tree(3)
NAME
Tk::Tree - Create and manipulate Tree widgets
SYNOPSIS
use Tk::Tree; $tree = $parent->Tree(?options?);
SUPER-CLASS
The Tree class is derived from the HList class and inher
its all the methods, options and subwidgets of its
super-class. A Tree widget is not scrolled by default.
STANDARD OPTIONS
Tree supports all the standard options of an HList widget.
See Tk::options for details on the standard options.
WIDGET-SPECIFIC OPTIONS
- Name: browseCmd
Class: BrowseCmd
Switch: -browsecmd - Specifies a callback to call whenever the user browses
on an entry (usually by single-clicking on the entry).
The callback is called with one argument, the pathname
of the entry. - Name: closeCmd
Class: CloseCmd
Switch: -closecmd - Specifies a callback to call whenever an entry needs
to be closed (See "BINDINGS" below). This method is
called with one argument, the pathname of the entry.
This method should perform appropriate actions to
close the specified entry. If the -closecmd option is not specified, the default closing action is to hide
all child entries of the specified entry. - Name: command
Class: Command
Switch: -command - Specifies a callback to call whenever the user acti
vates an entry (usually by double-clicking on the
entry). The callback is called with one argument, the
pathname of the entry. - Name: ignoreInvoke
Class: IgnoreInvoke
Switch: -ignoreinvoke - A Boolean value that specifies when a branch should be
opened or closed. A branch will always be opened or
closed when the user presses the (+) and (-) indica
tors. However, when the user invokes a branch (by dou
blc-clicking or pressing <Return>), the branch will be
opened or closed only if -ignoreinvoke is set to false (the default setting). - Name: openCmd
Class: OpenCmd
Switch: -opencmd - Specifies a callback to call whenever an entry needs
to be opened (See "BINDINGS" below). This method is
called with one argument, the pathname of the entry.
This method should perform appropriate actions to open
the specified entry. If the -opencmd option is not specified, the default opening action is to show all
the child entries of the specified entry.
DESCRIPTION
The Tree method creates a new window and makes it into a
Tree widget and return a reference to it. Additional
options, described above, may be specified on the command
line or in the option database to configure aspects of the
Tree widget such as its cursor and relief.
The Tree widget can be used to display hierarchical data
in a tree form. The user can adjust the view of the tree
by opening or closing parts of the tree.
To display a static tree structure, you can add the
entries into the Tree widget and hide any entries as
desired. Then you can call the autosetmode method. This
will set up the Tree widget so that it handles all the
open and close events automatically. the demonstration
program Tixish/examples/perl-tix-tree).
The above method is not applicable if you want to maintain
a dynamic tree structure, i.e, you do not know all the
entries in the tree and you need to add or delete entries
subsequently. To do this, you should first create the
entries in the Tree widget. Then, use the setmode method
to indicate the entries that can be opened or closed, and
use the -opencmd and -closecmd options to handle the open
ing and closing events. (Please see the demonstration pro
gram Tixish/examples/perl-tix-dyntree).
- Use either
- $parent->Scrolled('Tree', ... );
- or
$parent->ScrlTree( ... );- to create a scrolled Tree. See Tk::Scrolled for details.
WIDGET METHODS
The Tree method creates a widget object. This object sup
ports the configure and cget methods described in
Tk::options which can be used to enquire and modify the
options described above. The widget also inherits all the
methods provided by the generic Tk::Widget class.
The following additional methods are available for Tree
widgets:
- $tree->autosetmode
- This method calls the setmode method for all the
entries in this Tree widget: if an entry has no child
entries, its mode is set to none. Otherwise, if the
entry has any hidden child entries, its mode is set to
open; otherwise its mode is set to close. - $tree->close(entryPath)
- Close the entry given by entryPath if its mode is close.
- $tree->getmode(entryPath)
- Returns the current mode of the entry given by
entryPath. - $tree->open(entryPath)
- Open the entry given by entryPath if its mode is open.
- $tree->setmode(entryPath, mode)
- This method is used to indicate whether the entry
given by entryPath has children entries and whether the children are visible. mode must be one of open, close or none. If mode is set to open, a (+) indicator is drawn next the the entry. If mode is set to close, a (-) indicator is drawn next the the entry. If mode
is set to none, no indicators will be drawn for this
entry. The default mode is none. The open mode indi cates the entry has hidden children and this entry can
be opened by the user. The close mode indicates that
all the children of the entry are now visible and the
entry can be closed by the user.
BINDINGS
The basic mouse and keyboard bindings of the Tree widget
are the same as the bindings of the HList widget. In
addition, the entries can be opened or closed under the
following conditions:
- [1] If the mode of the entry is open, it can be opened by
- clicking on its (+) indicator.
- [2] If the mode of the entry is close, it can be closed by
- clicking on its (-) indicator.
SEE ALSO
Tk::HList
AUTHOR
Perl/TK version by Chris Dean <ctdean@cogit.com>. Origi
nal Tcl/Tix version by Ioi Kim Lam.
ACKNOWLEDGEMENTS
- Thanks to Achim Bohnet <ach@mpe.mpg.de> for all his help.