The winfo command is used to retrieve information about windows
managed by Tk. It can take any of a number of different forms,
depending on the option argument. The legal forms are:
Returns a decimal string giving the integer identifier for the
atom whose name is name. If no atom exists with the name
name then a new one is created.
If the -displayof option is given then the atom is looked
up on the display of window; otherwise it is looked up on
the display of the application's main window.
Returns the textual name for the atom whose integer identifier is
id.
If the -displayof option is given then the identifier is looked
up on the display of window; otherwise it is looked up on
the display of the application's main window.
This command is the inverse of the winfo atom command.
It generates an error if no such atom exists.
Returns a list containing the path names of all the children
of window. Top-level windows are returned as children
of their logical parents. The list is in stacking order, with
the lowest window first, except for Top-level windows which
are not returned in stacking order. Use the wm stackorder
command to query the stacking order of Top-level windows.
Returns 1 if the colormap for window is known to be full, 0
otherwise. The colormap for a window is
“known”
to be full if the last
attempt to allocate a new color on that window failed and this
application has not freed any colors in the colormap since the
failed allocation.
Returns the path name for the window containing the point given
by rootX and rootY.
RootX and rootY are specified in screen units (i.e.
any form acceptable to Tk_GetPixels) in the coordinate
system of the root window (if a virtual-root window manager is in
use then the coordinate system of the virtual root window is used).
If the -displayof option is given then the coordinates refer
to the screen containing window; otherwise they refer to the
screen of the application's main window.
If no window in this application contains the point then an empty
string is returned.
An empty string is also returned if the point lies in the title bar
or border of its highest containing toplevel in this application.
(Note that with some window managers the borders may be invisible.)
In selecting the containing window, children are given higher priority
than parents and among siblings the highest one in the stacking order is
chosen.
Returns a floating-point value giving the number of pixels
in window corresponding to the distance given by number.
Number may be specified in any of the forms acceptable
to Tk_GetScreenMM, such as
“2.0c”
or
“1i”.
The return value may be fractional; for an integer value, use
winfo pixels.
Returns a decimal string giving window's height in pixels.
When a window is first created its height will be 1 pixel; the
height will eventually be changed by a geometry manager to fulfil
the window's needs.
If you need the true height immediately after creating a widget,
invoke update to force the geometry manager to arrange it,
or use winfo reqheight to get the window's requested height
instead of its actual height.
Returns a hexadecimal string giving a low-level platform-specific
identifier for window. On Unix platforms, this is the X
window identifier. Under Windows, this is the Windows
HWND. On the Macintosh the value has no meaning outside Tk.
Returns a list whose members are the names of all Tcl interpreters
(e.g. all Tk-based applications) currently registered for a particular display.
If the -displayof option is given then the return value refers
to the display of window; otherwise it refers to
the display of the application's main window.
Returns the name of the geometry manager currently
responsible for window, or an empty string if window
is not managed by any geometry manager.
The name is usually the name of the Tcl command for the geometry
manager, such as pack or place.
If the geometry manager is a widget, such as canvases or text, the
name is the widget's class command, such as canvas.
Returns window's name (i.e. its name within its parent, as opposed
to its full path name).
The command winfo name . will return the name of the application.
Returns the path name of the window whose X identifier is id.
Id must be a decimal, hexadecimal, or octal integer and must
correspond to a window in the invoking application.
If the -displayof option is given then the identifier is looked
up on the display of window; otherwise it is looked up on
the display of the application's main window.
Returns the number of pixels in window corresponding
to the distance given by number.
Number may be specified in any of the forms acceptable
to Tk_GetPixels, such as
“2.0c”
or
“1i”.
The result is rounded to the nearest integer value; for a
fractional result, use winfo fpixels.
If the mouse pointer is on the same screen as window, returns the
pointer's x coordinate, measured in pixels in the screen's root window.
If a virtual root window is in use on the screen, the position is
measured in the virtual root.
If the mouse pointer is not on the same screen as window then
-1 is returned.
If the mouse pointer is on the same screen as window, returns a list
with two elements, which are the pointer's x and y coordinates measured
in pixels in the screen's root window.
If a virtual root window is in use on the screen, the position
is computed in the virtual root.
If the mouse pointer is not on the same screen as window then
both of the returned coordinates are -1.
If the mouse pointer is on the same screen as window, returns the
pointer's y coordinate, measured in pixels in the screen's root window.
If a virtual root window is in use on the screen, the position
is computed in the virtual root.
If the mouse pointer is not on the same screen as window then
-1 is returned.
Returns a list containing three decimal values in the range 0 to
65535, which are the
red, green, and blue intensities that correspond to color in
the window given by window. Color
may be specified in any of the forms acceptable for a color
option.
Returns a decimal string giving the x-coordinate, in the root
window of the screen, of the
upper-left corner of window's border (or window if it
has no border).
Returns a decimal string giving the y-coordinate, in the root
window of the screen, of the
upper-left corner of window's border (or window if it
has no border).
Returns one of the following strings to indicate the default visual
class for window's screen: directcolor, grayscale,
pseudocolor, staticcolor, staticgray, or
truecolor.
Returns a string containing information about the server for
window's display. The exact format of this string may vary
from platform to platform. For X servers the string
has the form
“XmajorRminor vendor vendorVersion”
where major and minor are the version and revision
numbers provided by the server (e.g., X11R5), vendor
is the name of the vendor for the server, and vendorRelease
is an integer release number provided by the server.
Returns the path name of the top-of-hierarchy window containing window.
In standard Tk this will always be a toplevel widget, but extensions may
create other kinds of top-of-hierarchy widgets.
Returns one of the following strings to indicate the visual
class for window: directcolor, grayscale,
pseudocolor, staticcolor, staticgray, or
truecolor.
Returns a list whose elements describe the visuals available for
window's screen.
Each element consists of a visual class followed by an integer depth.
The class has the same form as returned by winfo visual.
The depth gives the number of bits per pixel in the visual.
In addition, if the includeids argument is provided, then the
depth is followed by the X identifier for the visual.
Returns the x-offset of the virtual root window associated with window,
relative to the root window of its screen.
This is normally either zero or negative.
Returns 0 if there is no virtual root window for window.
Returns the y-offset of the virtual root window associated with window,
relative to the root window of its screen.
This is normally either zero or negative.
Returns 0 if there is no virtual root window for window.
Returns a decimal string giving window's width in pixels.
When a window is first created its width will be 1 pixel; the
width will eventually be changed by a geometry manager to fulfil
the window's needs.
If you need the true width immediately after creating a widget,
invoke update to force the geometry manager to arrange it,
or use winfo reqwidth to get the window's requested width
instead of its actual width.
Print where the mouse pointer is and what window it is currently over:
lassign [winfo pointerxy .] x y
puts -nonewline "Mouse pointer at ($x,$y) which is "
set win [winfo containing $x $y]
if {$win eq ""} {
puts "over no window"
} else {
puts "over $win"
}
