'\" '\" Copyright (c) 1991-1994 The Regents of the University of California. '\" Copyright (c) 1994-1996 Sun Microsystems, Inc. '\" '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" '\" RCS: @(#) $Id: wm.n,v 1.11.2.4 2006/04/11 07:36:40 das Exp $ '\" .so man.macros .TH wm n 8.4 Tk "Tk Built-In Commands" .BS '\" Note: do not modify the .SH NAME line immediately below! .SH NAME wm \- Communicate with window manager .SH SYNOPSIS \fBwm\fR \fIoption window \fR?\fIargs\fR? .BE .SH DESCRIPTION .PP The \fBwm\fR 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 \fBwm\fR command can take any of a number of different forms, depending on the \fIoption\fR argument. All of the forms expect at least one additional argument, \fIwindow\fR, which must be the path name of a top-level window. .PP The legal forms for the \fBwm\fR command are: .TP \fBwm aspect \fIwindow\fR ?\fIminNumer minDenom maxNumer maxDenom\fR? If \fIminNumer\fR, \fIminDenom\fR, \fImaxNumer\fR, and \fImaxDenom\fR 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 \fIwindow\fR. The aspect ratio of \fIwindow\fR (width/length) will be constrained to lie between \fIminNumer\fR/\fIminDenom\fR and \fImaxNumer\fR/\fImaxDenom\fR. If \fIminNumer\fR etc. are all specified as empty strings, then any existing aspect ratio restrictions are removed. If \fIminNumer\fR 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 \fIminNumer\fR, \fIminDenom\fR, \fImaxNumer\fR, and \fImaxDenom\fR (if no aspect restrictions are in effect, then an empty string is returned). .VS 8.4 .TP \fBwm attributes \fIwindow\fR .TP \fBwm attributes \fIwindow\fR ?\fBoption\fR? .TP \fBwm attributes \fIwindow\fR ?\fBoption value option value...\fR? .RS 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: .PP On Windows, \fB\-disabled\fR gets or sets whether the window is in a disabled state. \fB\-toolwindow\fR gets or sets the style of the window to toolwindow (as defined in the MSDN). \fB\-topmost\fR gets or sets whether this is a topmost window (displays above all other windows). \fB\-alpha\fR sets the alpha transparency level of the toplevel. It accepts a value from \fB0.0\fR (fully transparent) to \fB1.0\fR (opaque). Values outside that range will be constrained. This is supported on Windows 2000/XP+. Where not supported, the \fB\-alpha\fR value remains at \fB1.0\fR. .PP On Mac OS X, \fB\-modified\fR gets or sets the modification state of the window (determines whether the window close widget contains the modification indicator and whether the proxy icon is draggable). \fB\-titlepath\fR gets or sets 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). \fB\-alpha\fR sets the alpha transparency level of the window, it accepts a value from \fB0.0\fR (fully transparent) to \fB1.0\fR (opaque), values outside that range will be constrained. .PP On Unix, there are currently no special attribute values. .RE .VE 8.4 .TP \fBwm client \fIwindow\fR ?\fIname\fR? If \fIname\fR is specified, this command stores \fIname\fR (which should be the name of the host on which the application is executing) in \fIwindow\fR's \fBWM_CLIENT_MACHINE\fR property for use by the window manager or session manager. The command returns an empty string in this case. If \fIname\fR isn't specified, the command returns the last name set in a \fBwm client\fR command for \fIwindow\fR. If \fIname\fR is specified as an empty string, the command deletes the \fBWM_CLIENT_MACHINE\fR property from \fIwindow\fR. .TP \fBwm colormapwindows \fIwindow\fR ?\fIwindowList\fR? This command is used to manipulate the \fBWM_COLORMAP_WINDOWS\fR property, which provides information to the window managers about windows that have private colormaps. If \fIwindowList\fR isn't specified, the command returns a list whose elements are the names of the windows in the \fBWM_COLORMAP_WINDOWS\fR property. If \fIwindowList\fR is specified, it consists of a list of window path names; the command overwrites the \fBWM_COLORMAP_WINDOWS\fR property with the given windows and returns an empty string. The \fBWM_COLORMAP_WINDOWS\fR property should normally contain a list of the internal windows within \fIwindow\fR 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 \fIwindow\fR gets the colormap focus. If \fIwindow\fR is not included among the windows in \fIwindowList\fR, Tk implicitly adds it at the end of the \fBWM_COLORMAP_WINDOWS\fR property, so that its colormap is lowest in priority. If \fBwm colormapwindows\fR 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 \fBWM_COLORMAP_WINDOWS\fR property. .TP \fBwm command \fIwindow\fR ?