NAME
Prima::Widget - window management
SYNOPSIS
# create a widget
my $widget = Prima::Widget-> new(
size => [ 200, 200],
color => cl::Green,
visible => 0,
onPaint => sub {
my ($self,$canvas) = @_;
$canvas-> clear;
$canvas-> text_out( "Hello world!", 10, 10);
},
);
# manipulate the widget
$widget-> origin( 10, 10);
$widget-> show;
DESCRIPTION
Prima::Widget is a descendant of Prima::Component, a class, especially
crafted to reflect and govern properties of a system-dependent window,
such as its position, hierarchy, outlook etc. Prima::Widget is mapped
into the screen space as a rectangular area, with distinct boundaries,
pointer and sometimes cursor, and a user-selectable input focus.
USAGE
Prima::Widget class and its descendants are used widely throughout the
toolkit, and, indeed provide almost all its user interaction and input-
output. The notification system, explained in Prima::Object, is
employed in Prima::Widget heavily, providing the programmer with
unified access to the system-generated events, that occur when the user
moves windows, clicks the mouse, types the keyboard, etc. Descendants
of Prima::Widget use the internal, the direct method of overriding the
notifications, whereas end programs tend to use the toolkit widgets
equipped with anonymous subroutines ( see Prima::Object for the
details).
The class functionality is much more extensive comparing to the other
built-in classes, and therefore the explanations are grouped in several
topics.
Creation and destruction
The widget creation syntax is the same as for the other Prima objects:
Prima::Widget-> create(
name => 'Widget',
size => [ 20, 10],
onMouseClick => sub { print "click\n"; },
owner => $owner,
);
In the real life, a widget must be almost always explicitly told about
its owner. The owner object is either a Prima::Widget descendant, in
which case the widget is drawn inside its inferior, or the application
object, and in the latter case a widget becomes top-level. This is the
reason why the "insert" syntax is much more often used, as it is more
illustrative and is more convenient for creating several widgets in one
call ( see Prima::Object ).
$owner-> insert( 'Prima::Widget',
name => 'Widget',
size => [ 20, 10],
onMouseClick => sub { print "click\n"; },
);
These two examples produce identical results.
As a descendant of Prima::Component, Prima::Widget sends "Create"
notification when created ( more precisely, after its init stage is
finished. See Prima::Object for details). This notification is called
and processed within "create()" call. In addition, another notification
"Setup" is sent after the widget is created. This message is posted, so
it is called within "create()" but processed in the application event
loop. This means that the execution time of "Setup" is uncertain, as it
is with all posted messages; its delivery time is system-dependent, so
its use must be considered with care.
After a widget is created, it is usually asked to render its content,
provided that the widget is visible. This request is delivered by means
of "Paint" notification.
When the life time of a widget is over, its method "destroy()" is
called, often implicitly. If a widget gets destroyed because its owner
also does, it is guaranteed that the children widgets will be destroyed
first, and the owner afterwards. In such situation, widget can operate
with a limited functionality both on itself and its owners ( see
Prima::Object, Creation section ).
Graphic content
A widget can use two different ways for representing its graphic
content to the user. The first method is event-driven, when the "Paint"
notification arrives, notifying the widget that it must re-paint
itself. The second is the ’direct’ method, when the widget generates
graphic output unconditionally.
Event-driven rendering
A notification responsible for widget repainting is "Paint". It
provides a single ( besides the widget itself ) parameter, an object,
where the drawing is performed. In an event-driven call, it is always
equals to the widget. However, if a custom mechanism should be used
that directly calls, for example,
$widget-> notify('Paint', $some_other_widget);
for whatever purpose, it is recommended ( not required, though ), to
use this parameter, not the widget itself for painting and drawing
calls.
The example of "Paint" callback is quite simple:
Prima::Widget-> create(
...
onPaint => sub {
my ( $self, $canvas) = @_;
$canvas-> clear;
$canvas-> text_out("Clicked $self->{clicked} times", 10, 10);
},
onMouseClick => sub {
$_[0]-> {clicked}++;
$_[0]-> repaint;
},
);
The example uses several important features of the event-driven
mechanism. First, no "begin_paint()"/"end_paint()" brackets are used
within the callback. These are called implicitly. Second, when the
custom refresh of the widget’s graphic content is needed, no code like
"notify(q(Paint))" is used - "repaint()" method is used instead. It
must be noted, that the actual execution of "Paint" callbacks might or
might not occur inside the "repaint()" call. This behavior is governed
by the "::syncPaint" property. "repaint()" marks the whole widget’s
area to be refreshed, or invalidates the area. For the finer gradation
of the area that should be repainted, "invalidate_rect()" and
"validate_rect()" pair of functions is used. Thus,
$x-> repaint()
code is a mere alias to
$x-> invalidate_rect( 0, 0, $x-> size);
call. It must be realized, that the area, passed to "invalidate_rect()"
only in its ideal ( but a quite often ) execution case will be
pertained as a clipping rectangle when a widget executes its "Paint"
notification. The user and system interactions can result in
exposition of other parts of a widget ( like, moving windows over a
widget ), and the resulting clipping rectangle can be different from
the one that was passed to "invalidate_rect()". Moreover, the clipping
rectangle can become empty as the result of these influences, and the
notification will not be called at all.
Invalid rectangle is presented differently inside and outside the
drawing mode. The first, returned by "::clipRect", employs inclusive-
inclusive coordinates, whereas "invalidate_rect()", "validate_rect()"
and "get_invalid_rect()" - inclusive-exclusive coordinates. The ideal
case exemplifies the above said:
$x-> onPaint( sub {
my @c = $_[0]-> clipRect;
print "clip rect:@c\n";
});
$x-> invalidate_rect( 10, 10, 20, 20);
...
clip rect: 10 10 19 19
As noted above, "::clipRect" property is set to the clipping rectangle
of the widget area that is needed to be refreshed, and an event handler
code can take advantage of this information, increasing the efficiency
of the painting procedure.
Further assignments of "::clipRect" property do not make possible over-
painting on the screen area that lies outside the original clipping
region. This is also valid for all paint operations, however since the
original clipping rectangle is the full area of a canvas, this rule is
implicit and unnecessary, because whatever large the clipping rectangle
is, drawing and painting cannot be performed outside the physical
boundaries of the canvas.
Direct rendering
The direct rendering, contrary to the event-driven, is initiated by the
program, not by the system. If a programmer wishes to paint over a
widget immediately, then "begin_paint()" is called, and, if successful,
the part of the screen occupied by the widget is accessible to the
drawing and painting routines.
This method is useful, for example, for graphic demonstration programs,
that draw continuously without any input. Another field is the screen
drawing, which is performed with Prima::Application class, that does
not have "Paint" notification. Application’s graphic canvas represents
the whole screen, allowing over-drawing the graphic content of other
programs.
The event-driven rendering method adds implicit
"begin_paint()"/"end_paint()" brackets ( plus some system-dependent
actions ) and is a convenience version of the direct rendering.
Sometimes, however, the changes needed to be made to a widget’s graphic
context are so insignificant, so the direct rendering method is
preferable, because of the cleaner and terser code. As an example might
serve a simple progress bar, that draws a simple colored bar. The
event-driven code would be ( in short, omitting many details ) as such:
$bar = Widget-> create(
width => 100,
onPaint => sub {
my ( $self, $canvas) = @_;
$canvas-> color( cl::Blue);
$canvas-> bar( 0, 0, $self-> {progress}, $self-> height);
$canvas-> color( cl::Back);
$canvas-> bar( $self-> {progress}, 0, $self-> size);
},
);
...
$bar-> {progress} += 10;
$bar-> repaint;
# or, more efficiently, ( but clumsier )
# $bar-> invalidate_rect( $bar->{progress}-10, 0,
# $bar->{progress}, $bar-> height);
And the direct driven:
$bar = Widget-> create( width => 100 );
...
$bar-> begin_paint;
$bar-> color( cl::Blue);
$bar-> bar( $progress, 0, $progress + 10, $bar-> height);
$bar-> end_paint;
$progress += 10;
The pros and contras are obvious: the event-driven rendered widget
correctly represents the status after an eventual repaint, for example
when the user sweeps a window over the progress bar widget. The direct
method cannot be that smart, but if the status bar is an insignificant
part of the program, the trade-off of the functionality in favor to the
code simplicity might be preferred.
Both methods can be effectively disabled using the paint locking
mechanism. The "lock()" and "unlock()" methods can be called several
times, stacking the requests. This feature is useful because many
properties implicitly call "repaint()", and if several of these
properties activate in a row, the unnecessary redrawing of the widget
can be avoided. The drawback is that the last "unlock()" call triggers
"repaint()" unconditionally.
Geometry
Basic properties
A widget always has its position and size determined, even if it is not
visible on the screen. Prima::Widget provides several properties with
overlapping functionality, that govern the geometry of a widget. The
base properties are "::origin" and "::size", and the derived are
"::left", "::bottom", "::right", "::top", "::width", "::height" and
"::rect". "::origin" and "::size" operate with two integers, "::rect"
with four, others with one integer value.
As the Prima toolkit coordinate space begins in the lower bottom
corner, the combination of "::left" and "::bottom" is same as
"::origin", and combination of "::left", "::bottom", "::right" and
"::top" - same as "::rect".
When a widget is moved or resized, correspondingly two notifications
occur: "Move" and "Size". The parameters to both are old and new
position and size. The notifications occur irrespectable to whether the
geometry change was issued by the program itself or by the user.
Implicit size regulations
Concerning the size of a widget, two additional two-integer properties
exist, "::sizeMin" and "::sizeMax", that constrain the extension of a
widget in their boundaries. The direct call that assigns values to the
size properties that lie outside "::sizeMin" and "::sizeMax"
boundaries, will fail - the widget extension will be adjusted to the
boundary values, not to the specified ones.
Change to widget’s position and size can occur not only by an explicit
call to one of the geometry properties. The toolkit contains implicit
rules, that can move and resize a widget corresponding to the flags,
given to the "::growMode" property. The exact meaning of the "gm::XXX"
flags is not given here ( see description to "::growMode" in API
section ), but in short, it is possible with simple means to maintain
widget’s size and position regarding its owner, when the latter is
resized. By default, and the default behavior corresponds to
"::growMode" 0, widget does not change neither its size nor position
when its owner is resized. It stays always in ’the left bottom corner’.
When, for example, a widget is expected to stay in ’the right bottom
corner’, or ’the left top corner’, the "gm::GrowLoX" and "gm::GrowLoY"
values must be used, correspondingly. When a widget is expected to
cover, for example, its owner’s lower part and change its width in
accord with the owner’s, ( a horizontal scroll bar in an editor window
is the example), the "gm::GrowHiX" value must be used.
