1wm(n) Tk Built-In Commands wm(n)
2______________________________________________________________________________
6
8 wm - Communicate with window manager
9
11 wm option window ?args?
12_________________________________________________________________
13
15 The wm command is used to interact with window managers in order to
16 control such things as the title for a window, its geometry, or the
17 increments in terms of which it may be resized. The wm command can
18 take any of a number of different forms, depending on the option argu‐
19 ment. All of the forms expect at least one additional argument, win‐
20 dow, which must be the path name of a top-level window.
21 The legal forms for the wm command are:
23 wm aspect window ?minNumer minDenom maxNumer maxDenom?
25 If minNumer, minDenom, maxNumer, and maxDenom are all specified,
26 then they will be passed to the window manager and the window
27 manager should use them to enforce a range of acceptable aspect
28 ratios for window. The aspect ratio of window (width/length)
29 will be constrained to lie between minNumer/minDenom and maxNu‐
30 mer/maxDenom. If minNumer etc. are all specified as empty
31 strings, then any existing aspect ratio restrictions are
32 removed. If minNumer etc. are specified, then the command
33 returns an empty string. Otherwise, it returns a Tcl list con‐
34 taining four elements, which are the current values of minNumer,
35 minDenom, maxNumer, and maxDenom (if no aspect restrictions are
36 in effect, then an empty string is returned).
37 wm attributes window
39 wm attributes window ?option?
41 wm attributes window ?option value option value...?
43 This subcommand returns or sets platform specific attributes
44 associated with a window. The first form returns a list of the
45 platform specific flags and their values. The second form
46 returns the value for the specific option. The third form sets
47 one or more of the values. The values are as follows:
48 All platforms support the following attributes (though X11 users
50 should see the notes below):
51 -fullscreen
53 Places the window in a mode that takes up the entire
54 screen, has no borders, and covers the general use area
55 (i.e. Start menu and taskbar on Windows, dock and menubar
56 on OSX, general window decorations on X11).
57 -topmost
59 Specifies whether this is a topmost window (displays
60 above all other windows).
61 On Windows, the following attributes may be set.
63 -alpha Specifies the alpha transparency level of the toplevel. │
65 It accepts a value from 0.0 (fully transparent) to 1.0 │
66 (opaque). Values outside that range will be constrained. │
67 This is supported on Windows 2000/XP+. Where not sup‐ │
68 ported, the -alpha value remains at 1.0.
69 -disabled
71 Specifies whether the window is in a disabled state.
72 -toolwindow
74 Specifies a toolwindow style window (as defined in the
75 MSDN).
76 -transparentcolor
78 Specifies the transparent color index of the toplevel. │
79 It takes any color value accepted by Tk_GetColor. If the │
80 empty string is specified (default), no transparent color │
81 is used. This is supported on Windows 2000/XP+. Where │
82 not supported, the -transparentcolor value remains at {}.
83 On Mac OS X, the following attributes may be set.
85 -alpha Specifies the alpha transparency level of the window. It
87 accepts a value from 0.0 (fully transparent) to 1.0
88 (opaque), values outside that range will be constrained.
89 -modified
91 Specifies the modification state of the window (deter‐
92 mines whether the window close widget contains the modi‐
93 fication indicator and whether the proxy icon is drag‐
94 gable).
95 -notify
97 Specifies process notification state (bouncing of the
98 application dock icon).
99 -titlepath
101 Specifies the path of the file referenced as the window
102 proxy icon (which can be dragged and dropped in lieu of
103 the file's finder icon).
104 -transparent
106 Makes the window content area transparent and turns off
107 the window shadow. For the transparency to be effecive,
108 the toplevel background needs to be set to a color with
109 some alpha, e.g. “systemTransparent”.
110 On X11, the following attributes may be set. These are not sup‐
112 ported by all window managers, and will have no effect under
113 older WMs.
114 -zoomed
116 Requests that the window should be maximized. This is
117 the same as wm state zoomed on Windows and Mac OS X.
