Provided by: libprima-perl_1.28-1.2_amd64 bug

NAME

       Prima::Application - root of widget objects hierarchy

DESCRIPTION

       Prima::Application class serves as a hierarchy root for all objects with child-owner
       relationship. All toolkit objects, existing with non-null owner property, belong by their
       top-level parental relationship to Prima::Application object. There can be only one
       instance of Prima::Application class at a time.

SYNOPSIS

               use Prima;
               use Prima::Application;

       or

               use Prima qw(Application);

               Prima::MainWindow-> create();

               run Prima;

USAGE

       Prima::Application class, and its only instance are treated specially throughout the
       toolkit. The object instance is contained in

               $::application

       scalar, defined in Prima.pm module.  The application instance must be created whenever
       widget and window, or event loop functionality is desired. Usually

               use Prima::Application;

       code is enough, but $::application can also be assigned explicitly. The 'use' syntax has
       advantage as more resistant to eventual changes in the toolkit design.  It can also be
       used in conjunction with custom parameters hash, alike the general create() syntax:

               use Prima::Application name => 'Test application', icon => $icon;

       In addition to this functionality Prima::Application is also a wrapper to a set of system
       functions, not directly related to object classes. This functionality is generally
       explained in "API".

   Inherited functionality
       Prima::Application is a descendant of Prima::Widget, but it is designed so because their
       functional outliers are closest to each other.  Prima::Application does not strictly
       conform ( in OO sense ) to any of the built-in classes. It has methods copied from both
       Prima::Widget and Prima::Window at one time, and the inherited Prima::Widget methods and
       properties function differently.  For example, "::origin", a property from Prima::Widget,
       is also implemented in Prima::Application, but returns always (0,0), an expected but not
       much usable result.  "::size", on the contrary, returns the extent of the screen in
       pixels.  There are few properties, inherited from Prima::Widget, which return actual, but
       uninformative results, - "::origin" is one of those, but same are "::buffered",
       "::clipOwner", "::enabled", "::growMode", "::owner" and owner-inheritance properties,
       "::selectable", "::shape", "::syncPaint", "::tabOrder", "::tabStop", "::transparent",
       "::visible".  To this group also belongs "::modalHorizon", Prima::Window class property,
       but defined for consistency and returning always 1.  Other methods and properties, like
       "::size", that provide different functionality are described in "API".

   Global functionality
       Prima::Application is a wrapper to functionality, that is not related to one or another
       class clearly.  A notable example, paint mode, which is derived from Prima::Drawable
       class, allows painting on the screen, overwriting the graphic information created by the
       other programs. Although being subject to begin_paint()/end_paint() brackets, this
       functionality can not be attached to a class-shared API, an therefore is considered
       global. All such functionality is gathered in the Prima::Application class.

       These topics enumerated below, related to the global scope, but occupying more than one
       method or property - such functions described in "API".

       Painting
           As stated above, Prima::Application provides interface to the on-screen painting. This
           mode is triggered by begin_paint()/end_paint() methods pair, and the other pair,
           begin_paint_info()/end_paint_info() triggers the information mode. This three-state
           paint functionality is more thoroughly described in Prima::Drawable.

       Hint
           $::application hosts a special Prima::HintWidget class object, accessible via
           "get_hint_widget()", but with color and font functions aliased ( "::hintColor",
           "::hintBackColor", "::hintFont" ).

           This widget serves as a hint label, floating over widgets if the mouse pointer hovers
           longer than "::hintPause" milliseconds.

           Prima::Application internally manages all hint functionality.  The hint widget itself,
           however, can be replaced before application object is created, using "::hintClass"
           create-only property.

       Printer
           Result of get_printer method points to an automatically created printer object,
           responsible for the system-driven printing. Depending on the operating system, it is
           either Prima::Printer, if the system provides GUI printing capabilities, or generic
           Prima::PS::Printer, the PostScript document interface.

           See Prima::Printer for details.

