| 1 | '\" |
| 2 | '\" Copyright (c) 1992-1994 The Regents of the University of California. |
| 3 | '\" Copyright (c) 1994-1996 Sun Microsystems, Inc. |
| 4 | '\" Copyright (c) 1997-1999 Scriptics Corporation. |
| 5 | '\" |
| 6 | '\" See the file "license.terms" for information on usage and redistribution |
| 7 | '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. |
| 8 | '\" |
| 9 | '\" RCS: @(#) $Id: canvas.n,v 1.13.2.2 2005/05/12 22:50:59 dgp Exp $ |
| 10 | '\" |
| 11 | '\" The definitions below are for supplemental macros used in Tcl/Tk |
| 12 | '\" manual entries. |
| 13 | '\" |
| 14 | '\" .AP type name in/out ?indent? |
| 15 | '\" Start paragraph describing an argument to a library procedure. |
| 16 | '\" type is type of argument (int, etc.), in/out is either "in", "out", |
| 17 | '\" or "in/out" to describe whether procedure reads or modifies arg, |
| 18 | '\" and indent is equivalent to second arg of .IP (shouldn't ever be |
| 19 | '\" needed; use .AS below instead) |
| 20 | '\" |
| 21 | '\" .AS ?type? ?name? |
| 22 | '\" Give maximum sizes of arguments for setting tab stops. Type and |
| 23 | '\" name are examples of largest possible arguments that will be passed |
| 24 | '\" to .AP later. If args are omitted, default tab stops are used. |
| 25 | '\" |
| 26 | '\" .BS |
| 27 | '\" Start box enclosure. From here until next .BE, everything will be |
| 28 | '\" enclosed in one large box. |
| 29 | '\" |
| 30 | '\" .BE |
| 31 | '\" End of box enclosure. |
| 32 | '\" |
| 33 | '\" .CS |
| 34 | '\" Begin code excerpt. |
| 35 | '\" |
| 36 | '\" .CE |
| 37 | '\" End code excerpt. |
| 38 | '\" |
| 39 | '\" .VS ?version? ?br? |
| 40 | '\" Begin vertical sidebar, for use in marking newly-changed parts |
| 41 | '\" of man pages. The first argument is ignored and used for recording |
| 42 | '\" the version when the .VS was added, so that the sidebars can be |
| 43 | '\" found and removed when they reach a certain age. If another argument |
| 44 | '\" is present, then a line break is forced before starting the sidebar. |
| 45 | '\" |
| 46 | '\" .VE |
| 47 | '\" End of vertical sidebar. |
| 48 | '\" |
| 49 | '\" .DS |
| 50 | '\" Begin an indented unfilled display. |
| 51 | '\" |
| 52 | '\" .DE |
| 53 | '\" End of indented unfilled display. |
| 54 | '\" |
| 55 | '\" .SO |
| 56 | '\" Start of list of standard options for a Tk widget. The |
| 57 | '\" options follow on successive lines, in four columns separated |
| 58 | '\" by tabs. |
| 59 | '\" |
| 60 | '\" .SE |
| 61 | '\" End of list of standard options for a Tk widget. |
| 62 | '\" |
| 63 | '\" .OP cmdName dbName dbClass |
| 64 | '\" Start of description of a specific option. cmdName gives the |
| 65 | '\" option's name as specified in the class command, dbName gives |
| 66 | '\" the option's name in the option database, and dbClass gives |
| 67 | '\" the option's class in the option database. |
| 68 | '\" |
| 69 | '\" .UL arg1 arg2 |
| 70 | '\" Print arg1 underlined, then print arg2 normally. |
| 71 | '\" |
| 72 | '\" RCS: @(#) $Id: man.macros,v 1.4 2000/08/25 06:18:32 ericm Exp $ |
| 73 | '\" |
| 74 | '\" # Set up traps and other miscellaneous stuff for Tcl/Tk man pages. |
| 75 | .if t .wh -1.3i ^B |
| 76 | .nr ^l \n(.l |
| 77 | .ad b |
| 78 | '\" # Start an argument description |
| 79 | .de AP |
| 80 | .ie !"\\$4"" .TP \\$4 |
| 81 | .el \{\ |
| 82 | . ie !"\\$2"" .TP \\n()Cu |
| 83 | . el .TP 15 |
| 84 | .\} |
| 85 | .ta \\n()Au \\n()Bu |
| 86 | .ie !"\\$3"" \{\ |
| 87 | \&\\$1 \\fI\\$2\\fP (\\$3) |
| 88 | .\".b |
| 89 | .\} |
| 90 | .el \{\ |
| 91 | .br |
| 92 | .ie !"\\$2"" \{\ |
| 93 | \&\\$1 \\fI\\$2\\fP |
| 94 | .\} |
| 95 | .el \{\ |
| 96 | \&\\fI\\$1\\fP |
| 97 | .\} |
| 98 | .\} |
| 99 | .. |
| 100 | '\" # define tabbing values for .AP |
| 101 | .de AS |
| 102 | .nr )A 10n |
| 103 | .if !"\\$1"" .nr )A \\w'\\$1'u+3n |
| 104 | .nr )B \\n()Au+15n |
| 105 | .\" |
| 106 | .if !"\\$2"" .nr )B \\w'\\$2'u+\\n()Au+3n |
| 107 | .nr )C \\n()Bu+\\w'(in/out)'u+2n |
| 108 | .. |
| 109 | .AS Tcl_Interp Tcl_CreateInterp in/out |
| 110 | '\" # BS - start boxed text |
| 111 | '\" # ^y = starting y location |
| 112 | '\" # ^b = 1 |
| 113 | .de BS |
| 114 | .br |
| 115 | .mk ^y |
| 116 | .nr ^b 1u |
| 117 | .if n .nf |
| 118 | .if n .ti 0 |
| 119 | .if n \l'\\n(.lu\(ul' |
| 120 | .if n .fi |
| 121 | .. |
| 122 | '\" # BE - end boxed text (draw box now) |
| 123 | .de BE |
| 124 | .nf |
| 125 | .ti 0 |
| 126 | .mk ^t |
| 127 | .ie n \l'\\n(^lu\(ul' |
| 128 | .el \{\ |
| 129 | .\" Draw four-sided box normally, but don't draw top of |
| 130 | .\" box if the box started on an earlier page. |
| 131 | .ie !\\n(^b-1 \{\ |
| 132 | \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul' |
| 133 | .\} |
| 134 | .el \}\ |
| 135 | \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul' |
| 136 | .\} |
| 137 | .\} |
| 138 | .fi |
| 139 | .br |
| 140 | .nr ^b 0 |
| 141 | .. |
| 142 | '\" # VS - start vertical sidebar |
| 143 | '\" # ^Y = starting y location |
| 144 | '\" # ^v = 1 (for troff; for nroff this doesn't matter) |
| 145 | .de VS |
| 146 | .if !"\\$2"" .br |
| 147 | .mk ^Y |
| 148 | .ie n 'mc \s12\(br\s0 |
| 149 | .el .nr ^v 1u |
| 150 | .. |
| 151 | '\" # VE - end of vertical sidebar |
| 152 | .de VE |
| 153 | .ie n 'mc |
| 154 | .el \{\ |
| 155 | .ev 2 |
| 156 | .nf |
| 157 | .ti 0 |
| 158 | .mk ^t |
| 159 | \h'|\\n(^lu+3n'\L'|\\n(^Yu-1v\(bv'\v'\\n(^tu+1v-\\n(^Yu'\h'-|\\n(^lu+3n' |
| 160 | .sp -1 |
| 161 | .fi |
| 162 | .ev |
| 163 | .\} |
| 164 | .nr ^v 0 |
| 165 | .. |
| 166 | '\" # Special macro to handle page bottom: finish off current |
| 167 | '\" # box/sidebar if in box/sidebar mode, then invoked standard |
| 168 | '\" # page bottom macro. |
| 169 | .de ^B |
| 170 | .ev 2 |
| 171 | 'ti 0 |
| 172 | 'nf |
| 173 | .mk ^t |
| 174 | .if \\n(^b \{\ |
| 175 | .\" Draw three-sided box if this is the box's first page, |
| 176 | .\" draw two sides but no top otherwise. |
| 177 | .ie !\\n(^b-1 \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c |
| 178 | .el \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c |
| 179 | .\} |
| 180 | .if \\n(^v \{\ |
| 181 | .nr ^x \\n(^tu+1v-\\n(^Yu |
| 182 | \kx\h'-\\nxu'\h'|\\n(^lu+3n'\ky\L'-\\n(^xu'\v'\\n(^xu'\h'|0u'\c |
| 183 | .\} |
| 184 | .bp |
| 185 | 'fi |
| 186 | .ev |
| 187 | .if \\n(^b \{\ |
| 188 | .mk ^y |
| 189 | .nr ^b 2 |
| 190 | .\} |
| 191 | .if \\n(^v \{\ |
| 192 | .mk ^Y |
| 193 | .\} |
| 194 | .. |
| 195 | '\" # DS - begin display |
| 196 | .de DS |
| 197 | .RS |
| 198 | .nf |
| 199 | .sp |
| 200 | .. |
| 201 | '\" # DE - end display |
| 202 | .de DE |
| 203 | .fi |
| 204 | .RE |
| 205 | .sp |
| 206 | .. |
| 207 | '\" # SO - start of list of standard options |
| 208 | .de SO |
| 209 | .SH "STANDARD OPTIONS" |
| 210 | .LP |
| 211 | .nf |
| 212 | .ta 5.5c 11c |
| 213 | .ft B |
| 214 | .. |
| 215 | '\" # SE - end of list of standard options |
| 216 | .de SE |
| 217 | .fi |
| 218 | .ft R |
| 219 | .LP |
| 220 | See the \\fBoptions\\fR manual entry for details on the standard options. |
| 221 | .. |
| 222 | '\" # OP - start of full description for a single option |
| 223 | .de OP |
| 224 | .LP |
| 225 | .nf |
| 226 | .ta 4c |
| 227 | Command-Line Name: \\fB\\$1\\fR |
| 228 | Database Name: \\fB\\$2\\fR |
| 229 | Database Class: \\fB\\$3\\fR |
| 230 | .fi |
| 231 | .IP |
| 232 | .. |
| 233 | '\" # CS - begin code excerpt |
| 234 | .de CS |
| 235 | .RS |
| 236 | .nf |
| 237 | .ta .25i .5i .75i 1i |
| 238 | .. |
| 239 | '\" # CE - end code excerpt |
| 240 | .de CE |
| 241 | .fi |
| 242 | .RE |
| 243 | .. |
| 244 | .de UL |
| 245 | \\$1\l'|0\(ul'\\$2 |
| 246 | .. |
| 247 | .TH canvas n 8.3 Tk "Tk Built-In Commands" |
| 248 | .BS |
| 249 | '\" Note: do not modify the .SH NAME line immediately below! |
| 250 | .SH NAME |
| 251 | canvas \- Create and manipulate canvas widgets |
| 252 | .SH SYNOPSIS |
| 253 | \fBcanvas\fR \fIpathName \fR?\fIoptions\fR? |
| 254 | .SO |
| 255 | \-background \-insertborderwidth \-selectborderwidth |
| 256 | \-borderwidth \-insertofftime \-selectforeground |
| 257 | \-cursor \-insertontime \-takefocus |
| 258 | \-highlightbackground \-insertwidth \-xscrollcommand |
| 259 | \-highlightcolor \-relief \-yscrollcommand |
| 260 | \-highlightthickness \-state |
| 261 | \-insertbackground \-selectbackground |
| 262 | .SE |
| 263 | .SH "WIDGET-SPECIFIC OPTIONS" |
| 264 | .OP \-closeenough closeEnough CloseEnough |
| 265 | Specifies a floating-point value indicating how close the mouse cursor |
| 266 | must be to an item before it is considered to be ``inside'' the item. |
| 267 | Defaults to 1.0. |
| 268 | .OP \-confine confine Confine |
| 269 | Specifies a boolean value that indicates whether or not it should be |
| 270 | allowable to set the canvas's view outside the region defined by the |
| 271 | \fBscrollRegion\fR argument. |
| 272 | Defaults to true, which means that the view will |
| 273 | be constrained within the scroll region. |
| 274 | .OP \-height height Height |
| 275 | Specifies a desired window height that the canvas widget should request from |
| 276 | its geometry manager. The value may be specified in any |
| 277 | of the forms described in the \fBCOORDINATES\fR section below. |
| 278 | .OP \-scrollregion scrollRegion ScrollRegion |
| 279 | Specifies a list with four coordinates describing the left, top, right, and |
| 280 | bottom coordinates of a rectangular region. |
| 281 | This region is used for scrolling purposes and is considered to be |
| 282 | the boundary of the information in the canvas. |
| 283 | Each of the coordinates may be specified |
| 284 | in any of the forms given in the \fBCOORDINATES\fR section below. |
| 285 | .OP \-state state State |
| 286 | Modifies the default state of the canvas where \fIstate\fR may be set to |
| 287 | one of: \fBnormal\fR, \fBdisabled\fR, or \fBhidden\fR. Individual canvas |
| 288 | objects all have their own state option which may override the default |
| 289 | state. Many options can take separate specifications such that the |
| 290 | appearance of the item can be different in different situations. The |
| 291 | options that start with \fBactive\fR control the appearence when the mouse |
| 292 | pointer is over it, while the option starting with \fBdisabled\fR controls |
| 293 | the appearence when the state is disabled. Canvas items which are |
| 294 | \fBdisabled\fR will not react to canvas bindings. |
| 295 | .OP \-width width width |
| 296 | Specifies a desired window width that the canvas widget should request from |
| 297 | its geometry manager. The value may be specified in any |
| 298 | of the forms described in the \fBCOORDINATES\fR section below. |
| 299 | .OP \-xscrollincrement xScrollIncrement ScrollIncrement |
| 300 | Specifies an increment for horizontal scrolling, in any of the usual forms |
| 301 | permitted for screen distances. If the value of this option is greater |
| 302 | than zero, the horizontal view in the window will be constrained so that |
| 303 | the canvas x coordinate at the left edge of the window is always an even |
| 304 | multiple of \fBxScrollIncrement\fR; furthermore, the units for scrolling |
| 305 | (e.g., the change in view when the left and right arrows of a scrollbar |
| 306 | are selected) will also be \fBxScrollIncrement\fR. If the value of |
| 307 | this option is less than or equal to zero, then horizontal scrolling |
| 308 | is unconstrained. |
| 309 | .OP \-yscrollincrement yScrollIncrement ScrollIncrement |
| 310 | Specifies an increment for vertical scrolling, in any of the usual forms |
| 311 | permitted for screen distances. If the value of this option is greater |
| 312 | than zero, the vertical view in the window will be constrained so that |
| 313 | the canvas y coordinate at the top edge of the window is always an even |
| 314 | multiple of \fByScrollIncrement\fR; furthermore, the units for scrolling |
| 315 | (e.g., the change in view when the top and bottom arrows of a scrollbar |
| 316 | are selected) will also be \fByScrollIncrement\fR. If the value of |
| 317 | this option is less than or equal to zero, then vertical scrolling |
| 318 | is unconstrained. |
| 319 | .BE |
| 320 | |
| 321 | .SH INTRODUCTION |
| 322 | .PP |
| 323 | The \fBcanvas\fR command creates a new window (given |
| 324 | by the \fIpathName\fR argument) and makes it into a canvas widget. |
| 325 | Additional options, described above, may be specified on the |
| 326 | command line or in the option database |