118 On X11, changes to window attributes are performed asyn‐
120 chronously. Querying the value of an attribute returns the cur‐
121 rent state, which will not be the same as the value most
122 recently set if the window manager has not yet processed the
123 request or if it does not support the attribute.
124 wm client window ?name?
126 If name is specified, this command stores name (which should be
127 the name of the host on which the application is executing) in
128 window's WM_CLIENT_MACHINE property for use by the window man‐
129 ager or session manager. The command returns an empty string in
130 this case. If name is not specified, the command returns the
131 last name set in a wm client command for window. If name is
132 specified as an empty string, the command deletes the
133 WM_CLIENT_MACHINE property from window.
134 wm colormapwindows window ?windowList?
136 This command is used to manipulate the WM_COLORMAP_WINDOWS prop‐
137 erty, which provides information to the window managers about
138 windows that have private colormaps.
139 If windowList is not specified, the command returns a list whose
141 elements are the names of the windows in the WM_COLORMAP_WINDOWS
142 property. If windowList is specified, it consists of a list of
143 window path names; the command overwrites the WM_COLORMAP_WIN‐
144 DOWS property with the given windows and returns an empty
145 string. The WM_COLORMAP_WINDOWS property should normally con‐
146 tain a list of the internal windows within window whose col‐
147 ormaps differ from their parents.
148 The order of the windows in the property indicates a priority
150 order: the window manager will attempt to install as many col‐
151 ormaps as possible from the head of this list when window gets
152 the colormap focus. If window is not included among the windows
153 in windowList, Tk implicitly adds it at the end of the WM_COL‐
154 ORMAP_WINDOWS property, so that its colormap is lowest in prior‐
155 ity. If wm colormapwindows is not invoked, Tk will automati‐
156 cally set the property for each top-level window to all the
157 internal windows whose colormaps differ from their parents, fol‐
158 lowed by the top-level itself; the order of the internal win‐
159 dows is undefined. See the ICCCM documentation for more infor‐
160 mation on the WM_COLORMAP_WINDOWS property.
161 wm command window ?value?
163 If value is specified, this command stores value in window's
164 WM_COMMAND property for use by the window manager or session
165 manager and returns an empty string. Value must have proper
166 list structure; the elements should contain the words of the
167 command used to invoke the application. If value is not speci‐
168 fied then the command returns the last value set in a wm command
169 command for window. If value is specified as an empty string,
170 the command deletes the WM_COMMAND property from window.
171 wm deiconify window
173 Arrange for window to be displayed in normal (non-iconified)
174 form. This is done by mapping the window. If the window has
175 never been mapped then this command will not map the window, but
176 it will ensure that when the window is first mapped it will be
177 displayed in de-iconified form. On Windows, a deiconified win‐
178 dow will also be raised and be given the focus (made the active
179 window). Returns an empty string.
180 wm focusmodel window ?active|passive?
182 If active or passive is supplied as an optional argument to the
183 command, then it specifies the focus model for window. In this
184 case the command returns an empty string. If no additional
185 argument is supplied, then the command returns the current focus
186 model for window.
187 An active focus model means that window will claim the input
189 focus for itself or its descendants, even at times when the
190 focus is currently in some other application. Passive means
191 that window will never claim the focus for itself: the window
192 manager should give the focus to window at appropriate times.
193 However, once the focus has been given to window or one of its
194 descendants, the application may re-assign the focus among win‐
195 dow's descendants. The focus model defaults to passive, and
196 Tk's focus command assumes a passive model of focusing.
197 wm forget window
199 The window will be unmapped from the screen and will no longer
200 be managed by wm. Windows created with the toplevel command
201 will be treated like frame windows once they are no longer man‐
202 aged by wm, however, the -menu configuration will be remembered
203 and the menus will return once the widget is managed again.
204 wm frame window
206 If window has been reparented by the window manager into a deco‐
207 rative frame, the command returns the platform specific window
208 identifier for the outermost frame that contains window (the
209 window whose parent is the root or virtual root). If window has
210 not been reparented by the window manager then the command
211 returns the platform specific window identifier for window.
212 wm geometry window ?newGeometry?