\fIvalue\fR? If \fIvalue\fR is specified, this command stores \fIvalue\fR in \fIwindow\fR's \fBWM_COMMAND\fR property for use by the window manager or session manager and returns an empty string. \fIValue\fR must have proper list structure; the elements should contain the words of the command used to invoke the application. If \fIvalue\fR isn't specified then the command returns the last value set in a \fBwm command\fR command for \fIwindow\fR. If \fIvalue\fR is specified as an empty string, the command deletes the \fBWM_COMMAND\fR property from \fIwindow\fR. .TP \fBwm deiconify \fIwindow\fR Arrange for \fIwindow\fR 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. .TP \fBwm focusmodel \fIwindow\fR ?\fBactive\fR|\fBpassive\fR? If \fBactive\fR or \fBpassive\fR is supplied as an optional argument to the command, then it specifies the focus model for \fIwindow\fR. In this case the command returns an empty string. If no additional argument is supplied, then the command returns the current focus model for \fIwindow\fR. An \fBactive\fR focus model means that \fIwindow\fR will claim the input focus for itself or its descendants, even at times when the focus is currently in some other application. \fBPassive\fR means that \fIwindow\fR will never claim the focus for itself: the window manager should give the focus to \fIwindow\fR at appropriate times. However, once the focus has been given to \fIwindow\fR or one of its descendants, the application may re-assign the focus among \fIwindow\fR's descendants. The focus model defaults to \fBpassive\fR, and Tk's \fBfocus\fR command assumes a passive model of focusing. .TP \fBwm frame \fIwindow\fR .VS If \fIwindow\fR 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 \fIwindow\fR (the window whose parent is the root or virtual root). If \fIwindow\fR hasn't been reparented by the window manager then the command returns the platform specific window identifier for \fIwindow\fR. .VE .TP \fBwm geometry \fIwindow\fR ?\fInewGeometry\fR? If \fInewGeometry\fR is specified, then the geometry of \fIwindow\fR is changed and an empty string is returned. Otherwise the current geometry for \fIwindow\fR is returned (this is the most recent geometry specified either by manual resizing or in a \fBwm geometry\fR command). \fINewGeometry\fR has the form \fB=\fIwidth\fBx\fIheight\fB\(+-\fIx\fB\(+-\fIy\fR, where any of \fB=\fR, \fIwidth\fBx\fIheight\fR, or \fB\(+-\fIx\fB\(+-\fIy\fR may be omitted. \fIWidth\fR and \fIheight\fR are positive integers specifying the desired dimensions of \fIwindow\fR. If \fIwindow\fR is gridded (see GRIDDED GEOMETRY MANAGEMENT below) then the dimensions are specified in grid units; otherwise they are specified in pixel units. \fIX\fR and \fIy\fR specify the desired location of \fIwindow\fR on the screen, in pixels. If \fIx\fR is preceded by \fB+\fR, it specifies the number of pixels between the left edge of the screen and the left edge of \fIwindow\fR's border; if preceded by \fB\-\fR then \fIx\fR specifies the number of pixels between the right edge of the screen and the right edge of \fIwindow\fR's border. If \fIy\fR is preceded by \fB+\fR then it specifies the number of pixels between the top of the screen and the top of \fIwindow\fR's border; if \fIy\fR is preceded by \fB\-\fR then it specifies the number of pixels between the bottom of \fIwindow\fR's border and the bottom of the screen. If \fInewGeometry\fR is specified as an empty string then any existing user-specified geometry for \fIwindow\fR is cancelled, and the window will revert to the size requested internally by its widgets. .TP \fBwm grid \fIwindow\fR ?\fIbaseWidth baseHeight widthInc heightInc\fR? This command indicates that \fIwindow\fR is to be managed as a gridded window. It also specifies the relationship between grid units and pixel units. \fIBaseWidth\fR and \fIbaseHeight\fR specify the number of grid units corresponding to the pixel dimensions requested internally by \fIwindow\fR using \fBTk_GeometryRequest\fR. \fIWidthInc\fR and \fIheightInc\fR specify the number of pixels in each horizontal and vertical grid unit. These four values determine a range of acceptable sizes for \fIwindow\fR, 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 \fIbaseWidth\fR etc. are all specified as empty strings, then \fIwindow\fR will no longer be managed as a gridded window. If \fIbaseWidth\fR 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 \fIbaseWidth\fR, \fIbaseHeight\fR, \fIwidthInc\fR, and \fIheightInc\fR; if \fIwindow\fR is not currently gridded, then an empty string is returned. Note: this command should not be needed very often, since the \fBTk_SetGrid\fR library procedure and the \fBsetGrid\fR option provide easier access to the same functionality. .TP \fBwm group \fIwindow\fR ?