wm(n) Tk Built-In Commands wm(n) ______________________________________________________________________________
NAME
wm - Communicate with window manager
SYNOPSIS
wm option window ?args?
______________________________________________________________________________
DESCRIPTION
The wm command is used to interact with window managers in order to
control such things as the title for a window, its geometry, or the
increments in terms of which it may be resized. The wm command can
take any of a number of different forms, depending on the option
argument. All of the forms expect at least one additional argument,
window, which must be the path name of a top-level window.
The legal forms for the wm command are:
wm aspect window ?minNumer minDenom maxNumer maxDenom?
If minNumer, minDenom, maxNumer, and maxDenom are all specified,
then they will be passed to the window manager and the window
manager should use them to enforce a range of acceptable aspect
ratios for window. The aspect ratio of window (width/length)
will be constrained to lie between minNumer/minDenom and
maxNumer/maxDenom. If minNumer etc. are all specified as empty
strings, then any existing aspect ratio restrictions are
removed. If minNumer etc. are specified, then the command
returns an empty string. Otherwise, it returns a Tcl list
containing four elements, which are the current values of
minNumer, minDenom, maxNumer, and maxDenom (if no aspect
restrictions are in effect, then an empty string is returned).
wm attributes window
wm attributes window ?option?
wm attributes window ?option value option value...?
This subcommand returns or sets platform specific attributes
associated with a window. The first form returns a list of the
platform specific flags and their values. The second form
returns the value for the specific option. The third form sets
one or more of the values. The values are as follows:
All platforms support the following attributes (though X11 users
should see the notes below):
-alpha Specifies the alpha transparency level of the toplevel.
It accepts a value from 0.0 (fully transparent) to 1.0
(opaque). Values outside that range will be constrained.
Where not supported, the -alpha value remains at 1.0.
-fullscreen
Places the window in a mode that takes up the entire
screen, has no borders, and covers the general use area
(i.e. Start menu and taskbar on Windows, dock and menubar
on macOS, general window decorations on X11).
-topmost
Specifies whether this is a topmost window (displays
above all other windows).
On Windows, the following attributes may be set.
-disabled
Specifies whether the window is in a disabled state.
-toolwindow
Specifies a toolwindow style window (as defined in the
MSDN).
-transparentcolor
Specifies the transparent color index of the toplevel.
It takes any color value accepted by Tk_GetColor. If the
empty string is specified (default), no transparent color
is used. This is supported on Windows 2000/XP+. Where
not supported, the -transparentcolor value remains at {}.
On macOS, the following attributes may be set.
-modified
Specifies the modification state of the window
(determines whether the window close widget contains the
modification indicator and whether the proxy icon is
draggable).
-notify
Specifies process notification state (bouncing of the
application dock icon).
-titlepath
Specifies the path of the file referenced as the window
proxy icon (which can be dragged and dropped in lieu of
the file's finder icon).
-transparent
Makes the window content area transparent and turns off
the window shadow. For the transparency to be effective,
the toplevel background needs to be set to a color with
some alpha, e.g. "systemTransparent".
On X11, the following attributes may be set. These are not
supported by all window managers, and will have no effect under
older WMs.