       Clipboard
           $::application hosts set of Prima::Clipboard objects, created automatically to reflect
           the system-provided clipboard IPC functionality. Their number depends on the system, -
           under X11 environment there is three clipboard objects, and only one under Win32 and
           OS/2.

           These are no methods to access these clipboard objects, except fetch() ( or, the
           indirect name calling ) - the clipboard objects are named after the system clipboard
           names, which are returned by Prima::Clipboard::get_standard_clipboards.

           The default clipboard is named Clipboard, and is accessible via

                   my $clipboard = $::application-> Clipboard;

           code.

           See Prima::Clipboard for details.

       Help subsystem
           The toolkit has a built-in help viewer, that understands perl's native POD ( plain old
           documentation ) format.  Whereas the viewer functionality itself is part of the
           toolkit, and resides in "Prima::HelpViewer" module, any custom help viewing module can
           be assigned. Create-only "Prima::Application" properties "::helpClass" and
           "::helpModule" can be used to set these options.

           "Prima::Application" provides two methods for communicating with the help viewer
           window: "open_help()" opens a selected topic in the help window, and "close_help()"
           closes the window.

       System-dependent information
           A complex program will need eventually more information than the toolkit provides. Or,
           knowing the toolkit boundaries in some platforms, the program changes its behavior
           accordingly. Both these topics are facilitated by extra system information, returned
           by Prima::Application methods.  "get_system_value" returns a system value for one of
           "sv::XXX" constants, so the program can read the system-specific information. As well
           as "get_system_info" method, that returns the short description of the system, it is
           the portable call.  To the contrary, "sys_action" method is a wrapper to system-
           dependent functionality, called in non-portable way. This method is never used within
           the toolkit, and its usage is discouraged, primarily because its options do not serve
           the toolkit design, are subject to changes and cannot be relied upon.

API

   Properties
       autoClose BOOLEAN
           If set to 1, issues "close()" after the last top-level window is destroyed. Does not
           influence anything if set to 0.

           This feature is designed to help with general 'one main window' application layouts.

           Default value: 0

       icon OBJECT
           Holds the icon object, associated with the application.  If "undef", a system-provided
           default icon is assumed.  Prima::Window object instances inherit the application icon
           by default.

       insertMode BOOLEAN
           A system boolean flag, showing whether text widgets through the system should insert (
           1 ) or overwrite ( 0 ) text on user input. Not all systems provide the global state of
           the flag.

       helpClass STRING
           Specifies a class of object, used as a help viewing package.  The default value is
           Prima::HelpViewer.

           Run-time changes to the property do not affect the help subsystem until "close_help"
           call is made.

       helpModule STRING
           Specifies a perl module, loaded indirectly when a help viewing call is made via
           "open_help".  Used when "::helpClass" property is overridden and the new class is
           contained in a third-party module.

           Run-time changes to the property do not affect the help subsystem until "close_help"
           call is made.

       hintClass STRING
           Create-only property.

           Specifies a class of widget, used as the hint label.

           Default value: Prima::HintWidget

       hintColor COLOR
           An alias to foreground color property for the hint label widget.

       hintBackColor COLOR
           An alias to background color property for the hint label widget.

       hintFont %FONT
           An alias to font property for the hint label widget.

       hintPause TIMEOUT
           Selects the timeout in milliseconds before the hint label is shown when the mouse
           pointer hovers over a widget.

       modalHorizon BOOLEAN
           A read-only property. Used as a landmark for the lowest-level modal horizon.  Always
           returns 1.

       palette [ @PALETTE ]
           Used only within paint and information modes.  Selects solid colors in a system
           palette, as many as possible.  PALETTE is an array of integer triplets, where each is
           red, green, and blue component, with intensity range from 0 to 255.

       printerClass STRING
           Create-only property.

           Specifies a class of object, used as a printer.  The default value is system-
           dependent, but is either "Prima::Printer" or "Prima::PS::Printer".

       printerModule STRING
           Create-only property.

