/ 
Tk800.0_02
River stage three • 163 direct dependents • 174 total dependents
/ Tk::Tree

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 inherits all the commands, options and subwidgets of its super-class. A Tree is not scrolled by default.

STANDARD OPTIONS

Tree supports all the standard options of an HList widget. See options for details on the standard options.

WIDGET-SPECIFIC OPTIONS

Name: browseCmd
Class: BrowseCmd
Switch: -browsecmd

Specifies a command to call whenever the user browses on an entry (usually by single-clicking on the entry). The command is called with one argument, the pathname of the entry.

Name: closeCmd
Class: CloseCmd
Switch: -closecmd

Specifies a command to call whenever an entry needs to be closed (See "BINDINGS" below). This command is called with one argument, the pathname of the entry. This command 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 command to call whenever the user activates an entry (usually by double-clicking on the entry). The command 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 (-) indicators. However, when the user invokes a branch (by doublc-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 command to call whenever an entry needs to be opened (See "BINDINGS" below). This command is called with one argument, the pathname of the entry. This command 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 hierachical 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 hlist subwidget 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. (Please see the demonstration program 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 hlist subwidget. 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 opening and closing events. (Please see the demonstration program examples/perl-tix-dyntree).

Use either

$w->Scrolled( "Tree", ... )
or
$w->ScrlTree(  ... )

to create a scrolled Tree.

WIDGET METHODS

The Tree method creates a widget object. This command may be used to invoke various operations on the widget. It has the following general form:

$widget->method(?arg arg ...?)

$widget is a reference to the Tree widget as returned by the Tree constructor method. Option and the args determine the exact behavior of the method. The following commands are possible for Tree widgets:

$widget->autosetmode

This command 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.

$widget->cget(option)

Returns the current value of the configuration option given by option. Option may have any of the values accepted by the Tree constructor method.

$widget->close(entryPath)

Close the entry given by entryPath if its mode is close.

$widget->configure(?option?, ?value, option, value, ...?)

Query or modify the configuration options of the widget. If no option is specified, returns a list describing all of the available options for $widget (see configure for information on the format of this list). If option is specified with no value, then the command returns a list describing the one named option (this list will be identical to the corresponding sublist of the value returned if no option is specified). If one or more option-value pairs are specified, then the command modifies the given widget option(s) to have the given value(s); in this case the command returns an empty string. Option may have any of the values accepted by the Tree constructor method.

$widget->getmode(entryPath)

Returns the current mode of the entry given by entryPath.

$widget->open(entryPath)

Open the entry given by entryPath if its mode is open.

$widget->setmode(entryPath, mode)

This command 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 indicates 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, Tix(n)

AUTHOR

Perl/TK version by Chris Dean <ctdean@cogit.com>. Original Tcl/Tix version by Ioi Kim Lam.

ACKNOWLEDGEMENTS

Thanks to Achim Bohnet <ach@mpe.mpg.de> for all his help.