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).
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
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 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_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