           Specifies a perl module, loaded indirectly before a printer object of "::printerClass"
           class is created.  Used when "::printerClass" property is overridden and the new class
           is contained in a third-party module.

       pointerVisible BOOLEAN
           Governs the system pointer visibility.  If 0, hides the pointer so it is not visible
           in all system windows. Therefore this property usage must be considered with care.

       size WIDTH, HEIGHT
           A read-only property.

           Returns two integers, width and height of the screen.

       showHint BOOLEAN
           If 1, the toolkit is allowed to show the hint label over a widget. If 0, the display
           of the hint is forbidden. In addition to functionality of "::showHint" property in
           Prima::Widget, Prima::Application::showHint is another layer of hint visibility
           control - if it is 0, all hint actions are disabled, disregarding "::showHint" value
           in widgets.

       wantUnicodeInput BOOLEAN
           Selects if the system is allowed to generate key codes in unicode.  Returns the
           effective state of the unicode input flag, which cannot be changed if perl or
           operating system do not support UTF8.

           If 1, "Prima::Clipboard::text" property may return UTF8 text from system clipboards is
           available.

           Default value: 0

   Events
       PasteText $CLIPBOARD, $$TEXT_REF
           The notification queries $CLIPBOARD for text content and stores in $$TEXT_REF. Default
           action is that 'Text' format is queried if "wantUnicodeInput" is unset. Otherwise,
           'UTF8' format is queried beforehand.

           The "PasteText" mechanism is devised to ease defining text unicode/ascii conversion
           between clipboard and standard widgets, in a standard way.

   Methods
       add_startup_notification @CALLBACK
           CALLBACK is an array of anonymous subs, which is executed when Prima::Application
           object is created. If the application object is already created during the call,
           CALLBACKs called immediately.

           Useful for add-on packages initialization.

       begin_paint
           Enters the enabled ( active paint ) state, returns success flag.  Once the object is
           in enabled state, painting and drawing methods can perform write operations on the
           whole screen.

       begin_paint_info
           Enters the information state, returns success flag.  The object information state is
           same as enabled state ( see "begin_paint()"), except that painting and drawing methods
           are not permitted to change the screen.

       close
           Issues a system termination call, resulting in calling "close" for all top-level
           windows. The call can be interrupted by these, and thus canceled. If not canceled,
           stops the application event loop.

       close_help
           Closes the help viewer window.

       end_paint
           Quits the enabled state and returns application object to the normal state.

       end_paint_info
           Quits the information state and returns application object to the normal state.

       font_encodings
           Returns array of encodings, represented by strings, that are recognized by the system
           and available for at least one font. Each system provides different sets of encoding
           strings; the font encodings are not portable.

       fonts NAME = '', ENCODING = ''
           Returns hash of font hashes ( see "Fonts" in Prima::Drawable ) describing fonts of
           NAME font family and of ENCODING. If NAME is '' or "undef", returns one fonts hash for
           each of the font families that match the ENCODING string. If ENCODING is '' or
           "undef", no encoding match is performed.  If ENCODING is not valid ( not present in
           "font_encodings" result), it is treated as if it was '' or "undef".

           In the special case, when both NAME and ENCODING are '' or "undef", each font metric
           hash contains element "encodings", that points to array of the font encodings,
           available for the fonts of NAME font family.

       get_active_window
           Returns object reference to a currently active window, if any, that belongs to the
           program. If no such window exists, "undef" is returned.