214 If newGeometry is specified, then the geometry of window is
215 changed and an empty string is returned. Otherwise the current
216 geometry for window is returned (this is the most recent geome‐
217 try specified either by manual resizing or in a wm geometry com‐
218 mand). NewGeometry has the form =widthxheight±x±y, where any of
219 =, widthxheight, or ±x±y may be omitted. Width and height are
220 positive integers specifying the desired dimensions of window.
221 If window is gridded (see GRIDDED GEOMETRY MANAGEMENT below)
222 then the dimensions are specified in grid units; otherwise they
223 are specified in pixel units.
224 X and y specify the desired location of window on the screen, in
226 pixels. If x is preceded by +, it specifies the number of pix‐
227 els between the left edge of the screen and the left edge of
228 window's border; if preceded by - then x specifies the number
229 of pixels between the right edge of the screen and the right
230 edge of window's border. If y is preceded by + then it speci‐
231 fies the number of pixels between the top of the screen and the
232 top of window's border; if y is preceded by - then it specifies
233 the number of pixels between the bottom of window's border and
234 the bottom of the screen.
235 If newGeometry is specified as an empty string then any existing
237 user-specified geometry for window is cancelled, and the window
238 will revert to the size requested internally by its widgets.
239 Note that this is related to winfo geometry, but not the same.
241 That can only query the geometry, and always reflects Tk's cur‐
242 rent understanding of the actual size and location of window,
243 whereas wm geometry allows both setting and querying of the win‐
244 dow manager's understanding of the size and location of the win‐
245 dow. This can vary significantly, for example to reflect the
246 addition of decorative elements to window such as title bars,
247 and window managers are not required to precisely follow the
248 requests made through this command.
249 wm grid window ?baseWidth baseHeight widthInc heightInc?
251 This command indicates that window is to be managed as a gridded
252 window. It also specifies the relationship between grid units
253 and pixel units. BaseWidth and baseHeight specify the number of
254 grid units corresponding to the pixel dimensions requested
255 internally by window using Tk_GeometryRequest. WidthInc and
256 heightInc specify the number of pixels in each horizontal and
257 vertical grid unit. These four values determine a range of
258 acceptable sizes for window, corresponding to grid-based widths
259 and heights that are non-negative integers. Tk will pass this
260 information to the window manager; during manual resizing, the
261 window manager will restrict the window's size to one of these
262 acceptable sizes.
263 Furthermore, during manual resizing the window manager will dis‐
265 play the window's current size in terms of grid units rather
266 than pixels. If baseWidth etc. are all specified as empty
267 strings, then window will no longer be managed as a gridded win‐
268 dow. If baseWidth etc. are specified then the return value is
269 an empty string.
270 Otherwise the return value is a Tcl list containing four ele‐
272 ments corresponding to the current baseWidth, baseHeight,
273 widthInc, and heightInc; if window is not currently gridded,
274 then an empty string is returned.
275 Note: this command should not be needed very often, since the
277 Tk_SetGrid library procedure and the setGrid option provide eas‐
278 ier access to the same functionality.
279 wm group window ?pathName?
281 If pathName is specified, it gives the path name for the leader
282 of a group of related windows. The window manager may use this
283 information, for example, to unmap all of the windows in a group
284 when the group's leader is iconified. PathName may be specified
285 as an empty string to remove window from any group association.
286 If pathName is specified then the command returns an empty
287 string; otherwise it returns the path name of window's current
288 group leader, or an empty string if window is not part of any
289 group.
290 wm iconbitmap window ?bitmap?
292 If bitmap is specified, then it names a bitmap in the standard
293 forms accepted by Tk (see the Tk_GetBitmap manual entry for
294 details). This bitmap is passed to the window manager to be
295 displayed in window's icon, and the command returns an empty
296 string. If an empty string is specified for bitmap, then any
297 current icon bitmap is cancelled for window. If bitmap is spec‐
298 ified then the command returns an empty string. Otherwise it
299 returns the name of the current icon bitmap associated with win‐
300 dow, or an empty string if window has no icon bitmap. On the
301 Windows operating system, an additional flag is supported:
302 wm iconbitmap window ?-default? ?image?
