Provided by: libprima-perl_1.28-1.2_amd64 
NAME
Prima::Lists - user-selectable item list widgets
DESCRIPTION
The module provides classes for several abstraction layers of item representation. The hierarchy of
classes is as follows:
AbstractListViewer
AbstractListBox
ListViewer
ProtectedListBox
ListBox
The root class, "Prima::AbstractListViewer", provides common interface, while by itself it is not
directly usable. The main differences between classes are centered around the way the item list is
stored. The simplest organization of a text-only item list, provided by "Prima::ListBox", stores an array
of text scalars in a widget. More elaborated storage and representation types are not realized, and the
programmer is urged to use the more abstract classes to derive own mechanisms. For example, for a list
of items that contain text strings and icons see "Prima::DirectoryListBox" in Prima::FileDialog. To
organize an item storage, different from "Prima::ListBox", it is usually enough to overload either the
"Stringify", "MeasureItem", and "DrawItem" events, or their method counterparts: "get_item_text",
"get_item_width", and "draw_items".
Prima::AbstractListViewer
"Prima::AbstractListViewer" is a descendant of "Prima::GroupScroller", and some properties are not
described here. See "Prima::GroupScroller" in Prima::IntUtils.
The class provides interface to generic list browsing functionality, plus functionality for text-oriented
lists. The class is not usable directly.
Properties
autoHeight BOOLEAN
If 1, the item height is changed automatically when the widget font is changed; this is useful for
text items. If 0, item height is not changed; this is useful for non-text items.
Default value: 1
count INTEGER
An integer property, destined to reflect number of items in the list. Since it is tied to the item
storage organization, and hence, to possibility of changing the number of items, this property is
often declared as read-only in descendants of "Prima::AbstractListViewer".
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
drawGrid BOOLEAN
If 1, vertical grid lines between columns are drawn with "gridColor". Actual only in multi-column
mode.
Default value: 1
extendedSelect BOOLEAN
Regards the way the user selects multiple items and is only actual when "multiSelect" is 1. If 0, the
user must click each item in order to mark as selected. If 1, the user can drag mouse or use "Shift"
key plus arrow keys to perform range selection; the "Control" key can be used to select individual
items.
Default value: 0
focusedItem INDEX
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.
Default value: -1
gridColor COLOR
Color, used for drawing vertical divider lines for multi-column list widgets. The list classes
support also the indirect way of setting the grid color, as well as widget does, via the "colorIndex"
property. To achieve this, "ci::Grid" constant is declared ( for more detail see "colorIndex" in
Prima::Widget ).
Default value: "cl::Black".
integralHeight BOOLEAN
If 1, only the items that fit vertically in the widget interiors are drawn. If 0, the items that are
partially visible are drawn also.
Default value: 0
integralWidth BOOLEAN
If 1, only the items that fit horizontally in the widget interiors are drawn. If 0, the items that
are partially visible are drawn also. Actual only in multi-column mode.
Default value: 0
itemHeight INTEGER
Selects the height of the items in pixels. Since the list classes do not support items with different
dimensions, changes to this property affect all items.
Default value: default font height
itemWidth INTEGER
Selects the width of the items in pixels. Since the list classes do not support items with different
dimensions, changes to this property affect all items.
Default value: default widget width
multiSelect BOOLEAN
If 0, the user can only select one item, and it is reported by the "focusedItem" property. If 1, the
user can select more than one item. In this case, "focusedItem"'th item is not necessarily selected.
To access selected item list, use "selectedItems" property.
Default value: 0
multiColumn BOOLEAN
If 0, the items are arrayed vertically in one column, and the main scroll bar is vertical. If 1, the
items are arrayed in several columns, "itemWidth" pixels wide each. In this case, the main scroll bar
is horizontal.
offset INTEGER
Horizontal offset of an item list in pixels.
topItem INTEGER
Selects the first item drawn.
selectedCount INTEGER
A read-only property. Returns number of selected items.
selectedItems ARRAY
ARRAY is an array of integer indices of selected items.
vertical BOOLEAN
Sets seneral direction of items in multi-column mode. If 1, items increase down-to-right. Otherwise,
right-to-down.
Doesn't have any effect in single-column mode. Default value: 1.
Methods
add_selection ARRAY, FLAG
Sets item indices from ARRAY in selected or deselected state, depending on FLAG value,
correspondingly 1 or 0.
Only for multi-select mode.
deselect_all
Removes selection from all items.
Only for multi-select mode.
draw_items CANVAS, ITEM_DRAW_DATA
Called from within "Paint" notification to draw items. The default behavior is to call "DrawItem"
notification for every item in ITEM_DRAW_DATA array. ITEM_DRAW_DATA is an array or arrays, where
each array consists of parameters, passed to "DrawItem" notification.
This method is overridden in some descendant classes, to increase the speed of drawing routine. For
example, "std_draw_text_items" is the optimized routine for drawing unified text-based items. It is
used in "Prima::ListBox" class.
See DrawItem for parameters description.
draw_text_items CANVAS, FIRST, LAST, STEP, X, Y, OFFSET, CLIP_RECT
Called by "std_draw_text_items" to draw sequence of text items with indices from FIRST to LAST, by
STEP, on CANVAS, starting at point X, Y, and incrementing the vertical position with OFFSET.
CLIP_RECT is a reference to array of four integers with inclusive-inclusive coordinates of the active
clipping rectangle.
get_item_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_item_width INDEX
Returns width in pixels of INDEXth item. Since the class does not assume the item storage
organization, the value is queried via "MeasureItem" notification.
is_selected INDEX
Returns 1 if INDEXth item is selected, 0 if it is not.
item2rect INDEX, [ WIDTH, HEIGHT ]
Calculates and returns four integers with rectangle coordinates of INDEXth item within the widget.
