NAME¶

Tk::HList - Create and manipulate Tix Hierarchial List widgets

SYNOPSIS¶

$hlist = $parent->HList(?options?);

STANDARD OPTIONS¶

-background -borderwidth -cursor -exportselection -foreground -font -height -highlightcolor -highlightthickness -relief -selectbackground -selectforeground -xscrollcommand -yscrollcommand -width See Tk::options for details of the standard options.

WIDGET-SPECIFIC OPTIONS¶

Name: browsecmd

Class: BrowseCmd

Switch: -browsecmd

Specifies a perl/Tk callback to be executed when the user browses through the entries in the HList widget.

Name: columns

Class: Columns

Switch: -columns

Specifies the number of columns in this HList widget. This option can only be set during the creation of the HList widget and cannot be changed subsequently.

Name: command

Class: Command

Switch: -command

Specifies the perl/Tk callback to be executed when the user invokes a list entry in the HList widget. Normally the user invokes a list entry by double-clicking it or pressing the Return key.

Name: drawBranch

Class: DrawBranch

Switch: -drawbranch

A Boolean value to specify whether branch line should be drawn to connect list entries to their parents.

Name: foreground

Class: Foreground

Switch: -foreground

Alias: -fg

[OBSOLETE] Specifies the default foreground color for the list entries.

Name: gap

Class: Gap

Switch: -gap

[OBSOLETE] The default distance between the bitmap/image and the text in list entries.

Name: header

Class: Header

Switch: -header

A Boolean value specifying whether headers should be displayed for this HList widget (see the header method below).

Name: height

Class: Height

Switch: -height

Specifies the desired height for the window in number of characters.

Name: indent

Class: Indent

Switch: -indent

Specifies the amount of horizontal indentation between a list entry and its children. Must be a valid screen distance value.

Name: indicator

Class: Indicator

Switch: -indicator

Specifies whether the indicators should be displayed inside the HList widget. See the indicator method below.

Name: indicatorCmd

Class: IndicatorCmd

Switch: -indicatorcmd

Specifies a perl/Tk callback to be executed when the user manipulates the indicator of an HList entry. The -indicatorcmd is triggered when the user press or releases the mouse button over the indicator in an HList entry. By default the perl/Tk callback specified by -indicatorcmd is executed with two additional arguments, the entryPath of the entry whose indicator has been triggered and additional information about the event. The additional information is one of the following strings: <Arm>, <Disarm>, and <Activate>.

Name: itemType

Class: ItemType

Switch: -itemtype

Specifies the default type of display item for this HList widget. When you call the itemCreate, add and addchild methods, display items of this type will be created if the -itemtype option is not specified .

Name: padX

Class: Pad

Switch: -padx

[OBSOLETE] The default horizontal padding for list entries.

Name: padY

Class: Pad

Switch: -padx

[OBSOLETE] The default vertical padding for list entries.

Name: selectBackground

Class: SelectBackground

Switch: -selectbackground

Specifies the background color for the selected list entries.

Name: selectBorderWidth

Class: BorderWidth

Switch: -selectborderwidth

Specifies a non-negative value indicating the width of the 3-D border to draw around selected items. The value may have any of the forms acceptable to Tk_GetPixels.

Name: selectForeground

Class: SelectForeground

Switch: -selectforeground

Specifies the foreground color for the selected list entries.

Name: selectMode

Class: SelectMode

Switch: -selectmode

Specifies one of several styles for manipulating the selection. The value of the option may be arbitrary, but the default bindings expect it to be either single, browse, multiple, or extended; the default value is single.

Name: sizeCmd

Class: SizeCmd

Switch: -sizecmd

Specifies a perl/Tk callback to be called whenever the HList widget changes its size. This method can be useful to implement `` user scroll bars when needed'' features.

Name: separator

Class: Separator

Switch: -separator

Specifies the character to used as the separator character when intepreting the path-names of list entries. By default the character "." is used.

Name: width

Class: Width

Switch: -width

Specifies the desired width for the window in characters.