-type Requests that the window should be interpreted by the |
window manager as being of the specified type(s). This |
may cause the window to be decorated in a different way |
or otherwise managed differently, though exactly what |
happens is entirely up to the window manager. A list of |
types may be used, in order of preference. The following |
values are mapped to constants defined in the EWMH |
specification (using others is possible, but not |
advised): |
desktop |
indicates a desktop feature, |
dock indicates a dock/panel feature, |
toolbar |
indicates a toolbar window that should be acting |
on behalf of another window, as indicated with wm |
transient, |
menu indicates a torn-off menu that should be acting on |
behalf of another window, as indicated with wm |
transient, |
utility |
indicates a utility window (e.g., palette or |
toolbox) that should be acting on behalf of |
another window, as indicated with wm transient, |
splash indicates a splash screen, displayed during |
application start up, |
dialog indicates a general dialog window, that should be |
acting on behalf of another window, as indicated |
with wm transient, |
dropdown_menu |
indicates a menu summoned from a menu bar, which |
should usually also be set to be override- |
redirected (with wm overrideredirect), |
popup_menu |
indicates a popup menu, which should usually also |
be set to be override-redirected (with wm |
overrideredirect), |
tooltip |
indicates a tooltip window, which should usually |
also be set to be override-redirected (with wm |
overrideredirect), |
notification |
indicates a window that provides a background |
notification of some event, which should usually |
also be set to be override-redirected (with wm |
overrideredirect), |
combo indicates the drop-down list of a combobox widget, |
which should usually also be set to be override- |
redirected (with wm overrideredirect), |
dnd indicates a window that represents something being |
dragged, which should usually also be set to be |
override-redirected (with wm overrideredirect), |
normal indicates a window that has no special |
interpretation. |
-zoomed
Requests that the window should be maximized. This is the
same as wm state zoomed on Windows and macOS.
On X11, changes to window attributes are performed
asynchronously. Querying the value of an attribute returns the
current state, which will not be the same as the value most
recently set if the window manager has not yet processed the
request or if it does not support the attribute.
wm client window ?name?
If name is specified, this command stores name (which should be
the name of the host on which the application is executing) in
window's WM_CLIENT_MACHINE property for use by the window
manager or session manager. The command returns an empty string
in this case. If name is not specified, the command returns the
last name set in a wm client command for window. If name is
specified as an empty string, the command deletes the
WM_CLIENT_MACHINE property from window.
wm colormapwindows window ?windowList?
This command is used to manipulate the WM_COLORMAP_WINDOWS
property, which provides information to the window managers
about windows that have private colormaps.
If windowList is not specified, the command returns a list whose
elements are the names of the windows in the WM_COLORMAP_WINDOWS
property. If windowList is specified, it consists of a list of
window path names; the command overwrites the
WM_COLORMAP_WINDOWS property with the given windows and returns
an empty string. The WM_COLORMAP_WINDOWS property should
normally contain a list of the internal windows within window
whose colormaps differ from their parents.
The order of the windows in the property indicates a priority
order: the window manager will attempt to install as many
colormaps as possible from the head of this list when window
gets the colormap focus. If window is not included among the
windows in windowList, Tk implicitly adds it at the end of the
WM_COLORMAP_WINDOWS property, so that its colormap is lowest in
priority. If wm colormapwindows is not invoked, Tk will
automatically set the property for each top-level window to all
the internal windows whose colormaps differ from their parents,
followed by the top-level itself; the order of the internal
windows is undefined. See the ICCCM documentation for more
information on the WM_COLORMAP_WINDOWS property.
wm command window ?value?
If value is specified, this command stores value in window's
WM_COMMAND property for use by the window manager or session
manager and returns an empty string. Value must have proper
list structure; the elements should contain the words of the
command used to invoke the application. If value is not
specified then the command returns the last value set in a wm
command command for window. If value is specified as an empty
string, the command deletes the WM_COMMAND property from window.
wm deiconify window
Arrange for window to be displayed in normal (non-iconified)
form. This is done by mapping the window. If the window has
never been mapped then this command will not map the window, but
it will ensure that when the window is first mapped it will be
displayed in de-iconified form. On Windows, a deiconified
window will also be raised and be given the focus (made the
active window). Returns an empty string.
wm focusmodel window ?active|passive?
If active or passive is supplied as an optional argument to the
command, then it specifies the focus model for window. In this
case the command returns an empty string. If no additional
argument is supplied, then the command returns the current focus
model for window.
An active focus model means that window will claim the input
focus for itself or its descendants, even at times when the
focus is currently in some other application. Passive means
that window will never claim the focus for itself: the window
manager should give the focus to window at appropriate times.