| 327 | to configure aspects of the canvas such as its colors and 3-D relief. |
| 328 | The \fBcanvas\fR command returns its |
| 329 | \fIpathName\fR argument. At the time this command is invoked, |
| 330 | there must not exist a window named \fIpathName\fR, but |
| 331 | \fIpathName\fR's parent must exist. |
| 332 | .PP |
| 333 | Canvas widgets implement structured graphics. |
| 334 | A canvas displays any number of \fIitems\fR, which may be things like |
| 335 | rectangles, circles, lines, and text. |
| 336 | Items may be manipulated (e.g. moved or re-colored) and commands may |
| 337 | be associated with items in much the same way that the \fBbind\fR |
| 338 | command allows commands to be bound to widgets. For example, |
| 339 | a particular command may be associated with the <Button-1> event |
| 340 | so that the command is invoked whenever button 1 is pressed with |
| 341 | the mouse cursor over an item. |
| 342 | This means that items in a canvas can have behaviors defined by |
| 343 | the Tcl scripts bound to them. |
| 344 | .SH "DISPLAY LIST" |
| 345 | .PP |
| 346 | The items in a canvas are ordered for purposes of display, |
| 347 | with the first item in the display list being displayed |
| 348 | first, followed by the next item in the list, and so on. |
| 349 | Items later in the display list obscure those that are |
| 350 | earlier in the display list and are sometimes referred to |
| 351 | as being ``on top'' of earlier items. |
| 352 | When a new item is created it is placed at the end of the |
| 353 | display list, on top of everything else. |
| 354 | Widget commands may be used to re-arrange the order of the |
| 355 | display list. |
| 356 | .PP |
| 357 | Window items are an exception to the above rules. The underlying |
| 358 | window systems require them always to be drawn on top of other items. |
| 359 | In addition, the stacking order of window items |
| 360 | is not affected by any of the canvas widget commands; you must use |
| 361 | the \fBraise\fR and \fBlower\fR Tk commands instead. |
| 362 | .SH "ITEM IDS AND TAGS" |
| 363 | .PP |
| 364 | Items in a canvas widget may be named in either of two ways: |
| 365 | by id or by tag. |
| 366 | Each item has a unique identifying number, which is assigned to |
| 367 | that item when it is created. The id of an item never changes |
| 368 | and id numbers are never re-used within the lifetime of a |
| 369 | canvas widget. |
| 370 | .PP |
| 371 | Each item may also have any number of \fItags\fR associated |
| 372 | with it. A tag is just a string of characters, and it may |
| 373 | take any form except that of an integer. |
| 374 | For example, ``x123'' is OK but ``123'' isn't. |
| 375 | The same tag may be associated with many different items. |
| 376 | This is commonly done to group items in various interesting |
| 377 | ways; for example, all selected items might be given the |
| 378 | tag ``selected''. |
| 379 | .PP |
| 380 | The tag \fBall\fR is implicitly associated with every item |
| 381 | in the canvas; it may be used to invoke operations on |
| 382 | all the items in the canvas. |
| 383 | .PP |
| 384 | The tag \fBcurrent\fR is managed automatically by Tk; |
| 385 | it applies to the \fIcurrent item\fR, which is the |
| 386 | topmost item whose drawn area covers the position of |
| 387 | the mouse cursor. |
| 388 | If the mouse is not in the canvas widget or is not over |
| 389 | an item, then no item has the \fBcurrent\fR tag. |
| 390 | .PP |
| 391 | When specifying items in canvas widget commands, if the |
| 392 | specifier is an integer then it is assumed to refer to |
| 393 | the single item with that id. |
| 394 | If the specifier is not an integer, then it is assumed to |
| 395 | refer to all of the items in the canvas that have a tag |
| 396 | matching the specifier. |
| 397 | The symbol \fItagOrId\fR is used below to indicate that |
| 398 | an argument specifies either an id that selects a single |
| 399 | item or a tag that selects zero or more items. |
| 400 | .PP |
| 401 | \fItagOrId\fR may contain a logical expressions of |
| 402 | tags by using operators: '&&', '||', '^' '!', and parenthesized |
| 403 | subexpressions. For example: |
| 404 | .CS |
| 405 | .c find withtag {(a&&!b)||(!a&&b)} |
| 406 | .CE |
| 407 | or equivalently: |
| 408 | .CS |
| 409 | .c find withtag {a^b} |
| 410 | .CE |
| 411 | will find only those items with either "a" or "b" tags, but not both. |
| 412 | .PP |
| 413 | Some widget commands only operate on a single item at a |
| 414 | time; if \fItagOrId\fR is specified in a way that |
| 415 | names multiple items, then the normal behavior is for |
| 416 | the command to use the first (lowest) of these items in |
| 417 | the display list that is suitable for the command. |
| 418 | Exceptions are noted in the widget command descriptions |
| 419 | below. |
| 420 | .SH "COORDINATES" |
| 421 | .PP |
| 422 | All coordinates related to canvases are stored as floating-point |
| 423 | numbers. |
| 424 | Coordinates and distances are specified in screen units, |
| 425 | which are floating-point numbers optionally followed |
| 426 | by one of several letters. |
| 427 | If no letter is supplied then the distance is in pixels. |
| 428 | If the letter is \fBm\fR then the distance is in millimeters on |
| 429 | the screen; if it is \fBc\fR then the distance is in centimeters; |
| 430 | \fBi\fR means inches, and \fBp\fR means printers points (1/72 inch). |
| 431 | Larger y-coordinates refer to points lower on the screen; larger |
| 432 | x-coordinates refer to points farther to the right. |
| 433 | .VS |
| 434 | Coordinates can be specified either as an even number of parameters, |
| 435 | or as a single list parameter containing an even number of x and y |
| 436 | coordinate values. |
| 437 | .VE |
| 438 | .SH TRANSFORMATIONS |
| 439 | .PP |
| 440 | Normally the origin of the canvas coordinate system is at the |
| 441 | upper-left corner of the window containing the canvas. |
| 442 | It is possible to adjust the origin of the canvas |
| 443 | coordinate system relative to the origin of the window using the |
| 444 | \fBxview\fR and \fByview\fR widget commands; this is typically used |
| 445 | for scrolling. |
| 446 | Canvases do not support scaling or rotation of the canvas coordinate |
| 447 | system relative to the window coordinate system. |
| 448 | .PP |
| 449 | Individual items may be moved or scaled using widget commands |
| 450 | described below, but they may not be rotated. |
| 451 | .PP |
| 452 | Note that the default origin of the canvas's visible area is |
| 453 | coincident with the origin for the whole window as that makes bindings |
| 454 | using the mouse position easier to work with; you only need to use the |
| 455 | \fBcanvasx\fR and \fBcanvasy\fR widget commands if you adjust the |
| 456 | origin of the visible area. However, this also means that any focus |
| 457 | ring (as controlled by the \fB\-highlightthickness\fR option) and |
| 458 | window border (as controlled by the \fB\-borderwidth\fR option) must |
| 459 | be taken into account before you get to the visible area of the |
| 460 | canvas. |
| 461 | .SH "INDICES" |
| 462 | .PP |
| 463 | Text items support the notion of an \fIindex\fR for identifying |
| 464 | particular positions within the item. |
| 465 | In a similar fashion, line and polygon items support \fIindex\fR for |
| 466 | identifying, inserting and deleting subsets of their coordinates. |
| 467 | Indices are used for commands such as inserting or deleting |
| 468 | a range of characters or coordinates, and setting the insertion |
| 469 | cursor position. An index may be specified in any of a number |
| 470 | of ways, and different types of items may support different forms |
| 471 | for specifying indices. |
| 472 | Text items support the following forms for an index; if you |
| 473 | define new types of text-like items, it would be advisable to |
| 474 | support as many of these forms as practical. |
| 475 | Note that it is possible to refer to the character just after |
| 476 | the last one in the text item; this is necessary for such |
| 477 | tasks as inserting new text at the end of the item. |
| 478 | Lines and Polygons don't support the insertion cursor |
| 479 | and the selection. Their indices are supposed to be even |
| 480 | always, because coordinates always appear in pairs. |
| 481 | .TP 10 |
| 482 | \fInumber\fR |
| 483 | A decimal number giving the position of the desired character |
| 484 | within the text item. |
| 485 | 0 refers to the first character, 1 to the next character, and |
| 486 | so on. If indexes are odd for lines and polygons, they will be |
| 487 | automatically decremented by one. |
| 488 | A number less than 0 is treated as if it were zero, and a |
| 489 | number greater than the length of the text item is treated |
| 490 | as if it were equal to the length of the text item. For |
| 491 | polygons, numbers less than 0 or greater then the length |
| 492 | of the coordinate list will be adjusted by adding or subtracting |
| 493 | the length until the result is between zero and the length, |
| 494 | inclusive. |
| 495 | .TP 10 |
| 496 | \fBend\fR |
| 497 | Refers to the character or coordinate just after the last one |
| 498 | in the item (same as the number of characters or coordinates |
| 499 | in the item). |
| 500 | .TP 10 |
| 501 | \fBinsert\fR |
| 502 | Refers to the character just before which the insertion cursor |
| 503 | is drawn in this item. Not valid for lines and polygons. |
| 504 | .TP 10 |
| 505 | \fBsel.first\fR |
| 506 | Refers to the first selected character in the item. |
| 507 | If the selection isn't in this item then this form is illegal. |
| 508 | .TP 10 |
| 509 | \fBsel.last\fR |
| 510 | Refers to the last selected character in the item. |
| 511 | If the selection isn't in this item then this form is illegal. |
| 512 | .TP 10 |
| 513 | \fB@\fIx,y\fR |
| 514 | Refers to the character or coordinate at the point given by \fIx\fR and |
| 515 | \fIy\fR, where \fIx\fR and \fIy\fR are specified in the coordinate |
| 516 | system of the canvas. |
| 517 | If \fIx\fR and \fIy\fR lie outside the coordinates covered by the |
| 518 | text item, then they refer to the first or last character in the |
| 519 | line that is closest to the given point. |
| 520 | .SH "DASH PATTERNS" |
| 521 | .PP |
| 522 | Many items support the notion of a dash pattern for outlines. |
| 523 | .PP |
| 524 | The first possible syntax is a list of integers. Each element |
| 525 | represents the number of pixels of a line segment. Only the odd |
| 526 | segments are drawn using the "outline" color. The other segments |
| 527 | are drawn transparent. |
| 528 | .PP |
| 529 | The second possible syntax is a character list containing only |
| 530 | 5 possible characters \fB[.,-_ ]\fR. The space can be used |
| 531 | to enlarge the space between other line elements, and can not |
| 532 | occur as the first position in the string. Some examples: |
| 533 | -dash . = -dash {2 4} |
| 534 | -dash - = -dash {6 4} |
| 535 | -dash -. = -dash {6 4 2 4} |
| 536 | -dash -.. = -dash {6 4 2 4 2 4} |
| 537 | -dash {. } = -dash {2 8} |
| 538 | -dash , = -dash {4 4} |
| 539 | .PP |
| 540 | The main difference of this syntax with the previous is that it |
| 541 | is shape-conserving. This means that all values in the dash |
| 542 | list will be multiplied by the line width before display. This |
| 543 | assures that "." will always be displayed as a dot and "-" |
| 544 | always as a dash regardless of the line width. |
| 545 | .PP |
| 546 | On systems which support only a limited set of dash patterns, the dash |
| 547 | pattern will be displayed as the closest dash pattern that is available. |
| 548 | For example, on Windows only the first 4 of the above examples are |
| 549 | available. The last 2 examples will be displayed identically to the first |
| 550 | one. |
| 551 | .SH "WIDGET COMMAND" |
| 552 | .PP |
| 553 | The \fBcanvas\fR command creates a new Tcl command whose |
| 554 | name is \fIpathName\fR. This |
| 555 | command may be used to invoke various |
| 556 | operations on the widget. It has the following general form: |
| 557 | .CS |
| 558 | \fIpathName option \fR?\fIarg arg ...\fR? |
| 559 | .CE |
| 560 | \fIOption\fR and the \fIarg\fRs |
| 561 | determine the exact behavior of the command. |
| 562 | The following widget commands are possible for canvas widgets: |
| 563 | .TP |
| 564 | \fIpathName \fBaddtag \fItag searchSpec \fR?\fIarg arg ...\fR? |