When this implicit size change does occur, the "::sizeMin" and
"::sizeMax" do take their part as well - they still do not allow the
widget’s size excess their boundaries. However, this algorithm derives
a problem, that is illustrated by the following setup. Imagine a widget
with size-dependent "::growMode" ( with "gm::GrowHiX" or "gm::GrowHiY"
bits set ) that must maintain certain relation between the owner’s size
and its own. If the implicit size change would be dependent on the
actual widget size, derived as a result from the previous implicit size
action, then its size (and probably position) will be incorrect after
an attempt is made to change the widget’s size to values outside the
size boundaries.
Example: child widget has width 100, growMode set to "gm::GrowHiX" and
sizeMin set to (95, 95). Its owner has width 200. If the owner widget
changes gradually its width from 200 to 190 and then back, the
following width table emerges:
Owner Child
Initial state 200 100
Shrink 195 -5 95
Shrink 190 -5 95 - as it can not be less than 95.
Grow 195 +5 100
Grow 200 +5 105
That effect would exist if the differential-size algorithm would be
implemented, - the owner changes width by 5, and the child does the
same. The situation is fixed by introducing the virtual size term.
The "::size" property is derived from virtual size, and as "::size"
cannot exceed the size boundaries, virtual size can. It can even
accept the negative values. With this intermediate stage added, the
correct picture occurs:
Owner Child's Child's
virtual width width
Initial state 200 100 100
Shrink 195 -5 95 95
Shrink 190 -5 90 95
Grow 195 +5 95 95
Grow 200 +5 100 100
Strictly speaking, the virtual size must be declared a read-only
property, but currently it is implemented as a "get_virtual_size()"
function, and it is planned to fix this discrepancy between the
document and the implementation in favor of the property syntax.
Geometry managers
The concept of geometry managers is imported from Tk, which in turn is
a port of Tcl-Tk. The idea behind it is that a widget size and position
is governed by one of the managers, which operate depending on the
specific options given to the widget. The selection is operated by
"::geometry" property, and is one of "gt::XXX" constants. The native (
and the default ) geometry manager is the described above grow-mode
algorithm ( "gt::GrowMode" ). The currently implemented Tk managers are
packer ( "gt::Pack" ) and placer ( "gt::Place"). Each has its own set
of options and methods, and their manuals are provided separately in
Prima::Widget::pack and Prima::Widget::place ( the manpages are also
imported from Tk ).
Another concept that comes along with geometry managers is the
’geometry request size’. It is realized as a two-integer property
"::geomSize", which reflects the size selected by some intrinsic widget
knowledge, and the idea is that "::geomSize" it is merely a request to
a geometry manager, whereas the latter changes "::size" accordingly.
For example, a button might set its ’intrinsic’ width in accord with
the width of text string displayed in it. If the default width for such
a button is not overridden, it is assigned with such a width. By
default, under "gt::GrowMode" geometry manager, setting "::geomSize" (
and its two semi-alias properties "::geomWidth" and "::geomHeight" )
also changes the actual widget size.Moreover, when the size is passed
to the Widget initialization code, "::size" properties are used to
initialize "::geomSize". Such design minimizes the confusion between
the two properties, and also minimizes the direct usage of
"::geomSize", limiting it for selecting advisory size in widget
internal code.
The geometry request size is useless under "gt::GrowMode" geometry
manager, but Tk managers use it extensively.
Relative coordinates
Another geometry issue, or rather a programming technique must be
mentioned - the relative coordinates. It is the well-known problem,
when a dialog window, developed with one font looks garbled on another
system with another font. The relative coordinates solve the problem;
the solution provides the "::designScale" two-integer property, the
width and height of the font, that was used when the dialog window was
designed. With this property supplied, the position and size supplied
when a widget is actually created, are transformed in proportion
between the designed and the actual font metrics.
The relative coordinates can be used only when passing the geometry
properties values, and only before the creation stage, before a widget
is created, because the scaling calculations perform in
Prima::Widget::"profile_check_in()" method.
In order to employ the relative coordinates scheme, the owner ( or the
dialog ) widget must set its "::designScale" to the font metrics and
"::scaleChildren" property to 1. Widgets, created with owner that
meets these requirements, participate in the relative coordinates
scheme. If a widget must be excluded from the relative geometry
applications, either the owner’s property "::scaleChildren" must be set
to 0, or the widget’s "::designScale" must be set to "undef". As the
default "::designScale" value is "undef", no default implicit relative
geometry schemes are applied.
The "::designScale" property is auto-inherited; its value is copied to
the children widgets, unless the explicit "::designScale" was given
during the widget’s creation. This is used when such a child widget
serves as an owner for some other grand-children widgets; the
inheritance scheme allows the grand- ( grand- etc ) children to
participate in the relative geometry scheme.
Note: it is advised to test such applications with the Prima::Stress
module, which assigns a random font as the default, so the testing
phase does not involve tweaking of the system settings.
Z-order
In case when two widgets overlap, one of these is drawn in full,
whereas the another only partly. Prima::Widget provides management of
the Z-axis ordering, but since Z-ordering paradigm can hardly be fit
into the properties scheme, the toolkit uses methods instead.
A widget can use four query methods: "first()", "last()", "next()", and
"prev()". These return, correspondingly, the first and the last widgets
in Z-order stack, and the direct neighbors of a widget ( $widget->
next-> prev always equals to the $widget itself, given that $widget->
next exists ).
The last widget is the topmost one, the one that is drawn fully. The
first is the most obscured one, given that all the widgets overlap.
Z-order can also be changed at runtime ( but not during widget’s
creation). There are three methods: "bring_to_front()", that sets the
widget last in the order, making it topmost, "send_to_back()", that
does the reverse, and "insert_behind()", that sets a widget behind the
another widget, passed as an argument.
Changes to Z-order trigger "ZOrderChanged" notification.
Parent-child relationship
By default, if a widget is a child to a widget or window, it maintains
two features: it is clipped by its owner’s boundaries and is moved
together as the owner widget moves. It is said also that a child is
inferior to its parent. However, a widget without a parent still does
have a valid owner. Instead of implementing parent property, the
"::clipOwner" property was devised. It is 1 by default, and if it is 1,
then owner of a widget is its parent, at the same time. However, when
it is 0, many things change. The widget is neither clipped nor moved
together with its parent. The widget become parentless, or, more
strictly speaking, the screen becomes its parent. Moreover, the
widget’s origin offset is calculated then not from the owner’s
coordinates but from the screen, and mouse events in the widget do not
transgress implicitly to the owner’s top-level window eventual
decorations.
The same results are produced if a widget is inserted in the
application object, which does not have screen visualization. A widget
that belongs to the application object, can not reset its "::clipOwner"
value to 1.
The "::clipOwner" property opens a possibility for the toolkit widgets
to live inside other programs’ windows. If the "::parentHandle" is
changed from its default "undef" value to a valid system window handle,
the widget becomes child to this window, which can belong to any
application residing on the same display. This option is dangerous,
however: normally widgets never get destroyed by no reason. A top-level
window is never destroyed before its "Close" notification grants the
destruction. The case with "::parentHandle" is special, because a
widget, inserted into an alien application, must be prepared to be
destroyed at any moment. It is recommended to use prior knowledge about
such the application, and, even better, use one or another inter-
process communication scheme to interact with it.
A widget does not need to undertake anything special to become an
’owner’. Any widget, that was set in "::owner" property on any other
widget, becomes owner automatically. Its "get_widgets()" method returns
non-empty widget list. "get_widgets()" serves same purpose as
Prima::Component::"get_components()", but returns only Prima::Widget
descendants.
A widget can change its owner at any moment. The "::owner" property is
both readable and writable, and if a widget is visible during the owner
change, it is immediately appeared under different coordinates and
different clipping condition after the property change, given that its
"::clipOwner" is set to 1.
Visibility
A widget is visible by default. Visible means that it is shown on the
screen if it is not shadowed by other widgets or windows. The
visibility is governed by the "::visible" property, and its two
convenience aliases, "show()" and "hide()".
When a widget is invisible, its geometry is not discarded; the widget
pertains its position and size, and is subject to all previously
discussed implicit sizing issues. When change to "::visible" property
is made, the screen is not updated immediately, but in the next event
loop invocation, because uncovering of the underlying area of a hidden
widget, and repainting of a new-shown widget both depend onto the
event-driven rendering functionality. If the graphic content must be
updated, "update_view()" must be called, but there’s a problem. It is
obvious that if a widget is shown, the only content to be updated is
its own. When a widget becomes hidden, it may uncover more than one
widget, depending on the geometry, so it is unclear what widgets must
be updated. For the practical reasons, it is enough to get one event
loop passed, by calling "yield()" method of the $::application object.
The other notifications may pass here as well, however.
There are other kinds of visibility. A widget might be visible, but one
of its owners might not. Or, a widget and its owners might be visible,
but they might be over-shadowed by the other windows. These conditions
are returned by "showing()" and "exposed()" functions. These return
boolean values corresponding to the condition described. So, if a
widget is ’exposed’, it is ’showing’ and ’visible’; "exposed()" returns
always 0 if a widget is either not ’showing’ or not ’visible’. If a
widget is ’showing’, then it is always ’visible’. "showing()" returns
always 0 if a widget is invisible.
Visibility changes trigger "Hide" and "Show" notifications.
Focus
One of the key points of any GUI is that only one window at a time can
possess a focus. The widget is focused, if the user’s keyboard input is
directed to it. The toolkit adds another layer in the focusing scheme,
as often window managers do, highlighting the decorations of a top-
level window over a window with the input focus.
Prima::Widget property "::focused" governs the focused state of a
widget. It is sometimes too powerful to be used. Its more often
substitutes, "::selected" and "::current" properties provide more
respect to widget hierarchy.
"::selected" property sets focus to a widget if it is allowed to be
focused, by the usage of the "::selectable" property. With this
granted, the focus is passed to the widget or to the one of its (
grand-) children. So to say, when ’selecting’ a window with a text
field by clicking on a window, one does not expect the window to be
focused, but the text field. To achieve this goal and reduce
unnecessary coding, the "::current" property is introduced. With all
equal conditions, a widget that is ’current’ gets precedence in getting
selected over widgets that are not ’current’.
De-selecting, in its turn, leaves the system in such a state when no
window has input focus. There are two convenience shortcuts "select()"
and "deselect()" defined, aliased to selected(1) and selected(0),
correspondingly.
As within the GUI space, there can be only one ’focused’ widget, so
within the single widget space, there can be only one ’current’ widget.
A widget can be marked as a current by calling "::current" ( or,
identically, "::currentWidget" on the owner widget ). The
reassignments are performed automatically when a widget is focused.
