## NAME

wm - Communicate with window manager

## SYNOPSIS

$toplevel->method(?args?)

## DESCRIPTION

The wm methods are 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 methods can take any of a number of different forms, depending on the particular method argument. All of the forms expect $toplevel, which must be a top-level window object.

The legal forms for the wm methods are:

$toplevel->aspect(?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 $toplevel. The aspect ratio of $toplevel (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 array 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).
$toplevel->client(?name?)
  If name is specified, this command stores name (which should be the name of the host on which the application is executing) in $toplevel'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 isn't specified, the command returns the last name set in a client command for $toplevel. If name is specified as an empty string, the command deletes the WM_CLIENT_MACHINE property from $toplevel.
$toplevel->colormapwindows(?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 isn't 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 widgets; 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 $toplevel 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 $toplevel gets the colormap focus. If 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, but the order is undefined. See the ICCCM documentation for more information on the WM_COLORMAP_WINDOWS property.
$toplevel->command(?value?)
  If value is specified, this command stores value in $toplevel'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 isn't specified then the command returns the last value set in a command command for $toplevel. If value is specified as an empty string, the command deletes the WM_COMMAND property from $toplevel.
$toplevel->deiconify
  Arrange for $toplevel 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. Returns an empty string.
$toplevel->focusmodel(?active|passive?)
  If active or passive is supplied as an optional argument to the command, then it specifies the focus model for $toplevel. In this case the command returns an empty string. If no additional argument is supplied, then the command returns the current focus model for $toplevel. An active focus model means that $toplevel 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 $toplevel will never claim the focus for itself: the window manager should give the focus to $toplevel at appropriate times. However, once the focus has been given to $toplevel or one of its descendants, the application may re-assign the focus among $toplevel's descendants. The focus model defaults to passive, and Tk's focus command assumes a passive model of focussing.
$toplevel->frame
  If $toplevel has been reparented by the window manager into a decorative frame, the command returns the X window identifier for the outermost frame that contains $toplevel (the window whose parent is the root or virtual root). If $toplevel hasn't been reparented by the window manager then the command returns the X window identifier for $toplevel.
$toplevel->geometry(?newGeometry?)
  If newGeometry is specified, then the geometry of $toplevel is changed and an empty string is returned. Otherwise the current geometry for $toplevel is returned (this is the most recent geometry specified either by manual resizing or in a geometry command). NewGeometry has the form =width x height±x±y, where any of =, width x height, or ±x±y may be omitted. Width and height are positive integers specifying the desired dimensions of $toplevel. If $toplevel 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 $toplevel 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 $toplevel's border; if preceded by - then x specifies the number of pixels between the right edge of the screen and the right edge of $toplevel's border. If y is preceded by + then it specifies the number of pixels between the top of the screen and the top of $toplevel's border; if y is preceded by - then it specifies the number of pixels between the bottom of $toplevel's border and the bottom of the screen. If newGeometry is specified as an empty string then any existing user-specified geometry for $toplevel is cancelled, and the window will revert to the size requested internally by its widgets.
$toplevel->grid(?baseWidth,baseHeight,widthInc,heightInc?)
  This command indicates that $toplevel 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 $toplevel 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 $toplevel, 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 $toplevel 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 array containing four elements corresponding to the current baseWidth, baseHeight, widthInc, and heightInc; if $toplevel is not currently gridded, then an empty string is returned. Note: 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.
$toplevel->group(?$widget?)
  If $widget is specified, it is the 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. $widget may be specified as an empty string to remove $toplevel from any group association. If $widget is specified then the method returns an empty string; otherwise it returns the $toplevel's current group leader, or an empty string if $toplevel isn't part of any group.
$toplevel->iconbitmap(?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 $toplevel'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 $toplevel. If bitmap is specified then the command returns an empty string. Otherwise it returns the name of the current icon bitmap associated with $toplevel, or an empty string if $toplevel has no icon bitmap.
$toplevel->iconify
  Arrange for $toplevel to be iconified. It $toplevel 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.
$toplevel->iconmask(?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 $toplevel (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 $toplevel, or an empty string if no mask is in effect.
$toplevel->iconname(?newName?)
  If newName is specified, then it is passed to the window manager; the window manager should display newName inside the icon associated with $toplevel. In this case an empty string is returned as result. If newName isn't specified then the command returns the current icon name for $toplevel, 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 title command).
$toplevel->iconposition(?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 $toplevel. 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 array containing two values, which are the current icon position hints (if no hints are in effect then an empty string is returned).
$toplevel->iconwindow(?$widget?)
  If $widget is specified, it is a window to use as icon for $toplevel: when $toplevel is iconified then $widget will be mapped to serve as icon, and when $toplevel is de-iconified then $widget will be unmapped again. If $widget is specified as an empty string then any existing icon window association for $toplevel will be cancelled. If the $widget argument is specified then an empty string is returned. Otherwise the method returns the current icon window for $toplevel, or an empty string if there is no icon window currently specified for $toplevel. Button press events are disabled for $toplevel 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.
$toplevel->maxsize(?width,height?)
  If width and height are specified, they give the maximum permissible dimensions for $toplevel. 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 array with two elements, which are the maximum width and height currently in effect. The maximum size defaults to the size of the screen. If resizing has been disabled with the resizable command, then this command has no effect. See the sections on geometry management below for more information.
$toplevel->minsize(?width,height?)
  If width and height are specified, they give the minimum permissible dimensions for $toplevel. 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 array with two elements, which are the minimum width and height currently in effect. The minimum size defaults to one pixel in each dimension. If resizing has been disabled with the resizable command, then this command has no effect. See the sections on geometry management below for more information.
$toplevel->overrideredirect(?boolean?)
  If boolean is specified, it must have a proper boolean form and the override-redirect flag for $toplevel 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 $toplevel. 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.
$toplevel->positionfrom(?who?)
  If who is specified, it must be either program or user, or an abbreviation of one of these two. It indicates whether $toplevel'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 $widget 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 geometry command is invoked, unless the source has been set explicitly to program.
$toplevel->protocol(?name?,?callback?)
  This method is used to manage window manager protocols such as WM_DELETE_WINDOW. Name is the name of an atom corresponding to a window manager protocol, such as WM_DELETE_WINDOW or WM_SAVE_YOURSELF or WM_TAKE_FOCUS. If both name and callback are specified, then callback is associated with the protocol specified by name. Name will be added to $toplevel's WM_PROTOCOLS property to tell the window manager that the application has a protocol handler for name, and callback will be invoked in the future whenever the window manager sends a message to the client for that protocol. In this case the method returns an empty string. If name is specified but callback isn't, then the current callback for name is returned, or an empty string if there is no handler defined for name. If callback is specified as an empty string then the current handler for name is deleted and it is removed from the WM_PROTOCOLS property on $toplevel; an empty string is returned. Lastly, if neither name nor callback is specified, the method returns a list of all the protocols for which handlers are currently defined for $toplevel.