| 565 | For each item that meets the constraints specified by |
| 566 | \fIsearchSpec\fR and the \fIarg\fRs, add |
| 567 | \fItag\fR to the list of tags associated with the item if it |
| 568 | isn't already present on that list. |
| 569 | It is possible that no items will satisfy the constraints |
| 570 | given by \fIsearchSpec\fR and \fIarg\fRs, in which case the |
| 571 | command has no effect. |
| 572 | This command returns an empty string as result. |
| 573 | \fISearchSpec\fR and \fIarg\fR's may take any of the following |
| 574 | forms: |
| 575 | .RS |
| 576 | .TP |
| 577 | \fBabove \fItagOrId\fR |
| 578 | Selects the item just after (above) the one given by \fItagOrId\fR |
| 579 | in the display list. |
| 580 | If \fItagOrId\fR denotes more than one item, then the last (topmost) |
| 581 | of these items in the display list is used. |
| 582 | .TP |
| 583 | \fBall\fR |
| 584 | Selects all the items in the canvas. |
| 585 | .TP |
| 586 | \fBbelow \fItagOrId\fR |
| 587 | Selects the item just before (below) the one given by \fItagOrId\fR |
| 588 | in the display list. |
| 589 | If \fItagOrId\fR denotes more than one item, then the first (lowest) |
| 590 | of these items in the display list is used. |
| 591 | .TP |
| 592 | \fBclosest \fIx y \fR?\fIhalo\fR? ?\fIstart\fR? |
| 593 | Selects the item closest to the point given by \fIx\fR and \fIy\fR. |
| 594 | If more than one item is at the same closest distance (e.g. two |
| 595 | items overlap the point), then the top-most of these items (the |
| 596 | last one in the display list) is used. |
| 597 | If \fIhalo\fR is specified, then it must be a non-negative |
| 598 | value. |
| 599 | Any item closer than \fIhalo\fR to the point is considered to |
| 600 | overlap it. |
| 601 | The \fIstart\fR argument may be used to step circularly through |
| 602 | all the closest items. |
| 603 | If \fIstart\fR is specified, it names an item using a tag or id |
| 604 | (if by tag, it selects the first item in the display list with |
| 605 | the given tag). |
| 606 | Instead of selecting the topmost closest item, this form will |
| 607 | select the topmost closest item that is below \fIstart\fR in |
| 608 | the display list; if no such item exists, then the selection |
| 609 | behaves as if the \fIstart\fR argument had not been specified. |
| 610 | .TP |
| 611 | \fBenclosed\fR \fIx1\fR \fIy1\fR \fIx2\fR \fIy2\fR |
| 612 | Selects all the items completely enclosed within the rectangular |
| 613 | region given by \fIx1\fR, \fIy1\fR, \fIx2\fR, and \fIy2\fR. |
| 614 | \fIX1\fR must be no greater then \fIx2\fR and \fIy1\fR must be |
| 615 | no greater than \fIy2\fR. |
| 616 | .TP |
| 617 | \fBoverlapping\fR \fIx1\fR \fIy1\fR \fIx2\fR \fIy2\fR |
| 618 | Selects all the items that overlap or are enclosed within the |
| 619 | rectangular region given by \fIx1\fR, \fIy1\fR, \fIx2\fR, |
| 620 | and \fIy2\fR. |
| 621 | \fIX1\fR must be no greater then \fIx2\fR and \fIy1\fR must be |
| 622 | no greater than \fIy2\fR. |
| 623 | .TP |
| 624 | \fBwithtag \fItagOrId\fR |
| 625 | Selects all the items given by \fItagOrId\fR. |
| 626 | .RE |
| 627 | .TP |
| 628 | \fIpathName \fBbbox \fItagOrId\fR ?\fItagOrId tagOrId ...\fR? |
| 629 | Returns a list with four elements giving an approximate bounding box |
| 630 | for all the items named by the \fItagOrId\fR arguments. |
| 631 | The list has the form ``\fIx1 y1 x2 y2\fR'' such that the drawn |
| 632 | areas of all the named elements are within the region bounded by |
| 633 | \fIx1\fR on the left, \fIx2\fR on the right, \fIy1\fR on the top, |
| 634 | and \fIy2\fR on the bottom. |
| 635 | The return value may overestimate the actual bounding box by |
| 636 | a few pixels. |
| 637 | If no items match any of the \fItagOrId\fR arguments or if the |
| 638 | matching items have empty bounding boxes (i.e. they have nothing |
| 639 | to display) |
| 640 | then an empty string is returned. |
| 641 | .TP |
| 642 | \fIpathName \fBbind \fItagOrId\fR ?\fIsequence\fR? ?\fIcommand\fR? |
| 643 | This command associates \fIcommand\fR with all the items given by |
| 644 | \fItagOrId\fR such that whenever the event sequence given by |
| 645 | \fIsequence\fR occurs for one of the items the command will |
| 646 | be invoked. |
| 647 | This widget command is similar to the \fBbind\fR command except that |
| 648 | it operates on items in a canvas rather than entire widgets. |
| 649 | See the \fBbind\fR manual entry for complete details |
| 650 | on the syntax of \fIsequence\fR and the substitutions performed |
| 651 | on \fIcommand\fR before invoking it. |
| 652 | If all arguments are specified then a new binding is created, replacing |
| 653 | any existing binding for the same \fIsequence\fR and \fItagOrId\fR |
| 654 | (if the first character of \fIcommand\fR is ``+'' then \fIcommand\fR |
| 655 | augments an existing binding rather than replacing it). |
| 656 | In this case the return value is an empty string. |
| 657 | If \fIcommand\fR is omitted then the command returns the \fIcommand\fR |
| 658 | associated with \fItagOrId\fR and \fIsequence\fR (an error occurs |
| 659 | if there is no such binding). |
| 660 | If both \fIcommand\fR and \fIsequence\fR are omitted then the command |
| 661 | returns a list of all the sequences for which bindings have been |
| 662 | defined for \fItagOrId\fR. |
| 663 | .RS |
| 664 | .PP |
| 665 | The only events for which bindings may be specified are those related to |
| 666 | the mouse and keyboard (such as \fBEnter\fR, \fBLeave\fR, |
| 667 | \fBButtonPress\fR, \fBMotion\fR, and \fBKeyPress\fR) or virtual events. |
| 668 | The handling of events in canvases uses the current item defined in ITEM |
| 669 | IDS AND TAGS above. \fBEnter\fR and \fBLeave\fR events trigger for an |
| 670 | item when it becomes the current item or ceases to be the current item; |
| 671 | note that these events are different than \fBEnter\fR and \fBLeave\fR |
| 672 | events for windows. Mouse-related events are directed to the current |
| 673 | item, if any. Keyboard-related events are directed to the focus item, if |
| 674 | any (see the \fBfocus\fR widget command below for more on this). If a |
| 675 | virtual event is used in a binding, that binding can trigger only if the |
| 676 | virtual event is defined by an underlying mouse-related or |
| 677 | keyboard-related event. |
| 678 | .PP |
| 679 | It is possible for multiple bindings to match a particular event. |
| 680 | This could occur, for example, if one binding is associated with the |
| 681 | item's id and another is associated with one of the item's tags. |
| 682 | When this occurs, all of the matching bindings are invoked. |
| 683 | A binding associated with the \fBall\fR tag is invoked first, |
| 684 | followed by one binding for each of the item's tags (in order), |
| 685 | followed by a binding associated with the item's id. |
| 686 | If there are multiple matching bindings for a single tag, |
| 687 | then only the most specific binding is invoked. |
| 688 | A \fBcontinue\fR command in a binding script terminates that |
| 689 | script, and a \fBbreak\fR command terminates that script |
| 690 | and skips any remaining scripts for the event, just as for the |
| 691 | \fBbind\fR command. |
| 692 | .PP |
| 693 | If bindings have been created for a canvas window using the \fBbind\fR |
| 694 | command, then they are invoked in addition to bindings created for |
| 695 | the canvas's items using the \fBbind\fR widget command. |
| 696 | The bindings for items will be invoked before any of the bindings |
| 697 | for the window as a whole. |
| 698 | .RE |
| 699 | .TP |
| 700 | \fIpathName \fBcanvasx \fIscreenx\fR ?\fIgridspacing\fR? |
| 701 | Given a window x-coordinate in the canvas \fIscreenx\fR, this command returns |
| 702 | the canvas x-coordinate that is displayed at that location. |
| 703 | If \fIgridspacing\fR is specified, then the canvas coordinate is |
| 704 | rounded to the nearest multiple of \fIgridspacing\fR units. |
| 705 | .TP |
| 706 | \fIpathName \fBcanvasy \fIscreeny\fR ?\fIgridspacing\fR? |
| 707 | Given a window y-coordinate in the canvas \fIscreeny\fR this command returns |
| 708 | the canvas y-coordinate that is displayed at that location. |
| 709 | If \fIgridspacing\fR is specified, then the canvas coordinate is |
| 710 | rounded to the nearest multiple of \fIgridspacing\fR units. |
| 711 | .TP |
| 712 | \fIpathName \fBcget\fR \fIoption\fR |
| 713 | Returns the current value of the configuration option given |
| 714 | by \fIoption\fR. |
| 715 | \fIOption\fR may have any of the values accepted by the \fBcanvas\fR |
| 716 | command. |
| 717 | .TP |
| 718 | \fIpathName \fBconfigure ?\fIoption\fR? ?\fIvalue\fR? ?\fIoption value ...\fR? |
| 719 | Query or modify the configuration options of the widget. |
| 720 | If no \fIoption\fR is specified, returns a list describing all of |
| 721 | the available options for \fIpathName\fR (see \fBTk_ConfigureInfo\fR for |
| 722 | information on the format of this list). If \fIoption\fR is specified |
| 723 | with no \fIvalue\fR, then the command returns a list describing the |
| 724 | one named option (this list will be identical to the corresponding |
| 725 | sublist of the value returned if no \fIoption\fR is specified). If |
| 726 | one or more \fIoption\-value\fR pairs are specified, then the command |
| 727 | modifies the given widget option(s) to have the given value(s); in |
| 728 | this case the command returns an empty string. |
| 729 | \fIOption\fR may have any of the values accepted by the \fBcanvas\fR |
| 730 | command. |
| 731 | .TP |
| 732 | \fIpathName\fR \fBcoords \fItagOrId \fR?\fIx0 y0 ...\fR? |
| 733 | .TP |
| 734 | \fIpathName\fR \fBcoords \fItagOrId \fR?\fIcoordList\fR? |
| 735 | Query or modify the coordinates that define an item. |
| 736 | If no coordinates are specified, this command returns a list |
| 737 | whose elements are the coordinates of the item named by |
| 738 | \fItagOrId\fR. |
| 739 | If coordinates are specified, then they replace the current |
| 740 | coordinates for the named item. |
| 741 | If \fItagOrId\fR refers to multiple items, then |
| 742 | the first one in the display list is used. |
| 743 | .TP |
| 744 | \fIpathName \fBcreate \fItype x y \fR?\fIx y ...\fR? ?\fIoption value ...\fR? |
| 745 | .TP |
| 746 | \fIpathName \fBcreate \fItype coordList \fR?\fIoption value ...\fR? |
| 747 | Create a new item in \fIpathName\fR of type \fItype\fR. |
| 748 | The exact format of the arguments after \fBtype\fR depends |
| 749 | on \fBtype\fR, but usually they consist of the coordinates for |
| 750 | one or more points, followed by specifications for zero or |
| 751 | more item options. |
| 752 | See the subsections on individual item types below for more |
| 753 | on the syntax of this command. |
| 754 | This command returns the id for the new item. |
| 755 | .TP |
| 756 | \fIpathName \fBdchars \fItagOrId first \fR?\fIlast\fR? |
| 757 | For each item given by \fItagOrId\fR, delete the characters, or coordinates, |
| 758 | in the range given by \fIfirst\fR and \fIlast\fR, inclusive. |
| 759 | If some of the items given by \fItagOrId\fR don't support |
| 760 | indexing operations then they ignore dchars. |
| 761 | Text items interpret \fIfirst\fR and \fIlast\fR as indices to a character, |
| 762 | line and polygon items interpret them indices to a coordinate (an x,y pair). |
| 763 | Indices are described in INDICES above. |
| 764 | If \fIlast\fR is omitted, it defaults to \fIfirst\fR. |
| 765 | This command returns an empty string. |
| 766 | .TP |
| 767 | \fIpathName \fBdelete \fR?\fItagOrId tagOrId ...\fR? |
| 768 | Delete each of the items given by each \fItagOrId\fR, and return |
| 769 | an empty string. |
| 770 | .TP |
| 771 | \fIpathName \fBdtag \fItagOrId \fR?\fItagToDelete\fR? |
| 772 | For each of the items given by \fItagOrId\fR, delete the |
| 773 | tag given by \fItagToDelete\fR from the list of those |
| 774 | associated with the item. |
| 775 | If an item doesn't have the tag \fItagToDelete\fR then |
| 776 | the item is unaffected by the command. |
| 777 | If \fItagToDelete\fR is omitted then it defaults to \fItagOrId\fR. |
| 778 | This command returns an empty string. |
| 779 | .TP |
| 780 | \fIpathName \fBfind \fIsearchCommand \fR?\fIarg arg ...\fR? |
| 781 | This command returns a list consisting of all the items that |
| 782 | meet the constraints specified by \fIsearchCommand\fR and |