\fIpathName\fR? If \fIpathName\fR 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. \fIPathName\fR may be specified as an empty string to remove \fIwindow\fR from any group association. If \fIpathName\fR is specified then the command returns an empty string; otherwise it returns the path name of \fIwindow\fR's current group leader, or an empty string if \fIwindow\fR isn't part of any group. .TP \fBwm iconbitmap \fIwindow\fR ?\fIbitmap\fR? If \fIbitmap\fR is specified, then it names a bitmap in the standard forms accepted by Tk (see the \fBTk_GetBitmap\fR manual entry for details). This bitmap is passed to the window manager to be displayed in \fIwindow\fR's icon, and the command returns an empty string. If an empty string is specified for \fIbitmap\fR, then any current icon bitmap is cancelled for \fIwindow\fR. If \fIbitmap\fR is specified then the command returns an empty string. Otherwise it returns the name of the current icon bitmap associated with \fIwindow\fR, or an empty string if \fIwindow\fR has no icon bitmap. On the Windows operating system, an additional flag is supported: \fBwm iconbitmap \fIwindow\fR ?\fB\-default\fR? ?\fIimage\fR?. If the \fB\-default\fR 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. .TP \fBwm iconify \fIwindow\fR Arrange for \fIwindow\fR to be iconified. It \fIwindow\fR hasn't yet been mapped for the first time, this command will arrange for it to appear in the iconified state when it is eventually mapped. .TP \fBwm iconmask \fIwindow\fR ?\fIbitmap\fR? If \fIbitmap\fR is specified, then it names a bitmap in the standard forms accepted by Tk (see the \fBTk_GetBitmap\fR manual entry for details). This bitmap is passed to the window manager to be used as a mask in conjunction with the \fBiconbitmap\fR 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 \fIbitmap\fR then any current icon mask is cancelled for \fIwindow\fR (this is equivalent to specifying a bitmap of all ones). If \fIbitmap\fR is specified then the command returns an empty string. Otherwise it returns the name of the current icon mask associated with \fIwindow\fR, or an empty string if no mask is in effect. .TP \fBwm iconname \fIwindow\fR ?\fInewName\fR? If \fInewName\fR is specified, then it is passed to the window manager; the window manager should display \fInewName\fR inside the icon associated with \fIwindow\fR. In this case an empty string is returned as result. If \fInewName\fR isn't specified then the command returns the current icon name for \fIwindow\fR, 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 \fBwm title\fR command). .TP \fBwm iconposition \fIwindow\fR ?\fIx y\fR? If \fIx\fR and \fIy\fR are specified, they are passed to the window manager as a hint about where to position the icon for \fIwindow\fR. In this case an empty string is returned. If \fIx\fR and \fIy\fR are specified as empty strings then any existing icon position hint is cancelled. If neither \fIx\fR nor \fIy\fR 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). .TP \fBwm iconwindow \fIwindow\fR ?\fIpathName\fR? If \fIpathName\fR is specified, it is the path name for a window to use as icon for \fIwindow\fR: when \fIwindow\fR is iconified then \fIpathName\fR will be mapped to serve as icon, and when \fIwindow\fR is de-iconified then \fIpathName\fR will be unmapped again. If \fIpathName\fR is specified as an empty string then any existing icon window association for \fIwindow\fR will be cancelled. If the \fIpathName\fR argument is specified then an empty string is returned. Otherwise the command returns the path name of the current icon window for \fIwindow\fR, or an empty string if there is no icon window currently specified for \fIwindow\fR. Button press events are disabled for \fIwindow\fR as long as it is an icon window; this is needed in order to allow window managers to ``own'' those events. Note: not all window managers support the notion of an icon window. .TP \fBwm maxsize \fIwindow\fR ?\fIwidth height\fR? If \fIwidth\fR and \fIheight\fR are specified, they give the maximum permissible dimensions for \fIwindow\fR. 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 \fIwidth\fR and \fIheight\fR. If \fIwidth\fR and \fIheight\fR 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. .TP \fBwm minsize \fIwindow\fR ?\fIwidth height\fR? If \fIwidth\fR and \fIheight\fR are specified, they give the minimum permissible dimensions for \fIwindow\fR. 