git.zerfleddert.de Git - micropolis/blob - src/tk/library/demos/tkSquare.c

   1 /*
   2  * tkSquare.c --
   3  *
   4  *      This module implements "square" widgets.  A "square" is
   5  *      a widget that displays a single square that can be moved
   6  *      around and resized.  This file is intended as an example
   7  *      of how to build a widget.
   8  *
   9  * Copyright 1991-1992 Regents of the University of California.
  10  * Permission to use, copy, modify, and distribute this
  11  * software and its documentation for any purpose and without
  12  * fee is hereby granted, provided that the above copyright
  13  * notice appear in all copies.  The University of California
  14  * makes no representations about the suitability of this
  15  * software for any purpose.  It is provided "as is" without
  16  * express or implied warranty.
  17  */
  18
  19 #ifndef lint
  20 static char rcsid[] = "$Header: /user6/ouster/wish/scripts/demos/RCS/tkSquare.c,v 1.2 92/04/29 11:45:17 ouster Exp $ SPRITE (Berkeley)";
  21 #endif
  22
  23 #include "tkConfig.h"
  24 #include "tk.h"
  25
  26 /*
  27  * A data structure of the following type is kept for each square
  28  * widget managed by this file:
  29  */
  30
  31 typedef struct {
  32     Tk_Window tkwin;            /* Window that embodies the square.  NULL
  33                                  * means that the window has been destroyed
  34                                  * but the data structures haven't yet been
  35                                  * cleaned up.*/
  36     Tcl_Interp *interp;         /* Interpreter associated with widget. */
  37     int x, y;                   /* Position of square's upper-left corner
  38                                  * within widget. */
  39     int size;                   /* Width and height of square. */
  40     int flags;                  /* Various flags;  see below for
  41                                  * definitions. */
  42
  43     /*
  44      * Information used when displaying widget:
  45      */
  46
  47     int borderWidth;            /* Width of 3-D border around whole widget. */
  48     Tk_3DBorder bgBorder;       /* Used for drawing background. */
  49     Tk_3DBorder fgBorder;       /* For drawing square. */
  50     int relief;                 /* Indicates whether window as a whole is
  51                                  * raised, sunken, or flat. */
  52     int doubleBuffer;           /* Non-zero means double-buffer redisplay
  53                                  * with pixmap;  zero means draw straight
  54                                  * onto the display. */
  55 } Square;
  56
  57 /*
  58  * Flag bits for squares:
  59  *
  60  * REDRAW_PENDING -             1 means redraw has already been scheduled.
  61  */
  62
  63 #define REDRAW_PENDING          1
  64
  65 /*
  66  * Information used for argv parsing.
  67  */
  68
  69 static Tk_ConfigSpec configSpecs[] = {
  70     {TK_CONFIG_BORDER, "-background", "background", "Background",
  71         "#cdb79e", Tk_Offset(Square, bgBorder), TK_CONFIG_COLOR_ONLY},
  72     {TK_CONFIG_BORDER, "-background", "background", "Background",
  73         "white", Tk_Offset(Square, bgBorder), TK_CONFIG_MONO_ONLY},
  74     {TK_CONFIG_SYNONYM, "-bd", "borderWidth", (char *) NULL,
  75         (char *) NULL, 0, 0},
  76     {TK_CONFIG_SYNONYM, "-bg", "background", (char *) NULL,
  77         (char *) NULL, 0, 0},
  78     {TK_CONFIG_INT, "-borderwidth", "borderWidth", "BorderWidth",
  79         "2", Tk_Offset(Square, borderWidth), 0},
  80     {TK_CONFIG_INT, "-dbl", "doubleBuffer", "DoubleBuffer",
  81         "1", Tk_Offset(Square, doubleBuffer), 0},
  82     {TK_CONFIG_SYNONYM, "-fg", "foreground", (char *) NULL,
  83         (char *) NULL, 0, 0},
  84     {TK_CONFIG_BORDER, "-foreground", "foreground", "Foreground",
  85         "#b03060", Tk_Offset(Square, fgBorder), TK_CONFIG_COLOR_ONLY},
  86     {TK_CONFIG_BORDER, "-foreground", "foreground", "Foreground",
  87         "black", Tk_Offset(Square, fgBorder), TK_CONFIG_MONO_ONLY},
  88     {TK_CONFIG_RELIEF, "-relief", "relief", "Relief",
  89         "raised", Tk_Offset(Square, relief), 0},
  90     {TK_CONFIG_END, (char *) NULL, (char *) NULL, (char *) NULL,
  91         (char *) NULL, 0, 0}
  92 };
  93
  94 /*
  95  * Forward declarations for procedures defined later in this file:
  96  */
  97
  98 static int              ConfigureSquare _ANSI_ARGS_((Tcl_Interp *interp,
  99                             Square *squarePtr, int argc, char **argv,
 100                             int flags));
 101 static void             DestroySquare _ANSI_ARGS_((ClientData clientData));
 102 static void             DisplaySquare _ANSI_ARGS_((ClientData clientData));
 103 static void             KeepInWindow _ANSI_ARGS_((Square *squarePtr));
 104 static void             SquareEventProc _ANSI_ARGS_((ClientData clientData,
 105                             XEvent *eventPtr));
 106 static int              SquareWidgetCmd _ANSI_ARGS_((ClientData clientData,
 107                             Tcl_Interp *, int argc, char **argv));
 108 \f
 109 /*
 110  *--------------------------------------------------------------
 111  *
 112  * Tk_SquareCmd --
 113  *
 114  *      This procedure is invoked to process the "square" Tcl
 115  *      command.  It creates a new "square" widget.