| 783 | \fIarg\fR's. |
| 784 | \fISearchCommand\fR and \fIargs\fR have any of the forms |
| 785 | accepted by the \fBaddtag\fR command. |
| 786 | The items are returned in stacking order, with the lowest item first. |
| 787 | .TP |
| 788 | \fIpathName \fBfocus \fR?\fItagOrId\fR? |
| 789 | Set the keyboard focus for the canvas widget to the item given by |
| 790 | \fItagOrId\fR. |
| 791 | If \fItagOrId\fR refers to several items, then the focus is set |
| 792 | to the first such item in the display list that supports the |
| 793 | insertion cursor. |
| 794 | If \fItagOrId\fR doesn't refer to any items, or if none of them |
| 795 | support the insertion cursor, then the focus isn't changed. |
| 796 | If \fItagOrId\fR is an empty |
| 797 | string, then the focus item is reset so that no item has the focus. |
| 798 | If \fItagOrId\fR is not specified then the command returns the |
| 799 | id for the item that currently has the focus, or an empty string |
| 800 | if no item has the focus. |
| 801 | .RS |
| 802 | .PP |
| 803 | Once the focus has been set to an item, the item will display |
| 804 | the insertion cursor and all keyboard events will be directed |
| 805 | to that item. |
| 806 | The focus item within a canvas and the focus window on the |
| 807 | screen (set with the \fBfocus\fR command) are totally independent: |
| 808 | a given item doesn't actually have the input focus unless (a) |
| 809 | its canvas is the focus window and (b) the item is the focus item |
| 810 | within the canvas. |
| 811 | In most cases it is advisable to follow the \fBfocus\fR widget |
| 812 | command with the \fBfocus\fR command to set the focus window to |
| 813 | the canvas (if it wasn't there already). |
| 814 | .RE |
| 815 | .TP |
| 816 | \fIpathName \fBgettags\fR \fItagOrId\fR |
| 817 | Return a list whose elements are the tags associated with the |
| 818 | item given by \fItagOrId\fR. |
| 819 | If \fItagOrId\fR refers to more than one item, then the tags |
| 820 | are returned from the first such item in the display list. |
| 821 | If \fItagOrId\fR doesn't refer to any items, or if the item |
| 822 | contains no tags, then an empty string is returned. |
| 823 | .TP |
| 824 | \fIpathName \fBicursor \fItagOrId index\fR |
| 825 | Set the position of the insertion cursor for the item(s) given by \fItagOrId\fR |
| 826 | to just before the character whose position is given by \fIindex\fR. |
| 827 | If some or all of the items given by \fItagOrId\fR don't support |
| 828 | an insertion cursor then this command has no effect on them. |
| 829 | See INDICES above for a description of the |
| 830 | legal forms for \fIindex\fR. |
| 831 | Note: the insertion cursor is only displayed in an item if |
| 832 | that item currently has the keyboard focus (see the widget |
| 833 | command \fBfocus\fR, below), but the cursor position may |
| 834 | be set even when the item doesn't have the focus. |
| 835 | This command returns an empty string. |
| 836 | .TP |
| 837 | \fIpathName \fBindex \fItagOrId index\fR |
| 838 | This command returns a decimal string giving the numerical index |
| 839 | within \fItagOrId\fR corresponding to \fIindex\fR. |
| 840 | \fIIndex\fR gives a textual description of the desired position |
| 841 | as described in INDICES above. |
| 842 | Text items interpret \fIindex\fR as an index to a character, |
| 843 | line and polygon items interpret it as an index to a coordinate (an x,y pair). |
| 844 | The return value is guaranteed to lie between 0 and the number |
| 845 | of characters, or coordinates, within the item, inclusive. |
| 846 | If \fItagOrId\fR refers to multiple items, then the index |
| 847 | is processed in the first of these items that supports indexing |
| 848 | operations (in display list order). |
| 849 | .TP |
| 850 | \fIpathName \fBinsert \fItagOrId beforeThis string\fR |
| 851 | For each of the items given by \fItagOrId\fR, if the item supports |
| 852 | text or coordinate, insertion then \fIstring\fR is inserted into the item's |
| 853 | text just before the character, or coordinate, whose index is \fIbeforeThis\fR. |
| 854 | Text items interpret \fIbeforeThis\fR as an index to a character, |
| 855 | line and polygon items interpret it as an index to a coordinate (an x,y pair). |
| 856 | For lines and polygons the \fIstring\fR must be a valid coordinate |
| 857 | sequence. |
| 858 | See INDICES above for information about the forms allowed |
| 859 | for \fIbeforeThis\fR. |
| 860 | This command returns an empty string. |
| 861 | .TP |
| 862 | \fIpathName \fBitemcget\fR \fItagOrId\fR \fIoption\fR |
| 863 | Returns the current value of the configuration option for the |
| 864 | item given by \fItagOrId\fR whose name is \fIoption\fR. |
| 865 | This command is similar to the \fBcget\fR widget command except that |
| 866 | it applies to a particular item rather than the widget as a whole. |
| 867 | \fIOption\fR may have any of the values accepted by the \fBcreate\fR |
| 868 | widget command when the item was created. |
| 869 | If \fItagOrId\fR is a tag that refers to more than one item, |
| 870 | the first (lowest) such item is used. |
| 871 | .TP |
| 872 | \fIpathName \fBitemconfigure \fItagOrId\fR ?\fIoption\fR? ?\fIvalue\fR? ?\fIoption value ...\fR? |
| 873 | This command is similar to the \fBconfigure\fR widget command except |
| 874 | that it modifies item-specific options for the items given by |
| 875 | \fItagOrId\fR instead of modifying options for the overall |
| 876 | canvas widget. |
| 877 | If no \fIoption\fR is specified, returns a list describing all of |
| 878 | the available options for the first item given by \fItagOrId\fR |
| 879 | (see \fBTk_ConfigureInfo\fR for |
| 880 | information on the format of this list). If \fIoption\fR is specified |
| 881 | with no \fIvalue\fR, then the command returns a list describing the |
| 882 | one named option (this list will be identical to the corresponding |
| 883 | sublist of the value returned if no \fIoption\fR is specified). If |
| 884 | one or more \fIoption\-value\fR pairs are specified, then the command |
| 885 | modifies the given widget option(s) to have the given value(s) in |
| 886 | each of the items given by \fItagOrId\fR; in |
| 887 | this case the command returns an empty string. |
| 888 | The \fIoption\fRs and \fIvalue\fRs are the same as those permissible |
| 889 | in the \fBcreate\fR widget command when the item(s) were created; |
| 890 | see the sections describing individual item types below for details |
| 891 | on the legal options. |
| 892 | .TP |
| 893 | \fIpathName \fBlower \fItagOrId \fR?\fIbelowThis\fR? |
| 894 | Move all of the items given by \fItagOrId\fR to a new position |
| 895 | in the display list just before the item given by \fIbelowThis\fR. |
| 896 | If \fItagOrId\fR refers to more than one item then all are moved |
| 897 | but the relative order of the moved items will not be changed. |
| 898 | \fIBelowThis\fR is a tag or id; if it refers to more than one |
| 899 | item then the first (lowest) of these items in the display list is used |
| 900 | as the destination location for the moved items. |
| 901 | Note: this command has no effect on window items. Window items always |
| 902 | obscure other item types, and the stacking order of window items is |
| 903 | determined by the \fBraise\fR and \fBlower\fR commands, not the |
| 904 | \fBraise\fR and \fBlower\fR widget commands for canvases. |
| 905 | This command returns an empty string. |
| 906 | .TP |
| 907 | \fIpathName \fBmove \fItagOrId xAmount yAmount\fR |
| 908 | Move each of the items given by \fItagOrId\fR in the canvas coordinate |
| 909 | space by adding \fIxAmount\fR to the x-coordinate of each point |
| 910 | associated with the item and \fIyAmount\fR to the y-coordinate of |
| 911 | each point associated with the item. |
| 912 | This command returns an empty string. |
| 913 | .TP |
| 914 | \fIpathName \fBpostscript \fR?\fIoption value option value ...\fR? |
| 915 | Generate a Postscript representation for part or all of the canvas. |
| 916 | If the \fB\-file\fR option is specified then the Postscript is written |
| 917 | to a file and an empty string is returned; otherwise the Postscript |
| 918 | is returned as the result of the command. |
| 919 | If the interpreter that owns the canvas is marked as safe, the operation |
| 920 | will fail because safe interpreters are not allowed to write files. |
| 921 | If the \fB\-channel\fR option is specified, the argument denotes the name |
| 922 | of a channel already opened for writing. The Postscript is written to |
| 923 | that channel, and the channel is left open for further writing at the end |
| 924 | of the operation. |
| 925 | The Postscript is created in Encapsulated Postscript form using |
| 926 | version 3.0 of the Document Structuring Conventions. |
| 927 | Note: by default Postscript is only generated for information that |
| 928 | appears in the canvas's window on the screen. If the canvas is |
| 929 | freshly created it may still have its initial size of 1x1 pixel |
| 930 | so nothing will appear in the Postscript. To get around this problem |
| 931 | either invoke the "update" command to wait for the canvas window |
| 932 | to reach its final size, or else use the \fB\-width\fR and \fB\-height\fR |
| 933 | options to specify the area of the canvas to print. |
| 934 | The \fIoption\fR\-\fIvalue\fR argument pairs provide additional |
| 935 | information to control the generation of Postscript. The following |
| 936 | options are supported: |
| 937 | .RS |
| 938 | .TP |
| 939 | \fB\-colormap \fIvarName\fR |
| 940 | \fIVarName\fR must be the name of an array variable |
| 941 | that specifies a color mapping to use in the Postscript. |
| 942 | Each element of \fIvarName\fR must consist of Postscript |
| 943 | code to set a particular color value (e.g. ``\fB1.0 1.0 0.0 setrgbcolor\fR''). |
| 944 | When outputting color information in the Postscript, Tk checks |
| 945 | to see if there is an element of \fIvarName\fR with the same |
| 946 | name as the color. |
| 947 | If so, Tk uses the value of the element as the Postscript command |
| 948 | to set the color. |
| 949 | If this option hasn't been specified, or if there isn't an entry |
| 950 | in \fIvarName\fR for a given color, then Tk uses the red, green, |
| 951 | and blue intensities from the X color. |
| 952 | .TP |
| 953 | \fB\-colormode \fImode\fR |
| 954 | Specifies how to output color information. \fIMode\fR must be either |
| 955 | \fBcolor\fR (for full color output), \fBgray\fR (convert all colors |
| 956 | to their gray-scale equivalents) or \fBmono\fR (convert all colors |
| 957 | to black or white). |
| 958 | .TP |
| 959 | \fB\-file \fIfileName\fR |
| 960 | Specifies the name of the file in which to write the Postscript. |
| 961 | If this option isn't specified then the Postscript is returned as the |
| 962 | result of the command instead of being written to a file. |
| 963 | .TP |
| 964 | \fB\-fontmap \fIvarName\fR |
| 965 | \fIVarName\fR must be the name of an array variable |
| 966 | that specifies a font mapping to use in the Postscript. |
| 967 | Each element of \fIvarName\fR must consist of a Tcl list with |
| 968 | two elements, which are the name and point size of a Postscript font. |
| 969 | When outputting Postscript commands for a particular font, Tk |
| 970 | checks to see if \fIvarName\fR contains an element with the same |
| 971 | name as the font. |
| 972 | If there is such an element, then the font information contained in |
| 973 | that element is used in the Postscript. |
| 974 | Otherwise Tk attempts to guess what Postscript font to use. |
| 975 | Tk's guesses generally only work for well-known fonts such as |
| 976 | Times and Helvetica and Courier, and only if the X font name does not |
| 977 | omit any dashes up through the point size. |
| 978 | For example, \fB\-*\-Courier\-Bold\-R\-Normal\-\-*\-120\-*\fR will work but |
| 979 | \fB*Courier\-Bold\-R\-Normal*120*\fR will not; Tk needs the dashes to |
| 980 | parse the font name). |
| 981 | .TP |
| 982 | \fB\-height \fIsize\fR |
| 983 | Specifies the height of the area of the canvas to print. |
| 984 | Defaults to the height of the canvas window. |
| 985 | .TP |
| 986 | \fB\-pageanchor \fIanchor\fR |
| 987 | Specifies which point of the printed area of the canvas should appear over |
| 988 | the positioning point on the page (which is given by the \fB\-pagex\fR |
| 989 | and \fB\-pagey\fR options). |