The reverse is also true: if a widget is explicitly marked as
’current’, and belongs to the widget tree with the focus in one of its
widgets, then the focus passed to the ’current’ widget, or down to
hierarchy if it is not selectable.
These relations between current widget pointer and focus allow the
toolkit easily implement the focusing hierarchy. The focused widget is
always on the top of the chain of its owner widgets, each of whose is a
’current’ widget. If, for example, a window that contains a widget that
contains a focused button, become un-focused, and then user selects the
window again, then the button will become focused automatically.
Changes to focus produce "Enter" and "Leave" notifications.
Below discussed mouse- and keyboard- driven focusing schemes. Note
that all of these work via "::selected", and do not focus the widgets
with "::selectable" property set to 0.
Mouse-aided focusing
Typically, when the user clicks the left mouse button on a widget, the
latter becomes focused. One can note that not all widgets become
focused after the mouse click - scroll bars are the examples. Another
kind of behavior is the described above window with the text field -
clicking mouse on a window focuses a text field.
Prima::Widget has the "::selectingButtons" property, a combination of
mb::XXX ( mouse buttons ) flags. If the bits corresponding to the
buttons are set, then click of this button will automatically call
::selected(1) ( not ::focused(1) ).
Another boolean property, "::firstClick" determines the behavior when
the mouse button action is up to focus a widget, but the widget’s top-
level window is not active. The default value of "::firstClick" is 1,
but if set otherwise, the user must click twice to a widget to get it
focused. The property does not influence anything if the top-level
window was already active when the click event occured.
Due to some vendor-specific GUI designs, it is hardly possibly to force
selection of one top-level window when the click was on the another.
The window manager or the OS can interfere, although this does not
always happen, and produce different results on different platforms.
Since the primary goal of the toolkit is portability, such
functionality must be considered with care. Moreover, when the user
selects a window by clicking not on the toolkit-created widgets, but on
the top-level window decorations, it is not possible to discern the
case from any other kind of focusing.
Keyboard focusing
The native way to navigate between the toolkit widgets are tab- and
arrow- navigation. The tab ( and its reverse, shift-tab ) key
combinations circulate the focus between the widgets in same top-level
group ( but not inside the same owner widget group ). The arrow keys,
if the focused widget is not interested in these keystrokes, move the
focus in the specified direction, if it is possible. The methods that
provide the navigations are available and called "next_tab()" and
"next_positional()", correspondingly ( see API for the details).
When "next_positional()" operates with the geometry of the widgets,
"next_tab()" uses the "::tabStop" and "::tabOrder" properties.
"::tabStop", the boolean property, set to 1 by default, tells if a
widget is willing to participate in tab-aided focus circulation. If it
doesn’t, "next_tab()" never uses it in its iterations. "::tabOrder"
value is an integer, unique within the sibling widgets ( sharing same
owner ) list, and is used as simple tag when the next tab-focus
candidate is picked up. The default "::tabOrder" value is -1, which
changes automatically after widget creation to a unique value.
User input
The toolkit responds to the two basic means of the user input - the
keyboard and the mouse. Below described three aspects of the input
handling - the event-driven, the polling and the simulated input
issues. The event-driven input is the more or less natural way of
communicating with the user, so when the user presses the key or moves
the mouse, a system event occurs and triggers the notification in one
or more widgets. Polling methods provide the immediate state of the
input devices; the polling is rarely employed, primarily because of its
limited usability, and because the information it provides is passed to
the notification callbacks anyway. The simulated input is little more
than "notify()" call with specifically crafted parameters. It interacts
with the system, so the emulation can gain the higher level of
similarity to the user actions. The simulated input functions allow the
notifications to be called right away, or post it, delaying the
notification until the next event loop invocation.
Keyboard
Event-driven
Keyboard input generates several notifications, where the most
important are "KeyDown" and "KeyUp". Both have almost the same list
of parameters ( see API ), that contain the key code, its modifiers
( if any ) that were pressed and an eventual character code. The
algorithms that extract the meaning of the key, for example,
discretion between character and functional keys etc are not
described here. The reader is advised to look at Prima::KeySelector
module, which provides convenience functions for keyboard input
values transformations, and to the Prima::Edit and Prima::InputLine
modules, the classes that use extensively the keyboard input. But
in short, the key code is one of the "kb::XXX" ( like, kb::F10,
kb::Esc ) constants, and the modifier value is a combination of the
"km::XXX" ( km::Ctrl, km::Shift) constants. The notable exception
is kb::None value, which hints that the character code is of value.
Some other "kb::XXX"-marked keys have the character code as well,
and it is up to a programmer how to treat these combinations. It is
advised, however, to look at the key code first, and then to the
character code.
"KeyDown" event has also the repeat integer parameter, that shows
the repetitive count how many times the key was pressed. Usually
it is 1, but if a widget was not able to get its portion of events
between the key presses, its value can be higher. If a code
doesn’t check for this parameter, some keyboard input may be lost.
If the code will be too much complicated by introducing the repeat-
value, one may consider setting the "::briefKeys" property to 0.
"::briefKeys", the boolean property, is 1 by default. If set to 0,
it guarantees that the repeat value will always be 1, but with the
price of certain under-optimization. If the core "KeyDown"
processing code sees repeat value greater than 1, it simply calls
the notification again.
Along with these two notifications, the "TranslateAccel" event is
generated after "KeyDown", if the focused widget is not interested
in the key event. Its usage covers the needs of the other widgets
that are willing to read the user input, even being out of focus.
A notable example can be a button with a hot key, that reacts on
the key press when the focus is elsewhere within its top-level
window. "TranslateAccel" has same parameters as "KeyDown", except
the REPEAT parameter.
Such out-of-focus input is also used with built-in menu keys
translations. If a descendant of Prima::AbstractMenu is in the
reach of the widget tree hierarchy, then it is checked whether it
contains some hot keys that match the user input. See Prima::Menu
for the details. In particular, Prima::Widget has "::accelTable"
property, a mere slot for an object that contains a table of hot
keys mappings to custom subroutines.
Polling
The polling function for the keyboard is limited to the modifier
keys only. "get_shift_state()" method returns the press state of
the modifier keys, a combination of "km::XXX" constants.
Simulated input
There are two methods, corresponding to the major notifications -
"key_up()" and "key_down()", that accept the same parameters as the
"KeyUp" and "KeyDown" notifications do, plus the POST boolean flag.
See "API" for details.
These methods are convenience wrappers for "key_event()" method,
which is never used directly.
Mouse
Event-driven
Mouse notifications are send in response when the user moves the
mouse, or presses and releases mouse buttons. The notifications
are logically grouped in two sets, the first contains "MouseDown",
"MouseUp", "MouseClick", and "MouseWheel", and the second -
"MouseMove", "MouseEnter", end "MouseLeave".
The first set deals with button actions. Pressing, de-pressing,
clicking ( and double-clicking ), the turn of mouse wheel
correspond to the four notifications. The notifications are sent
together with the mouse pointer coordinates, the button that was
touched, and the eventual modifier keys that were pressed. In
addition, "MouseClick" provides the boolean flag if the click was
single or double, and "MouseWheel" - the Z-range of the wheel turn.
These notifications occur when the mouse event occurs within the
geometrical bounds of a widget, with one notable exception, when a
widget is in capture mode. If the "::capture" is set to 1, then
these events are sent to the widget even if the mouse pointer is
outside, and not sent to the widgets and windows that reside under
the pointer.
The second set deals with the pointer movements. When the pointer
passes over a widget, it receives first "MouseEnter", then series
of "MouseMove", and finally "MouseLeave". "MouseMove" and
"MouseEnter" notifications provide X,Y-coordinates and modificator
keys; "MouseLeave" passes no parameters.
Polling
The mouse input polling procedures are "get_mouse_state()" method,
that returns combination of "mb::XXX" constants, and the
"::pointerPos" two-integer property that reports the current
position of the mouse pointer.
Simulated input
There are five methods, corresponding to the mouse events -
"mouse_up()", "mouse_down()", "mouse_click()", "mouse_wheel()" and
"mouse_move()", that accept the same parameters as their event
counterparts do, plus the POST boolean flag. See "API" for details.
These methods are convenience wrappers for "mouse_event()" method,
which is never used directly.
Color schemes
Prima::Drawable deals only with such color values, that can be
unambiguously decomposed to their red, green and blue components.
Prima::Widget extends the range of the values acceptable by its color
properties, introducing the color schemes. The color can be set
indirectly, without prior knowledge of what is its RGB value. There are
several constants defined in "cl::" name space, that correspond to the
default values of different color properties of a widget.
Prima::Widget revises the usage of "::color" and "::backColor", the
properties inherited from Prima::Drawable. Their values are widget’s
’foreground’ and ’background’ colors, in addition to their function as
template values. Moreover, their dynamic change induces the repainting
of a widget, and they can be inherited from the owner. The inheritance
is governed by properties "::ownerColor" and "::ownerBackColor". While
these are true, changes to owner "::color" or "::backColor" copied
automatically to a widget. Once the widget’s "::color" or "::backColor"
are explicitly set, the owner link breaks automatically by setting
"::ownerColor" or "::ownerBackColor" to 0.
In addition to these two color properties, Prima::Widget introduces six
others. These are "::disabledColor", "::disabledBackColor",
"::hiliteColor", "::hiliteBackColor", "::light3DColor", and
"::dark3DColor". The ’disabled’ color pair contains the values that
are expected to be used as foreground and background when a widget is
in the disabled state ( see API, "::enabled" property ). The ’hilite’
values serve as the colors for representation of selection inside a
widget. Selection may be of any kind, and some widgets do not provide
any. But for those that do, the ’hilite’ color values provide distinct
alternative colors. Examples are selections in the text widgets, or in
the list boxes. The last pair, "::light3DColor" and "::dark3DColor" is
used for drawing 3D-looking outlines of a widget. The purpose of all
these properties is the adequate usage of the color settings, selected
by the user using system-specific tools, so the program written with
the toolkit would look not such different, and more or less conformant
to the user’s color preferences.
The additional "cl::" constants, mentioned above, represent these eight
color properties. These named correspondingly, cl::NormalText,
cl::Normal, cl::HiliteText, cl::Hilite, cl::DisabledText, cl::Disabled,
cl::Light3DColor and cl::Dark3DColor. cl::NormalText is alias to
cl::Fore, and cl::Normal - to cl::Back. Another constant set, "ci::"
can be used with the "::colorIndex" property, a multiplexer for all
eight color properties. "ci::" constants mimic their non-RGB "cl::"
counterparts, so the call "hiliteBackColor(cl::Red)" is equal to
"colorIndex(ci::Hilite, cl::Red)".