 116  *
 117  * Results:
 118  *      A standard Tcl result.
 119  *
 120  * Side effects:
 121  *      A new widget is created and configured.
 122  *
 123  *--------------------------------------------------------------
 124  */
 125
 126 int
 127 Tk_SquareCmd(clientData, interp, argc, argv)
 128     ClientData clientData;      /* Main window associated with
 129                                  * interpreter. */
 130     Tcl_Interp *interp;         /* Current interpreter. */
 131     int argc;                   /* Number of arguments. */
 132     char **argv;                /* Argument strings. */
 133 {
 134     Tk_Window main = (Tk_Window) clientData;
 135     register Square *squarePtr;
 136     Tk_Window tkwin;
 137
 138     if (argc < 2) {
 139         Tcl_AppendResult(interp, "wrong # args:  should be \"",
 140                 argv[0], " pathName ?options?\"", (char *) NULL);
 141         return TCL_ERROR;
 142     }
 143
 144     tkwin = Tk_CreateWindowFromPath(interp, main, argv[1], (char *) NULL);
 145     if (tkwin == NULL) {
 146         return TCL_ERROR;
 147     }
 148
 149     /*
 150      * Initialize fields that won't be initialized by ConfigureSquare,
 151      * or which ConfigureSquare expects to have reasonable values
 152      * (e.g. resource pointers).
 153      */
 154
 155     squarePtr = (Square *) ckalloc(sizeof(Square));
 156     squarePtr->tkwin = tkwin;
 157     squarePtr->interp = interp;
 158     squarePtr->x = 0;
 159     squarePtr->y = 0;
 160     squarePtr->size = 20;
 161     squarePtr->bgBorder = NULL;
 162     squarePtr->fgBorder = NULL;
 163     squarePtr->flags = 0;
 164
 165     Tk_SetClass(squarePtr->tkwin, "Square");
 166     Tk_CreateEventHandler(squarePtr->tkwin, ExposureMask|StructureNotifyMask,
 167             SquareEventProc, (ClientData) squarePtr);
 168     Tcl_CreateCommand(interp, Tk_PathName(squarePtr->tkwin), SquareWidgetCmd,
 169             (ClientData) squarePtr, (void (*)()) NULL);
 170     if (ConfigureSquare(interp, squarePtr, argc-2, argv+2, 0) != TCL_OK) {
 171         Tk_DestroyWindow(squarePtr->tkwin);
 172         return TCL_ERROR;
 173     }
 174
 175     interp->result = Tk_PathName(squarePtr->tkwin);
 176     return TCL_OK;
 177 }
 178 \f
 179 /*
 180  *----------------------------------------------------------------------
 181  *
 182  * ConfigureSquare --
 183  *
 184  *      This procedure is called to process an argv/argc list in
 185  *      conjunction with the Tk option database to configure (or
 186  *      reconfigure) a square widget.
 187  *
 188  * Results:
 189  *      The return value is a standard Tcl result.  If TCL_ERROR is
 190  *      returned, then interp->result contains an error message.
 191  *
 192  * Side effects:
 193  *      Configuration information, such as colors, border width,
 194  *      etc. get set for squarePtr;  old resources get freed,
 195  *      if there were any.