| 990 | For example, \fB\-pageanchor n\fR means that the top center of the |
| 991 | area of the canvas being printed (as it appears in the canvas window) |
| 992 | should be over the positioning point. Defaults to \fBcenter\fR. |
| 993 | .TP |
| 994 | \fB\-pageheight \fIsize\fR |
| 995 | Specifies that the Postscript should be scaled in both x and y so |
| 996 | that the printed area is \fIsize\fR high on the Postscript page. |
| 997 | \fISize\fR consists of a floating-point number followed by |
| 998 | \fBc\fR for centimeters, \fBi\fR for inches, \fBm\fR for millimeters, |
| 999 | or \fBp\fR or nothing for printer's points (1/72 inch). |
| 1000 | Defaults to the height of the printed area on the screen. |
| 1001 | If both \fB\-pageheight\fR and \fB\-pagewidth\fR are specified then |
| 1002 | the scale factor from \fB\-pagewidth\fR is used (non-uniform scaling |
| 1003 | is not implemented). |
| 1004 | .TP |
| 1005 | \fB\-pagewidth \fIsize\fR |
| 1006 | Specifies that the Postscript should be scaled in both x and y so |
| 1007 | that the printed area is \fIsize\fR wide on the Postscript page. |
| 1008 | \fISize\fR has the same form as for \fB\-pageheight\fR. |
| 1009 | Defaults to the width of the printed area on the screen. |
| 1010 | If both \fB\-pageheight\fR and \fB\-pagewidth\fR are specified then |
| 1011 | the scale factor from \fB\-pagewidth\fR is used (non-uniform scaling |
| 1012 | is not implemented). |
| 1013 | .TP |
| 1014 | \fB\-pagex \fIposition\fR |
| 1015 | \fIPosition\fR gives the x-coordinate of the positioning point on |
| 1016 | the Postscript page, using any of the forms allowed for \fB\-pageheight\fR. |
| 1017 | Used in conjunction with the \fB\-pagey\fR and \fB\-pageanchor\fR options |
| 1018 | to determine where the printed area appears on the Postscript page. |
| 1019 | Defaults to the center of the page. |
| 1020 | .TP |
| 1021 | \fB\-pagey \fIposition\fR |
| 1022 | \fIPosition\fR gives the y-coordinate of the positioning point on |
| 1023 | the Postscript page, using any of the forms allowed for \fB\-pageheight\fR. |
| 1024 | Used in conjunction with the \fB\-pagex\fR and \fB\-pageanchor\fR options |
| 1025 | to determine where the printed area appears on the Postscript page. |
| 1026 | Defaults to the center of the page. |
| 1027 | .TP |
| 1028 | \fB\-rotate \fIboolean\fR |
| 1029 | \fIBoolean\fR specifies whether the printed area is to be rotated 90 |
| 1030 | degrees. |
| 1031 | In non-rotated output the x-axis of the printed area runs along |
| 1032 | the short dimension of the page (``portrait'' orientation); |
| 1033 | in rotated output the x-axis runs along the long dimension of the |
| 1034 | page (``landscape'' orientation). |
| 1035 | Defaults to non-rotated. |
| 1036 | .TP |
| 1037 | \fB\-width \fIsize\fR |
| 1038 | Specifies the width of the area of the canvas to print. |
| 1039 | Defaults to the width of the canvas window. |
| 1040 | .TP |
| 1041 | \fB\-x \fIposition\fR |
| 1042 | Specifies the x-coordinate of the left edge of the area of the |
| 1043 | canvas that is to be printed, in canvas coordinates, not window |
| 1044 | coordinates. |
| 1045 | Defaults to the coordinate of the left edge of the window. |
| 1046 | .TP |
| 1047 | \fB\-y \fIposition\fR |
| 1048 | Specifies the y-coordinate of the top edge of the area of the |
| 1049 | canvas that is to be printed, in canvas coordinates, not window |
| 1050 | coordinates. |
| 1051 | Defaults to the coordinate of the top edge of the window. |
| 1052 | .RE |
| 1053 | .TP |
| 1054 | \fIpathName \fBraise \fItagOrId \fR?\fIaboveThis\fR? |
| 1055 | Move all of the items given by \fItagOrId\fR to a new position |
| 1056 | in the display list just after the item given by \fIaboveThis\fR. |
| 1057 | If \fItagOrId\fR refers to more than one item then all are moved |
| 1058 | but the relative order of the moved items will not be changed. |
| 1059 | \fIAboveThis\fR is a tag or id; if it refers to more than one |
| 1060 | item then the last (topmost) of these items in the display list is used |
| 1061 | as the destination location for the moved items. |
| 1062 | Note: this command has no effect on window items. Window items always |
| 1063 | obscure other item types, and the stacking order of window items is |
| 1064 | determined by the \fBraise\fR and \fBlower\fR commands, not the |
| 1065 | \fBraise\fR and \fBlower\fR widget commands for canvases. |
| 1066 | This command returns an empty string. |
| 1067 | .TP |
| 1068 | \fIpathName \fBscale \fItagOrId xOrigin yOrigin xScale yScale\fR |
| 1069 | Rescale all of the items given by \fItagOrId\fR in canvas coordinate |
| 1070 | space. |
| 1071 | \fIXOrigin\fR and \fIyOrigin\fR identify the origin for the scaling |
| 1072 | operation and \fIxScale\fR and \fIyScale\fR identify the scale |
| 1073 | factors for x- and y-coordinates, respectively (a scale factor of |
| 1074 | 1.0 implies no change to that coordinate). |
| 1075 | For each of the points defining each item, the x-coordinate is |
| 1076 | adjusted to change the distance from \fIxOrigin\fR by a factor |
| 1077 | of \fIxScale\fR. |
| 1078 | Similarly, each y-coordinate is adjusted to change the distance |
| 1079 | from \fIyOrigin\fR by a factor of \fIyScale\fR. |
| 1080 | This command returns an empty string. |
| 1081 | .TP |
| 1082 | \fIpathName \fBscan\fR \fIoption args\fR |
| 1083 | This command is used to implement scanning on canvases. It has |
| 1084 | two forms, depending on \fIoption\fR: |
| 1085 | .RS |
| 1086 | .TP |
| 1087 | \fIpathName \fBscan mark \fIx y\fR |
| 1088 | Records \fIx\fR and \fIy\fR and the canvas's current view; used |
| 1089 | in conjunction with later \fBscan dragto\fR commands. |
| 1090 | Typically this command is associated with a mouse button press in |
| 1091 | the widget and \fIx\fR and \fIy\fR are the coordinates of the |
| 1092 | mouse. It returns an empty string. |
| 1093 | .TP |
| 1094 | \fIpathName \fBscan dragto \fIx y ?gain?\fR. |
| 1095 | This command computes the difference between its \fIx\fR and \fIy\fR |
| 1096 | arguments (which are typically mouse coordinates) and the \fIx\fR and |
| 1097 | \fIy\fR arguments to the last \fBscan mark\fR command for the widget. |
| 1098 | It then adjusts the view by \fIgain\fR times the |
| 1099 | difference in coordinates, where \fIgain\fR defaults to 10. |
| 1100 | This command is typically associated |
| 1101 | with mouse motion events in the widget, to produce the effect of |
| 1102 | dragging the canvas at high speed through its window. The return |
| 1103 | value is an empty string. |
| 1104 | .RE |
| 1105 | .TP |
| 1106 | \fIpathName \fBselect \fIoption\fR ?\fItagOrId arg\fR? |
| 1107 | Manipulates the selection in one of several ways, depending on |
| 1108 | \fIoption\fR. |
| 1109 | The command may take any of the forms described below. |
| 1110 | In all of the descriptions below, \fItagOrId\fR must refer to |
| 1111 | an item that supports indexing and selection; if it refers to |
| 1112 | multiple items then the first of |
| 1113 | these that supports indexing and the selection is used. |
| 1114 | \fIIndex\fR gives a textual description of a position |
| 1115 | within \fItagOrId\fR, as described in INDICES above. |
| 1116 | .RS |
| 1117 | .TP |
| 1118 | \fIpathName \fBselect adjust \fItagOrId index\fR |
| 1119 | Locate the end of the selection in \fItagOrId\fR nearest |
| 1120 | to the character given by \fIindex\fR, and adjust that |
| 1121 | end of the selection to be at \fIindex\fR (i.e. including |
| 1122 | but not going beyond \fIindex\fR). |
| 1123 | The other end of the selection is made the anchor point |
| 1124 | for future \fBselect to\fR commands. |
| 1125 | If the selection isn't currently in \fItagOrId\fR then |
| 1126 | this command behaves the same as the \fBselect to\fR widget |
| 1127 | command. |
| 1128 | Returns an empty string. |
| 1129 | .TP |
| 1130 | \fIpathName \fBselect clear\fR |
| 1131 | Clear the selection if it is in this widget. |
| 1132 | If the selection isn't in this widget then the command |
| 1133 | has no effect. |
| 1134 | Returns an empty string. |
| 1135 | .TP |
| 1136 | \fIpathName \fBselect from \fItagOrId index\fR |
| 1137 | Set the selection anchor point for the widget to be just |
| 1138 | before the character |
| 1139 | given by \fIindex\fR in the item given by \fItagOrId\fR. |
| 1140 | This command doesn't change the selection; it just sets |
| 1141 | the fixed end of the selection for future \fBselect to\fR |
| 1142 | commands. |
| 1143 | Returns an empty string. |
| 1144 | .TP |
| 1145 | \fIpathName \fBselect item\fR |
| 1146 | Returns the id of the selected item, if the selection is in an |
| 1147 | item in this canvas. |
| 1148 | If the selection is not in this canvas then an empty string |
| 1149 | is returned. |
| 1150 | .TP |
| 1151 | \fIpathName \fBselect to \fItagOrId index\fR |
| 1152 | Set the selection to consist of those characters of \fItagOrId\fR |
| 1153 | between the selection anchor point and |
| 1154 | \fIindex\fR. |
| 1155 | The new selection will include the character given by \fIindex\fR; |
| 1156 | it will include the character given by the anchor point only if |
| 1157 | \fIindex\fR is greater than or equal to the anchor point. |
| 1158 | The anchor point is determined by the most recent \fBselect adjust\fR |
| 1159 | or \fBselect from\fR command for this widget. |
| 1160 | If the selection anchor point for the widget isn't currently in |
| 1161 | \fItagOrId\fR, then it is set to the same character given |
| 1162 | by \fIindex\fR. |
| 1163 | Returns an empty string. |
| 1164 | .RE |
| 1165 | .TP |
| 1166 | \fIpathName \fBtype\fI tagOrId\fR |
| 1167 | Returns the type of the item given by \fItagOrId\fR, such as |
| 1168 | \fBrectangle\fR or \fBtext\fR. |
| 1169 | If \fItagOrId\fR refers to more than one item, then the type |
| 1170 | of the first item in the display list is returned. |
| 1171 | If \fItagOrId\fR doesn't refer to any items at all then |
| 1172 | an empty string is returned. |
| 1173 | .TP |
| 1174 | \fIpathName \fBxview \fR?\fIargs\fR? |
| 1175 | This command is used to query and change the horizontal position of the |
| 1176 | information displayed in the canvas's window. |
| 1177 | It can take any of the following forms: |
| 1178 | .RS |
| 1179 | .TP |
| 1180 | \fIpathName \fBxview\fR |
| 1181 | Returns a list containing two elements. |
| 1182 | Each element is a real fraction between 0 and 1; together they describe |
| 1183 | the horizontal span that is visible in the window. |
| 1184 | For example, if the first element is .2 and the second element is .6, |
| 1185 | 20% of the canvas's area (as defined by the \fB\-scrollregion\fR option) |
| 1186 | is off-screen to the left, the middle 40% is visible |
| 1187 | in the window, and 40% of the canvas is off-screen to the right. |
| 1188 | These are the same values passed to scrollbars via the \fB\-xscrollcommand\fR |
| 1189 | option. |
| 1190 | .TP |
| 1191 | \fIpathName \fBxview moveto\fI fraction\fR |
| 1192 | Adjusts the view in the window so that \fIfraction\fR of the |
| 1193 | total width of the canvas is off-screen to the left. |
| 1194 | \fIFraction\fR must be a fraction between 0 and 1. |
| 1195 | .TP |
| 1196 | \fIpathName \fBxview scroll \fInumber what\fR |
| 1197 | This command shifts the view in the window left or right according to |
| 1198 | \fInumber\fR and \fIwhat\fR. |
| 1199 | \fINumber\fR must be an integer. |
| 1200 | \fIWhat\fR must be either \fBunits\fR or \fBpages\fR or an abbreviation |
| 1201 | of one of these. |
| 1202 | If \fIwhat\fR is \fBunits\fR, the view adjusts left or right in units |
| 1203 | of the \fBxScrollIncrement\fR option, if it is greater than zero, |
| 1204 | or in units of one-tenth the window's width otherwise. |
| 1205 | If \fIwhat is \fBpages\fR then the view |
| 1206 | adjusts in units of nine-tenths the window's width. |
| 1207 | If \fInumber\fR is negative then information farther to the left |
| 1208 | becomes visible; if it is positive then information farther to the right |
| 1209 | becomes visible. |
| 1210 | .RE |
| 1211 | .TP |
| 1212 | \fIpathName \fByview \fI?args\fR? |
| 1213 | This command is used to query and change the vertical position of the |
| 1214 | information displayed in the canvas's window. |
| 1215 | It can take any of the following forms: |
| 1216 | .RS |
| 1217 | .TP |
| 1218 | \fIpathName \fByview\fR |
| 1219 | Returns a list containing two elements. |
