Prima::Outlines - tree view widgets


Prima::Outlines - tree view widgets


The module provides a set of widget classes, designed to display a tree-like hierarchy of items. Prima::OutlineViewer presents a generic class that contains basic functionality and defines the interface for the descendants, which are Prima::StringOutline, Prima::Outline, and Prima::DirectoryOutline.


  my $outline = Prima::StringOutline-> create(
    items => [
       [  'Simple item' ],
       [[ 'Embedded item ']],
       [[ 'More embedded items', [ '#1', '#2' ]]],
  $outline-> expand_all;


Presents a generic interface for browsing the tree-like lists. A node in a linked list represents each item. The format of node is predefined, and is an anonymous array with the following definitions of indexes:

  1. Item id with non-defined format. The simplest implementation, Prima::StringOutline, treats the scalar as a text string. The more complex classes store references to arrays or hashes here. See items article of a concrete class for the format of a node record.

  2. Reference to a child node. undef if there is none.

  3. A boolean flag, which selects if the node shown as expanded, e.g. all its immediate children are visible.

  4. Width of an item in pixels.

The indexes above 3 should not be used, because eventual changes to the implementation of the class may use these. It should be enough item 0 to store any value.

To support a custom format of node, it is sufficient to overload the following notifications: DrawItem, MeasureItem, Stringify. Since DrawItem is called for every item, a gross method draw_items can be overloaded instead. See also the Prima::StringOutline manpage and the Prima::Outline manpage.

The class employs two addressing methods, index-wise and item-wise. The index-wise counts only the visible ( non-expanded ) items, and is represented by an integer index. The item-wise addressing cannot be expressed by an integer index, and the full node structure is used as a reference. It is important to use a valid reference here, since the class does not always perform the check if the node belongs to internal node list due to the speed reasons.

Prima::OutlineViewer is a descendant of Prima::GroupScroller and Prima::MouseScroller, so some properties and methods are not described here. See the Prima::IntUtils manpage for these.

The class is not usable directly.


autoHeight INTEGER
If set to 1, changes itemHeight automatically according to the widget font height. If 0, does not influence anything. When itemHeight is set explicitly, changes value to 0.

Default value: 1

dragable BOOLEAN
If 1, allows the items to be dragged interactively by pressing control key together with left mouse button. If 0, item dragging is disabled.

Default value: 1

focusedItem INTEGER
Selects the focused item index. If -1, no item is focused. It is mostly a run-time property, however, it can be set during the widget creation stage given that the item list is accessible on this stage as well.

indent INTEGER
Width in pixels of the indent between item levels.

Default value: 12

itemHeight INTEGER
Selects the height of the items in pixels. Since the outline classes do not support items with different vertical dimensions, changes to this property affect all items.

Default value: default font height

items ARRAY
Provides access to the items as an anonymous array. The format of items is described in the opening article ( see the Prima::OutlineViewer manpage ).

Default value: []

offset INTEGER
Horizontal offset of an item list in pixels.

Selects the first item drawn.

showItemHint BOOLEAN
If 1, allows activation of a hint label when the mouse pointer is hovered above an item that does not fit horizontally into the widget inferiors. If 0, the hint is never shown.

See also: makehint.

Default value: 1


Performs expansion ( 1 ) or collapse ( 0 ) of INDEXth item, depending on EXPAND boolean flag value.

Recalculates the node tree and the item dimensions. Used internally.

delete_items [ NODE = undef, OFFSET = 0, LENGTH = undef ]
Deletes LENGTH children items of NODE at OFFSET. If NODE is undef, the root node is assumed. If LENGTH is undef, all items after OFFSET are deleted.

delete_item NODE
Deletes NODE from the item list.

Called from within Paint notification to draw items. The default behavior is to call DrawItem notification for every visible item. PAINT_DATA is an array of arrays, where each array consists of parameters, passed to DrawItem notification.

This method is overridden in some descendant classes, to increase the speed of the drawing routine.

See DrawItem for PAINT_DATA parameters description.

get_index NODE
Traverses all items for NODE and finds if it is visible. If it is, returns two integers: the first is item index and the second is item depth level. If it is not visible, -1, undef is returned.

get_index_text INDEX
Returns text string assigned to INDEXth item. Since the class does not assume the item storage organization, the text is queried via Stringify notification.

get_index_width INDEX
Returns width in pixels of INDEXth item, which is a cached result of MeasureItem notification, stored under index #3 in node.

get_item INDEX
Returns two scalars corresponding to INDEXth item: node reference and its depth level. If INDEX is outside the list boundaries, empty array is returned.

get_item_parent NODE
Returns two scalars, corresponding to NODE: its parent node reference and offset of NODE in the parent's immediate children list.

get_item_text NODE
Returns text string assigned to NODE. Since the class does not assume the item storage organization, the text is queried via Stringify notification.

get_item_width NODE
Returns width in pixels of INDEXth item, which is a cached result of MeasureItem notification, stored under index #3 in node.

expand_all [ NODE = undef ].
Expands all nodes under NODE. If NODE is undef, the root node is assumed. If the tree is large, the execution can take significant amount of time.

insert_items NODE, OFFSET, @ITEMS
Inserts one or more ITEMS under NODE with OFFSET. If NODE is undef, the root node is assumed.

iterate ACTION, FULL
Traverses the item tree and calls ACTION subroutine for each node. If FULL boolean flag is 1, all nodes are traversed. If 0, only the expanded nodes are traversed.