However, once the focus has been given to window or one of its
descendants, the application may re-assign the focus among
window's descendants. The focus model defaults to passive, and
Tk's focus command assumes a passive model of focusing.
wm forget window
The window will be unmapped from the screen and will no longer
be managed by wm. Windows created with the toplevel command
will be treated like frame windows once they are no longer
managed by wm, however, the -menu configuration will be
remembered and the menus will return once the widget is managed
again.
wm frame window
If window has been reparented by the window manager into a
decorative frame, the command returns the platform specific
window identifier for the outermost frame that contains window
(the window whose parent is the root or virtual root). If
window has not been reparented by the window manager then the
command returns the platform specific window identifier for
window.
wm geometry window ?newGeometry?
If newGeometry is specified, then the geometry of window is
changed and an empty string is returned. Otherwise the current
geometry for window is returned (this is the most recent
geometry specified either by manual resizing or in a wm geometry
command). NewGeometry has the form =widthxheight+-x+-y, where
any of =, widthxheight, or +-x+-y may be omitted. Width and
height are positive integers specifying the desired dimensions
of window. If window is gridded (see GRIDDED GEOMETRY
MANAGEMENT below) then the dimensions are specified in grid
units; otherwise they are specified in pixel units.
X and y specify the desired location of window on the screen, in
pixels. If x is preceded by +, it specifies the number of
pixels between the left edge of the screen and the left edge of
window's border; if preceded by - then x specifies the number
of pixels between the right edge of the screen and the right
edge of window's border. If y is preceded by + then it
specifies the number of pixels between the top of the screen and
the top of window's border; if y is preceded by - then it
specifies the number of pixels between the bottom of window's
border and the bottom of the screen.
If newGeometry is specified as an empty string then any existing
user-specified geometry for window is cancelled, and the window
will revert to the size requested internally by its widgets.
Note that this is related to winfo geometry, but not the same.
That can only query the geometry, and always reflects Tk's
current understanding of the actual size and location of window,
whereas wm geometry allows both setting and querying of the
window manager's understanding of the size and location of the
window. This can vary significantly, for example to reflect the
addition of decorative elements to window such as title bars,
and window managers are not required to precisely follow the
requests made through this command.
wm grid window ?baseWidth baseHeight widthInc heightInc?
This command indicates that window is to be managed as a gridded
window. It also specifies the relationship between grid units
and pixel units. BaseWidth and baseHeight specify the number of
grid units corresponding to the pixel dimensions requested
internally by window using Tk_GeometryRequest. WidthInc and
heightInc specify the number of pixels in each horizontal and
vertical grid unit. These four values determine a range of
acceptable sizes for window, corresponding to grid-based widths
and heights that are non-negative integers. Tk will pass this
information to the window manager; during manual resizing, the
window manager will restrict the window's size to one of these
acceptable sizes.
Furthermore, during manual resizing the window manager will
display the window's current size in terms of grid units rather
than pixels. If baseWidth etc. are all specified as empty
strings, then window will no longer be managed as a gridded
window. If baseWidth etc. are specified then the return value
is an empty string.
Otherwise the return value is a Tcl list containing four
elements corresponding to the current baseWidth, baseHeight,
widthInc, and heightInc; if window is not currently gridded,
then an empty string is returned.
Note that this command should not be needed very often, since
the Tk_SetGrid library procedure and the setGrid option provide
easier access to the same functionality.
wm group window ?pathName?
If pathName is specified, it gives the path name for the leader
of a group of related windows. The window manager may use this
information, for example, to unmap all of the windows in a group
when the group's leader is iconified. PathName may be specified
as an empty string to remove window from any group association.
If pathName is specified then the command returns an empty
string; otherwise it returns the path name of window's current
group leader, or an empty string if window is not part of any
group.
wm iconbitmap window ?bitmap?
If bitmap is specified, then it names a bitmap in the standard
forms accepted by Tk (see the Tk_GetBitmap manual entry for
details). This bitmap is passed to the window manager to be
displayed in window's icon, and the command returns an empty
string. If an empty string is specified for bitmap, then any
current icon bitmap is cancelled for window. If bitmap is
specified then the command returns an empty string. Otherwise
it returns the name of the current icon bitmap associated with
window, or an empty string if window has no icon bitmap. On the
Windows operating system, an additional flag is supported:
wm iconbitmap window ?-default? ?image?