| 1220 | Each element is a real fraction between 0 and 1; together they describe |
| 1221 | the vertical span that is visible in the window. |
| 1222 | For example, if the first element is .6 and the second element is 1.0, |
| 1223 | the lowest 40% of the canvas's area (as defined by the \fB\-scrollregion\fR |
| 1224 | option) is visible in the window. |
| 1225 | These are the same values passed to scrollbars via the \fB\-yscrollcommand\fR |
| 1226 | option. |
| 1227 | .TP |
| 1228 | \fIpathName \fByview moveto\fI fraction\fR |
| 1229 | Adjusts the view in the window so that \fIfraction\fR of the canvas's |
| 1230 | area is off-screen to the top. |
| 1231 | \fIFraction\fR is a fraction between 0 and 1. |
| 1232 | .TP |
| 1233 | \fIpathName \fByview scroll \fInumber what\fR |
| 1234 | This command adjusts the view in the window up or down according to |
| 1235 | \fInumber\fR and \fIwhat\fR. |
| 1236 | \fINumber\fR must be an integer. |
| 1237 | \fIWhat\fR must be either \fBunits\fR or \fBpages\fR. |
| 1238 | If \fIwhat\fR is \fBunits\fR, the view adjusts up or down in units |
| 1239 | of the \fByScrollIncrement\fR option, if it is greater than zero, |
| 1240 | or in units of one-tenth the window's height otherwise. |
| 1241 | If \fIwhat\fR is \fBpages\fR then |
| 1242 | the view adjusts in units of nine-tenths the window's height. |
| 1243 | If \fInumber\fR is negative then higher information becomes |
| 1244 | visible; if it is positive then lower information |
| 1245 | becomes visible. |
| 1246 | .RE |
| 1247 | .SH "OVERVIEW OF ITEM TYPES" |
| 1248 | .PP |
| 1249 | The sections below describe the various types of items supported |
| 1250 | by canvas widgets. Each item type is characterized by two things: |
| 1251 | first, the form of the \fBcreate\fR command used to create |
| 1252 | instances of the type; and second, a set of configuration options |
| 1253 | for items of that type, which may be used in the |
| 1254 | \fBcreate\fR and \fBitemconfigure\fR widget commands. |
| 1255 | Most items don't support indexing or selection or the commands |
| 1256 | related to them, such as \fBindex\fR and \fBinsert\fR. |
| 1257 | Where items do support these facilities, it is noted explicitly |
| 1258 | in the descriptions below. |
| 1259 | At present, text, line and polygon items provide this support. |
| 1260 | For lines and polygons the indexing facility is used to manipulate |
| 1261 | the coordinates of the item. |
| 1262 | .SH "COMMON ITEM OPTIONS" |
| 1263 | .PP |
| 1264 | Many items share a common set of options. These options are |
| 1265 | explained here, and then referred to be each widget type for brevity. |
| 1266 | .PP |
| 1267 | .TP |
| 1268 | \fB\-dash \fIpattern\fR |
| 1269 | .TP |
| 1270 | \fB\-activedash \fIpattern\fR |
| 1271 | .TP |
| 1272 | \fB\-disableddash \fIpattern\fR |
| 1273 | This option specifies dash patterns for the normal, active |
| 1274 | state, and disabled state of an item. |
| 1275 | \fIpattern\fR may have any of the forms accepted by \fBTk_GetDash\fR. |
| 1276 | If the dash options are omitted then the default is a solid outline. |
| 1277 | See "DASH PATTERNS" for more information. |
| 1278 | .TP |
| 1279 | \fB\-dashoffset \fIoffset\fR |
| 1280 | The starting \fIoffset\fR in pixels into the pattern provided by the |
| 1281 | \fB\-dash\fR option. \fB\-dashoffset\fR is ignored if there is no |
| 1282 | \fB-dash\fR pattern. The \fIoffset\fR may have any of the forms described |
| 1283 | in the \fBCOORDINATES\fR section above. |
| 1284 | .TP |
| 1285 | \fB\-fill \fIcolor\fR |
| 1286 | .TP |
| 1287 | \fB\-activefill \fIcolor\fR |
| 1288 | .TP |
| 1289 | \fB\-disabledfill \fIcolor\fR |
| 1290 | Specifies the color to be used to fill item's area. |
| 1291 | in its normal, active, and disabled states, |
| 1292 | \fIColor\fR may have any of the forms accepted by \fBTk_GetColor\fR. |
| 1293 | If \fIcolor\fR is an empty string (the default), |
| 1294 | then the item will not be filled. |
| 1295 | For the line item, it specifies the color of the line drawn. |
| 1296 | For the text item, it specifies the foreground color of the text. |
| 1297 | .TP |
| 1298 | \fB\-outline \fIcolor\fR |
| 1299 | .TP |
| 1300 | \fB\-activeoutline \fIcolor\fR |
| 1301 | .TP |
| 1302 | \fB\-disabledoutline \fIcolor\fR |
| 1303 | This option specifies the color that should be used to draw the |
| 1304 | outline of the item in its normal, active and disabled states. |
| 1305 | \fIColor\fR may have any of the forms accepted by \fBTk_GetColor\fR. |
| 1306 | This option defaults to \fBblack\fR. If \fIcolor\fR is specified |
| 1307 | as an empty string then no outline is drawn for the item. |
| 1308 | .TP |
| 1309 | \fB\-offset \fIoffset\fR |
| 1310 | Specifies the offset of stipples. The offset value can be of the form |
| 1311 | \fBx,y\fR or \fBside\fR, where side can be \fBn\fR, \fBne\fR, \fBe\fR, |
| 1312 | \fBse\fR, \fBs\fR, \fBsw\fR, \fBw\fR, \fBnw\fR, or \fBcenter\fR. In the |
| 1313 | first case the origin is the origin of the toplevel of the current window. |
| 1314 | For the canvas itself and canvas objects the origin is the canvas origin, |
| 1315 | but putting \fB#\fR in front of the coordinate pair indicates using the |
| 1316 | toplevel origin instead. For canvas objects, the \fB-offset\fR option is |
| 1317 | used for stippling as well. For the line and polygon canvas items you can |
| 1318 | also specify an index as argument, which connects the stipple origin to one |
| 1319 | of the coordinate points of the line/polygon. |
| 1320 | .TP |
| 1321 | \fB\-outlinestipple \fIbitmap\fR |
| 1322 | .TP |
| 1323 | \fB\-activeoutlinestipple \fIbitmap\fR |
| 1324 | .TP |
| 1325 | \fB\-disabledoutlinestipple \fIbitmap\fR |
| 1326 | This option specifies stipple patterns that should be used to draw the |
| 1327 | outline of the item in its normal, active and disabled states. |
| 1328 | Indicates that the outline for the item should be drawn with a stipple pattern; |
| 1329 | \fIbitmap\fR specifies the stipple pattern to use, in any of the |
| 1330 | forms accepted by \fBTk_GetBitmap\fR. |
| 1331 | If the \fB\-outline\fR option hasn't been specified then this option |
| 1332 | has no effect. |
| 1333 | If \fIbitmap\fR is an empty string (the default), then the outline is drawn |
| 1334 | in a solid fashion. |
| 1335 | .TP |
| 1336 | \fB\-stipple \fIbitmap\fR |
| 1337 | .TP |
| 1338 | \fB\-activestipple \fIbitmap\fR |
| 1339 | .TP |
| 1340 | \fB\-disabledstipple \fIbitmap\fR |
| 1341 | This option specifies stipple patterns that should be used to fill |
| 1342 | the item in its normal, active and disabled states. |
| 1343 | \fIbitmap\fR specifies the stipple pattern to use, in any of the |
| 1344 | forms accepted by \fBTk_GetBitmap\fR. |
| 1345 | If the \fB\-fill\fR option hasn't been specified then this option |
| 1346 | has no effect. |
| 1347 | If \fIbitmap\fR is an empty string (the default), then filling is done |
| 1348 | in a solid fashion. |
| 1349 | For the text item, it affects the actual text. |
| 1350 | .TP |
| 1351 | \fB\-state \fIstate\fR |
| 1352 | This allows an item to override the canvas widget's global \fIstate\fR |
| 1353 | option. It takes the same values: |
| 1354 | \fInormal\fR, \fIdisabled\fR or \fIhidden\fR. |
| 1355 | .TP |
| 1356 | \fB\-tags \fItagList\fR |
| 1357 | Specifies a set of tags to apply to the item. |
| 1358 | \fITagList\fR consists of a list of tag names, which replace any |
| 1359 | existing tags for the item. \fITagList\fR may be an empty list. |
| 1360 | .TP |
| 1361 | \fB\-width \fIoutlineWidth\fR |
| 1362 | .TP |
| 1363 | \fB\-activewidth \fIoutlineWidth\fR |
| 1364 | .TP |
| 1365 | \fB\-disabledwidth \fIoutlineWidth\fR |
| 1366 | Specifies the width of the outline to be drawn around |
| 1367 | the item's region, in its normal, active and disabled states. |
| 1368 | \fIoutlineWidth\fR may be in any of the forms described in the |
| 1369 | \fBCOORDINATES\fR section above. |
| 1370 | If the \fB\-outline\fR option has been specified as an empty string then |
| 1371 | this option has no effect. This option defaults to 1.0. |
| 1372 | For arcs, wide outlines will be drawn centered on the edges of the |
| 1373 | arc's region. |
| 1374 | .SH "ARC ITEMS" |
| 1375 | .PP |
| 1376 | Items of type \fBarc\fR appear on the display as arc-shaped regions. |
| 1377 | An arc is a section of an oval delimited by two angles (specified |
| 1378 | by the \fB\-start\fR and \fB\-extent\fR options) and displayed in |
| 1379 | one of several ways (specified by the \fB\-style\fR option). |
| 1380 | Arcs are created with widget commands of the following form: |
| 1381 | .CS |
| 1382 | \fIpathName \fBcreate arc \fIx1 y1 x2 y2 \fR?\fIoption value option value ...\fR? |
| 1383 | \fIpathName \fBcreate arc \fIcoordList\fR ?\fIoption value option value ...\fR? |
| 1384 | .CE |
| 1385 | The arguments \fIx1\fR, \fIy1\fR, \fIx2\fR, and \fIy2\fR or \fIcoordList\fR give |
| 1386 | the coordinates of two diagonally opposite corners of a |
| 1387 | rectangular region enclosing the oval that defines the arc. |
| 1388 | After the coordinates there may be any number of \fIoption\fR\-\fIvalue\fR |
| 1389 | pairs, each of which sets one of the configuration options |
| 1390 | for the item. These same \fIoption\fR\-\fIvalue\fR pairs may be |
| 1391 | used in \fBitemconfigure\fR widget commands to change the item's |
| 1392 | configuration. |
| 1393 | .br |
| 1394 | The following standard options are supported by arcs: |
| 1395 | .CS |
| 1396 | \-dash |
| 1397 | \-activedash |
| 1398 | \-disableddash |
| 1399 | \-dashoffset |
| 1400 | \-fill |
| 1401 | \-activefill |
| 1402 | \-disabledfill |
| 1403 | \-offset |
| 1404 | \-outline |
| 1405 | \-activeoutline |
| 1406 | \-disabledoutline |
| 1407 | \-outlinestipple |
| 1408 | \-activeoutlinestipple |
| 1409 | \-disabledoutlinestipple |
| 1410 | \-stipple |
| 1411 | \-activestipple |
| 1412 | \-disabledstipple |
| 1413 | \-state |
| 1414 | \-tags |
| 1415 | \-width |
| 1416 | \-activewidth |
| 1417 | \-disabledwidth |
| 1418 | .CE |
| 1419 | The following extra options are supported for arcs: |
| 1420 | .TP |
| 1421 | \fB\-extent \fIdegrees\fR |
| 1422 | Specifies the size of the angular range occupied by the arc. |
| 1423 | The arc's range extends for \fIdegrees\fR degrees counter-clockwise |
| 1424 | from the starting angle given by the \fB\-start\fR option. |
| 1425 | \fIDegrees\fR may be negative. |
| 1426 | If it is greater than 360 or less than -360, then \fIdegrees\fR |
| 1427 | modulo 360 is used as the extent. |
| 1428 | .TP |
| 1429 | \fB\-start \fIdegrees\fR |
| 1430 | Specifies the beginning of the angular range occupied by the |
| 1431 | arc. |
| 1432 | \fIDegrees\fR is given in units of degrees measured counter-clockwise |
| 1433 | from the 3-o'clock position; it may be either positive or negative. |
| 1434 | .TP |
| 1435 | \fB\-style \fItype\fR |
| 1436 | Specifies how to draw the arc. If \fItype\fR is \fBpieslice\fR |
| 1437 | (the default) then the arc's region is defined by a section |
| 1438 | of the oval's perimeter plus two line segments, one between the center |
| 1439 | of the oval and each end of the perimeter section. |
| 1440 | If \fItype\fR is \fBchord\fR then the arc's region is defined |
| 1441 | by a section of the oval's perimeter plus a single line segment |
| 1442 | connecting the two end points of the perimeter section. |
| 1443 | If \fItype\fR is \fBarc\fR then the arc's region consists of |
| 1444 | a section of the perimeter alone. |
| 1445 | In this last case the \fB\-fill\fR option is ignored. |
| 1446 | .SH "BITMAP ITEMS" |
| 1447 | .PP |
| 1448 | Items of type \fBbitmap\fR appear on the display as images with |
| 1449 | two colors, foreground and background. |
| 1450 | Bitmaps are created with widget commands of the following form: |
| 1451 | .CS |
| 1452 | \fIpathName \fBcreate bitmap \fIx y \fR?\fIoption value option value ...\fR? |
| 1453 | \fIpathName \fBcreate bitmap \fIcoordList\fR ?\fIoption value option value ...\fR? |
| 1454 | .CE |
| 1455 | The arguments \fIx\fR and \fIy\fR or \fIcoordList\fR specify the coordinates of a |
| 1456 | point used to position the bitmap on the display (see the \fB\-anchor\fR |
| 1457 | option below for more information on how bitmaps are displayed). |
| 1458 | After the coordinates there may be any number of \fIoption\fR\-\fIvalue\fR |
| 1459 | pairs, each of which sets one of the configuration options |
