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 isn't 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 chil-dren children
dren 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 cre-ated created
ated 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 couldn't be created |
successfully, then NULL is returned and interp->result 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 toplevel
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 manipulable 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_CreateWin-dowFromPath Tk_CreateWindowFromPath
dowFromPath 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 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 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 inter-ested interested
ested 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
create, deferred creation, destroy, display, internal window, screen, top-level window, window
Tk 4.2 Tk_CreateWindow(3)
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