If the -default flag is given, the icon is applied to all
toplevel windows (existing and future) to which no other
specific icon has yet been applied. In addition to
bitmap image types, a full path specification to any file
which contains a valid Windows icon is also accepted
(usually .ico or .icr files), or any file for which the
shell has assigned an icon. Tcl will first test if the
file contains an icon, then if it has an assigned icon,
and finally, if that fails, test for a bitmap.
wm iconify window
Arrange for window to be iconified. It window has not yet been
mapped for the first time, this command will arrange for it to
appear in the iconified state when it is eventually mapped.
wm iconmask window ?bitmap?
If bitmap is specified, then it names a bitmap in the standard
forms accepted by Tk (see the Tk_GetBitmap manual entry for
details). This bitmap is passed to the window manager to be
used as a mask in conjunction with the iconbitmap option: where
the mask has zeroes no icon will be displayed; where it has
ones, the bits from the icon bitmap will be displayed. If an
empty string is specified for bitmap then any current icon mask
is cancelled for window (this is equivalent to specifying a
bitmap of all ones). If bitmap is specified then the command
returns an empty string. Otherwise it returns the name of the
current icon mask associated with window, or an empty string if
no mask is in effect.
wm iconname window ?newName?
If newName is specified, then it is passed to the window
manager; the window manager should display newName inside the
icon associated with window. In this case an empty string is
returned as result. If newName is not specified then the
command returns the current icon name for window, or an empty
string if no icon name has been specified (in this case the
window manager will normally display the window's title, as
specified with the wm title command).
wm iconphoto window ?-default? image1 ?image2 ...?
Sets the titlebar icon for window based on the named photo
images. If -default is specified, this is applied to all future
created toplevels as well. The data in the images is taken as a
snapshot at the time of invocation. If the images are later
changed, this is not reflected to the titlebar icons. Multiple
images are accepted to allow different images sizes (e.g., 16x16
and 32x32) to be provided. The window manager may scale provided
icons to an appropriate size.
On Windows, the images are packed into a Windows icon structure.
This will override an ico specified to wm iconbitmap, and vice
versa.
On X, the images are arranged into the _NET_WM_ICON X property,
which most modern window managers support. A wm iconbitmap may
exist simultaneously. It is recommended to use not more than 2
icons, placing the larger icon first.
On Macintosh, the first image called is loaded into an OS-native
icon format, and becomes the application icon in dialogs, the
Dock, and other contexts. At the script level the command will
accept only the first image passed in the parameters as support
for multiple sizes/resolutions on macOS is outside Tk's scope.
Developers should use the largest icon they can support
(preferably 512 pixels) to ensure smooth rendering on the Mac.
wm iconposition window ?x y?
If x and y are specified, they are passed to the window manager
as a hint about where to position the icon for window. In this
case an empty string is returned. If x and y are specified as
empty strings then any existing icon position hint is cancelled.
If neither x nor y is specified, then the command returns a Tcl
list containing two values, which are the current icon position
hints (if no hints are in effect then an empty string is
returned).
wm iconwindow window ?pathName?
If pathName is specified, it is the path name for a window to
use as icon for window: when window is iconified then pathName
will be mapped to serve as icon, and when window is de-iconified
then pathName will be unmapped again. If pathName is specified
as an empty string then any existing icon window association for
window will be cancelled. If the pathName argument is specified
then an empty string is returned. Otherwise the command returns
the path name of the current icon window for window, or an empty
string if there is no icon window currently specified for
window. Button press events are disabled for window as long as
it is an icon window; this is needed in order to allow window
managers to "own" those events. Note that not all window
managers support the notion of an icon window, and the concept
is entirely meaningless on non-X11 platforms.
wm manage widget
The widget specified will become a stand alone top-level window.
The window will be decorated with the window managers title bar,
etc. Only frame, labelframe and toplevel widgets can be used
with this command. Attempting to pass any other widget type will
raise an error. Attempting to manage a toplevel widget is benign
and achieves nothing. See also GEOMETRY MANAGEMENT.
wm maxsize window ?width height?