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 \fIwidth\fR and \fIheight\fR. If \fIwidth\fR and \fIheight\fR 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. .TP \fBwm overrideredirect \fIwindow\fR ?\fIboolean\fR? If \fIboolean\fR is specified, it must have a proper boolean form and the override-redirect flag for \fIwindow\fR is set to that value. If \fIboolean\fR is not specified then \fB1\fR or \fB0\fR is returned to indicate whether or not the override-redirect flag is currently set for \fIwindow\fR. 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. .TP \fBwm positionfrom \fIwindow\fR ?\fIwho\fR? If \fIwho\fR is specified, it must be either \fBprogram\fR or \fBuser\fR, or an abbreviation of one of these two. It indicates whether \fIwindow\fR'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 \fBuser\fR is specified then the window manager should position the window at the given place without asking the user for assistance. If \fIwho\fR is specified as an empty string, then the current position source is cancelled. If \fIwho\fR is specified, then the command returns an empty string. Otherwise it returns \fBuser\fR or \fBprogram\fR 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 \fBprogram\fR. Tk will automatically set the position source to \fBuser\fR when a \fBwm geometry\fR command is invoked, unless the source has been set explicitly to \fBprogram\fR. .TP \fBwm protocol \fIwindow\fR ?\fIname\fR? ?\fIcommand\fR? This command is used to manage window manager protocols such as \fBWM_DELETE_WINDOW\fR. \fIName\fR is the name of an atom corresponding to a window manager protocol, such as \fBWM_DELETE_WINDOW\fR or \fBWM_SAVE_YOURSELF\fR or \fBWM_TAKE_FOCUS\fR. If both \fIname\fR and \fIcommand\fR are specified, then \fIcommand\fR is associated with the protocol specified by \fIname\fR. \fIName\fR will be added to \fIwindow\fR's \fBWM_PROTOCOLS\fR property to tell the window manager that the application has a protocol handler for \fIname\fR, and \fIcommand\fR will be invoked in the future whenever the window manager sends a message to the client for that protocol. In this case the command returns an empty string. If \fIname\fR is specified but \fIcommand\fR isn't, then the current command for \fIname\fR is returned, or an empty string if there is no handler defined for \fIname\fR. If \fIcommand\fR is specified as an empty string then the current handler for \fIname\fR is deleted and it is removed from the \fBWM_PROTOCOLS\fR property on \fIwindow\fR; an empty string is returned. Lastly, if neither \fIname\fR nor \fIcommand\fR is specified, the command returns a list of all the protocols for which handlers are currently defined for \fIwindow\fR. .RS .PP Tk always defines a protocol handler for \fBWM_DELETE_WINDOW\fR, even if you haven't asked for one with \fBwm protocol\fR. If a \fBWM_DELETE_WINDOW\fR message arrives when you haven't defined a handler, then Tk handles the message by destroying the window for which it was received. .RE .TP \fBwm resizable \fIwindow\fR ?\fIwidth height\fR? This command controls whether or not the user may interactively resize a top-level window. If \fIwidth\fR and \fIheight\fR are specified, they are boolean values that determine whether the width and height of \fIwindow\fR may be modified by the user. In this case the command returns an empty string. If \fIwidth\fR and \fIheight\fR are omitted then the command returns a list with two 0/1 elements that indicate whether the width and height of \fIwindow\fR 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 \fBwm geometry\fR command. If there has been no such operation then the window's natural size will be used. .TP \fBwm sizefrom \fIwindow\fR ?\fIwho\fR? If \fIwho\fR is specified, it must be either \fBprogram\fR or \fBuser\fR, or an abbreviation of one of these two. It indicates whether \fIwindow\fR'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 \fBuser\fR is specified then the window manager should give the window its specified size without asking the user for assistance. If \fIwho\fR is specified as an empty string, then the current size source is cancelled. If \fIwho\fR is specified, then the command returns an empty string. Otherwise it returns \fBuser\fR or \fBwindow\fR 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 \fBprogram\fR. .TP \fBwm stackorder \fIwindow\fR ?\fIisabove|isbelow window\fR? 