| 1460 | for the item. These same \fIoption\fR\-\fIvalue\fR pairs may be |
| 1461 | used in \fBitemconfigure\fR widget commands to change the item's |
| 1462 | configuration. |
| 1463 | .br |
| 1464 | The following standard options are supported by bitmaps: |
| 1465 | .CS |
| 1466 | \-state |
| 1467 | \-tags |
| 1468 | .CE |
| 1469 | The following extra options are supported for bitmaps: |
| 1470 | .TP |
| 1471 | \fB\-anchor \fIanchorPos\fR |
| 1472 | \fIAnchorPos\fR tells how to position the bitmap relative to the |
| 1473 | positioning point for the item; it may have any of the forms |
| 1474 | accepted by \fBTk_GetAnchor\fR. For example, if \fIanchorPos\fR |
| 1475 | is \fBcenter\fR then the bitmap is centered on the point; if |
| 1476 | \fIanchorPos\fR is \fBn\fR then the bitmap will be drawn so that |
| 1477 | its top center point is at the positioning point. |
| 1478 | This option defaults to \fBcenter\fR. |
| 1479 | .TP |
| 1480 | \fB\-background \fIcolor\fR |
| 1481 | .TP |
| 1482 | \fB\-activebackground \fIbitmap\fR |
| 1483 | .TP |
| 1484 | \fB\-disabledbackground \fIbitmap\fR |
| 1485 | Specifies the color to use for each of the bitmap's '0' valued pixels |
| 1486 | in its normal, active and disabled states. |
| 1487 | \fIColor\fR may have any of the forms accepted by \fBTk_GetColor\fR. |
| 1488 | If this option isn't specified, or if it is specified as an empty |
| 1489 | string, then nothing is displayed where the bitmap pixels are 0; this |
| 1490 | produces a transparent effect. |
| 1491 | .TP |
| 1492 | \fB\-bitmap \fIbitmap\fR |
| 1493 | .TP |
| 1494 | \fB\-activebitmap \fIbitmap\fR |
| 1495 | .TP |
| 1496 | \fB\-disabledbitmap \fIbitmap\fR |
| 1497 | Specifies the bitmaps to display in the item in its normal, active and |
| 1498 | disabled states. |
| 1499 | \fIBitmap\fR may have any of the forms accepted by \fBTk_GetBitmap\fR. |
| 1500 | .TP |
| 1501 | \fB\-foreground \fIcolor\fR |
| 1502 | .TP |
| 1503 | \fB\-activeforeground \fIbitmap\fR |
| 1504 | .TP |
| 1505 | \fB\-disabledforeground \fIbitmap\fR |
| 1506 | Specifies the color to use for each of the bitmap's '1' valued pixels |
| 1507 | in its normal, active and disabled states. |
| 1508 | \fIColor\fR may have any of the forms accepted by \fBTk_GetColor\fR and |
| 1509 | defaults to \fBblack\fR. |
| 1510 | .SH "IMAGE ITEMS" |
| 1511 | .PP |
| 1512 | Items of type \fBimage\fR are used to display images on a |
| 1513 | canvas. |
| 1514 | Images are created with widget commands of the following form: |
| 1515 | .CS |
| 1516 | \fIpathName \fBcreate image \fIx y \fR?\fIoption value option value ...\fR? |
| 1517 | \fIpathName \fBcreate image \fIcoordList\fR ?\fIoption value option value ...\fR? |
| 1518 | .CE |
| 1519 | The arguments \fIx\fR and \fIy\fR or \fIcoordList\fR specify the coordinates of a |
| 1520 | point used to position the image on the display (see the \fB\-anchor\fR |
| 1521 | option below for more information). |
| 1522 | After the coordinates there may be any number of \fIoption\fR\-\fIvalue\fR |
| 1523 | pairs, each of which sets one of the configuration options |
| 1524 | for the item. These same \fIoption\fR\-\fIvalue\fR pairs may be |
| 1525 | used in \fBitemconfigure\fR widget commands to change the item's |
| 1526 | configuration. |
| 1527 | .br |
| 1528 | The following standard options are supported by images: |
| 1529 | .CS |
| 1530 | \-state |
| 1531 | \-tags |
| 1532 | .CE |
| 1533 | The following extra options are supported for images: |
| 1534 | .TP |
| 1535 | \fB\-anchor \fIanchorPos\fR |
| 1536 | \fIAnchorPos\fR tells how to position the image relative to the |
| 1537 | positioning point for the item; it may have any of the forms |
| 1538 | accepted by \fBTk_GetAnchor\fR. For example, if \fIanchorPos\fR |
| 1539 | is \fBcenter\fR then the image is centered on the point; if |
| 1540 | \fIanchorPos\fR is \fBn\fR then the image will be drawn so that |
| 1541 | its top center point is at the positioning point. |
| 1542 | This option defaults to \fBcenter\fR. |
| 1543 | .TP |
| 1544 | \fB\-image \fIname\fR |
| 1545 | .TP |
| 1546 | \fB\-activeimage \fIname\fR |
| 1547 | .TP |
| 1548 | \fB\-disabledimage \fIname\fR |
| 1549 | Specifies the name of the images to display in the item in is normal, |
| 1550 | active and disabled states. |
| 1551 | This image must have been created previously with the |
| 1552 | \fBimage create\fR command. |
| 1553 | .SH "LINE ITEMS" |
| 1554 | .PP |
| 1555 | Items of type \fBline\fR appear on the display as one or more connected |
| 1556 | line segments or curves. |
| 1557 | Line items support coordinate indexing operations using the canvas |
| 1558 | widget commands: \fBdchars, index, insert.\fR |
| 1559 | Lines are created with widget commands of the following form: |
| 1560 | .CS |
| 1561 | \fIpathName \fBcreate line \fIx1 y1... xn yn \fR?\fIoption value option value ...\fR? |
| 1562 | \fIpathName \fBcreate line \fIcoordList\fR ?\fIoption value option value ...\fR? |
| 1563 | .CE |
| 1564 | The arguments \fIx1\fR through \fIyn\fR or \fIcoordList\fR give |
| 1565 | the coordinates for a series of two or more points that describe |
| 1566 | a series of connected line segments. |
| 1567 | After the coordinates there may be any number of \fIoption\fR\-\fIvalue\fR |
| 1568 | pairs, each of which sets one of the configuration options |
| 1569 | for the item. These same \fIoption\fR\-\fIvalue\fR pairs may be |
| 1570 | used in \fBitemconfigure\fR widget commands to change the item's |
| 1571 | configuration. |
| 1572 | .br |
| 1573 | The following standard options are supported by lines: |
| 1574 | .CS |
| 1575 | \-dash |
| 1576 | \-activedash |
| 1577 | \-disableddash |
| 1578 | \-dashoffset |
| 1579 | \-fill |
| 1580 | \-activefill |
| 1581 | \-disabledfill |
| 1582 | \-stipple |
| 1583 | \-activestipple |
| 1584 | \-disabledstipple |
| 1585 | \-state |
| 1586 | \-tags |
| 1587 | \-width |
| 1588 | \-activewidth |
| 1589 | \-disabledwidth |
| 1590 | .CE |
| 1591 | The following extra options are supported for lines: |
| 1592 | .TP |
| 1593 | \fB\-arrow \fIwhere\fR |
| 1594 | Indicates whether or not arrowheads are to be drawn at one or both |
| 1595 | ends of the line. |
| 1596 | \fIWhere\fR must have one of the values \fBnone\fR (for no arrowheads), |
| 1597 | \fBfirst\fR (for an arrowhead at the first point of the line), |
| 1598 | \fBlast\fR (for an arrowhead at the last point of the line), or |
| 1599 | \fBboth\fR (for arrowheads at both ends). |
| 1600 | This option defaults to \fBnone\fR. |
| 1601 | .TP |
| 1602 | \fB\-arrowshape \fIshape\fR |
| 1603 | This option indicates how to draw arrowheads. |
| 1604 | The \fIshape\fR argument must be a list with three elements, each |
| 1605 | specifying a distance in any of the forms described in |
| 1606 | the \fBCOORDINATES\fR section above. |
| 1607 | The first element of the list gives the distance along the line |
| 1608 | from the neck of the arrowhead to its tip. |
| 1609 | The second element gives the distance along the line from the |
| 1610 | trailing points of the arrowhead to the tip, and the third |
| 1611 | element gives the distance from the outside edge of the line to the |
| 1612 | trailing points. |
| 1613 | If this option isn't specified then Tk picks a ``reasonable'' shape. |
| 1614 | .TP |
| 1615 | \fB\-capstyle \fIstyle\fR |
| 1616 | Specifies the ways in which caps are to be drawn at the endpoints |
| 1617 | of the line. |
| 1618 | \fIStyle\fR may have any of the forms accepted by \fBTk_GetCapStyle\fR |
| 1619 | (\fBbutt\fR, \fBprojecting\fR, or \fBround\fR). |
| 1620 | If this option isn't specified then it defaults to \fBbutt\fR. |
| 1621 | Where arrowheads are drawn the cap style is ignored. |
| 1622 | .TP |
| 1623 | \fB\-joinstyle \fIstyle\fR |
| 1624 | Specifies the ways in which joints are to be drawn at the vertices |
| 1625 | of the line. |
| 1626 | \fIStyle\fR may have any of the forms accepted by \fBTk_GetCapStyle\fR |
| 1627 | (\fBbevel\fR, \fBmiter\fR, or \fBround\fR). |
| 1628 | If this option isn't specified then it defaults to \fBmiter\fR. |
| 1629 | If the line only contains two points then this option is |
| 1630 | irrelevant. |
| 1631 | .TP |
| 1632 | \fB\-smooth \fIsmoothMethod\fR |
| 1633 | \fIsmoothMethod\fR must have one of the forms accepted by |
| 1634 | \fBTcl_GetBoolean\fR or a line smoothing method. Only \fBbezier\fR is |
| 1635 | supported in the core, but more can be added at runtime. If a boolean |
| 1636 | false value or empty string is given, no smoothing is applied. A boolean |
| 1637 | truth value assume \fBbezier\fR smoothing. |
| 1638 | It indicates whether or not the line should be drawn as a curve. |
| 1639 | If so, the line is rendered as a set of parabolic splines: one spline |
| 1640 | is drawn for the first and second line segments, one for the second |
| 1641 | and third, and so on. Straight-line segments can be generated within |
| 1642 | a curve by duplicating the end-points of the desired line segment. |
| 1643 | .TP |
| 1644 | \fB\-splinesteps \fInumber\fR |
| 1645 | Specifies the degree of smoothness desired for curves: each spline |
| 1646 | will be approximated with \fInumber\fR line segments. This |
| 1647 | option is ignored unless the \fB\-smooth\fR option is true. |
| 1648 | |
| 1649 | .SH "OVAL ITEMS" |
| 1650 | .PP |
| 1651 | Items of type \fBoval\fR appear as circular or oval regions on |
| 1652 | the display. Each oval may have an outline, a fill, or |
| 1653 | both. Ovals are created with widget commands of the |
| 1654 | following form: |
| 1655 | .CS |
| 1656 | \fIpathName \fBcreate oval \fIx1 y1 x2 y2 \fR?\fIoption value option value ...\fR? |
| 1657 | \fIpathName \fBcreate oval \fIcoordList\fR ?\fIoption value option value ...\fR? |
| 1658 | .CE |
| 1659 | The arguments \fIx1\fR, \fIy1\fR, \fIx2\fR, and \fIy2\fR or \fIcoordList\fR give |
| 1660 | the coordinates of two diagonally opposite corners of a |
| 1661 | rectangular region enclosing the oval. |
| 1662 | The oval will include the top and left edges of the rectangle |
| 1663 | not the lower or right edges. |
| 1664 | If the region is square then the resulting oval is circular; |
| 1665 | otherwise it is elongated in shape. |
| 1666 | After the coordinates there may be any number of \fIoption\fR\-\fIvalue\fR |
| 1667 | pairs, each of which sets one of the configuration options |
| 1668 | for the item. These same \fIoption\fR\-\fIvalue\fR pairs may be |
| 1669 | used in \fBitemconfigure\fR widget commands to change the item's |
| 1670 | configuration. |
| 1671 | .br |
| 1672 | The following standard options are supported by ovals: |
| 1673 | .CS |
| 1674 | \-dash |
| 1675 | \-activedash |
| 1676 | \-disableddash |
| 1677 | \-dashoffset |
| 1678 | \-fill |
| 1679 | \-activefill |
| 1680 | \-disabledfill |
| 1681 | \-offset |
| 1682 | \-outline |
| 1683 | \-activeoutline |
| 1684 | \-disabledoutline |
| 1685 | \-outlinestipple |
| 1686 | \-activeoutlinestipple |
| 1687 | \-disabledoutlinestipple |
| 1688 | \-stipple |
| 1689 | \-activestipple |
| 1690 | \-disabledstipple |
| 1691 | \-state |
| 1692 | \-tags |
| 1693 | \-width |
| 1694 | \-activewidth |
| 1695 | \-disabledwidth |
| 1696 | .CE |
| 1697 | .SH "POLYGON ITEMS" |
| 1698 | .PP |
| 1699 | Items of type \fBpolygon\fR appear as polygonal or curved filled regions |
| 1700 | on the display. |
| 1701 | Polygon items support coordinate indexing operations using the canvas |
| 1702 | widget commands: \fBdchars, index, insert.\fR |
| 1703 | Polygons are created with widget commands of the following form: |
| 1704 | .CS |
| 1705 | \fIpathName \fBcreate polygon \fIx1 y1 ... xn yn \fR?\fIoption value option value ...\fR? |
| 1706 | \fIpathName \fBcreate polygon \fIcoordList\fR ?\fIoption value option value ...\fR? |
| 1707 | .CE |
| 1708 | The arguments \fIx1\fR through \fIyn\fR or \fIcoordList\fR specify the coordinates for |
| 1709 | three or more points that define a polygon. |
| 1710 | The first point should not be repeated as the last to |
| 1711 | close the shape; Tk will automatically close the periphery between |
| 1712 | the first and last points. |
| 1713 | After the coordinates there may be any number of \fIoption\fR\-\fIvalue\fR |
| 1714 | pairs, each of which sets one of the configuration options |
| 1715 | for the item. These same \fIoption\fR\-\fIvalue\fR pairs may be |
| 1716 | used in \fBitemconfigure\fR widget commands to change the item's |
| 1717 | configuration. |
