Tk_CreateMainWindow

Tk_Window
Tk_CreateMainWindow(interp, screenName, baseName, className)

Tk_Window
Tk_CreateWindow(interp, parent, name, 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 isn't modified. For Tk_CreateMainWindow,
this interpreter is associated permanently with the created window,
and Tk-related commands are bound into the interpreter.

char *screenName (in)

String name of screen on which to create window. Has the form
displayName.screenNum, where displayName is the
name of a display and screenNum is a screen number. If
the dot and screenNum are omitted, the screen number defaults
to 0. If screenName is NULL or empty string, defaults to
contents of DISPLAY environment variable.

char *baseName (in)

Name to use for this main window. See below for details.

char *className (in)

Class to use for application and for main window.

Tk_Window parent (in)

Token for the window that is to serve as the logical parent of
the new window.

char *name (in)

Name to use for this window. Must be unique among all children of
the same parent.

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.

char *pathName (in)

Name of new window, specified as path name within application
(e.g. .a.b.c).

The three procedures Tk_CreateMainWindow, Tk_CreateWindow,
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 couldn't be created successfully, then NULL
is returned and interp->result is modified to hold an error
message.

Tk supports three different kinds of windows: main windows, internal
windows, and top-level windows.
A main window is the outermost window corresponding to an application.
Main windows correspond to the independent units of an application,
such as a view on a file that is part of an editor, or a clock, or
a terminal emulator. A main window is created as a child of the root
window of the screen indicated by the screenName. Each main
window, and all its descendants, are typically associated with a
single Tcl command interpreter.
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.

Tk_CreateMainWindow creates a new main window and associates
its interp argument with that window and all its eventual
descendants.
Tk_CreateMainWindow also carries out several other actions to
set up the new application.
First, it adds all the Tk commands to those already defined
for interp.
Second, it turns the new window into a toplevel widget, which
will cause the X window to be created and mapped as soon as the
application goes idle.
Third, Tk_CreateMainWindow registers interp so that it
can be accessed remotely by other Tk applications using the send
command and the name baseName. Normally, baseName consists
of the name of the application followed by a space and an identifier for this
particular main window (if such an identifier is relevant). For example,
an editor named mx displaying the file foo.c would use
``mx foo.c'' as the basename. An application that doesn't usually
have multiple instances, such as a clock program, would just use the
name of the application, e.g. ``xclock''. If baseName is already
in use by some other registered interpreter, then Tk_CreateMainWindow
extends baseName with a number to produce a unique name like
``mx foo.c #2'' or ``xclock #12''. This name is used both as the name
of the window (returned by Tk_Name) and as the registered name
of the interpreter.
Fourth, Tk_CreateMainWindow sets className as the class of
the application (among other things, this is used for lookups in
the option database), and also as the class of the main widget.

Either internal or top-level 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. This approach
means that all the windows of an application fall into a hierarchical
arrangement with a single logical root: the application's main window.

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.

In truth, the window-creation procedures don't
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 can't be, since X hasn't 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 Tk_WindowId manual entry for details.

Tk_DestroyWindow deletes a window and all the data
strutures 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 was created by Tk_CreateInternalWindow 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 hasn't 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