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 \fIisabove\fR or \fIisbelow\fR are passed, a boolean result indicates whether or not the first window is currently above or below the second window in the stacking order. .TP \fBwm state \fIwindow\fR ?newstate? If \fInewstate\fR is specified, the window will be set to the new state, otherwise it returns the current state of \fIwindow\fR: either \fBnormal\fR, \fBiconic\fR, \fBwithdrawn\fR, \fBicon\fR, or (Windows and Mac OS X only) \fBzoomed\fR. The difference between \fBiconic\fR and \fBicon\fR is that \fBiconic\fR refers to a window that has been iconified (e.g., with the \fBwm iconify\fR command) while \fBicon\fR refers to a window whose only purpose is to serve as the icon for some other window (via the \fBwm iconwindow\fR command). The \fBicon\fR state cannot be set. .TP \fBwm title \fIwindow\fR ?\fIstring\fR? If \fIstring\fR is specified, then it will be passed to the window manager for use as the title for \fIwindow\fR (the window manager should display this string in \fIwindow\fR's title bar). In this case the command returns an empty string. If \fIstring\fR isn't specified then the command returns the current title for the \fIwindow\fR. The title for a window defaults to its name. .TP \fBwm transient \fIwindow\fR ?\fImaster\fR? If \fImaster\fR is specified, then the window manager is informed that \fIwindow\fR is a transient window (e.g. pull-down menu) working on behalf of \fImaster\fR (where \fImaster\fR is the path name for a top-level window). If \fImaster\fR is specified as an empty string then \fIwindow\fR is marked as not being a transient window any more. Otherwise the command returns the path name of \fIwindow\fR's current master, or an empty string if \fIwindow\fR isn't currently a transient window. A transient window will mirror state changes in the master and inherit the state of the master when initially mapped. It is an error to attempt to make a window a transient of itself. .TP \fBwm withdraw \fIwindow\fR Arranges for \fIwindow\fR 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: it sometimes seems to be necessary to withdraw a window and then re-map it (e.g. with \fBwm deiconify\fR) to get some window managers to pay attention to changes in window attributes such as group. .SH "GEOMETRY MANAGEMENT" .PP By default a top-level window appears on the screen in its \fInatural size\fR, 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 \fBwm geometry\fR 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 \fBwm geometry\fR with an empty \fIgeometry\fR string. .PP 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 \fBwm minsize\fR and \fBwm maxsize\fR commands to limit the range of allowable sizes. The range set by \fBwm minsize\fR and \fBwm maxsize\fR applies to all forms of resizing, including the window's natural size as well as manual resizes and the \fBwm geometry\fR command. You can also use the command \fBwm resizable\fR to completely disable interactive resizing in one or both dimensions. .SH "GRIDDED GEOMETRY MANAGEMENT" .PP 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 \fBwm geometry\fR 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. .PP 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 \fIgrid units\fR rather than pixels. Gridded geometry management is typically invoked by turning on the \fBsetGrid\fR option for a widget; it can also be invoked with the \fBwm grid\fR command or by calling \fBTk_SetGrid\fR. 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 \fBwm grid\fR with empty argument strings. .PP When gridded geometry management is enabled then all the dimensions specified in \fBwm minsize\fR, \fBwm maxsize\fR, and \fBwm geometry\fR 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. .SH BUGS .PP Most existing window managers appear to have bugs that affect the operation of the \fBwm\fR command. For example, some changes won't 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. .SH EXAMPLES A fixed-size window that says that it is fixed-size too: .CS toplevel .fixed \fBwm title\fR .fixed "Fixed-size Window" \fBwm resizable\fR .fixed 0 0 .CE .PP A simple dialog-like window, centred on the screen: .CS # 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... \fBwm withdraw\fR .msg update set x [expr {([winfo screenwidth .]\-[winfo width .msg])/2}] set y [expr {([winfo screenheight .]\-[winfo height .msg])/2}] \fBwm geometry\fR .msg +$x+$y \fBwm transient\fR .msg . \fBwm title\fR .msg "Dialog demo" \fBwm deiconify\fR .msg .CE .SH "SEE ALSO" toplevel(n), winfo(n) .SH KEYWORDS aspect ratio, deiconify, focus model, geometry, grid, group, icon, iconify, increments, position, size, title, top-level window, units, window manager