace[TK_TAG_SPACE];/* Built-in space for limited # of
  44                                          * tags. */
  45     Tk_Uid *tagPtr;                     /* Pointer to array of tags.  Usually
  46                                          * points to staticTagSpace, but
  47                                          * may point to malloc-ed space if
  48                                          * there are lots of tags. */
  49     int tagSpace;                       /* Total amount of tag space available
  50                                          * at tagPtr. */
  51     int numTags;                        /* Number of tag slots actually used
  52                                          * at *tagPtr. */
  53     struct Tk_ItemType *typePtr;        /* Table of procedures that implement
  54                                          * this type of item. */
  55     int x1, y1, x2, y2;                 /* Bounding box for item, in integer
  56                                          * canvas units. Set by item-specific
  57                                          * code and guaranteed to contain every
  58                                          * pixel drawn in item.  Item area
  59                                          * includes x1 and y1 but not x2
  60                                          * and y2. */
  61
  62     /*
  63      *------------------------------------------------------------------
  64      * Starting here is additional type-specific stuff;  see the
  65      * declarations for individual types to see what is part of
  66      * each type.  The actual space below is determined by the
  67      * "itemInfoSize" of the type's Tk_ItemType record.
  68      *------------------------------------------------------------------
  69      */
  70 } Tk_Item;
  71
  72 /*
  73  * The record below describes a canvas widget.  It is made available
  74  * to the item procedures so they can access certain shared fields such
  75  * as the overall displacement and scale factor for the canvas.
  76  */
  77
  78 typedef struct {
  79     Tk_Window tkwin;            /* Window that embodies the canvas.  NULL
  80                                  * means that the window has been destroyed
  81                                  * but the data structures haven't yet been
  82                                  * cleaned up.*/
  83     Tcl_Interp *interp;         /* Interpreter associated with canvas. */
  84     Tk_Item *firstItemPtr;      /* First in list of all items in canvas,
  85                                  * or NULL if canvas empty. */
  86     Tk_Item *lastItemPtr;       /* Last in list of all items in canvas,
  87                                  * or NULL if canvas empty. */
  88
  89     /*
  90      * Information used when displaying widget:
  91      */
  92
  93     int borderWidth;            /* Width of 3-D border around window. */
  94     Tk_3DBorder bgBorder;       /* Used for canvas background. */
  95     XColor *bgColor;            /* Color used for clearing to background. */
  96     int relief;                 /* Indicates whether window as a whole is
  97                                  * raised, sunken, or flat. */
  98     GC pixmapGC;                /* Used to copy bits from a pixmap to the
  99                                  * screen and also to clear the pixmap. */
 100     int width, height;          /* Dimensions to request for canvas window,
 101                                  * specified in pixels. */
 102     int redrawX1, redrawY1;     /* Upper left corner of area to redraw,
 103                                  * in pixel coordinates.  Border pixels
 104                                  * are included.  Only valid if
 105                                  * REDRAW_PENDING flag is set. */
 106     int redrawX2, redrawY2;     /* Lower right corner of area to redraw,
 107                                  * in pixel coordinates.  Border pixels
 108                                  * will *not* be redrawn. */
 109     int confine;                /* Non-zero means constrain view to keep
 110                                  * as much of canvas visible as possible. */
 111
 112     /*
 113      * Information used to manage and display selection:
 114      */
 115
 116     Tk_3DBorder selBorder;      /* Border and background for selected
 117                                  * characters. */
 118     int selBorderWidth;         /* Width of border around selection. */
 119     XColor *selFgColorPtr;      /* Foreground color for selected text. */
 120     Tk_Item *selItemPtr;        /* Pointer to selected item.  NULL means
 121                                  * selection isn't in this canvas. */
 122     int selectFirst;            /* Index of first selected character. */
 123     int selectLast;             /* Index of last selected character. */
 124     Tk_Item *anchorItemPtr;     /* Item corresponding to "selectAnchor":
 125                                  * not necessarily selItemPtr. */
 126     int selectAnchor;           /* Fixed end of selection (i.e. "select to"
 127                                  * operation will use this as one end of the
 128                                  * selection). */
 129
 130     /*
 131      * Information for display insertion cursor in text:
 132      */
 133
 134     Tk_3DBorder cursorBorder;   /* Used to draw vertical bar for insertion
 135                                  * cursor. */
 136     int cursorWidth;            /* Total width of insertion cursor. */
 137     int cursorBorderWidth;      /* Width of 3-D border around insert cursor. */
 138     int cursorOnTime;           /* Number of milliseconds cursor should spend
 139                                  * in "on" state for each blink. */
 140     int cursorOffTime;          /* Number of milliseconds cursor should spend
 141                                  * in "off" state for each blink. */
 142     Tk_TimerToken cursorBlinkHandler;
 143                                 /* Timer handler used to blink cursor on and
 144                                  * off. */
 145     Tk_Item *focusItemPtr;      /* Item that currently has the input focus,
 146                                  * or NULL if no such item. */
 147
 148     /*
 149      * Transformation applied to canvas as a whole:  to compute screen
 150      * coordinates (X,Y) from canvas coordinates (x,y), do the following:
 151      *
 152      * X = x - xOrigin;
 153      * Y = y - yOrigin;
 154      */
 155
 156     int xOrigin, yOrigin;       /* Canvas coordinates corresponding to
 157                                  * upper-left corner of window, given in
 158                                  * canvas pixel units. */
 159     int drawableXOrigin, drawableYOrigin;
 160                                 /* During redisplay, these fields give the
 161                                  * canvas coordinates corresponding to
 162                                  * the upper-left corner of the drawable
 163                                  * where items are actually being drawn
 164                                  * (typically a pixmap smaller than the
 165                                  * whole window). */
 166
 167     /*
 168      * Information used for event bindings associated with items.