Mapping from these constants to the RGB color representation is used
with "map_color()" method. These "cl::" constants alone are sufficient
for acquiring the default values, but the toolkit provides wider
functionality than this. The "cl::" constants can be combined with the
"wc::" constants, that represent standard widget class. The widget
class is implicitly used when single "cl::" constant is used; its value
is read from the "::widgetClass" property, unless one of "wc::"
constants is combined with the non-RGB "cl::" value. "wc::" constants
are described in "API"; their usage can make call of, for example,
"backColor( cl::Back)" on a button and on an input line result in
different colors, because the "cl::Back" is translated in the first
case into "cl::Back|wc::Button", and in another -
"cl::Back|wc::InputLine".
Dynamic change of the color properties result in the "ColorChanged"
notification.
Fonts
Prima::Widget does not change the handling of fonts - the font
selection inside and outside "begin_paint()"/"end_paint()" is not
different at all. A matter of difference is how does Prima::Widget
select the default font.
First, if the "::ownerFont" property is set to 1, then font of the
owner is copied to the widget, and is maintained all the time while the
property is true. If it is not, the default font values read from the
system.
The default font metrics for a widget returned by "get_default_font()"
method, that often deals with system-dependent and user-selected
preferences ( see "Additional resources" ). Because a widget can host
an eventual Prima::Popup object, it contains "get_default_popup_font()"
method, that returns the default font for the popup objects. The
dynamic popup font settings governed, naturally, by the "::popupFont"
property. Prima::Window extends the functionality to
"get_default_menu_font()" and the "::menuFont" property.
Dynamic change of the font property results in the "FontChanged"
notification.
Additional resources
The resources, operated via Prima::Widget class but not that strictly
bound to the widget concept, are gathered in this section. The section
includes overview of pointer, cursor, hint, menu objects and user-
specified resources.
Pointer
The mouse pointer is the shared resource, that can change its visual
representation when it hovers over different kinds of widgets. It is
usually a good practice for a text field, for example, set the pointer
icon to a jagged vertical line, or indicate a moving window with a
cross-arrowed pointer.
A widget can select either one of the predefined system pointers,
mapped by the "cr::XXX" constant set, or supply its own pointer icon of
an arbitrary size and color depth.
NB: Not all systems allow the colored pointer icons. System value under
sv::ColorPointer index containing a boolean value, whether the colored
icons are allowed or not.
In general, the "::pointer" property is enough for these actions. It
discerns whether it has an icon or a constant passed, and sets the
appropriate properties. These properties are also accessible
separately, although their usage is not encouraged, primarily because
of the tangled relationship between them. These properties are:
"::pointerType", "::pointerIcon", and "::pointerHotSpot". See their
details in the "API" sections.
Another property, which is present only in Prima::Application name
space is called "::pointerVisible", and governs the visibility of the
pointer - but for all widget instances at once.
Cursor
The cursor is a blinking rectangular area, indicating the availability
of the input focus in a widget. There can be only one active cursor per
a GUI space, or none at all. Prima::Widget provides several cursor
properties: "::cursorVisible", "::cursorPos", and "::cursorSize". There
are also two methods, "show_cursor()" and "hide_cursor()", which are
not the convenience shortcuts but the functions accounting the cursor
hide count. If "hide_cursor()" was called three times, then
"show_cursor()" must be called three times as well for the cursor to
become visible.
Hint
"::hint" is a text string, that usually describes the widget’s purpose
to the user in a brief manner. If the mouse pointer is hovered over the
widget longer than some timeout ( see Prima::Application::hintPause ),
then a label appears with the hint text, until the pointer is drawn
away. The hint behavior is governed by Prima::Application, but a
widget can do two additional things about hint: it can enable and
disable it by calling "::showHint" property, and it can inherit the
owner’s "::hint" and "::showHint" properties using "::ownerHint" and
"::ownerShowHint" properties. If, for example, "::ownerHint" is set to
1, then "::hint" value is automatically copied from the widget’s owner,
when it changes. If, however, the widget’s "::hint" or "::showHint" are
explicitly set, the owner link breaks automatically by setting
"::ownerHint" or "::ownerShowHint" to 0.
The widget can also operate the "::hintVisible" property, that shows or
hides the hint label immediately, if the mouse pointer is inside the
widget’s boundaries.
Menu objects
The default functionality of Prima::Widget coexists with two kinds of
the Prima::AbstractMenu descendants - Prima::AccelTable and
Prima::Popup ( Prima::Window is also equipped with Prima::Menu
reference). The "::items" property of these objects are accessible
through "::accelItems" and "::popupItems", whereas the objects
themselves - through "::accelTable" and "::popup", correspondingly. As
mentioned in "User input", these objects hook the user keyboard input
and call the programmer-defined callback subroutine if the key stroke
equals to one of their table values. As for "::accelTable", its
function ends here. "::popup" provides access to a context pop-up menu,
which can be invoked by either right-clicking or pressing a system-
dependent key combination. As a little customization, the
"::popupColorIndex" and "::popupFont" properties are introduced. (
"::popupColorIndex" is multiplexed to "::popupColor",
"::popupHiliteColor", "::popupHiliteBackColor", etc etc properties
exactly like the "::colorIndex" property ).
The font and color of a menu object might not always be writable. The
underlying system capabilities in this area range from total inability
for a program to manage the menu fonts and colors in Win32, to a sport
in interactive changing menu fonts and colors in OS/2.
The Prima::Window class provides equivalent methods for the menu bar,
introducing "::menu", "::menuItems", "::menuColorIndex" ( with
multiplexing ) and "::menuFont" properties.
User-specified resources
It is considered a good idea to incorporate the user preferences into
the toolkit look-and-feel. Prima::Widget relies to the system-specific
code that tries to map these preferences as close as possible to the
toolkit paradigm.
Unix version employs XRDB ( X resource database ), which is the natural
way for the user to tell the preferences with fine granularity. Win32
and OS/2 read the setting that the user has to set interactively, using
system tools. Nevertheless, the toolkit can not emulate all user
settings that are available on the supported platforms; it rather takes
a ’least common denominator’, which is colors and fonts.
"fetch_resource()" method is capable of returning any of such settings,
provided it’s format is font, color or a string. The method is rarely
called directly.
The appealing idea of making every widget property adjustable via the
user-specified resources is not implemented in full. It can be
accomplished up to a certain degree using "fetch_resource()" existing
functionality, but it is believed that calling up the method for the
every property for the every widget created is prohibitively expensive.
API
Properties
accelItems [ ITEM_LIST ]
Manages items of a Prima::AccelTable object associated with a
widget. The ITEM_LIST format is same as
"Prima::AbstractMenu::items" and is described in Prima::Menu.
See also: "accelTable"
accelTable OBJECT
Manages a Prima::AccelTable object associated with a widget. The
sole purpose of the accelTable object is to provide convenience
mapping of key combinations to anonymous subroutines. Instead of
writing an interface specifically for Prima::Widget, the existing
interface of Prima::AbstractMenu was taken.
The accelTable object can be destroyed safely; its cancellation can
be done either via "accelTable(undef)" or "destroy()" call.
Default value: undef
See also: "accelItems"
autoEnableChildren BOOLEAN
If TRUE, all immediate children widgets maintain the same "enabled"
state as the widget. This property is useful for the group-like
widgets ( ComboBox, SpinEdit etc ), that employ their children for
visual representation.
Default value: 0
backColor COLOR
In widget paint state, reflects background color in the graphic
context. In widget normal state, manages the basic background
color. If changed, initiates "ColorChanged" notification and
repaints the widget.
See also: "color", "colorIndex", "ColorChanged"
bottom INTEGER
Maintains the lower boundary of a widget. If changed, does not
affect the widget height; but does so, if called in "set()"
together with "::top".
See also: "left", "right", "top", "origin", "rect", "growMode",
"Move"
briefKeys BOOLEAN
If 1, contracts the repetitive key press events into one
notification, increasing REPEAT parameter of "KeyDown" callbacks.
If 0, REPEAT parameter is always 1.
Default value: 1
See also: "KeyDown"
buffered BOOLEAN
If 1, a widget "Paint" callback draws not on the screen, but on the
off-screen memory instead. The memory content is copied to the
screen then. Used when complex drawing methods are used, or if
output smoothness is desired.
This behavior can not be always granted, however. If there is not
enough memory, then widget draws in the usual manner.
Default value: 0
See also: "Paint"
capture BOOLEAN, CLIP_OBJECT = undef
Manipulates capturing of the mouse events. If 1, the mouse events
are not passed to the widget the mouse pointer is over, but are
redirected to the caller widget. The call for capture might not be
always granted due the race conditions between programs.
If CLIP_OBJECT widget is defined in set-mode call, the pointer
movements are confined to CLIP_OBJECT inferior.
See also: "MouseDown", "MouseUp", "MouseMove", "MouseWheel",
"MouseClick".
centered BOOLEAN
A write-only property. Once set, widget is centered by X and Y axis
relative to its owner.
See also: "x_centered", "y_centered", "growMode", "origin", "Move".
clipOwner BOOLEAN
If 1, a widget is clipped by its owner boundaries. It is the
default and expected behavior. If clipOwner is 0, a widget behaves
differently: it does not clipped by the owner, it is not moved
together with the parent, the origin offset is calculated not from
the owner’s coordinates but from the screen, and mouse events in a
widget do not transgress to the top-level window decorations. In
short, it itself becomes a top-level window, that, contrary to the
one created from Prima::Window class, does not have any
interference with system-dependent window stacking and positioning
( and any other ) policy, and is not ornamented by the window
manager decorations.
Default value: 1
See "Parent-child relationship"
See also: "Prima::Object" owner section, "parentHandle"
color COLOR
In widget paint state, reflects foreground color in the graphic
context. In widget normal state, manages the basic foreground
color. If changed, initiates "ColorChanged" notification and
repaints the widget.
See also: "backColor", "colorIndex", "ColorChanged"
colorIndex INDEX, COLOR
Manages the basic color properties indirectly, by accessing via
"ci::XXX" constant. Is a complete alias for "::color",
"::backColor", "::hiliteColor", "::hiliteBackColor",
"::disabledColor", "::disabledBackColor", "::light3DColor", and
"::dark3DColor" properties. The "ci::XXX" constants are:
ci::NormalText or ci::Fore
ci::Normal or ci::Back
ci::HiliteText
ci::Hilite
ci::DisabledText
ci::Disabled
ci::Light3DColor
ci::Dark3DColor
The non-RGB "cl::" constants, specific to the Prima::Widget color
usage are identical to their "ci::" counterparts:
cl::NormalText or cl::Fore
cl::Normal or cl::Back
cl::HiliteText
cl::Hilite
cl::DisabledText
cl::Disabled
cl::Light3DColor
cl::Dark3DColor
See also: "color", "backColor", "ColorChanged"
current BOOLEAN
If 1, a widget (or one of its children) is marked as the one to be
focused ( or selected) when the owner widget receives "select()"
call. Within children widgets, only one or none at all can be
marked as a current.