304 If the -default flag is given, the icon is applied to all
305 toplevel windows (existing and future) to which no other
306 specific icon has yet been applied. In addition to bit‐
307 map image types, a full path specification to any file
308 which contains a valid Windows icon is also accepted
309 (usually .ico or .icr files), or any file for which the
310 shell has assigned an icon. Tcl will first test if the
311 file contains an icon, then if it has an assigned icon,
312 and finally, if that fails, test for a bitmap.
313 wm iconify window
315 Arrange for window to be iconified. It window has not yet been
316 mapped for the first time, this command will arrange for it to
317 appear in the iconified state when it is eventually mapped.
318 wm iconmask window ?bitmap?
320 If bitmap is specified, then it names a bitmap in the standard
321 forms accepted by Tk (see the Tk_GetBitmap manual entry for
322 details). This bitmap is passed to the window manager to be
323 used as a mask in conjunction with the iconbitmap option: where
324 the mask has zeroes no icon will be displayed; where it has
325 ones, the bits from the icon bitmap will be displayed. If an
326 empty string is specified for bitmap then any current icon mask
327 is cancelled for window (this is equivalent to specifying a bit‐
328 map of all ones). If bitmap is specified then the command
329 returns an empty string. Otherwise it returns the name of the
330 current icon mask associated with window, or an empty string if
331 no mask is in effect.
332 wm iconname window ?newName?
334 If newName is specified, then it is passed to the window man‐
335 ager; the window manager should display newName inside the icon
336 associated with window. In this case an empty string is
337 returned as result. If newName is not specified then the com‐
338 mand returns the current icon name for window, or an empty
339 string if no icon name has been specified (in this case the win‐
340 dow manager will normally display the window's title, as speci‐
341 fied with the wm title command). │
342 wm iconphoto window ?-default? image1 ?image2 ...? │
344 Sets the titlebar icon for window based on the named photo │
345 images. If -default is specified, this is applied to all future │
346 created toplevels as well. The data in the images is taken as a │
347 snapshot at the time of invocation. If the images are later │
348 changed, this is not reflected to the titlebar icons. Multiple │
349 images are accepted to allow different images sizes (e.g., 16x16 │
350 and 32x32) to be provided. The window manager may scale provided │
351 icons to an appropriate size. │
352 On Windows, the images are packed into a Windows icon structure. │
354 This will override an ico specified to wm iconbitmap, and vice │
355 versa. │
356 On X, the images are arranged into the _NET_WM_ICON X property, │
358 which most modern window managers support. A wm iconbitmap may │
359 exist simultaneously. It is recommended to use not more than 2 │
360 icons, placing the larger icon first. │
361 On Macintosh, this currently does nothing.
363 wm iconposition window ?x y?
365 If x and y are specified, they are passed to the window manager
366 as a hint about where to position the icon for window. In this
367 case an empty string is returned. If x and y are specified as
368 empty strings then any existing icon position hint is cancelled.
369 If neither x nor y is specified, then the command returns a Tcl
370 list containing two values, which are the current icon position
371 hints (if no hints are in effect then an empty string is
372 returned).
373 wm iconwindow window ?pathName?
375 If pathName is specified, it is the path name for a window to
376 use as icon for window: when window is iconified then pathName
377 will be mapped to serve as icon, and when window is de-iconified
378 then pathName will be unmapped again. If pathName is specified
379 as an empty string then any existing icon window association for
380 window will be cancelled. If the pathName argument is specified
381 then an empty string is returned. Otherwise the command returns
382 the path name of the current icon window for window, or an empty
383 string if there is no icon window currently specified for win‐
384 dow. Button press events are disabled for window as long as it
385 is an icon window; this is needed in order to allow window man‐
386 agers to “own” those events. Note: not all window managers sup‐
387 port the notion of an icon window.
388 wm manage widget
390 The widget specified will become a stand alone top-level window.
391 The window will be decorated with the window managers title bar,
392 etc. Only frame, labelframe and toplevel widgets can be used
393 with this command. Attempting to pass any other widget type will
394 raise an error. Attempting to manage a toplevel widget is benign
395 and achieves nothing. See also GEOMETRY MANAGEMENT.