DESCRIPTION¶

The HList method creates a new window (given by the $widget argument) and makes it into a HList widget. Additional options, described above, may be specified on the command line or in the option database to configure aspects of the HList widget such as its cursor and relief. The HList widget can be used to display any data that have a hierarchical structure, for example, file system directory trees. The list entries are indented and connected by branch lines according to their places in the hierachy. Each list entry is identified by an entryPath. The entryPath is a sequence of entry names separated by the separator charactor (specified by the -separator option). An entry name can be any string that does not contain the separator charactor, or it can be the a string that contains only one separator charactor. For example, when "." is used as the separator charactor, "one.two.three" is the entryPath for a list entry whose parent is "one.two", whose parent is "one", which is a toplevel entry (has no parents). Another examples: ".two.three" is the entryPath for a list entry whose parent is ".two", whose parent is ".", which is a toplevel entry.

DISPLAY ITEMS¶

Each list entry in an HList widget is associated with a display item. The display item determines what visual information should be displayed for this list entry. Please see Tk::DItem for a list of all display items. When a list entry is created by the itemCreate, add or addchild widget methods, the type of its display item is determined by the -itemtype option passed to these methods. If the -itemtype is omitted, then by default the type specified by this HList widget's -itemtype option is used.

WIDGET METHODS¶

The HList method creates a widget object. This object supports 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 HList widgets:

$hlist->add($entryPath ?, option=>value, ...?)

Creates a new list entry with the pathname $entryPath . A list entry must be created after its parent is created (unless this entry is a top-level entry, which has no parent). See also "BUGS" below. This method returns the entryPath of the newly created list entry. The following configuration options can be given to configure the list entry:

$hlist->addchild($parentPath, ? option, value, ..., ?)

Adds a new child entry to the children list of the list entry identified by $parentPath. Or, if $parentPath is set to be the empty string, then creates a new toplevel entry. The name of the new list entry will be a unique name automatically generated by the HList widget. Usually if $parentPath is foo, then the entryPath of the new entry will be foo.0, foo.1, ... etc. This method returns the entryPath of the newly created list entry. option can be any option for the add method. See also "BUGS" below.

$hlist->anchorSet($entryPath)

Sets the anchor to the list entry identified by $entryPath . The anchor is the end of the selection that is fixed while the user is dragging out a selection with the mouse.

$hlist->anchorClear

Removes the anchor, if any, from this HList widget. This only removes the surrounding highlights of the anchor entry and does not affect its selection status.

$hlist->columnWidth($col?, -char?, ?width?)

Querys or sets the width of a the column $col in the HList widget. The value of $col is zero-based: 0 stands for the first column, 1 stands for the second, and so on. If no further parameters are given, returns the current width of this column (in number of pixels). Additional parameters can be given to set the width of this column:

$hlist->delete(option, $entryPath)

Delete one or more list entries. option may be one of the following:

$hlist->dragsiteSet($entryPath)

Sets the dragsite to the list entry identified by $entryPath. The dragsite is used to indicate the source of a drag-and-drop action. Currently drag-and-drop functionality has not been implemented in Tix yet.

$hlist->dragsiteClear

Remove the dragsite, if any, from the this HList widget. This only removes the surrounding highlights of the dragsite entry and does not affect its selection status.

$hlist->dropsiteSet($entryPath)

Sets the dropsite to the list entry identified by $entryPath. The dropsite is used to indicate the target of a drag-and-drop action. Currently drag-and-drop functionality has not been implemented in Tix yet.

$hlist->dropsiteClear

Remove the dropsite, if any, from the this HList widget. This only removes the surrounding highlights of the dropsite entry and does not affect its selection status.

$hlist->entrycget($entryPath, option)

Returns the current value of the configuration option given by option for the entry indentfied by $entryPath. Option may have any of the values accepted by the add method.

$hlist->entryconfigure($entryPath ?, option?, ?value=>option, ...?)

Query or modify the configuration options of the list entry indentfied by $entryPath. If no option is specified, returns a list describing all of the available options for $entryPath (see Tk::options for information on the format of this list.) If option is specified with no value, then the method 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 method modifies the given option(s) to have the given value(s); in this case the method returns an empty string. Option may have any of the values accepted by the add or addchild method. The exact set of options depends on the value of the -itemtype option passed to the the add or addchild method when this list entry is created.

$hlist->header(option, $col ?,args, ...?)

Manipulates the header items of this HList widget. If the -header option of this HList widget is set to true, then a header item is displayed at the top of each column. The $col argument for this method must be a valid integer. 0 indicates the first column, 1 the second column, ... and so on. This method supports the following options:

$hlist->hide(option ?, $entryPath?)

Makes some of entries invisible without deleting them. Option can be one of the following:

$hlist->indicator(option, $entryPath, ?args, ...?)