WIDTH and HEIGHT are optional parameters with pre-fetched dimension of the widget; if not set, the
dimensions are queried by calling "size" property. If set, however, the "size" property is not
called, thus some speed-up can be achieved.
point2item X, Y
Returns the index of an item that contains point (X,Y). If the point belongs to the item outside the
widget's interior, returns the index of the first item outside the widget's interior in the direction
of the point.
redraw_items INDICES
Redraws all items in INDICES array.
select_all
Selects all items.
Only for multi-select mode.
set_item_selected INDEX, FLAG
Sets selection flag of INDEXth item. If FLAG is 1, the item is selected. If 0, it is deselected.
Only for multi-select mode.
select_item INDEX
Selects INDEXth item.
Only for multi-select mode.
std_draw_text_items CANVAS, ITEM_DRAW_DATA
An optimized method, draws unified text-based items. It is fully compatible to "draw_items"
interface, and is used in "Prima::ListBox" class.
The optimization is derived from the assumption that items maintain common background and foreground
colors, that differ in selected and non-selected states only. The routine groups drawing requests for
selected and non-selected items, and draws items with reduced number of calls to "color" property.
While the background is drawn by the routine itself, the foreground ( usually text ) is delegated to
the "draw_text_items" method, so the text positioning and eventual decorations would not require full
rewrite of code.
ITEM_DRAW_DATA is an array of arrays of scalars, where each array contains parameters of "DrawItem"
notification. See DrawItem for parameters description.
toggle_item INDEX
Toggles selection of INDEXth item.
Only for multi-select mode.
unselect_item INDEX
Deselects INDEXth item.
Only for multi-select mode.
Events
Click
Called when the user presses return key or double-clicks on an item. The index of the item is stored
in "focusedItem".
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, INDEX, X1, Y1, X2, Y2, SELECTED, FOCUSED
Called when an INDEXth item is to be drawn on CANVAS. X1, Y1, X2, Y2 designate the item rectangle in
widget coordinates, where the item is to be drawn. SELECTED and FOCUSED are boolean flags, if the
item must be drawn correspondingly in selected and focused states.
MeasureItem INDEX, REF
Puts width in pixels of INDEXth item into REF scalar reference. This notification must be called from
within "begin_paint_info/end_paint_info" block.
SelectItem INDEX, FLAG
Called when the item changed its selection state. INDEX is the index of the item, FLAG is its new
selection state: 1 if it is selected, 0 if it is not.
Stringify INDEX, TEXT_REF
Puts text string, assigned to INDEXth item into TEXT_REF scalar reference.
Prima::AbstractListBox
Exactly the same as its ascendant, "Prima::AbstractListViewer", except that it does not propagate
"DrawItem" message, assuming that the items must be drawn as text.
Prima::ListViewer
The class implements items storage mechanism, but leaves the items format to the programmer. The items
are accessible via "items" property and several other helper routines.
The class also defines the user navigation, by accepting character keyboard input and jumping to the
items that have text assigned with the first letter that match the input.
"Prima::ListViewer" is derived from "Prima::AbstractListViewer".
Properties
autoWidth BOOLEAN
Selects if the gross item width must be recalculated automatically when either the font changes or
item list is changed.
Default value: 1
count INTEGER
A read-only property; returns number of items.
items ARRAY
Accesses the storage array of items. The format of items is not defined, it is merely treated as one
scalar per index.
Methods
add_items ITEMS
Appends array of ITEMS to the end of the list.
calibrate
Recalculates all item widths and adjusts "itemWidth" if "autoWidth" is set.
delete_items INDICES
Deletes items from the list. INDICES can be either an array, or a reference to an array of item
indices.
get_item_width INDEX
Returns width in pixels of INDEXth item from internal cache.
get_items INDICES
Returns array of items. INDICES can be either an array, or a reference to an array of item indices.
Depending on the caller context, the results are different: in array context the item list is
returned; in scalar - only the first item from the list. The semantic of the last call is naturally
usable only for single item retrieval.
insert_items OFFSET, ITEMS
Inserts array of items at OFFSET index in the list. Offset must be a valid index; to insert items at
the end of the list use "add_items" method.
ITEMS can be either an array, or a reference to an array of items.
replace_items OFFSET, ITEMS
Replaces existing items at OFFSET index in the list. Offset must be a valid index.
ITEMS can be either an array, or a reference to an array of items.
Prima::ProtectedListBox
A semi-demonstrational class, derived from "Prima::ListViewer", that applies certain protection for every
item drawing session. Assuming that several item drawing routines can be assembled in one widget,
"Prima::ProtectedListBox" provides a safety layer between these, so, for example, one drawing routine
that selects a font or a color and does not care to restore the old value back, does not affect the
outlook of the other items.
This functionality is implementing by overloading "draw_items" method and also all graphic properties.
Prima::ListBox
Descendant of "Prima::ListViewer", declares format of items as a single text string. Incorporating all of
functionality of its predecessors, provides a standard listbox widget.
Synopsis
my $lb = Prima::ListBox-> create(
items => [qw(First Second Third)],
focusedItem => 2,
onClick => sub {
print $_[0]-> get_items( $_[0]-> focusedItem), " is selected\n";
}
);
Methods
get_item_text INDEX
Returns text string assigned to INDEXth item. Since the item storage organization is implemented,
does so without calling "Stringify" notification.
AUTHOR
Dmitry Karasik, <dmitry@karasik.eu.org>.
SEE ALSO
Prima, Prima::Widget, Prima::ComboBox, Prima::FileDialog, examples/editor.pl