           The exact definition of 'active window' is system-dependent, but it is generally
           believed that an active window is the one that has keyboard focus on one of its
           children widgets.

       get_caption_font
           Returns a title font, that the system uses to draw top-level window captions.  The
           method can be called with a class string instead of an object instance.

       get_default_cursor_width
           Returns width of the system cursor in pixels.  The method can be called with a class
           string instead of an object instance.

       get_default_font
           Returns the default system font.  The method can be called with a class string instead
           of an object instance.

       get_default_scrollbar_metrics
           Returns dimensions of the system scrollbars - width of the standard vertical scrollbar
           and height of the standard horizon scrollbar.  The method can be called with a class
           string instead of an object instance.

       get_default_window_borders BORDER_STYLE = bs::Sizeable
           Returns width and height of standard system window border decorations for one of
           "bs::XXX" constants.  The method can be called with a class string instead of an
           object instance.

       get_focused_widget
           Returns object reference to a currently focused widget, if any, that belongs to the
           program. If no such widget exists, "undef" is returned.

       get_hint_widget
           Returns the hint label widget, attached automatically to Prima::Application object
           during startup. The widget is of "::hintClass" class, Prima::HintWidget by default.

       get_image X_OFFSET, Y_OFFSET, WIDTH, HEIGHT
           Returns Prima::Image object with WIDTH and HEIGHT dimensions filled with graphic
           content of the screen, copied from X_OFFSET and Y_OFFSET coordinates. If WIDTH and
           HEIGHT extend beyond the screen dimensions, they are adjusted.  If the offsets are
           outside screen boundaries, or WIDTH and HEIGHT are zero or negative, "undef" is
           returned.

       get_indents
           Returns 4 integers that corresponds to extensions of eventual desktop decorations that
           the windowing system may present on the left, bottom, right, and top edges of the
           screen. For example, for win32 this reports the size of the part of the scraan that
           windows taskbar may occupies, if any.

       get_printer
           Returns the printer object, attached automatically to Prima::Application object. The
           object is of "::printerClass" class.

       get_message_font
           Returns the font the system uses to draw the message text.  The method can be called
           with a class string instead of an object instance.

       get_modal_window MODALITY_TYPE = mt::Exclusive, TOPMOST = 1
           Returns the modal window, that resides on an end of a modality chain. MODALITY_TYPE
           selects the chain, and can be either "mt::Exclusive" or "mt::Shared". TOPMOST is a
           boolean flag, selecting the lookup direction; if it is 1, the 'topmost' window is
           returned, if 0, the 'lowest' one ( in a simple case when window A is made modal
           (executed) after modal window B, the A window is the 'topmost' one ).

           If a chain is empty "undef" is returned. In case when a chain consists of just one
           window, TOPMOST value is apparently irrelevant.

       get_scroll_rate
           Returns two integer values of two system-specific scrolling timeouts. The first is the
           initial timeout, that is applied when the user drags the mouse from a scrollable
           widget ( a text field, for example ), and the widget is about to scroll, but the
           actual scroll is performed after the timeout is expired. The second is the repetitive
           timeout, - if the dragging condition did not change, the scrolling performs
           automatically after this timeout. The timeout values are in milliseconds.

       get_system_info
           Returns a hash with information about the system.  The hash result contains the
           following keys:

           apc One of "apc::XXX" constants, reflecting the platform.  Currently, the list of the
               supported platforms is:

                       apc::Os2
                       apc::Win32
                       apc::Unix

           gui One of "gui::XXX" constants, reflecting the graphic user interface used in the
               system:

                       gui::Default
                       gui::PM
                       gui::Windows
                       gui::XLib
                       gui::GTK2

           guiDescription
               Description of graphic user interface, returned as an arbitrary string.

           system
               An arbitrary string, representing the operating system software.

           release
               An arbitrary string, reflecting the OS version information.

           vendor
               The OS vendor string

           architecture
               The machine architecture string

           The method can be called with a class string instead of an object instance.