See also: "currentWidget", "selectable", "selected",
"selectedWidget", "focused"
currentWidget OBJECT
Points to a children widget, that is to be focused ( or selected)
when the owner widget receives "select()" call.
See also: "current", "selectable", "selected", "selectedWidget",
"focused"
cursorPos X_OFFSET Y_OFFSET
Specifies the lower left corner of the cursor
See also: "cursorSize", "cursorVisible"
cursorSize WIDTH HEIGHT
Specifies width and height of the cursor
See also: "cursorPos", "cursorVisible"
cursorVisible BOOLEAN
Specifies cursor visibility flag. Default value is 0.
See also: "cursorSize", "cursorPos"
dark3DColor COLOR
The color used to draw dark shades.
See also: "light3DColor", "colorIndex", "ColorChanged"
designScale X_SCALE Y_SCALE
The width and height of a font, that was used when a widget (
usually a dialog or a grouping widget ) was designed.
See also: "scaleChildren", "width", "height", "size", "font"
disabledBackColor COLOR
The color used to substitute "::backColor" when a widget is in its
disabled state.
See also: "disabledColor", "colorIndex", "ColorChanged"
disabledColor COLOR
The color used to substitute "::color" when a widget is in its
disabled state.
See also: "disabledBackColor", "colorIndex", "ColorChanged"
enabled BOOLEAN
Specifies if a widget can accept focus, keyboard and mouse events.
Default value is 1, however, being ’enabled’ does not automatically
allow the widget become focused. Only the reverse is true - if
enabled is 0, focusing can never happen.
See also: "responsive", "visible", "Enable", "Disable"
font %FONT
Manages font context. Same syntax as in Prima::Drawable. If
changed, initiates "FontChanged" notification and repaints the
widget.
See also: "designScale", "FontChanged", "ColorChanged"
geometry INTEGER
Selects one of the available geometry managers. The corresponding
integer constants are:
gt::GrowMode, gt::Default - the default grow-mode algorithm
gt::Pack - Tk packer
gt::Place - Tk placer
See "growMode", Prima::Widget::pack, Prima::Widget::place.
growMode MODE
Specifies widget behavior, when its owner is resized or moved.
MODE can be 0 ( default ) or a combination of the following
constants:
Basic constants
gm::GrowLoX widget's left side is kept in constant
distance from owner's right side
gm::GrowLoY widget's bottom side is kept in constant
distance from owner's top side
gm::GrowHiX widget's right side is kept in constant
distance from owner's right side
gm::GrowHiY widget's top side is kept in constant
distance from owner's top side
gm::XCenter widget is kept in center on its owner's
horizontal axis
gm::YCenter widget is kept in center on its owner's
vertical axis
gm::DontCare widgets origin is maintained constant relative
to the screen
Derived or aliased constants
gm::GrowAll gm::GrowLoX|gm::GrowLoY|gm::GrowHiX|gm::GrowHiY
gm::Center gm::XCenter|gm::YCenter
gm::Client gm::GrowHiX|gm::GrowHiY
gm::Right gm::GrowLoX|gm::GrowHiY
gm::Left gm::GrowHiY
gm::Floor gm::GrowHiX
See also: "Move", "origin"
firstClick BOOLEAN
If 0, a widget bypasses first mouse click on it, if the top-level
window it belongs to was not activated, so selecting such a widget
it takes two mouse clicks.
Default value is 1
See also: "MouseDown", "selectable", "selected", "focused",
"selectingButtons"
focused BOOLEAN
Specifies whether a widget possesses the input focus or not.
Disregards "::selectable" property on set-call.
See also: "selectable", "selected", "selectedWidget", "KeyDown"
geomWidth, geomHeight, geomSize
Three properties that select geometry request size. Writing and
reading to "::geomWidth" and "::geomHeight" is equivalent to
"::geomSize". The properies are run-time only, and behave
differently under different circumstances:
· As the properties are run-time only, they can not be set in the
profile, and their initial value is fetched from "::size"
property. Thus, setting the explicit size is aditionally sets
the advised size in case the widget is to be used with the Tk
geometry managers.
· Setting the properties under the "gt::GrowMode" geometry
manager also sets the corresponding "::width", "::height", or
"::size". When the properties are read, though, the real size
properties are not read; the values are kept separately.
· Setting the properties under Tk geometry managers cause widgets
size and position changed according to the geometry manager
policy.
height
Maintains the height of a widget.
See also: "width", "growMode", "Move", "Size", "get_virtual_size",
"sizeMax", "sizeMin"
helpContext STRING
A string that binds a widget, a logical part it plays with the
application and an interactive help topic. STRING format is defined
as POD link ( see perlpod ) - "manpage/section", where ’manpage’ is
the file with POD content and ’section’ is the topic inside the
manpage.
See also: "help"
hiliteBackColor COLOR
The color used to draw alternate background areas with high
contrast.
See also: "hiliteColor", "colorIndex", "ColorChanged"
hiliteColor COLOR
The color used to draw alternate foreground areas with high
contrast.
See also: "hiliteBackColor", "colorIndex", "ColorChanged"
hint TEXT
A text, shown under mouse pointer if it is hovered over a widget
longer than "Prima::Application::hintPause" timeout. The text shows
only if the "::showHint" is 1.
See also: "hintVisible", "showHint", "ownerHint", "ownerShowHint"
hintVisible BOOLEAN
If called in get-form, returns whether the hint label is shown or
not. If in set-form, immediately turns on or off the hint label,
disregarding the timeouts. It does regard the mouse pointer
location, however, and does not turn on the hint label if the
pointer is away.
See also: "hint", "showHint", "ownerHint", "ownerShowHint"
left INTEGER
Maintains the left boundary of a widget. If changed, does not
affect the widget width; but does so, if called in "set()" together
with "::right".
See also: "bottom", "right", "top", "origin", "rect", "growMode",
"Move"
light3DColor COLOR
The color used to draw light shades.
See also: "dark3DColor", "colorIndex", "ColorChanged"
ownerBackColor BOOLEAN
If 1, the background color is synchronized with the owner’s.
Automatically set to 0 if "::backColor" property is explicitly set.
See also: "ownerColor", "backColor", "colorIndex"
ownerColor BOOLEAN
If 1, the foreground color is synchronized with the owner’s.
Automatically set to 0 if "::color" property is explicitly set.
See also: "ownerBackColor", "color", "colorIndex"
ownerFont BOOLEAN
If 1, the font is synchronized with the owner’s. Automatically set
to 0 if "::font" property is explicitly set.
See also: "font", "FontChanged"
ownerHint BOOLEAN
If 1, the hint is synchronized with the owner’s. Automatically set
to 0 if "::hint" property is explicitly set.
See also: "hint", "showHint", "hintVisible", "ownerShowHint"
ownerShowHint BOOLEAN
If 1, the show hint flag is synchronized with the owner’s.
Automatically set to 0 if "::showHint" property is explicitly set.
See also: "hint", "showHint", "hintVisible", "ownerHint"
ownerPalette BOOLEAN
If 1, the palette array is synchronized with the owner’s.
Automatically set to 0 if "::palette" property is explicitly set.
See also: "palette"
origin X Y
Maintains the left and bottom boundaries of a widget relative to
its owner ( or to the screen if "::clipOwner" is set to 0 ).
See also: "bottom", "right", "top", "left", "rect", "growMode",
"Move"
packInfo %OPTIONS
See Prima::Widget::pack
palette [ @PALETTE ]
Specifies array of colors, that are desired to be present into the
system palette, as close to the PALETTE as possible. This property
works only if the graphic device allows palette operations. See
"palette" in Prima::Drawable.
See also: "ownerPalette"
parentHandle SYSTEM_WINDOW
If SYSTEM_WINDOW is a valid system-dependent window handle, then a
widget becomes the child of the window specified, given the
widget’s "::clipOwner" is 0. The parent window can belong to
another application.
Default value is undef.
See also: "clipOwner"
placeInfo %OPTIONS
See Prima::Widget::place
pointer cr::XXX or ICON
Specifies the pointer icon; discerns between "cr::XXX" constants
and an icon. If an icon contains a hash variable "__pointerHotSpot"
with an array of two integers, these integers will be treated as
the pointer hot spot. In get-mode call, this variable is
automatically assigned to an icon, if the result is an icon object.
See also: "pointerHotSpot", "pointerIcon", "pointerType"
pointerHotSpot X_OFFSET Y_OFFSET
Specifies the hot spot coordinates of a pointer icon, associated
with a widget.
See also: "pointer", "pointerIcon", "pointerType"
pointerIcon ICON
Specifies the pointer icon, associated with a widget.
See also: "pointerHotSpot", "pointer", "pointerType"
pointerPos X_OFFSET Y_OFFSET
Specifies the mouse pointer coordinates relative to widget’s
coordinates.
See also: "get_mouse_state", "screen_to_client", "client_to_screen"
pointerType TYPE
Specifies the type of the pointer, associated with the widget.
TYPE can accept one constant of "cr::XXX" set:
cr::Default same pointer type as owner's
cr::Arrow arrow pointer
cr::Text text entry cursor-like pointer
cr::Wait hourglass
cr::Size general size action pointer
cr::Move general move action pointer
cr::SizeWest, cr::SizeW right-move action pointer
cr::SizeEast, cr::SizeE left-move action pointer
cr::SizeWE general horizontal-move action pointer
cr::SizeNorth, cr::SizeN up-move action pointer
cr::SizeSouth, cr::SizeS down-move action pointer
cr::SizeNS general vertical-move action pointer
cr::SizeNW up-right move action pointer
cr::SizeSE down-left move action pointer
cr::SizeNE up-left move action pointer
cr::SizeSW down-right move action pointer
cr::Invalid invalid action pointer
cr::User user-defined icon
All constants except "cr::User" and "cr::Default" present a system-
defined pointers, their icons and hot spot offsets. "cr::User" is a
sign that an icon object was specified explicitly via
"::pointerIcon" property. "cr::Default" is a way to tell that a
widget inherits its owner pointer type, no matter is it a system-
defined pointer or a custom icon.
See also: "pointerHotSpot", "pointerIcon", "pointer"
popup OBJECT
Manages a Prima::Popup object associated with a widget. The
purpose of the popup object is to show a context menu when the user
right-clicks or selects the corresponding keyboard combination.