396 wm maxsize window ?width height?
398 If width and height are specified, they give the maximum permis‐
399 sible dimensions for window. For gridded windows the dimensions
400 are specified in grid units; otherwise they are specified in
401 pixel units. The window manager will restrict the window's
402 dimensions to be less than or equal to width and height. If
403 width and height are specified, then the command returns an
404 empty string. Otherwise it returns a Tcl list with two ele‐
405 ments, which are the maximum width and height currently in
406 effect. The maximum size defaults to the size of the screen.
407 See the sections on geometry management below for more informa‐
408 tion.
409 wm minsize window ?width height?
411 If width and height are specified, they give the minimum permis‐
412 sible dimensions for window. For gridded windows the dimensions
413 are specified in grid units; otherwise they are specified in
414 pixel units. The window manager will restrict the window's
415 dimensions to be greater than or equal to width and height. If
416 width and height are specified, then the command returns an
417 empty string. Otherwise it returns a Tcl list with two ele‐
418 ments, which are the minimum width and height currently in
419 effect. The minimum size defaults to one pixel in each dimen‐
420 sion. See the sections on geometry management below for more
421 information.
422 wm overrideredirect window ?boolean?
424 If boolean is specified, it must have a proper boolean form and
425 the override-redirect flag for window is set to that value. If
426 boolean is not specified then 1 or 0 is returned to indicate
427 whether or not the override-redirect flag is currently set for
428 window. Setting the override-redirect flag for a window causes
429 it to be ignored by the window manager; among other things,
430 this means that the window will not be reparented from the root
431 window into a decorative frame and the user will not be able to
432 manipulate the window using the normal window manager mecha‐
433 nisms.
434 wm positionfrom window ?who?
436 If who is specified, it must be either program or user, or an
437 abbreviation of one of these two. It indicates whether window's
438 current position was requested by the program or by the user.
439 Many window managers ignore program-requested initial positions
440 and ask the user to manually position the window; if user is
441 specified then the window manager should position the window at
442 the given place without asking the user for assistance. If who
443 is specified as an empty string, then the current position
444 source is cancelled. If who is specified, then the command
445 returns an empty string. Otherwise it returns user or program
446 to indicate the source of the window's current position, or an
447 empty string if no source has been specified yet. Most window
448 managers interpret “no source” as equivalent to program. Tk
449 will automatically set the position source to user when a wm
450 geometry command is invoked, unless the source has been set
451 explicitly to program.
452 wm protocol window ?name? ?command?
454 This command is used to manage window manager protocols such as
455 WM_DELETE_WINDOW. Name is the name of an atom corresponding to
456 a window manager protocol, such as WM_DELETE_WINDOW or
457 WM_SAVE_YOURSELF or WM_TAKE_FOCUS. If both name and command are
458 specified, then command is associated with the protocol speci‐
459 fied by name. Name will be added to window's WM_PROTOCOLS prop‐
460 erty to tell the window manager that the application has a pro‐
461 tocol handler for name, and command will be invoked in the
462 future whenever the window manager sends a message to the client
463 for that protocol. In this case the command returns an empty
464 string. If name is specified but command is not, then the cur‐
465 rent command for name is returned, or an empty string if there
466 is no handler defined for name. If command is specified as an
467 empty string then the current handler for name is deleted and it
468 is removed from the WM_PROTOCOLS property on window; an empty
469 string is returned. Lastly, if neither name nor command is
470 specified, the command returns a list of all the protocols for
471 which handlers are currently defined for window.
472 Tk always defines a protocol handler for WM_DELETE_WINDOW, even
474 if you have not asked for one with wm protocol. If a
475 WM_DELETE_WINDOW message arrives when you have not defined a
476 handler, then Tk handles the message by destroying the window
477 for which it was received.
478 wm resizable window ?width height?