If width and height are specified, they give the maximum
permissible dimensions for window. For gridded windows the
dimensions are specified in grid units; otherwise they are
specified in pixel units. The window manager will restrict the
window's dimensions to be less than or equal to width and
height. If width and height are specified, then the command
returns an empty string. Otherwise it returns a Tcl list with
two elements, which are the maximum width and height currently
in effect. The maximum size defaults to the size of the screen.
See the sections on geometry management below for more
information.
wm minsize window ?width height?
If width and height are specified, they give the minimum
permissible dimensions for window. For gridded windows the
dimensions are specified in grid units; otherwise they are
specified in pixel units. The window manager will restrict the
window's dimensions to be greater than or equal to width and
height. If width and height are specified, then the command
returns an empty string. Otherwise it returns a Tcl list with
two elements, which are the minimum width and height currently
in effect. The minimum size defaults to one pixel in each
dimension. See the sections on geometry management below for
more information.
wm overrideredirect window ?boolean?
If boolean is specified, it must have a proper boolean form and
the override-redirect flag for window is set to that value. If
boolean is not specified then 1 or 0 is returned to indicate
whether or not the override-redirect flag is currently set for
window. Setting the override-redirect flag for a window causes
it to be ignored by the window manager; among other things,
this means that the window will not be reparented from the root
window into a decorative frame and the user will not be able to
manipulate the window using the normal window manager
mechanisms.
Note that the override-redirect flag is only guaranteed to be
taken notice of when the window is first mapped or when mapped
after the state is changed from withdrawn to normal. Some, but
not all, platforms will take notice at additional times.
wm positionfrom window ?who?
If who is specified, it must be either program or user, or an
abbreviation of one of these two. It indicates whether window's
current position was requested by the program or by the user.
Many window managers ignore program-requested initial positions
and ask the user to manually position the window; if user is
specified then the window manager should position the window at
the given place without asking the user for assistance. If who
is specified as an empty string, then the current position
source is cancelled. If who is specified, then the command
returns an empty string. Otherwise it returns user or program
to indicate the source of the window's current position, or an
empty string if no source has been specified yet. Most window
managers interpret "no source" as equivalent to program. Tk
will automatically set the position source to user when a wm
geometry command is invoked, unless the source has been set
explicitly to program.
wm protocol window ?name? ?command?
This command is used to manage window manager protocols. The
name argument in the wm protocol command is the name of an atom
corresponding to a window manager protocol. Examples include
WM_DELETE_WINDOW or WM_SAVE_YOURSELF or WM_TAKE_FOCUS.
A window manager protocol is a class of messages sent from a
window manager to a Tk application outside of the normal event
processing system. The main example is the WM_DELETE_WINDOW
protocol; these messages are sent when the user clicks the close
widget in the title bar of a window. Handlers for window
manager protocols are installed with the wm protocol command. As
a rule, if no handler has been installed for a protocol by the
wm protocol command then all messages of that protocol are
ignored. The WM_DELETE_WINDOW protocol is an exception to this
rule. At start-up Tk installs a handler for this protocol, which
responds by destroying the window. The wm protocol command can
be used to replace this default handler by one which responds
differently.
The list of available window manager protocols depends on the
window manager, but all window managers supported by Tk provide
WM_DELETE_WINDOW. On the Windows platform, a WM_SAVE_YOURSELF
message is sent on user logout or system restart.
If both name and command are specified, then command becomes the
handler for the protocol specified by name. The atom for name
will be added to window's WM_PROTOCOLS property to tell the
window manager that the application has a handler for the
protocol specified by name, and command will be invoked in the
future whenever the window manager sends a message of that
protocol to the Tk application. In this case the wm protocol
command returns an empty string. If name is specified but
command is not, then the current handler for name is returned,
or an empty string if there is no handler defined for name (as a
special case, the default handler for WM_DELETE_WINDOW is not
returned). If command is specified as an empty string then the
atom for name is removed from the WM_PROTOCOLS property of
window and the handler is destroyed; an empty string is
returned. Lastly, if neither name nor command is specified, the
wm protocol command returns a list of all of the protocols for
which handlers are currently defined for window.
wm resizable window ?width height?