Prima::Widget can host many children objects, Prima::Popup as well.
But only the one that is set in "::popup" property will be
activated automatically.
The popup object can be destroyed safely; its cancellation can be
done either via "popup(undef)" or "destroy()" call.
See also: "Prima::Menu", "Popup", "Menu", "popupItems",
"popupColorIndex", "popupFont"
popupColorIndex INDEX, COLOR
Maintains eight color properties of a pop-up context menu,
associated with a widget. INDEX must be one of "ci::XXX" constants
( see "::colorIndex" property ).
See also: "popupItems", "popupFont", "popup"
popupColor COLOR
Basic foreground in a popup context menu color.
See also: "popupItems", "popupColorIndex", "popupFont", "popup"
popupBackColor COLOR
Basic background in a popup context menu color.
See also: "popupItems", "popupColorIndex", "popupFont", "popup"
popupDark3DColor COLOR
Color for drawing dark shadings in a popup context menu.
See also: "popupItems", "popupColorIndex", "popupFont", "popup"
popupDisabledColor COLOR
Foreground color for disabled items in a popup context menu.
See also: "popupItems", "popupColorIndex", "popupFont", "popup"
popupDisabledBackColor COLOR
Background color for disabled items in a popup context menu.
See also: "popupItems", "popupColorIndex", "popupFont", "popup"
popupFont %FONT
Maintains the font of a pop-up context menu, associated with a
widget.
See also: "popupItems", "popupColorIndex", "popup"
popupHiliteColor COLOR
Foreground color for selected items in a popup context menu.
See also: "popupItems", "popupColorIndex", "popupFont", "popup"
popupHiliteBackColor COLOR
Background color for selected items in a popup context menu.
See also: "popupItems", "popupColorIndex", "popupFont", "popup"
popupItems [ ITEM_LIST ]
Manages items of a Prima::Popup object associated with a widget.
The ITEM_LIST format is same as "Prima::AbstractMenu::items" and is
described in Prima::Menu.
See also: "popup", "popupColorIndex", "popupFont"
popupLight3DColor COLOR
Color for drawing light shadings in a popup context menu.
See also: "popupItems", "popupColorIndex", "popupFont", "popup"
rect X_LEFT_OFFSET Y_BOTTOM_OFFSET X_RIGHT_OFFSET Y_TOP_OFFSET
Maintains the rectangular boundaries of a widget relative to its
owner ( or to the screen if "::clipOwner" is set to 0 ).
See also: "bottom", "right", "top", "left", "origin", "width",
"height", "size" "growMode", "Move", "Size", "get_virtual_size",
"sizeMax", "sizeMin"
right INTEGER
Maintains the right boundary of a widget. If changed, does not
affect the widget width; but does so, if called in "set()" together
with "::left".
See also: "left", "bottom", "top", "origin", "rect", "growMode",
"Move"
scaleChildren BOOLEAN
If a widget has "::scaleChildren" set to 1, then the newly-created
children widgets inserted in it will be scaled corresponding to the
owner’s "::designScale", given that widget’s "::designScale" is not
"undef" and the owner’s is not [0,0].
Default is 1.
See also: "designScale"
selectable BOOLEAN
If 1, a widget can be granted focus implicitly, or by means of the
user actions. "select()" regards this property, and does not focus
a widget that has "::selectable" set to 0.
Default value is 0
See also: "current", "currentWidget", "selected", "selectedWidget",
"focused"
selected BOOLEAN
If called in get-mode, returns whether a widget or one of its
(grand-) children is focused. If in set-mode, either simply turns
the system with no-focus state ( if 0 ), or sends input focus to
itself or one of the widgets tracked down by "::currentWidget"
chain.
See also: "current", "currentWidget", "selectable",
"selectedWidget", "focused"
selectedWidget OBJECT
Points to a child widget, that has property "::selected" set to 1.
See also: "current", "currentWidget", "selectable", "selected",
"focused"
selectingButtons FLAGS
FLAGS is a combination of "mb::XXX" ( mouse button ) flags. If a
widget receives a click with a mouse button, that has the
corresponding bit set in "::selectingButtons", then "select()" is
called.
See also: "MouseDown", "firstClick", "selectable", "selected",
"focused"
shape IMAGE
Maintains the non-rectangular shape of a widget. IMAGE is
monochrome Prima::Image, with 0 bits treated as transparent pixels,
and 1 bits as opaque pixels.
Successive only if "sv::ShapeExtension" value is true.
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. The "::hint" property
must contain non-empty string as well, if the hint label must be
shown.
Default value is 1.
See also: "hint", "ownerShowHint", "hintVisible", "ownerHint"
size WIDTH HEIGHT
Maintains the width and height of a widget.
See also: "width", "height" "growMode", "Move", "Size",
"get_virtual_size", "sizeMax", "sizeMin"
sizeMax WIDTH HEIGHT
Specifies the maximal size for a widget that it is allowed to
accept.
See also: "width", "height", "size" "growMode", "Move", "Size",
"get_virtual_size", "sizeMin"
sizeMin WIDTH HEIGHT
Specifies the minimal size for a widget that it is allowed to
accept.
See also: "width", "height", "size" "growMode", "Move", "Size",
"get_virtual_size", "sizeMax"
syncPaint BOOLEAN
If 0, the "Paint" request notifications are stacked until the event
loop is called. If 1, every time the widget surface gets
invalidated, the "Paint" notification is called.
Default value is 0.
See also: "invalidate_rect", "repaint", "validate_rect", "Paint"
tabOrder INTEGER
Maintains the order in which tab- and shift-tab- key navigation
algorithms select the sibling widgets. INTEGER is unique among the
sibling widgets. In set mode, if INTEGER value is already taken,
the occupier is assigned another unique value, but without
destruction of a queue - widgets with ::tabOrder greater than of
the widget, receive their new values too. Special value -1 is
accepted as ’the end of list’ indicator; the negative value is
never returned.
See also: "tabStop", "next_tab", "selectable", "selected",
"focused"
tabStop BOOLEAN
Specifies whether a widget is interested in tab- and shift-tab- key
navigation or not.
Default value is 1.
See also: "tabOrder", "next_tab", "selectable", "selected",
"focused"
text TEXT
A text string for generic purpose. Many Prima::Widget descendants
use this property heavily - buttons, labels, input lines etc, but
Prima::Widget itself does not.
top INTEGER
Maintains the upper boundary of a widget. If changed, does not
affect the widget height; but does so, if called in "set()"
together with "::bottom".
See also: "left", "right", "bottom", "origin", "rect", "growMode",
"Move"
transparent BOOLEAN
Specifies whether the background of a widget before it starts
painting is of any importance. If 1, a widget can gain certain
transparency look if it does not clear the background during
"Paint" event.
Default value is 0
See also: "Paint", "buffered".
visible BOOLEAN
Specifies whether a widget is visible or not. See "Visibility".
See also: "Show", "Hide", "showing", "exposed"
widgetClass CLASS
Maintains the integer value, designating the color class that is
defined by the system and is associated with Prima::Widget eight
basic color properties. CLASS can be one of "wc::XXX" constants:
wc::Undef
wc::Button
wc::CheckBox
wc::Combo
wc::Dialog
wc::Edit
wc::InputLine
wc::Label
wc::ListBox
wc::Menu
wc::Popup
wc::Radio
wc::ScrollBar
wc::Slider
wc::Widget or wc::Custom
wc::Window
wc::Application
These constants are not associated with the toolkit classes; any
class can use any of these constants in "::widgetClass".
See also: "map_color", "colorIndex"
widgets @WIDGETS
In get-mode, returns list of immediate children widgets (identical
to "get_widgets"). In set-mode accepts set of widget profiles, as
"insert" does, as a list or an array. This way it is possible to
create widget hierarchy in a single call.
width WIDTH
Maintains the width of a widget.
See also: "height" "growMode", "Move", "Size", "get_virtual_size",
"sizeMax", "sizeMin"
x_centered BOOLEAN
A write-only property. Once set, widget is centered by the
horizontal axis relative to its owner.
See also: "centered", "y_centered", "growMode", "origin", "Move".
y_centered BOOLEAN
A write-only property. Once set, widget is centered by the vertical
axis relative to its owner.
See also: "x_centered", "centered", "growMode", "origin", "Move".
Methods
bring_to_front
Sends a widget on top of all other siblings widgets
See also: "insert_behind", "send_to_back", "ZOrderChanged"
,"first", "next", "prev", "last"
can_close
Sends "Close" message, and returns its boolean exit state.
See also: "Close", "close"
client_to_screen @OFFSETS
Maps array of X and Y integer offsets from widget to screen
coordinates. Returns the mapped OFFSETS.
See also: "screen_to_client", "clipOwner"
close
Calls "can_close()", and if successful, destroys a widget. Returns
the "can_close()" result.
See also: "can_close", "Close"
defocus
Alias for focused(0) call
See also: "focus", "focused", "Enter", "Leave"
deselect
Alias for selected(0) call
See also: "select", "selected", "Enter", "Leave"
exposed
Returns a boolean value, indicating whether a widget is at least
partly visible on the screen. Never returns 1 if a widget has
"::visible" set to 0.
See also: "visible", "showing", "Show", "Hide"
fetch_resource CLASS_NAME, NAME, CLASS_RESOURCE, RESOURCE, OWNER,
RESOURCE_TYPE = fr::String
Returns a system-defined scalar of resource, defined by the widget
hierarchy, its class, name and owner. RESOURCE_TYPE can be one of
type qualificators:
fr::Color - color resource
fr::Font - font resource
fs::String - text string resource
Such a number of the parameters is used because the method can be
called before a widget is created. CLASS_NAME is widget class
string, NAME is widget name. CLASS_RESOURCE is class of resource,
and RESOURCE is the resource name.
For example, resources ’color’ and ’disabledColor’ belong to the
resource class ’Foreground’.
first
Returns the first ( from bottom ) sibling widget in Z-order.
See also: "last", "next", "prev"
focus
Alias for focused(1) call
See also: "defocus", "focused", "Enter", "Leave"
hide
Sets widget "::visible" to 0.
See also: "hide", "visible", "Show", "Hide", "showing", "exposed"
hide_cursor
Hides the cursor. As many times "hide_cursor()" was called, as many
time its counterpart "show_cursor()" must be called to reach the
cursor’s initial state.
See also: "show_cursor", "cursorVisible"
help
Starts an interactive help viewer opened on "::helpContext" string
value.
