DragonFly On-Line Manual Pages
Tk_CreateWindow(3) Tk Library Procedures Tk_CreateWindow(3)
Tk_CreateWindow, Tk_CreateWindowFromPath, Tk_DestroyWindow,
Tk_MakeWindowExist - create or delete window
Tk_CreateWindow(interp, parent, name, topLevScreen)
Tk_CreateAnonymousWindow(interp, parent, topLevScreen)
Tk_CreateWindowFromPath(interp, tkwin, pathName, topLevScreen)
Tcl_Interp *interp (out) Tcl interpreter to use for error
reporting. If no error occurs,
then *interp is not modified.
Tk_Window parent (in) Token for the window that is to
serve as the logical parent of
the new window.
const char *name (in) Name to use for this window.
Must be unique among all
children of the same parent.
const char *topLevScreen (in) Has same format as screenName.
If NULL, then new window is
created as an internal window.
If non-NULL, new window is
created as a top-level window on
screen topLevScreen. If
topLevScreen is an empty string
("") then new window is created
as top-level window of parent's
Tk_Window tkwin (in) Token for window.
const char *pathName (in) Name of new window, specified as
path name within application
The procedures Tk_CreateWindow, Tk_CreateAnonymousWindow, and
Tk_CreateWindowFromPath are used to create new windows for use in Tk-
based applications. Each of the procedures returns a token that can be
used to manipulate the window in other calls to the Tk library. If the
window could not be created successfully, then NULL is returned and the
result of interpreter interp is modified to hold an error message.
Tk supports two different kinds of windows: internal windows and top-
level windows. An internal window is an interior window of a Tk
application, such as a scrollbar or menu bar or button. A top-level
window is one that is created as a child of a screen's root window,
rather than as an interior window, but which is logically part of some
existing main window. Examples of top-level windows are pop-up menus
and dialog boxes.
New windows may be created by calling Tk_CreateWindow. If the
topLevScreen argument is NULL, then the new window will be an internal
window. If topLevScreen is non-NULL, then the new window will be a
top-level window: topLevScreen indicates the name of a screen and the
new window will be created as a child of the root window of
topLevScreen. In either case Tk will consider the new window to be the
logical child of parent: the new window's path name will reflect this
fact, options may be specified for the new window under this
assumption, and so on. The only difference is that new X window for a
top-level window will not be a child of parent's X window. For
example, a pull-down menu's parent would be the button-like window used
to invoke it, which would in turn be a child of the menu bar window. A
dialog box might have the application's main window as its parent.
Tk_CreateAnonymousWindow differs from Tk_CreateWindow in that it
creates an unnamed window. This window will be manipulatable only
using C interfaces, and will not be visible to Tcl scripts. Both
interior windows and top-level windows may be created with
Tk_CreateWindowFromPath offers an alternate way of specifying new
windows. In Tk_CreateWindowFromPath the new window is specified with a
token for any window in the target application (tkwin), plus a path
name for the new window. It produces the same effect as
Tk_CreateWindow and allows both top-level and internal windows to be
created, depending on the value of topLevScreen. In calls to
Tk_CreateWindowFromPath, as in calls to Tk_CreateWindow, the parent of
the new window must exist at the time of the call, but the new window
must not already exist.
The window creation procedures do not actually issue the command to X
to create a window. Instead, they create a local data structure
associated with the window and defer the creation of the X window. The
window will actually be created by the first call to Tk_MapWindow.
Deferred window creation allows various aspects of the window (such as
its size, background color, etc.) to be modified after its creation
without incurring any overhead in the X server. When the window is
finally mapped all of the window attributes can be set while creating
The value returned by a window-creation procedure is not the X token
for the window (it cannot be, since X has not been asked to create the
window yet). Instead, it is a token for Tk's local data structure for
the window. Most of the Tk library procedures take Tk_Window tokens,
rather than X identifiers. The actual X window identifier can be
retrieved from the local data structure using the Tk_WindowId macro;
see the manual entry for Tk_WindowId for details.
Tk_DestroyWindow deletes a window and all the data structures
associated with it, including any event handlers created with
Tk_CreateEventHandler. In addition, Tk_DestroyWindow will delete any
children of tkwin recursively (where children are defined in the Tk
sense, consisting of all windows that were created with the given
window as parent). If tkwin is an internal window, then event handlers
interested in destroy events are invoked immediately. If tkwin is a
top-level or main window, then the event handlers will be invoked
later, after X has seen the request and returned an event for it.
If a window has been created but has not been mapped, so no X window
exists, it is possible to force the creation of the X window by calling
Tk_MakeWindowExist. This procedure issues the X commands to
instantiate the window given by tkwin.
create, deferred creation, destroy, display, internal window, screen,
top-level window, window
Tk 4.2 Tk_CreateWindow(3)