 169      */
 170
 171     Tk_BindingTable bindingTable;
 172                                 /* Table of all bindings currently defined
 173                                  * for this canvas.  NULL means that no
 174                                  * bindings exist, so the table hasn't been
 175                                  * created.  Each "object" used for this
 176                                  * table is either a Tk_Uid for a tag or
 177                                  * the address of an item named by id. */
 178     Tk_Item *currentItemPtr;    /* The item currently containing the mouse
 179                                  * pointer, or NULL if none. */
 180     double closeEnough;         /* The mouse is assumed to be inside an
 181                                  * item if it is this close to it. */
 182     XEvent pickEvent;           /* The event upon which the current choice
 183                                  * of currentItem is based.  Must be saved
 184                                  * so that if the currentItem is deleted,
 185                                  * can pick another. */
 186
 187     /*
 188      * Information used for managing scrollbars:
 189      */
 190
 191     char *xScrollCmd;           /* Command prefix for communicating with
 192                                  * horizontal scrollbar.  NULL means no
 193                                  * horizontal scrollbar.  Malloc'ed*/
 194     char *yScrollCmd;           /* Command prefix for communicating with
 195                                  * vertical scrollbar.  NULL means no
 196                                  * vertical scrollbar.  Malloc'ed*/
 197     int scrollX1, scrollY1, scrollX2, scrollY2;
 198                                 /* These four coordinates define the region
 199                                  * that is the 100% area for scrolling (i.e.
 200                                  * these numbers determine the size and
 201                                  * location of the sliders on scrollbars).
 202                                  * Units are pixels in canvas coords. */
 203     char *regionString;         /* The option string from which scrollX1
 204                                  * etc. are derived.  Malloc'ed. */
 205     int scrollIncrement;        /* The number of canvas units that the
 206                                  * picture shifts when a scrollbar up or
 207                                  * down arrow is pressed. */
 208
 209     /*
 210      * Information used for scanning:
 211      */
 212
 213     int scanX;                  /* X-position at which scan started (e.g.
 214                                  * button was pressed here). */
 215     int scanXOrigin;            /* Value of xOrigin field when scan started. */
 216     int scanY;                  /* Y-position at which scan started (e.g.
 217                                  * button was pressed here). */
 218     int scanYOrigin;            /* Value of yOrigin field when scan started. */
 219
 220     /*
 221      * Information used to speed up searches by remembering the last item
 222      * created or found with an item id search.
 223      */
 224
 225     Tk_Item *hotPtr;            /* Pointer to "hot" item (one that's been
 226                                  * recently used.  NULL means there's no
 227                                  * hot item. */
 228     Tk_Item *hotPrevPtr;        /* Pointer to predecessor to hotPtr (NULL
 229                                  * means item is first in list).  This is
 230                                  * only a hint and may not really be hotPtr's
 231                                  * predecessor. */
 232
 233     /*
 234      * Miscellaneous information:
 235      */
 236
 237     Cursor cursor;              /* Current cursor for window, or None. */
 238     double pixelsPerMM;         /* Scale factor between MM and pixels;
 239                                  * used when converting coordinates. */
 240     int flags;                  /* Various flags;  see below for
 241                                  * definitions. */
 242     int nextId;                 /* Number to use as id for next item
 243                                  * created in widget. */
 244     Tk_TimerToken updateTimerToken; /* Added by Don to optimize rapid
 245                                      * updates. */
 246 } Tk_Canvas;
 247
 248 /*
 249  * Flag bits for canvases:
 250  *
 251  * REDRAW_PENDING -             1 means a DoWhenIdle handler has already
 252  *                              been created to redraw some or all of the
 253  *                              canvas.