The string value is combined from the widget’s owner
"::helpContext" strings if the latter is empty or begins with a
slash. A special meaning is assigned to an empty string " " - the
help() call fails when such value is found to be the section
component. This feature can be useful when a window or a dialog
presents a standalone functionality in a separate module, and the
documentation is related more to the module than to an embedding
program. In such case, the grouping widget holds "::helpContext" as
a pod manpage name with a trailing slash, and its children widgets
are assigned "::helpContext" to the topics without the manpage but
the leading slash instead. If the grouping widget has an empty
string " " as "::helpContext" then the help is forced to be
unavailable for all the children widgets.
See also: "helpContext"
insert CLASS, %PROFILE [[ CLASS, %PROFILE], ... ]
Creates one or more widgets with "owner" property set to the caller
widget, and returns the list of references to the newly created
widgets.
Has two calling formats:
Single widget
$parent-> insert( 'Child::Class',
name => 'child',
....
);
Multiple widgets
$parent-> insert(
[
'Child::Class1',
name => 'child1',
....
],
[
'Child::Class2',
name => 'child2',
....
],
);
insert_behind OBJECT
Sends a widget behind the OBJECT on Z-axis, given that the OBJECT
is a sibling to the widget.
See also: "bring_to_front", "send_to_back", "ZOrderChanged"
,"first", "next", "prev", "last"
invalidate_rect X_LEFT_OFFSET Y_BOTTOM_OFFSET X_RIGHT_OFFSET
Y_TOP_OFFSET
Marks the rectangular area of a widget as ’invalid’, so re-painting
of the area happens. See "Graphic content".
See also: "validate_rect", "get_invalid_rect", "repaint", "Paint",
"syncPaint", "update_view"
key_down CODE, KEY = kb::NoKey, MOD = 0, REPEAT = 1, POST = 0
The method sends or posts ( POST flag ) simulated "KeyDown" event
to the system. CODE, KEY, MOD and REPEAT are the parameters to be
passed to the notification callbacks.
See also: "key_up", "key_event", "KeyDown"
key_event COMMAND, CODE, KEY = kb::NoKey, MOD = 0, REPEAT = 1, POST = 0
The method sends or posts ( POST flag ) simulated keyboard event to
the system. CODE, KEY, MOD and REPEAT are the parameters to be
passed to an eventual "KeyDown" or "KeyUp" notifications. COMMAND
is allowed to be either "cm::KeyDown" or "cm::KeyUp".
See also: "key_down", "key_up", "KeyDown", "KeyUp"
key_up CODE, KEY = kb::NoKey, MOD = 0, POST = 0
The method sends or posts ( POST flag ) simulated "KeyUp" event to
the system. CODE, KEY and MOD are the parameters to be passed to
the notification callbacks.
See also: "key_down", "key_event", "KeyUp"
last
Returns the last ( the topmost ) sibling widget in Z-order.
See also: "first", "next", "prev"
lock
Turns off the ability of a widget to re-paint itself. As many
times "lock()" was called, as may times its counterpart, "unlock()"
must be called to enable re-painting again. Returns a boolean
success flag.
See also: "unlock", "repaint", "Paint", "get_locked"
map_color COLOR
Transforms "cl::XXX" and "ci::XXX" combinations into RGB color
representation and returns the result. If COLOR is already in RGB
format, no changes are made.
See also: "colorIndex"
mouse_click BUTTON = mb::Left, MOD = 0, X = 0, Y = 0, DBL_CLICK = 0,
POST = 0
The method sends or posts ( POST flag ) simulated "MouseClick"
event to the system. BUTTON, MOD, X, Y, and DBL_CLICK are the
parameters to be passed to the notification callbacks.
See also: "MouseDown", "MouseUp", "MouseWheel", "MouseMove",
"MouseEnter", "MouseLeave"
mouse_down BUTTON = mb::Left, MOD = 0, X = 0, Y = 0, POST = 0
The method sends or posts ( POST flag ) simulated "MouseDown" event
to the system. BUTTON, MOD, X, and Y are the parameters to be
passed to the notification callbacks.
See also: "MouseUp", "MouseWheel", "MouseClick", "MouseMove",
"MouseEnter", "MouseLeave"
mouse_enter MOD = 0, X = 0, Y = 0, POST = 0
The method sends or posts ( POST flag ) simulated "MouseEnter"
event to the system. MOD, X, and Y are the parameters to be passed
to the notification callbacks.
See also: "MouseDown", "MouseUp", "MouseWheel", "MouseClick",
"MouseMove", "MouseLeave"
mouse_event COMMAND = cm::MouseDown, BUTTON = mb::Left, MOD = 0, X = 0,
Y = 0, DBL_CLICK = 0, POST = 0
The method sends or posts ( POST flag ) simulated mouse event to
the system. BUTTON, MOD, X, Y and DBL_CLICK are the parameters to
be passed to an eventual mouse notifications. COMMAND is allowed
to be one of "cm::MouseDown", "cm::MouseUp", "cm::MouseWheel",
"cm::MouseClick", "cm::MouseMove", "cm::MouseEnter",
"cm::MouseLeave" constants.
See also: "mouse_down", "mouse_up", "mouse_wheel", "mouse_click",
"mouse_move", "mouse_enter", "mouse_leave", "MouseDown", "MouseUp",
"MouseWheel", "MouseClick", "MouseMove", "MouseEnter", "MouseLeave"
mouse_leave
The method sends or posts ( POST flag ) simulated "MouseLeave"
event to the system.
See also: "MouseDown", "MouseUp", "MouseWheel", "MouseClick",
"MouseMove", "MouseEnter", "MouseLeave"
mouse_move MOD = 0, X = 0, Y = 0, POST = 0
The method sends or posts ( POST flag ) simulated "MouseMove" event
to the system. MOD, X, and Y are the parameters to be passed to the
notification callbacks.
See also: "MouseDown", "MouseUp", "MouseWheel", "MouseClick",
"MouseEnter", "MouseLeave"
mouse_up BUTTON = mb::Left, MOD = 0, X = 0, Y = 0, POST = 0
The method sends or posts ( POST flag ) simulated "MouseUp" event
to the system. BUTTON, MOD, X, and Y are the parameters to be
passed to the notification callbacks.
See also: "MouseDown", "MouseWheel", "MouseClick", "MouseMove",
"MouseEnter", "MouseLeave"
mouse_wheel MOD = 0, X = 0, Y = 0, Z = 0, POST = 0
The method sends or posts ( POST flag ) simulated "MouseUp" event
to the system. MOD, X, Y and Z are the parameters to be passed to
the notification callbacks.
See also: "MouseDown", "MouseUp", "MouseClick", "MouseMove",
"MouseEnter", "MouseLeave"
next
Returns the neighbor sibling widget, next ( above ) in Z-order. If
none found, undef is returned.
See also: "first", "last", "prev"
next_tab FORWARD = 1
Returns the next widget in the sorted by "::tabOrder" list of
sibling widgets. FORWARD is a boolean lookup direction flag. If
none found, the first ( or the last, depending on FORWARD flag )
widget is returned. Only widgets with "::tabStop" set to 1
participate.
Also used by the internal keyboard navigation code.
See also: "next_positional", "tabOrder", "tabStop", "selectable"
next_positional DELTA_X DELTA_Y
Returns a sibling, (grand-)child of a sibling or (grand-)child
widget, that matched best the direction specified by DELTA_X and
DELTA_Y. At one time, only one of these parameters can be zero;
another parameter must be either 1 or -1.
Also used by the internal keyboard navigation code.
See also: "next_tab", "origin"
pack, packForget, packSlaves
See Prima::Widget::pack
place, placeForget, placeSlaves
See Prima::Widget::place
prev
Returns the neighbor sibling widget, previous ( below ) in Z-order.
If none found, undef is returned.
See also: "first", "last", "next"
repaint
Marks the whole widget area as ’invalid’, so re-painting of the
area happens. See "Graphic content".
See also: "validate_rect", "get_invalid_rect", "invalidate_rect",
"Paint", "update_view", "syncPaint"
rect_bevel $CANVAS, @RECT, %OPTIONS
Draws a rectangular area, similar to produced by "rect3d" over
@RECT that is 4-integer coordinates of the area, but implicitly
using widget’s "light3DColor" and "dark3DColor" properties’ values.
The following options are recognized:
fill COLOR
If set, the area is filled with COLOR, ortherwise is left
intact.
width INTEGER
Width of the border in pixels
concave BOOLEAN
If 1, draw a concave area, bulged otherwise
responsive
Returns a boolean flag, indicating whether a widget and its owners
have all "::enabled" 1 or not. Useful for fast check if a widget
should respond to the user actions.
See also: "enabled"
screen_to_client @OFFSETS
Maps array of X and Y integer offsets from screen to widget
coordinates. Returns the mapped OFFSETS.
See also: "client_to_screen"
scroll DELTA_X DELTA_Y %OPTIONS
Scrolls the graphic context area by DELTA_X and DELTA_Y pixels.
OPTIONS is hash, that contains optional parameters to the scrolling
procedure:
clipRect [X1, Y1, X2, Y2]
The clipping area is confined by X1, Y1, X2, Y2 rectangular
area. If not specified, the clipping area covers the whole
widget. Only the bits, covered by clipRect are affected. Bits
scrolled from the outside of the rectangle to the inside are
painted; bits scrolled from the inside of the rectangle to the
outside are not painted.
confineRect [X1, Y1, X2, Y2]
The scrolling area is confined by X1, Y1, X2, Y2 rectangular
area. If not specified, the scrolling area covers the whole
widget.
withChildren BOOLEAN
If 1, the scrolling performs with the eventual children widgets
change their positions to DELTA_X and DELTA_Y as well.
Cannot be used inside paint state.
See also: "Paint", "get_invalid_rect"
select
Alias for selected(1) call
See also: "deselect", "selected", "Enter", "Leave"
send_to_back
Sends a widget at bottom of all other siblings widgets
See also: "insert_behind", "bring_to_front", "ZOrderChanged"
,"first", "next", "prev", "last"
show
Sets widget "::visible" to 1.
See also: "hide", "visible", "Show", "Hide", "showing", "exposed"
show_cursor
Shows the cursor. As many times "hide_cursor()" was called, as many
time its counterpart "show_cursor()" must be called to reach the
cursor’s initial state.
See also: "hide_cursor", "cursorVisible"
showing
Returns a boolean value, indicating whether the widget and its
owners have all "::visible" 1 or not.
unlock
Turns on the ability of a widget to re-paint itself. As many times
"lock()" was called, as may times its counterpart, "unlock()" must
be called to enable re-painting again. When last "unlock()" is
called, an implicit "repaint()" call is made. Returns a boolean
success flag.
See also: "lock", "repaint", "Paint", "get_locked"
update_view
If any parts of a widget were marked as ’invalid’ by either
"invalidate_rect()" or "repaint()" calls or the exposure caused by
window movements ( or any other), then "Paint" notification is
immediately called. If no parts are invalid, no action is
performed. If a widget has "::syncPaint" set to 1, "update_view()"
is always a no-operation call.