480 This command controls whether or not the user may interactively
481 resize a top-level window. If width and height are specified,
482 they are boolean values that determine whether the width and
483 height of window may be modified by the user. In this case the
484 command returns an empty string. If width and height are omit‐
485 ted then the command returns a list with two 0/1 elements that
486 indicate whether the width and height of window are currently
487 resizable. By default, windows are resizable in both dimen‐
488 sions. If resizing is disabled, then the window's size will be
489 the size from the most recent interactive resize or wm geometry
490 command. If there has been no such operation then the window's
491 natural size will be used.
492 wm sizefrom window ?who?
494 If who is specified, it must be either program or user, or an
495 abbreviation of one of these two. It indicates whether window's
496 current size was requested by the program or by the user. Some
497 window managers ignore program-requested sizes and ask the user
498 to manually size the window; if user is specified then the win‐
499 dow manager should give the window its specified size without
500 asking the user for assistance. If who is specified as an empty
501 string, then the current size source is cancelled. If who is
502 specified, then the command returns an empty string. Otherwise
503 it returns user or window to indicate the source of the window's
504 current size, or an empty string if no source has been specified
505 yet. Most window managers interpret “no source” as equivalent
506 to program.
507 wm stackorder window ?isabove|isbelow window?
509 The stackorder command returns a list of toplevel windows in
510 stacking order, from lowest to highest. When a single toplevel
511 window is passed, the returned list recursively includes all of
512 the window's children that are toplevels. Only those toplevels
513 that are currently mapped to the screen are returned. The
514 stackorder command can also be used to determine if one toplevel
515 is positioned above or below a second toplevel. When two window
516 arguments separated by either isabove or isbelow are passed, a
517 boolean result indicates whether or not the first window is cur‐
518 rently above or below the second window in the stacking order.
519 wm state window ?newstate?
521 If newstate is specified, the window will be set to the new
522 state, otherwise it returns the current state of window: either
523 normal, iconic, withdrawn, icon, or (Windows and Mac OS X only)
524 zoomed. The difference between iconic and icon is that iconic
525 refers to a window that has been iconified (e.g., with the wm
526 iconify command) while icon refers to a window whose only pur‐
527 pose is to serve as the icon for some other window (via the wm
528 iconwindow command). The icon state cannot be set.
529 wm title window ?string?
531 If string is specified, then it will be passed to the window
532 manager for use as the title for window (the window manager
533 should display this string in window's title bar). In this case
534 the command returns an empty string. If string is not specified
535 then the command returns the current title for the window. The
536 title for a window defaults to its name.
537 wm transient window ?master?
539 If master is specified, then the window manager is informed that
540 window is a transient window (e.g. pull-down menu) working on
541 behalf of master (where master is the path name for a top-level
542 window). If master is specified as an empty string then window
543 is marked as not being a transient window any more. Otherwise
544 the command returns the path name of window's current master, or
545 an empty string if window is not currently a transient window.
546 A transient window will mirror state changes in the master and
547 inherit the state of the master when initially mapped. It is an
548 error to attempt to make a window a transient of itself.
549 wm withdraw window
551 Arranges for window to be withdrawn from the screen. This
552 causes the window to be unmapped and forgotten about by the win‐
553 dow manager. If the window has never been mapped, then this
554 command causes the window to be mapped in the withdrawn state.
555 Not all window managers appear to know how to handle windows
556 that are mapped in the withdrawn state. Note: it sometimes
557 seems to be necessary to withdraw a window and then re-map it
558 (e.g. with wm deiconify) to get some window managers to pay
559 attention to changes in window attributes such as group.
560
562 By default a top-level window appears on the screen in its natural
563 size, which is the one determined internally by its widgets and geome‐
564 try managers. If the natural size of a top-level window changes, then
565 the window's size changes to match. A top-level window can be given a
566 size other than its natural size in two ways. First, the user can
567 resize the window manually using the facilities of the window manager,
568 such as resize handles. Second, the application can request a particu‐
569 lar size for a top-level window using the wm geometry command. These
570 two cases are handled identically by Tk; in either case, the requested
571 size overrides the natural size. You can return the window to its nat‐
572 ural by invoking wm geometry with an empty geometry string.