This command controls whether or not the user may interactively
resize a top-level window. If width and height are specified,
they are boolean values that determine whether the width and
height of window may be modified by the user. In this case the
command returns an empty string. If width and height are
omitted then the command returns a list with two 0/1 elements
that indicate whether the width and height of window are
currently resizable. By default, windows are resizable in both
dimensions. If resizing is disabled, then the window's size
will be the size from the most recent interactive resize or wm
geometry command. If there has been no such operation then the
window's natural size will be used.
wm sizefrom window ?who?
If who is specified, it must be either program or user, or an
abbreviation of one of these two. It indicates whether window's
current size was requested by the program or by the user. Some
window managers ignore program-requested sizes and ask the user
to manually size the window; if user is specified then the
window manager should give the window its specified size without
asking the user for assistance. If who is specified as an empty
string, then the current size source is cancelled. If who is
specified, then the command returns an empty string. Otherwise
it returns user or window to indicate the source of the window's
current size, or an empty string if no source has been specified
yet. Most window managers interpret "no source" as equivalent
to program.
wm stackorder window ?isabove|isbelow window?
The stackorder command returns a list of toplevel windows in
stacking order, from lowest to highest. When a single toplevel
window is passed, the returned list recursively includes all of
the window's children that are toplevels. Only those toplevels
that are currently mapped to the screen are returned. The
stackorder command can also be used to determine if one toplevel
is positioned above or below a second toplevel. When two window
arguments separated by either isabove or isbelow are passed, a
boolean result indicates whether or not the first window is
currently above or below the second window in the stacking
order.
wm state window ?newstate?
If newstate is specified, the window will be set to the new
state, otherwise it returns the current state of window: either
normal, iconic, withdrawn, icon, or (Windows and macOS only)
zoomed. The difference between iconic and icon is that iconic
refers to a window that has been iconified (e.g., with the wm
iconify command) while icon refers to a window whose only
purpose is to serve as the icon for some other window (via the
wm iconwindow command). The icon state cannot be set.
wm title window ?string?
If string is specified, then it will be passed to the window
manager for use as the title for window (the window manager
should display this string in window's title bar). In this case
the command returns an empty string. If string is not specified
then the command returns the current title for the window. The
title for a window defaults to its name.
wm transient window ?container?
If container is specified, then the window manager is informed
that window is a transient window (e.g. pull-down menu) working
on behalf of container (where container is the path name for a
top-level window). If container is specified as an empty string
then window is marked as not being a transient window any more.
Otherwise the command returns the path name of window's current
container, or an empty string if window is not currently a
transient window. A transient window will mirror state changes
in the container and inherit the state of the container when
initially mapped. The directed graph with an edge from each
transient to its container must be acyclic. In particular, it
is an error to attempt to make a window a transient of itself.
The window manager may also decorate a transient window
differently, removing some features normally present (e.g.,
minimize and maximize buttons) though this is entirely at the
discretion of the window manager.
wm withdraw window
Arranges for window to be withdrawn from the screen. This
causes the window to be unmapped and forgotten about by the
window manager. If the window has never been mapped, then this
command causes the window to be mapped in the withdrawn state.
Not all window managers appear to know how to handle windows
that are mapped in the withdrawn state. Note that it sometimes
seems to be necessary to withdraw a window and then re-map it
(e.g. with wm deiconify) to get some window managers to pay
attention to changes in window attributes such as group.
GEOMETRY MANAGEMENT
By default a top-level window appears on the screen in its natural
size, which is the one determined internally by its widgets and
geometry managers. If the natural size of a top-level window changes,
then the window's size changes to match. A top-level window can be
given a size other than its natural size in two ways. First, the user
can resize the window manually using the facilities of the window
manager, such as resize handles. Second, the application can request a
particular size for a top-level window using the wm geometry command.