 196  *
 197  *----------------------------------------------------------------------
 198  */
 199
 200 static int
 201 ConfigureSquare(interp, squarePtr, argc, argv, flags)
 202     Tcl_Interp *interp;                 /* Used for error reporting. */
 203     register Square *squarePtr;         /* Information about widget. */
 204     int argc;                           /* Number of valid entries in argv. */
 205     char **argv;                        /* Arguments. */
 206     int flags;                          /* Flags to pass to
 207                                          * Tk_ConfigureWidget. */
 208 {
 209     if (Tk_ConfigureWidget(interp, squarePtr->tkwin, configSpecs,
 210             argc, argv, (char *) squarePtr, flags) != TCL_OK) {
 211         return TCL_ERROR;
 212     }
 213
 214     /*
 215      * A few options need special processing, such as setting the
 216      * background from a 3-D border.
 217      */
 218
 219     Tk_SetBackgroundFromBorder(squarePtr->tkwin, squarePtr->bgBorder);
 220
 221     /*
 222      * Register the desired geometry for the window.  Then arrange for
 223      * the window to be redisplayed.
 224      */
 225
 226     Tk_GeometryRequest(squarePtr->tkwin, 200, 150);
 227     Tk_SetInternalBorder(squarePtr->tkwin, squarePtr->borderWidth);
 228     if (!(squarePtr->flags & REDRAW_PENDING)) {
 229         Tk_DoWhenIdle(DisplaySquare, (ClientData) squarePtr);
 230         squarePtr->flags |= REDRAW_PENDING;
 231     }
 232     return TCL_OK;
 233 }
 234 \f
 235 /*
 236  *--------------------------------------------------------------
 237  *
 238  * DisplaySquare --
 239  *
 240  *      This procedure redraws the contents of a square window.
 241  *      It is invoked as a do-when-idle handler, so it only runs
 242  *      when there's nothing else for the application to do.
 243  *
 244  * Results:
 245  *      None.
 246  *
 247  * Side effects:
 248  *      Information appears on the screen.
 249  *
 250  *--------------------------------------------------------------
 251  */
 252
 253 static void
 254 DisplaySquare(clientData)
 255     ClientData clientData;      /* Information about window. */
 256 {
 257     register Square *squarePtr = (Square *) clientData;
 258     register Tk_Window tkwin = squarePtr->tkwin;
 259     Pixmap pm = None;
 260     Drawable d;
 261
 262     squarePtr->flags &= ~REDRAW_PENDING;
 263     if ((tkwin == NULL) || !Tk_IsMapped(tkwin)) {
 264         return;
 265     }
 266
 267     /*
 268      * Create a pixmap for double-buffering, if necessary.
 269      */
 270
 271     if (squarePtr->doubleBuffer) {
 272         pm = XCreatePixmap(Tk_Display(tkwin), Tk_WindowId(tkwin),
 273                 Tk_Width(tkwin), Tk_Height(tkwin),
 274                 DefaultDepthOfScreen(Tk_Screen(tkwin)));
 275         d = pm;
 276     } else {
 277         d = Tk_WindowId(tkwin);
 278     }
 279
 280     /*
 281      * Redraw the widget's background and border.
 282      */
 283
 284     Tk_Fill3DRectangle(Tk_Display(tkwin), d, squarePtr->bgBorder,
 285             0, 0, Tk_Width(tkwin), Tk_Height(tkwin),
 286             squarePtr->borderWidth, squarePtr->relief);
 287
 288     /*
 289      * Display the square.
 290      */
 291
 292     Tk_Fill3DRectangle(Tk_Display(tkwin), d, squarePtr->fgBorder,
 293             squarePtr->x, squarePtr->y, squarePtr->size, squarePtr->size,
 294             squarePtr->borderWidth, TK_RELIEF_RAISED);
 295
 296     /*
 297      * If double-buffered, copy to the screen and release the pixmap.
 298      */
 299
 300     if (squarePtr->doubleBuffer) {
 301         XCopyArea(Tk_Display(tkwin), pm, Tk_WindowId(tkwin),
 302                 DefaultGCOfScreen(Tk_Screen(tkwin)), 0, 0,
 303                 Tk_Width(tkwin), Tk_Height(tkwin), 0, 0);
 304         XFreePixmap(Tk_Display(tkwin), pm);
 305     }
 306 }
 307 \f
 308 /*
 309  *--------------------------------------------------------------
 310  *
 311  * SquareWidgetCmd --
 312  *
 313  *      This procedure is invoked to process the Tcl command
 314  *      that corresponds to a widget managed by this module.