573 Normally a top-level window can have any size from one pixel in each
575 dimension up to the size of its screen. However, you can use the wm
576 minsize and wm maxsize commands to limit the range of allowable sizes.
577 The range set by wm minsize and wm maxsize applies to all forms of
578 resizing, including the window's natural size as well as manual resizes
579 and the wm geometry command. You can also use the command wm resizable
580 to completely disable interactive resizing in one or both dimensions.
581 The wm manage and wm forget commands may be used to perform undocking
583 and docking of windows. After a widget is managed by wm manage com‐
584 mand, all other wm subcommands may be used with the widget. Only wid‐
585 gets created using the toplevel command may have an attached menu via
586 the -menu configure option. A toplevel widget may be used as a frame
587 and managed with any of the other geometry managers after using the wm
588 forget command. Any menu associated with a toplevel widget will be
589 hidden when managed by another geometry managers. The menus will reap‐
590 pear once the window is managed by wm. All custom bindtags for widgets
591 in a subtree that have their top-level widget changed via a wm manage
592 or wm forget command, must be redone to adjust any top-level widget
593 path in the bindtags. Bindtags that have not been customized do not
594 have to be redone.
595
597 Gridded geometry management occurs when one of the widgets of an appli‐
598 cation supports a range of useful sizes. This occurs, for example, in
599 a text editor where the scrollbars, menus, and other adornments are
600 fixed in size but the edit widget can support any number of lines of
601 text or characters per line. In this case, it is usually desirable to
602 let the user specify the number of lines or characters-per-line, either
603 with the wm geometry command or by interactively resizing the window.
604 In the case of text, and in other interesting cases also, only discrete
605 sizes of the window make sense, such as integral numbers of lines and
606 characters-per-line; arbitrary pixel sizes are not useful.
607 Gridded geometry management provides support for this kind of applica‐
609 tion. Tk (and the window manager) assume that there is a grid of some
610 sort within the application and that the application should be resized
611 in terms of grid units rather than pixels. Gridded geometry management
612 is typically invoked by turning on the setGrid option for a widget; it
613 can also be invoked with the wm grid command or by calling Tk_SetGrid.
614 In each of these approaches the particular widget (or sometimes code in
615 the application as a whole) specifies the relationship between integral
616 grid sizes for the window and pixel sizes. To return to non-gridded
617 geometry management, invoke wm grid with empty argument strings.
618 When gridded geometry management is enabled then all the dimensions
620 specified in wm minsize, wm maxsize, and wm geometry commands are
621 treated as grid units rather than pixel units. Interactive resizing is
622 also carried out in even numbers of grid units rather than pixels.
623
625 Most existing window managers appear to have bugs that affect the oper‐
626 ation of the wm command. For example, some changes will not take
627 effect if the window is already active: the window will have to be
628 withdrawn and de-iconified in order to make the change happen.
629
631 A fixed-size window that says that it is fixed-size too:
632 toplevel .fixed
633 wm title .fixed "Fixed-size Window"
634 wm resizable .fixed 0 0
635 A simple dialog-like window, centred on the screen:
637 # Create and arrange the dialog contents.
638 toplevel .msg
639 label .msg.l -text "This is a very simple dialog demo."
640 button .msg.ok -text OK -default active -command {destroy .msg}
641 pack .msg.ok -side bottom -fill x
642 pack .msg.l -expand 1 -fill both
643 # Now set the widget up as a centred dialog.
645 # But first, we need the geometry managers to finish setting
647 # up the interior of the dialog, for which we need to run the
648 # event loop with the widget hidden completely...
649 wm withdraw .msg
650 update
651 set x [expr {([winfo screenwidth .]-[winfo width .msg])/2}]
652 set y [expr {([winfo screenheight .]-[winfo height .msg])/2}]
653 wm geometry .msg +$x+$y
654 wm transient .msg .
655 wm title .msg "Dialog demo"
656 wm deiconify .msg
657
659 toplevel(n), winfo(n)
660
662 aspect ratio, deiconify, focus model, geometry, grid, group, icon,
663 iconify, increments, position, size, title, top-level window, units,
664 window manager
665Tk 8.5 wm(n)