| 1718 | .br |
| 1719 | The following standard options are supported by polygons: |
| 1720 | .CS |
| 1721 | \-dash |
| 1722 | \-activedash |
| 1723 | \-disableddash |
| 1724 | \-dashoffset |
| 1725 | \-fill |
| 1726 | \-activefill |
| 1727 | \-disabledfill |
| 1728 | \-offset |
| 1729 | \-outline |
| 1730 | \-activeoutline |
| 1731 | \-disabledoutline |
| 1732 | \-outlinestipple |
| 1733 | \-activeoutlinestipple |
| 1734 | \-disabledoutlinestipple |
| 1735 | \-stipple |
| 1736 | \-activestipple |
| 1737 | \-disabledstipple |
| 1738 | \-state |
| 1739 | \-tags |
| 1740 | \-width |
| 1741 | \-activewidth |
| 1742 | \-disabledwidth |
| 1743 | .CE |
| 1744 | The following extra options are supported for polygons: |
| 1745 | .TP |
| 1746 | \fB\-joinstyle \fIstyle\fR |
| 1747 | Specifies the ways in which joints are to be drawn at the vertices |
| 1748 | of the outline. |
| 1749 | \fIStyle\fR may have any of the forms accepted by \fBTk_GetCapStyle\fR |
| 1750 | (\fBbevel\fR, \fBmiter\fR, or \fBround\fR). |
| 1751 | If this option isn't specified then it defaults to \fBmiter\fR. |
| 1752 | .TP |
| 1753 | \fB\-smooth \fIboolean\fR |
| 1754 | \fIBoolean\fR must have one of the forms accepted by \fBTcl_GetBoolean\fR. |
| 1755 | It indicates whether or not the polygon should be drawn with a |
| 1756 | curved perimeter. |
| 1757 | If so, the outline of the polygon becomes a set of parabolic splines, |
| 1758 | one spline for the first and second line segments, one for the second |
| 1759 | and third, and so on. Straight-line segments can be generated in a |
| 1760 | smoothed polygon by duplicating the end-points of the desired line segment. |
| 1761 | .TP |
| 1762 | \fB\-splinesteps \fInumber\fR |
| 1763 | Specifies the degree of smoothness desired for curves: each spline |
| 1764 | will be approximated with \fInumber\fR line segments. This |
| 1765 | option is ignored unless the \fB\-smooth\fR option is true. |
| 1766 | .PP |
| 1767 | Polygon items are different from other items such as rectangles, ovals |
| 1768 | and arcs in that interior points are considered to be ``inside'' a |
| 1769 | polygon (e.g. for purposes of the \fBfind closest\fR and |
| 1770 | \fBfind overlapping\fR widget commands) even if it is not filled. |
| 1771 | For most other item types, an |
| 1772 | interior point is considered to be inside the item only if the item |
| 1773 | is filled or if it has neither a fill nor an outline. If you would |
| 1774 | like an unfilled polygon whose interior points are not considered |
| 1775 | to be inside the polygon, use a line item instead. |
| 1776 | .SH "RECTANGLE ITEMS" |
| 1777 | .PP |
| 1778 | Items of type \fBrectangle\fR appear as rectangular regions on |
| 1779 | the display. Each rectangle may have an outline, a fill, or |
| 1780 | both. Rectangles are created with widget commands of the |
| 1781 | following form: |
| 1782 | .CS |
| 1783 | \fIpathName \fBcreate rectangle \fIx1 y1 x2 y2 \fR?\fIoption value option value ...\fR? |
| 1784 | \fIpathName \fBcreate rectangle \fIcoordList\fR ?\fIoption value option value ...\fR? |
| 1785 | .CE |
| 1786 | The arguments \fIx1\fR, \fIy1\fR, \fIx2\fR, and \fIy2\fR or \fIcoordList\fR give |
| 1787 | the coordinates of two diagonally opposite corners of the rectangle |
| 1788 | (the rectangle will include its upper and left edges but not |
| 1789 | its lower or right edges). |
| 1790 | After the coordinates there may be any number of \fIoption\fR\-\fIvalue\fR |
| 1791 | pairs, each of which sets one of the configuration options |
| 1792 | for the item. These same \fIoption\fR\-\fIvalue\fR pairs may be |
| 1793 | used in \fBitemconfigure\fR widget commands to change the item's |
| 1794 | configuration. |
| 1795 | .br |
| 1796 | The following standard options are supported by rectangles: |
| 1797 | .CS |
| 1798 | \-dash |
| 1799 | \-activedash |
| 1800 | \-disableddash |
| 1801 | \-dashoffset |
| 1802 | \-fill |
| 1803 | \-activefill |
| 1804 | \-disabledfill |
| 1805 | \-offset |
| 1806 | \-outline |
| 1807 | \-activeoutline |
| 1808 | \-disabledoutline |
| 1809 | \-outlinestipple |
| 1810 | \-activeoutlinestipple |
| 1811 | \-disabledoutlinestipple |
| 1812 | \-stipple |
| 1813 | \-activestipple |
| 1814 | \-disabledstipple |
| 1815 | \-state |
| 1816 | \-tags |
| 1817 | \-width |
| 1818 | \-activewidth |
| 1819 | \-disabledwidth |
| 1820 | .CE |
| 1821 | .SH "TEXT ITEMS" |
| 1822 | .PP |
| 1823 | A text item displays a string of characters on the screen in one |
| 1824 | or more lines. |
| 1825 | Text items support indexing and selection, along with the |
| 1826 | following text-related canvas widget commands: \fBdchars\fR, |
| 1827 | \fBfocus\fR, \fBicursor\fR, \fBindex\fR, \fBinsert\fR, |
| 1828 | \fBselect\fR. |
| 1829 | Text items are created with widget commands of the following |
| 1830 | form: |
| 1831 | .CS |
| 1832 | \fIpathName \fBcreate text \fIx y \fR?\fIoption value option value ...\fR? |
| 1833 | \fIpathName \fBcreate text \fIcoordList\fR ?\fIoption value option value ...\fR? |
| 1834 | .CE |
| 1835 | The arguments \fIx\fR and \fIy\fR or \fIcoordList\fR specify the coordinates of a |
| 1836 | point used to position the text on the display (see the options |
| 1837 | below for more information on how text is displayed). |
| 1838 | After the coordinates there may be any number of \fIoption\fR\-\fIvalue\fR |
| 1839 | pairs, each of which sets one of the configuration options |
| 1840 | for the item. These same \fIoption\fR\-\fIvalue\fR pairs may be |
| 1841 | used in \fBitemconfigure\fR widget commands to change the item's |
| 1842 | configuration. |
| 1843 | .br |
| 1844 | The following standard options are supported by text items: |
| 1845 | .CS |
| 1846 | \-fill |
| 1847 | \-activefill |
| 1848 | \-disabledfill |
| 1849 | \-stipple |
| 1850 | \-activestipple |
| 1851 | \-disabledstipple |
| 1852 | \-state |
| 1853 | \-tags |
| 1854 | .CE |
| 1855 | The following extra options are supported for text items: |
| 1856 | .TP |
| 1857 | \fB\-anchor \fIanchorPos\fR |
| 1858 | \fIAnchorPos\fR tells how to position the text relative to the |
| 1859 | positioning point for the text; it may have any of the forms |
| 1860 | accepted by \fBTk_GetAnchor\fR. For example, if \fIanchorPos\fR |
| 1861 | is \fBcenter\fR then the text is centered on the point; if |
| 1862 | \fIanchorPos\fR is \fBn\fR then the text will be drawn such that |
| 1863 | the top center point of the rectangular region occupied by the |
| 1864 | text will be at the positioning point. |
| 1865 | This option defaults to \fBcenter\fR. |
| 1866 | .TP |
| 1867 | \fB\-font \fIfontName\fR |
| 1868 | Specifies the font to use for the text item. |
| 1869 | \fIFontName\fR may be any string acceptable to \fBTk_GetFont\fR. |
| 1870 | If this option isn't specified, it defaults to a system-dependent |
| 1871 | font. |
| 1872 | .TP |
| 1873 | \fB\-justify \fIhow\fR |
| 1874 | Specifies how to justify the text within its bounding region. |
| 1875 | \fIHow\fR must be one of the values \fBleft\fR, \fBright\fR, |
| 1876 | or \fBcenter\fR. |
| 1877 | This option will only matter if the text is displayed as multiple |
| 1878 | lines. |
| 1879 | If the option is omitted, it defaults to \fBleft\fR. |
| 1880 | .TP |
| 1881 | \fB\-text \fIstring\fR |
| 1882 | \fIString\fR specifies the characters to be displayed in the text item. |
| 1883 | Newline characters cause line breaks. |
| 1884 | The characters in the item may also be changed with the |
| 1885 | \fBinsert\fR and \fBdelete\fR widget commands. |
| 1886 | This option defaults to an empty string. |
| 1887 | .TP |
| 1888 | \fB\-width \fIlineLength\fR |
| 1889 | Specifies a maximum line length for the text, in any of the forms |
| 1890 | described in the \fBCOORDINATES\fR section above. |
| 1891 | If this option is zero (the default) the text is broken into |
| 1892 | lines only at newline characters. |
| 1893 | However, if this option is non-zero then any line that would |
| 1894 | be longer than \fIlineLength\fR is broken just before a space |
| 1895 | character to make the line shorter than \fIlineLength\fR; the |
| 1896 | space character is treated as if it were a newline |
| 1897 | character. |
| 1898 | .SH "WINDOW ITEMS" |
| 1899 | .PP |
| 1900 | Items of type \fBwindow\fR cause a particular window to be displayed |
| 1901 | at a given position on the canvas. |
| 1902 | Window items are created with widget commands of the following form: |
| 1903 | .CS |
| 1904 | \fIpathName \fBcreate window \fIx y \fR?\fIoption value option value ...\fR? |
| 1905 | \fIpathName \fBcreate window \fIcoordList\fR ?\fIoption value option value ...\fR? |
| 1906 | .CE |
| 1907 | The arguments \fIx\fR and \fIy\fR or \fIcoordList\fR specify the coordinates of a |
| 1908 | point used to position the window on the display (see the \fB\-anchor\fR |
| 1909 | option below for more information on how bitmaps are displayed). |
| 1910 | After the coordinates there may be any number of \fIoption\fR\-\fIvalue\fR |
| 1911 | pairs, each of which sets one of the configuration options |
| 1912 | for the item. These same \fIoption\fR\-\fIvalue\fR pairs may be |
| 1913 | used in \fBitemconfigure\fR widget commands to change the item's |
| 1914 | configuration. |
| 1915 | .br |
| 1916 | The following standard options are supported by window items: |
| 1917 | .CS |
| 1918 | \-state |
| 1919 | \-tags |
| 1920 | .CE |
| 1921 | The following extra options are supported for window items: |
| 1922 | .TP |
| 1923 | \fB\-anchor \fIanchorPos\fR |
| 1924 | \fIAnchorPos\fR tells how to position the window relative to the |
| 1925 | positioning point for the item; it may have any of the forms |
| 1926 | accepted by \fBTk_GetAnchor\fR. For example, if \fIanchorPos\fR |
| 1927 | is \fBcenter\fR then the window is centered on the point; if |
| 1928 | \fIanchorPos\fR is \fBn\fR then the window will be drawn so that |
| 1929 | its top center point is at the positioning point. |
| 1930 | This option defaults to \fBcenter\fR. |
| 1931 | .TP |
| 1932 | \fB\-height \fIpixels\fR |
| 1933 | Specifies the height to assign to the item's window. |
| 1934 | \fIPixels\fR may have any of the |
| 1935 | forms described in the \fBCOORDINATES\fR section above. |
| 1936 | If this option isn't specified, or if it is specified as an empty |
| 1937 | string, then the window is given whatever height it requests internally. |
| 1938 | .TP |
| 1939 | \fB\-width \fIpixels\fR |
| 1940 | Specifies the width to assign to the item's window. |
| 1941 | \fIPixels\fR may have any of the |
| 1942 | forms described in the \fBCOORDINATES\fR section above. |
| 1943 | If this option isn't specified, or if it is specified as an empty |
| 1944 | string, then the window is given whatever width it requests internally. |
| 1945 | .TP |
| 1946 | \fB\-window \fIpathName\fR |
| 1947 | Specifies the window to associate with this item. |
| 1948 | The window specified by \fIpathName\fR must either be a child of |
| 1949 | the canvas widget or a child of some ancestor of the canvas widget. |
| 1950 | \fIPathName\fR may not refer to a top-level window. |
| 1951 | .PP |
| 1952 | Note: due to restrictions in the ways that windows are managed, it is not |
| 1953 | possible to draw other graphical items (such as lines and images) on top |
| 1954 | of window items. A window item always obscures any graphics that |
| 1955 | overlap it, regardless of their order in the display list. |
| 1956 | .SH "APPLICATION-DEFINED ITEM TYPES" |
| 1957 | .PP |
| 1958 | It is possible for individual applications to define new item |
| 1959 | types for canvas widgets using C code. |
| 1960 | See the documentation for \fBTk_CreateItemType\fR. |
| 1961 | .SH BINDINGS |
| 1962 | .PP |
| 1963 | In the current implementation, new canvases are not given any |
| 1964 | default behavior: you'll have to execute explicit Tcl commands |
| 1965 | to give the canvas its behavior. |
| 1966 | .SH CREDITS |
| 1967 | .PP |
| 1968 | Tk's canvas widget is a blatant ripoff of ideas from Joel Bartlett's |
| 1969 | \fIezd\fR program. \fIEzd\fR provides structured graphics in a Scheme |
| 1970 | environment and preceded canvases by a year or two. Its simple |
| 1971 | mechanisms for placing and animating graphical objects inspired the |
| 1972 | functions of canvases. |
| 1973 | |
| 1974 | .SH "SEE ALSO" |
| 1975 | bind(n), font(n), image(n), scrollbar(n) |
| 1976 | |
| 1977 | .SH KEYWORDS |
| 1978 | canvas, widget |