 254  * REPICK_NEEDED -              1 means DisplayCanvas should pick a new
 255  *                              current item before redrawing the canvas.
 256  * GOT_FOCUS -                  1 means the focus is currently in this
 257  *                              widget, so should draw the insertion cursor.
 258  * CURSOR_ON -                  1 means the insertion cursor is in the "on"
 259  *                              phase of its blink cycle.  0 means either
 260  *                              we don't have the focus or the cursor is in
 261  *                              the "off" phase of its cycle.
 262  * BUTTON_DOWN -                1 means that a button is currently down;
 263  *                              this is used to implement grabs for the
 264  *                              duration of button presses.
 265  * UPDATE_SCROLLBARS -          1 means the scrollbars should get updated
 266  *                              as part of the next display operation.
 267  */
 268
 269 #define REDRAW_PENDING          1
 270 #define REPICK_NEEDED           2
 271 #define GOT_FOCUS               4
 272 #define CURSOR_ON               8
 273 #define BUTTON_DOWN             0x10
 274 #define UPDATE_SCROLLBARS       0x20
 275
 276 /*
 277  * Records of the following type are used to describe a type of
 278  * item (e.g.  lines, circles, etc.) that can form part of a
 279  * canvas widget.
 280  */
 281
 282 typedef int     Tk_ItemCreateProc _ANSI_ARGS_((Tk_Canvas *canvasPtr,
 283                     Tk_Item *itemPtr, int argc, char **argv));
 284 typedef int     Tk_ItemConfigureProc _ANSI_ARGS_((Tk_Canvas *canvasPtr,
 285                     Tk_Item *itemPtr, int argc, char **argv, int flags));
 286 typedef int     Tk_ItemCoordProc _ANSI_ARGS_((Tk_Canvas *canvasPtr,
 287                     Tk_Item *itemPtr, int argc, char **argv));
 288 typedef void    Tk_ItemDeleteProc _ANSI_ARGS_((Tk_Item *itemPtr));
 289 typedef void    Tk_ItemDisplayProc _ANSI_ARGS_((Tk_Canvas *canvasPtr,
 290                     Tk_Item *itemPtr, Drawable dst));
 291 typedef double  Tk_ItemPointProc _ANSI_ARGS_((Tk_Canvas *canvasPtr,
 292                     Tk_Item *itemPtr, double *pointPtr));
 293 typedef int     Tk_ItemAreaProc _ANSI_ARGS_((Tk_Canvas *canvasPtr,
 294                     Tk_Item *itemPtr, double *rectPtr));
 295 typedef void    Tk_ItemPostscriptProc _ANSI_ARGS_((Tk_Canvas *canvasPtr,
 296                     Tk_Item *itemPtr));
 297 typedef void    Tk_ItemScaleProc _ANSI_ARGS_((Tk_Canvas *canvasPtr,
 298                     Tk_Item *itemPtr, double originX, double originY,
 299                     double scaleX, double scaleY));
 300 typedef void    Tk_ItemTranslateProc _ANSI_ARGS_((Tk_Canvas *canvasPtr,
 301                     Tk_Item *itemPtr, double deltaX, double deltaY));
 302 typedef int     Tk_ItemIndexProc _ANSI_ARGS_((Tk_Canvas *canvasPtr,
 303                     Tk_Item *itemPtr, char *indexString,
 304                     int *indexPtr));
 305 typedef void    Tk_ItemCursorProc _ANSI_ARGS_((Tk_Canvas *canvasPtr,
 306                     Tk_Item *itemPtr, int index));
 307 typedef int     Tk_ItemSelectionProc _ANSI_ARGS_((Tk_Canvas *canvasPtr,
 308                     Tk_Item *itemPtr, int offset, char *buffer,
 309                     int maxBytes));
 310 typedef int     Tk_ItemInsertProc _ANSI_ARGS_((Tk_Canvas *canvasPtr,
 311                     Tk_Item *itemPtr, int beforeThis, char *string));
 312 typedef int     Tk_ItemDCharsProc _ANSI_ARGS_((Tk_Canvas *canvasPtr,
 313                     Tk_Item *itemPtr, int first, int last));
 314
 315 typedef struct Tk_ItemType {
 316     char *name;                         /* The name of this type of item, such
 317                                          * as "line". */
 318     int itemSize;                       /* Total amount of space needed for
 319                                          * item's record. */
 320     Tk_ItemCreateProc *createProc;      /* Procedure to create a new item of
 321                                          * this type. */
 322     Tk_ConfigSpec *configSpecs;         /* Pointer to array of configuration
 323                                          * specs for this type.  Used for
 324                                          * returning configuration info. */
 325     Tk_ItemConfigureProc *configProc;   /* Procedure to call to change
