Tk_CreateWindow(3) Tk Library Procedures Tk_CreateWindow(3)

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NAME

Tk_CreateWindow, Tk_CreateWindowFromPath, Tk_DestroyWindow,
Tk_MakeWindowExist - create or delete window

SYNOPSIS

#include <tk.h>

Tk_Window
Tk_CreateWindow(interp, parent, name, topLevScreen)

Tk_Window
Tk_CreateAnonymousWindow(interp, parent, topLevScreen)

Tk_Window
Tk_CreateWindowFromPath(interp, tkwin, pathName, topLevScreen)

Tk_DestroyWindow(tkwin)

Tk_MakeWindowExist(tkwin)

ARGUMENTS

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 screen.

Tk_Window tkwin (in) Token for window.

const char *pathName (in) Name of new window, specified
as path name within
application (e.g. .a.b.c).
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DESCRIPTION

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_CreateAnonymousWindow.

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 window.

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.

KEYWORDS

create, deferred creation, destroy, display, internal window, screen,
top-level window, window

Tk 4.2 Tk_CreateWindow(3)