 315  *      See the user documentation for details on what it does.
 316  *
 317  * Results:
 318  *      A standard Tcl result.
 319  *
 320  * Side effects:
 321  *      See the user documentation.
 322  *
 323  *--------------------------------------------------------------
 324  */
 325
 326 static int
 327 SquareWidgetCmd(clientData, interp, argc, argv)
 328     ClientData clientData;              /* Information about square widget. */
 329     Tcl_Interp *interp;                 /* Current interpreter. */
 330     int argc;                           /* Number of arguments. */
 331     char **argv;                        /* Argument strings. */
 332 {
 333     register Square *squarePtr = (Square *) clientData;
 334     int result = TCL_OK;
 335     int length;
 336     char c;
 337
 338     if (argc < 2) {
 339         Tcl_AppendResult(interp, "wrong # args: should be \"",
 340                 argv[0], " option ?arg arg ...?\"", (char *) NULL);
 341         return TCL_ERROR;
 342     }
 343     Tk_Preserve((ClientData) squarePtr);
 344     c = argv[1][0];
 345     length = strlen(argv[1]);
 346     if ((c == 'c') && (strncmp(argv[1], "configure", length) == 0)) {
 347         if (argc == 2) {
 348             result = Tk_ConfigureInfo(interp, squarePtr->tkwin, configSpecs,
 349                     (char *) squarePtr, (char *) NULL, 0);
 350         } else if (argc == 3) {
 351             result = Tk_ConfigureInfo(interp, squarePtr->tkwin, configSpecs,
 352                     (char *) squarePtr, argv[2], 0);
 353         } else {
 354             result = ConfigureSquare(interp, squarePtr, argc-2, argv+2,
 355                     TK_CONFIG_ARGV_ONLY);
 356         }
 357     } else if ((c == 'p') && (strncmp(argv[1], "position", length) == 0)) {
 358         if ((argc != 2) && (argc != 4)) {
 359             Tcl_AppendResult(interp, "wrong # args: should be \"",
 360                     argv[0], " position ?x y?\"", (char *) NULL);
 361             goto error;
 362         }
 363         if (argc == 4) {
 364             if ((Tcl_GetInt(interp, argv[2], &squarePtr->x) != TCL_OK)
 365                     || (Tcl_GetInt(interp, argv[3], &squarePtr->y) != TCL_OK)) {
 366                 goto error;
 367             }
 368             KeepInWindow(squarePtr);
 369         }
 370         sprintf(interp->result, "%d %d", squarePtr->x, squarePtr->y);
 371     } else if ((c == 's') && (strncmp(argv[1], "size", length) == 0)) {
 372         if ((argc != 2) && (argc != 3)) {
 373             Tcl_AppendResult(interp, "wrong # args: should be \"",
 374                     argv[0], " size ?amount?\"", (char *) NULL);
 375             goto error;
 376         }
 377         if (argc == 3) {
 378             int i;
 379
 380             if (Tcl_GetInt(interp, argv[2], &i) != TCL_OK) {
 381                 goto error;
 382             }
 383             if ((i <= 0) || (i > 100)) {
 384                 Tcl_AppendResult(interp, "bad size \"", argv[2],
 385                         "\"", (char *) NULL);
 386                 goto error;
 387             }
 388             squarePtr->size = i;
 389             KeepInWindow(squarePtr);
 390         }
 391         sprintf(interp->result, "%d", squarePtr->size);
 392     } else {
 393         Tcl_AppendResult(interp, "bad option \"", argv[1],
 394                 "\":  must be configure, position, or size", (char *) NULL);
 395         goto error;
 396     }
 397     if (!(squarePtr->flags & REDRAW_PENDING)) {
 398         Tk_DoWhenIdle(DisplaySquare, (ClientData) squarePtr);
 399         squarePtr->flags |= REDRAW_PENDING;
 400     }
 401     Tk_Release((ClientData) squarePtr);
 402     return result;
 403
 404     error:
 405     Tk_Release((ClientData) squarePtr);
 406     return TCL_ERROR;
 407 }
 408 \f
 409 /*
 410  *--------------------------------------------------------------
 411  *
 412  * SquareEventProc --
 413  *
 414  *      This procedure is invoked by the Tk dispatcher for various
 415  *      events on squares.