       get_system_value
           Returns the system integer value, associated with one of "sv::XXX" constants. The
           constants are:

                   sv::YMenu            - height of menu bar in top-level windows
                   sv::YTitleBar        - height of title bar in top-level windows
                   sv::XIcon            - width and height of main icon dimensions,
                   sv::YIcon              acceptable by the system
                   sv::XSmallIcon       - width and height of alternate icon dimensions,
                   sv::YSmallIcon         acceptable by the system
                   sv::XPointer         - width and height of mouse pointer icon
                   sv::YPointer           acceptable by the system
                   sv::XScrollbar       - width of the default vertical scrollbar
                   sv::YScrollbar       - height of the default horizontal scrollbar
                                                                           ( see get_default_scrollbar_metrics() )
                   sv::XCursor          - width of the system cursor
                                                                           ( see get_default_cursor_width() )
                   sv::AutoScrollFirst  - the initial and the repetitive
                   sv::AutoScrollNext     scroll timeouts
                                                                           ( see get_scroll_rate() )
                   sv::InsertMode       - the system insert mode
                                                                           ( see insertMode )
                   sv::XbsNone          - widths and heights of the top-level window
                   sv::YbsNone            decorations, correspondingly, with borderStyle
                   sv::XbsSizeable        bs::None, bs::Sizeable, bs::Single, and
                   sv::YbsSizeable        bs::Dialog.
                   sv::XbsSingle          ( see get_default_window_borders() )
                   sv::YbsSingle
                   sv::XbsDialog
                   sv::YbsDialog
                   sv::MousePresent     - 1 if the mouse is present, 0 otherwise
                   sv::MouseButtons     - number of the mouse buttons
                   sv::WheelPresent     - 1 if the mouse wheel is present, 0 otherwise
                   sv::SubmenuDelay     - timeout ( in ms ) before a sub-menu shows on
                                                                           an implicit selection
                   sv::FullDrag         - 1 if the top-level windows are dragged dynamically,
                                                                           0 - with marquee mode
                   sv::DblClickDelay    - mouse double-click timeout in milliseconds
                   sv::ShapeExtension   - 1 if Prima::Widget::shape functionality is supported,
                                                                           0 otherwise
                   sv::ColorPointer     - 1 if system accepts color pointer icons.
                   sv::CanUTF8_Input    - 1 if system can generate key codes in unicode
                   sv::CanUTF8_Output   - 1 if system can output utf8 text

           The method can be called with a class string instead of an object instance.

       get_widget_from_handle HANDLE
           HANDLE is an integer value of a toolkit widget. It is usually passed to the program by
           other IPC means, so it returns the associated widget. If no widget is associated with
           HANDLE, "undef" is returned.

       get_widget_from_point X_OFFSET, Y_OFFSET
           Returns the widget that occupies screen area under (X_OFFSET,Y_OFFSET) coordinates. If
           no toolkit widget are found, "undef" is returned.

       go  The main event loop. Called by

           run Prima;

           standard code. Returns when the program is about to terminate, or if the exception was
           signaled. In the latter case, the loop can be safely re-started.

       lock
           Effectively blocks the graphic output for all widgets.  The output can be restored
           with "unlock()".

       open_help TOPIC
           Opens the help viewer window with TOPIC string in link POD format ( see perlpod ) -
           the string is treated as "manpage/section", where 'manpage' is the file with POD
           content and 'section' is the topic inside the manpage.

       sync
           Synchronizes all pending requests where there are any. Is an effective "XSync(false)"
           on X11, and is a no-op otherwise.

       sys_action CALL
           CALL is an arbitrary string of the system service name and the parameters to it.  This
           functionality is non-portable, and its usage should be avoided.  The system services
           provided are not documented and subject to change. The actual services can be looked
           in the toolkit source code under apc_system_action tag.

       unlock
           Unblocks the graphic output for all widgets, previously locked with "lock()".

       yield
           An event dispatcher, called from within the event loop.  If the event loop can be
           schematized, then in

                   while ( application not closed ) {
                           yield
                   }

           draft yield() is the only function, called repeatedly within the event loop. yield()
           cannot be used to organize event loops, but it can be employed to process stacked
           system events explicitly, to increase responsiveness of a program, for example, inside
           a long calculation cycle.

           The method can be called with a class string instead of an object instance; however,
           the $::application object must be initialized.

AUTHOR

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

SEE ALSO

       Prima, Prima::Object, Prima::Widget, Prima::Window