 326                                          * configuration options. */
 327     Tk_ItemCoordProc *coordProc;        /* Procedure to call to get and set
 328                                          * the item's coordinates. */
 329     Tk_ItemDeleteProc *deleteProc;      /* Procedure to delete existing item of
 330                                          * this type. */
 331     Tk_ItemDisplayProc *displayProc;    /* Procedure to display items of
 332                                          * this type. */
 333     int alwaysRedraw;                   /* Non-zero means displayProc should
 334                                          * be called even when the item has
 335                                          * been moved off-screen. */
 336     Tk_ItemPointProc *pointProc;        /* Computes distance from item to
 337                                          * a given point. */
 338     Tk_ItemAreaProc *areaProc;          /* Computes whether item is inside,
 339                                          * outside, or overlapping an area. */
 340     Tk_ItemPostscriptProc *postscriptProc;
 341                                         /* Procedure to write a Postscript
 342                                          * description for items of this
 343                                          * type. */
 344     Tk_ItemScaleProc *scaleProc;        /* Procedure to rescale items of
 345                                          * this type. */
 346     Tk_ItemTranslateProc *translateProc;/* Procedure to translate items of
 347                                          * this type. */
 348     Tk_ItemIndexProc *indexProc;        /* Procedure to determine index of
 349                                          * indicated character.  NULL if
 350                                          * item doesn't support indexing. */
 351     Tk_ItemCursorProc *cursorProc;      /* Procedure to set cursor position
 352                                          * to just before a given position. */
 353     Tk_ItemSelectionProc *selectionProc;/* Procedure to return selection (in
 354                                          * STRING format) when it is in this
 355                                          * item. */
 356     Tk_ItemInsertProc *insertProc;      /* Procedure to insert something into
 357                                          * an item. */
 358     Tk_ItemDCharsProc *dCharsProc;      /* Procedure to delete characters
 359                                          * from an item. */
 360     struct Tk_ItemType *nextPtr;        /* Used to link types together into
 361                                          * a list. */
 362 } Tk_ItemType;
 363
 364 /*
 365  * Macros to transform a point from double-precision canvas coordinates
 366  * to integer pixel coordinates in the pixmap where redisplay is being
 367  * done.
 368  */
 369
 370 #define SCREEN_X(canvasPtr, x) \
 371         (((int) ((x) + 0.5)) - (canvasPtr)->drawableXOrigin)
 372 #define SCREEN_Y(canvasPtr, y) \
 373         (((int) ((y) + 0.5)) - (canvasPtr)->drawableYOrigin)
 374
 375 /*
 376  * Canvas-related variables that are shared among Tk modules but not
 377  * exported to the outside world:
 378  */
 379
 380 extern Tk_CustomOption tkCanvasTagsOption;
 381
 382 /*
 383  * Canvas-related procedures that are shared among Tk modules but not
 384  * exported to the outside world:
 385  */
 386
 387 extern void             TkBezierScreenPoints _ANSI_ARGS_((Tk_Canvas *canvasPtr,
 388                             double control[], int numSteps,
 389                             XPoint *xPointPtr));
 390 extern void             TkFillPolygon _ANSI_ARGS_((Tk_Canvas *canvasPtr,
 391                             double *coordPtr, int numPoints, Drawable drawable,
 392                             GC gc));
 393 extern int              TkGetCanvasCoord _ANSI_ARGS_((Tk_Canvas *canvasPtr,
 394                             char *string, double *doublePtr));
 395 extern void             TkIncludePoint _ANSI_ARGS_((Tk_Canvas *canvasPtr,
 396                             Tk_Item *itemPtr, double *pointPtr));
 397 extern int              TkMakeBezierCurve _ANSI_ARGS_((Tk_Canvas *canvasPtr,
 398                             double *pointPtr, int numPoints, int numSteps,
 399                             XPoint xPoints[], double dblPoints[]));
 400
 401 #endif /* _TKCANVAS */