Prima::Outlines(3)

NAME
Prima::Outlines - tree view widgets

DESCRIPTION
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".

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

Prima::OutlineViewer
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 indices:

0   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.

1   Reference to a child node. "undef" if there is none.

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

3   Width of an item in pixels.

The indices 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 Prima::StringOutline and Prima::Outline.

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 Prima::IntUtils for these.

The class is not usable directly.

  Properties

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 Prima::OutlineViewer ).

    Default value: []

offset INTEGER
    Horizontal offset of an item list in pixels.

topItem INTEGER
    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

  Methods

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

calibrate
    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.

draw_items CANVAS, PAINT_DATA
    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:

    0   Node reference

    1   Parent node reference; if "undef", the node is the root.

    2   Node offset in parent item list.

    3   Node index.

    4   Node depth level. 0 means the root node.

    5   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.

  Events

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

DragItem OLD_INDEX, NEW_INDEX
    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.

DrawItem CANVAS, NODE, X1, Y1, X2, Y2, INDEX, FOCUSED
    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.

Prima::StringOutline
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' ]]);

Prima::Outline
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.

Prima::DirectoryOutline
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:

0   Directory name, string.

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

2   Icon width in pixels, integer.

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

  Properties

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.

path STRING
    Runtime-only property. Selects current file system path.

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

  Methods

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 Prima::Utils ).

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.

AUTHOR
Dmitry Karasik, <dmitry@karasik.eu.org>.

SEE ALSO
Prima, Prima::Widget, Prima::IntUtils, <examples/outline.pl>.