These two cases are handled identically by Tk; in either case, the
requested size overrides the natural size. You can return the window
to its natural by invoking wm geometry with an empty geometry string.
Normally a top-level window can have any size from one pixel in each
dimension up to the size of its screen. However, you can use the wm
minsize and wm maxsize commands to limit the range of allowable sizes.
The range set by wm minsize and wm maxsize applies to all forms of
resizing, including the window's natural size as well as manual resizes
and the wm geometry command. You can also use the command wm resizable
to completely disable interactive resizing in one or both dimensions.
The wm manage and wm forget commands may be used to perform undocking
and docking of windows. After a widget is managed by wm manage
command, all other wm subcommands may be used with the widget. Only
widgets created using the toplevel command may have an attached menu
via the -menu configure option. A toplevel widget may be used as a
frame and managed with any of the other geometry managers after using
the wm forget command. Any menu associated with a toplevel widget will
be hidden when managed by another geometry managers. The menus will
reappear once the window is managed by wm. All custom bindtags for
widgets in a subtree that have their top-level widget changed via a wm
manage or wm forget command, must be redone to adjust any top-level
widget path in the bindtags. Bindtags that have not been customized do
not have to be redone.
GRIDDED GEOMETRY MANAGEMENT
Gridded geometry management occurs when one of the widgets of an
application supports a range of useful sizes. This occurs, for
example, in a text editor where the scrollbars, menus, and other
adornments are fixed in size but the edit widget can support any number
of lines of text or characters per line. In this case, it is usually
desirable to let the user specify the number of lines or characters-
per-line, either with the wm geometry command or by interactively
resizing the window. In the case of text, and in other interesting
cases also, only discrete sizes of the window make sense, such as
integral numbers of lines and characters-per-line; arbitrary pixel
sizes are not useful.
Gridded geometry management provides support for this kind of
application. Tk (and the window manager) assume that there is a grid
of some sort within the application and that the application should be
resized in terms of grid units rather than pixels. Gridded geometry
management is typically invoked by turning on the setGrid option for a
widget; it can also be invoked with the wm grid command or by calling
Tk_SetGrid. In each of these approaches the particular widget (or
sometimes code in the application as a whole) specifies the
relationship between integral grid sizes for the window and pixel
sizes. To return to non-gridded geometry management, invoke wm grid
with empty argument strings.
When gridded geometry management is enabled then all the dimensions
specified in wm minsize, wm maxsize, and wm geometry commands are
treated as grid units rather than pixel units. Interactive resizing is
also carried out in even numbers of grid units rather than pixels.
BUGS
Most existing window managers appear to have bugs that affect the
operation of the wm command. For example, some changes will not take
effect if the window is already active: the window will have to be
withdrawn and de-iconified in order to make the change happen.
EXAMPLES
A fixed-size window that says that it is fixed-size too:
toplevel .fixed
wm title .fixed "Fixed-size Window"
wm resizable .fixed 0 0
A simple dialog-like window, centred on the screen:
# Create and arrange the dialog contents.
toplevel .msg
label .msg.l -text "This is a very simple dialog demo."
button .msg.ok -text OK -default active -command {destroy .msg}
pack .msg.ok -side bottom -fill x
pack .msg.l -expand 1 -fill both
# Now set the widget up as a centred dialog.
# But first, we need the geometry managers to finish setting
# up the interior of the dialog, for which we need to run the
# event loop with the widget hidden completely...
wm withdraw .msg
update
set x [expr {([winfo screenwidth .] - [winfo width .msg]) / 2}]
set y [expr {([winfo screenheight .] - [winfo height .msg]) / 2}]
wm geometry .msg +$x+$y
wm transient .msg .
wm title .msg "Dialog demo"
wm deiconify .msg
SEE ALSO
toplevel(n), winfo(n)
KEYWORDS
aspect ratio, deiconify, focus model, geometry, grid, group, icon,
iconify, increments, position, size, title, top-level window, units,
window manager
Tk 8.5 wm(n)
tk 8.6.15 - Generated Thu Dec 5 08:32:19 CST 2024