Manipulates the indicator on the list entries. An indicator is usually a small display item (such as an image) that is displayed to the left to an entry to indicate the status of the entry. For example, it may be used to indicate whether a directory is opened or closed. Option can be one of the following:

$hlist->info(option, arg, ...)

Query information about the HList widget. option can be one of the following:

$hlist->item(option, ? args, ...?)

Creates and configures the display items at individual columns the entries. The form of additional of arguments depends on the choice of option:

$hlist->nearest(y)

$hlist->nearest(y) Given a y-coordinate within the HList window, this method returns the entryPath of the (visible) HList element nearest to that y-coordinate.

$hlist->see($entryPath)

Adjust the view in the HList so that the entry given by $entryPath is visible. If the entry is already visible then the method has no effect; if the entry is near one edge of the window then the HList scrolls to bring the element into view at the edge; otherwise the HList widget scrolls to center the entry.

$hlist->selection(option, arg, ...)

$hlist->selectionOption(arg, ...)

This method is used to adjust the selection within a HList widget. It has several forms, depending on option:

$hlist->show(option ?, $entryPath?)

Show the entries that are hidden by the hide method, option can be one of the following:

$hlist->xview(args)

This method is used to query and change the horizontal position of the information in the widget's window. It can take any of the following forms:

$hlist->yview(?args?)

This method is used to query and change the vertical position of the entries in the widget's window. It can take any of the following forms:

BINDINGS¶

[1]

If the -selectmode is "browse", when the user drags the mouse pointer over the list entries, the entry under the pointer will be highlighted and the -browsecmd callback will be called with one parameter, the entryPath of the highlighted entry. Only one entry can be highlighted at a time. The -command callback will be called when the user double-clicks on a list entry.

[2]

If the -selectmode is "single", the entries will only be highlighted by mouse <ButtonRelease-1> events. When a new list entry is highlighted, the -browsecmd callback will be called with one parameter indicating the highlighted list entry. The -command callback will be called when the user double-clicks on a list entry.

[3]

If the -selectmode is "multiple", when the user drags the mouse pointer over the list entries, all the entries under the pointer will be highlighted. However, only a contiguous region of list entries can be selected. When the highlighted area is changed, the -browsecmd callback will be called with an undefined parameter. It is the responsibility of the -browsecmd callback to find out the exact highlighted selection in the HList. The -command callback will be called when the user double-clicks on a list entry.

[4]

If the -selectmode is "extended", when the user drags the mouse pointer over the list entries, all the entries under the pointer will be highlighted. The user can also make disjointed selections using <Control-ButtonPress-1>. When the highlighted area is changed, the -browsecmd callback will be called with an undefined parameter. It is the responsibility of the -browsecmd callback to find out the exact highlighted selection in the HList. The -command callback will be called when the user double-clicks on a list entry.

[5]

Arrow key bindings: <Up> arrow key moves the anchor point to the item right on top of the current anchor item. <Down> arrow key moves the anchor point to the item right below the current anchor item. <Left> arrow key moves the anchor to the parent item of the current anchor item. <Right> moves the anchor to the first child of the current anchor item. If the current anchor item does not have any children, moves the anchor to the item right below the current anchor item.

EXAMPLE¶

This example demonstrates how to use an HList to store a file directory structure and respond to the user's browse events:

   use strict;
   use Tk;
   use Tk::Label;
   use Tk::HList;
   my $mw = MainWindow->new();
   my $label = $mw->Label(-width=>15);
   my $hlist = $mw->HList(
                       -itemtype   => 'text',
                       -separator  => '/',
                       -selectmode => 'single',
                       -browsecmd  => sub {
                                 my $file = shift;
                                 $label->configure(-text=>$file);
                              }
                       );
   foreach ( qw(/ /home /home/ioi /home/foo /usr /usr/lib) ) {
       $hlist->add($_, -text=>$_);
   }
   $hlist->pack;
   $label->pack;
   MainLoop;

BUGS¶

The fact that the display item at column 0 is implicitly associated with the whole entry is probably a design bug. This was done for backward compatibility purposes. The result is that there is a large overlap between the item method and the add, addchild, entrycget and entryconfigure methods. Whenever multiple columns exist, the programmer should use ONLY the item method to create and configure the display items in each column; the add, addchild, entrycget and entryconfigure should be used ONLY to create and configure entries.

KEYWORDS¶

Hierarchical Listbox

SEE ALSO¶

Tk::DItem