Tk always defines a protocol handler for WM_DELETE_WINDOW, even if you haven't asked for one with protocol. If a WM_DELETE_WINDOW message arrives when you haven't defined a handler, then Tk handles the message by destroying the window for which it was received.

$toplevel->resizable(?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 $toplevel 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 $toplevel 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 geometry command. If there has been no such operation then the window's natural size will be used.
$toplevel->sizefrom(?who?)
  If who is specified, it must be either program or user, or an abbreviation of one of these two. It indicates whether $toplevel'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 $widget 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.
$toplevel->state
  Returns the current state of $toplevel: either normal, iconic, or withdrawn.
$toplevel->title(?string?)
  If string is specified, then it will be passed to the window manager for use as the title for $toplevel (the window manager should display this string in $toplevel's title bar). In this case the command returns an empty string. If string isn't specified then the command returns the current title for the $toplevel. The title for a window defaults to its name.
$toplevel->transient(?master?)
  If master is specified, then the window manager is informed that $toplevel is a transient window (e.g. pull-down menu) working on behalf of master (where master is a top-level window). Some window managers will use this information to manage $toplevel specially. If master is specified as an empty string then $toplevel is marked as not being a transient window any more. If master is specified, then the command returns an empty string. Otherwise the command returns the path name of $toplevel's current master, or an empty string if $toplevel isn't currently a transient window.
$toplevel->withdraw
  Arranges for $toplevel 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 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 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 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 minsize and maxsize commands to limit the range of allowable sizes. The range set by minsize and maxsize applies to all forms of resizing, including the window's natural size as well as manual resizes and the geometry command. You can also use the command resizable to completely disable interactive resizing in one or both dimensions.

## 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 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 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 grid with empty argument strings.

When gridded geometry management is enabled then all the dimensions specified in minsize, maxsize, and 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 methods. 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.

## SEE ALSO

Wm winfo Mwm

## KEYWORDS

aspect ratio, deiconify, focus model, geometry, grid, group, icon, iconify, increments, position, size, title, top-level window, units, window manager