 416  *
 417  * Results:
 418  *      None.
 419  *
 420  * Side effects:
 421  *      When the window gets deleted, internal structures get
 422  *      cleaned up.  When it gets exposed, it is redisplayed.
 423  *
 424  *--------------------------------------------------------------
 425  */
 426
 427 static void
 428 SquareEventProc(clientData, eventPtr)
 429     ClientData clientData;      /* Information about window. */
 430     XEvent *eventPtr;           /* Information about event. */
 431 {
 432     Square *squarePtr = (Square *) clientData;
 433
 434     if ((eventPtr->type == Expose) && (eventPtr->xexpose.count == 0)) {
 435         if (!(squarePtr->flags & REDRAW_PENDING)) {
 436             Tk_DoWhenIdle(DisplaySquare, (ClientData) squarePtr);
 437             squarePtr->flags |= REDRAW_PENDING;
 438         }
 439     } else if (eventPtr->type == ConfigureNotify) {
 440         KeepInWindow(squarePtr);
 441         if (!(squarePtr->flags & REDRAW_PENDING)) {
 442             Tk_DoWhenIdle(DisplaySquare, (ClientData) squarePtr);
 443             squarePtr->flags |= REDRAW_PENDING;
 444         }
 445     } else if (eventPtr->type == DestroyNotify) {
 446         Tcl_DeleteCommand(squarePtr->interp, Tk_PathName(squarePtr->tkwin));
 447         squarePtr->tkwin = NULL;
 448         if (squarePtr->flags & REDRAW_PENDING) {
 449             Tk_CancelIdleCall(DisplaySquare, (ClientData) squarePtr);
 450         }
 451         Tk_EventuallyFree((ClientData) squarePtr, DestroySquare);
 452     }
 453 }
 454 \f
 455 /*
 456  *----------------------------------------------------------------------
 457  *
 458  * DestroySquare --
 459  *
 460  *      This procedure is invoked by Tk_EventuallyFree or Tk_Release
 461  *      to clean up the internal structure of a square at a safe time
 462  *      (when no-one is using it anymore).
 463  *
 464  * Results:
 465  *      None.
 466  *
 467  * Side effects:
 468  *      Everything associated with the square is freed up.
 469  *
 470  *----------------------------------------------------------------------
 471  */
 472
 473 static void
 474 DestroySquare(clientData)
 475     ClientData clientData;      /* Info about square widget. */
 476 {
 477     register Square *squarePtr = (Square *) clientData;
 478
 479     if (squarePtr->bgBorder != NULL) {
 480         Tk_Free3DBorder(squarePtr->bgBorder);
 481     }
 482     if (squarePtr->fgBorder != NULL) {
 483         Tk_Free3DBorder(squarePtr->fgBorder);
 484     }
 485     ckfree((char *) squarePtr);
 486 }
 487 \f
 488 /*
 489  *----------------------------------------------------------------------
 490  *
 491  * KeepInWindow --
 492  *
 493  *      Adjust the position of the square if necessary to keep it in
 494  *      the widget's window.
 495  *
 496  * Results:
 497  *      None.
 498  *
 499  * Side effects:
 500  *      The x and y position of the square are adjusted if necessary
 501  *      to keep the square in the window.
 502  *
 503  *----------------------------------------------------------------------
 504  */
 505
 506 static void
 507 KeepInWindow(squarePtr)
 508     register Square *squarePtr;         /* Pointer to widget record. */
 509 {
 510     int i, bd;
 511
 512     if (squarePtr->relief == TK_RELIEF_FLAT) {
 513         bd = 0;
 514     } else {
 515         bd = squarePtr->borderWidth;
 516     }
 517     i = (Tk_Width(squarePtr->tkwin) - bd) - (squarePtr->x + squarePtr->size);
 518     if (i < 0) {
 519         squarePtr->x += i;
 520     }
 521     i = (Tk_Height(squarePtr->tkwin) - bd) - (squarePtr->y + squarePtr->size);
 522     if (i < 0) {
 523         squarePtr->y += i;
 524     }
 525     if (squarePtr->x < bd) {
 526         squarePtr->x = bd;
 527     }
 528     if (squarePtr->y < bd) {
 529         squarePtr->y = bd;
 530     }
 531 }