ACTION subroutine is called with the following parameters:

  1. Node reference

  2. Parent node reference; if undef, the node is the root.

  3. Node offset in parent item list.

  4. Node index.

  5. Node depth level. 0 means the root node.

  6. A boolean flag, set to 1 if the node is the last child in parent node list, set to 0 otherwise.

makehint SHOW, INDEX
Controls hint label upon INDEXth item. If a boolean flag SHOW is set to 1, and showItemHint property is 1, and the item index does not fit horizontally in the widget inferiors then the hint label is shown. By default the label is removed automatically as the user moves the mouse pointer away from the item. If SHOW is set to 0, the hint label is hidden immediately.

point2item Y, [ HEIGHT ]
Returns index of an item that contains horizontal axis at Y in the widget coordinates. If HEIGHT is specified, it must be the widget height; if it is not, the value is fetched by calling Prima::Widget::height. If the value is known, passing it to point2item thus achieves some speed-up.

validate_items ITEMS
Traverses the array of ITEMS and puts every node to the common format: cuts scalars above index #3, if there are any, or adds default values to a node if it contains less than 3 scalars.


Called when NODE is expanded ( 1 ) or collapsed ( 0 ). The EXPAND boolean flag reflects the action taken.

Called when the user finishes the drag of an item from OLD_INDEX to NEW_INDEX position. The default action rearranges the item list in accord with the dragging action.

Called when INDEXth item, contained in NODE is to be drawn on CANVAS. X1, Y1, X2, Y2 coordinated define the exterior rectangle of the item in widget coordinates. FOCUSED boolean flag is set to 1 if the item is focused; 0 otherwise.

MeasureItem NODE, REF
Puts width of NODE item in pixels into REF scalar reference. This notification must be called from within begin_paint_info/end_paint_info block.

SelectItem INDEX
Called when INDEXth item gets focused.

Stringify NODE, TEXT_REF
Puts text string, assigned to NODE item into TEXT_REF scalar reference.


Descendant of Prima::OutlineViewer class, provides standard single-text items widget. The items can be set by merely supplying a text as the first scalar in node array structure:

  $string_outline-> items([ 'String', [ 'Descendant' ]]);


A variant of Prima::StringOutline, with the only difference that the text is stored not in the first scalar in a node but as a first scalar in an anonymous array, which in turn is the first node scalar. The class does not define neither format nor the amount of scalars in the array, and as such presents a half-abstract class.


Provides a standard widget with the item tree mapped to the directory structure, so each item is mapped to a directory. Depending on the type of the host OS, there is either single root directory ( unix ), or one or more disk drive root items ( win32, os2 ).

The format of a node is defined as follows:

  1. Directory name, string.

  2. Parent path; an empty string for the root items.

  3. Icon width in pixels, integer.

  4. Drive icon; defined only for the root items under non-unix hosts in order to reflect the drive type ( hard, floppy, etc ).


closedGlyphs INTEGER
Number of horizontal equal-width images, contained in closedIcon property.

Default value: 1

closedIcon ICON
Provides an icon representation for the collapsed items.

openedGlyphs INTEGER
Number of horizontal equal-width images, contained in openedIcon property.

Default value: 1

openedIcon OBJECT
Provides an icon representation for the expanded items.

showDotDirs BOOLEAN
Selects if the directories with the first dot character are shown the tree view. The treatment of the dot-prefixed names as hidden is traditional to unix, and is of doubtful use under win32 and os2.

Default value: 0


files [ FILE_TYPE ]
If FILE_TYPE value is not specified, the list of all files in the current directory is returned. If FILE_TYPE is given, only the files of the types are returned. The FILE_TYPE is a string, one of those returned by Prima::Utils::getdir ( see getdir in the Prima::Utils manpage ).

get_directory_tree PATH
Reads the file structure under PATH and returns a newly created hierarchy structure in the class node format. If showDotDirs property value is 0, the dot-prefixed names are not included.

Used internally inside Expand notification.


Dmitry Karasik, <>.


Prima, the Prima::Widget manpage, the Prima::IntUtils manpage, <examples/>.

 Prima::Outlines - tree view widgets