See also: "invalidate_rect", "get_invalid_rect", "repaint",
"Paint", "syncPaint", "update_view"
validate_rect X_LEFT_OFFSET Y_BOTTOM_OFFSET X_RIGHT_OFFSET Y_TOP_OFFSET
Reverses the effect of "invalidate_rect()", restoring the original,
’valid’ state of widget area covered by the rectangular area
passed. If a widget with previously invalid areas was wholly
validated by this method, no "Paint" notifications occur.
See also: "invalidate_rect", "get_invalid_rect", "repaint",
"Paint", "syncPaint", "update_view"
Get-methods
get_default_font
Returns the default font for a Prima::Widget class.
See also: "font"
get_default_popup_font
Returns the default font for a Prima::Popup class.
See also: "font"
get_invalid_rect
Returns the result of successive calls "invalidate_rect()",
"validate_rect()" and "repaint()", as a rectangular area ( four
integers ) that cover all invalid regions in a widget. If none
found, (0,0,0,0) is returned.
See also: "validate_rect", "invalidate_rect", "repaint", "Paint",
"syncPaint", "update_view"
get_handle
Returns a system handle for a widget
See also: "get_parent_handle"
get_locked
Returns 1 if a widget is in "lock()" - initiated repaint-blocked
state.
See also: "lock", "unlock"
get_mouse_state
Returns a combination of "mb::XXX" constants, reflecting the
currently pressed mouse buttons.
See also: "pointerPos", "get_shift_state"
get_parent
Returns the owner widget that clips the widget boundaries, or
application object if a widget is top-level.
See also: "clipOwner"
get_parent_handle
Returns a system handle for a parent of a widget, a window that
belongs to another program. Returns 0 if the widget’s owner and
parent are in the same application and process space.
See also: "get_handle", "clipOwner"
get_pointer_size
Returns two integers, width and height of a icon, that the system
accepts as valid for a pointer. If the icon is supplied that is
more or less than these values, it is truncated or padded with
transparency bits, but is not stretched. Can be called with class
syntax.
get_shift_state
Returns a combination of "km::XXX" constants, reflecting the
currently pressed keyboard modificator buttons.
See also: "get_shift_state"
get_virtual_size
Returns virtual width and height of a widget. See "Geometry",
Implicit size regulations.
See also: "width", "height", "size" "growMode", "Move", "Size",
"sizeMax", "sizeMin"
get_widgets
Returns list of children widgets.
Events
Change
Generic notification, used for Prima::Widget descendants;
Prima::Widget itself neither calls not uses the event. Designed to
be called when an arbitrary major state of a widget is changed.
Click
Generic notification, used for Prima::Widget descendants;
Prima::Widget itself neither calls not uses the event. Designed to
be called when an arbitrary major action for a widget is called.
Close
Triggered by "can_close()" and "close()" functions. If the event
flag is cleared during execution, these functions fail.
See also: "close", "can_close"
ColorChanged INDEX
Called when one of widget’s color properties is changed, either by
direct property change or by the system. INDEX is one of "ci::XXX"
constants.
See also: "colorIndex"
Disable
Triggered by a successive enabled(0) call
See also: "Enable", "enabled", "responsive"
DragDrop X Y
Design in progress. Supposed to be triggered when a drag-and-drop
session started by the widget. X and Y are mouse pointer
coordinates on the session start.
See also: "DragOver", "EndDrag"
DragOver X Y STATE
Design in progress. Supposed to be called when a mouse pointer is
passed over a widget during a drag-and-drop session. X and Y are
mouse pointer coordinates, identical to "MouseMove" X Y parameters.
STATE value is undefined.
See also: "DragDrop", "EndDrag"
Enable
Triggered by a successive enabled(1) call
See also: "Disable", "enabled", "responsive"
EndDrag X Y
Design in progress. Supposed to be called when a drag-and-drop
session is finished successfully over a widget. X and Y are mouse
pointer coordinates on the session end.
See also: "DragDrop", "DragOver"
Enter
Called when a widget receives the input focus.
See also: "Leave", "focused", "selected"
FontChanged
Called when a widget font is changed either by direct property
change or by the system.
See also: "font", "ColorChanged"
Hide
Triggered by a successive visible(0) call
See also: "Show", "visible", "showing", "exposed"
Hint SHOW_FLAG
Called when the hint label is about to show or hide, depending on
SHOW_FLAG. The hint show or hide action fails, if the event flag is
cleared during execution.
See also: "showHint", "ownerShowHint", "hintVisible", "ownerHint"
KeyDown CODE, KEY, MOD, REPEAT
Sent to the focused widget when the user presses a key. CODE
contains an eventual character code, KEY is one of "kb::XXX"
constants, MOD is a combination of the modificator keys pressed
when the event occurred ( "km::XXX" ). REPEAT is how many times the
key was pressed; usually it is 1. ( see "::briefKeys" ).
The valid "km::" constants are:
km::Shift
km::Ctrl
km::Alt
km::KeyPad
km::DeadKey
The valid "kb::" constants are grouped in several sets. Some codes
are aliased, like, "kb::PgDn" and "kb::PageDown".
Modificator keys
kb::ShiftL kb::ShiftR kb::CtrlL kb::CtrlR
kb::AltL kb::AltR kb::MetaL kb::MetaR
kb::SuperL kb::SuperR kb::HyperL kb::HyperR
kb::CapsLock kb::NumLock kb::ScrollLock kb::ShiftLock
Keys with character code defined
kb::Backspace kb::Tab kb::Linefeed kb::Enter
kb::Return kb::Escape kb::Esc kb::Space
Function keys
kb::F1 .. kb::F30
kb::L1 .. kb::L10
kb::R1 .. kb::R10
Other
kb::Clear kb::Pause kb::SysRq kb::SysReq
kb::Delete kb::Home kb::Left kb::Up
kb::Right kb::Down kb::PgUp kb::Prior
kb::PageUp kb::PgDn kb::Next kb::PageDown
kb::End kb::Begin kb::Select kb::Print
kb::PrintScr kb::Execute kb::Insert kb::Undo
kb::Redo kb::Menu kb::Find kb::Cancel
kb::Help kb::Break kb::BackTab
See also: "KeyUp", "briefKeys", "key_down", "help", "popup",
"tabOrder", "tabStop", "accelTable"
KeyUp CODE, KEY, MOD
Sent to the focused widget when the user releases a key. CODE
contains an eventual character code, KEY is one of "kb::XXX"
constants, MOD is a combination of the modificator keys pressed
when the event occurred ( "km::XXX" ).
See also: "KeyDown", "key_up"
Leave
Called when the input focus is removed from a widget
See also: "Enter", "focused", "selected"
Menu MENU VAR_NAME
Called before the user-navigated menu ( pop-up or pull-down ) is
about to show another level of submenu on the screen. MENU is
Prima::AbstractMenu descendant, that children to a widget, and
VAR_NAME is the name of the menu item that is about to be shown.
Used for making changes in the menu structures dynamically.
See also: "popupItems"
MouseClick BUTTON, MOD, X, Y, DOUBLE_CLICK
Called when a mouse click ( button is pressed, and then released
within system-defined interval of time ) is happened in the widget
area. BUTTON is one of "mb::XXX" constants, MOD is a combination of
"km::XXX" constants, reflecting pressed modificator keys during the
event, X and Y are the mouse pointer coordinates. DOUBLE_CLICK is a
boolean flag, set to 1 if it was a double click, 0 if a single.
"mb::XXX" constants are:
mb::b1 or mb::Left
mb::b2 or mb::Middle
mb::b3 or mb::Right
mb::b4
mb::b5
mb::b6
mb::b7
mb::b8
See also: "MouseDown", "MouseUp", "MouseWheel", "MouseMove",
"MouseEnter", "MouseLeave"
MouseDown BUTTON, MOD, X, Y
Occurs when the user presses mouse button on a widget. BUTTON is
one of "mb::XXX" constants, MOD is a combination of "km::XXX"
constants, reflecting the pressed modificator keys during the
event, X and Y are the mouse pointer coordinates.
See also: "MouseUp", "MouseClick", "MouseWheel", "MouseMove",
"MouseEnter", "MouseLeave"
MouseEnter MOD, X, Y
Occurs when the mouse pointer is entered the area occupied by a
widget ( without mouse button pressed ). MOD is a combination of
"km::XXX" constants, reflecting the pressed modificator keys during
the event, X and Y are the mouse pointer coordinates.
See also: "MouseDown", "MouseUp", "MouseClick", "MouseWheel",
"MouseMove", "MouseLeave"
MouseLeave
Occurs when the mouse pointer is driven off the area occupied by a
widget ( without mouse button pressed ).
See also: "MouseDown", "MouseUp", "MouseClick", "MouseWheel",
"MouseMove", "MouseEnter"
MouseMove MOD, X, Y
Occurs when the mouse pointer is transported over a widget. MOD is
a combination of "km::XXX" constants, reflecting the pressed
modificator keys during the event, X and Y are the mouse pointer
coordinates.
See also: "MouseDown", "MouseUp", "MouseClick", "MouseWheel",
"MouseEnter", "MouseLeave"
MouseUp BUTTON, MOD, X, Y
Occurs when the user depresses mouse button on a widget. BUTTON is
one of "mb::XXX" constants, MOD is a combination of "km::XXX"
constants, reflecting the pressed modificator keys during the
event, X and Y are the mouse pointer coordinates.
See also: "MouseDown", "MouseClick", "MouseWheel", "MouseMove",
"MouseEnter", "MouseLeave"
MouseWheel MOD, X, Y, Z
Occurs when the user rotates mouse wheel on a widget. MOD is a
combination of "km::XXX" constants, reflecting the pressed
modificator keys during the event, X and Y are the mouse pointer
coordinates. Z is the virtual coordinate of a wheel. Typical ( 2001
A.D. ) mouse produces Z 120-fold values.
See also: "MouseDown", "MouseUp", "MouseClick", "MouseMove",
"MouseEnter", "MouseLeave"
Move OLD_X, OLD_Y, NEW_X, NEW_Y
Triggered when widget changes its position relative to its parent,
either by Prima::Widget methods or by the user. OLD_X and OLD_Y
are the old coordinates of a widget, NEW_X and NEW_Y are the new
ones.
See also: "Size", "origin", "growMode", "centered", "clipOwner"
Paint CANVAS
Caused when the system calls for the refresh of a graphic context,
associated with a widget. CANVAS is the widget itself, however its
usage instead of widget is recommended ( see "Graphic content" ).
See also: "repaint", "syncPaint", "get_invalid_rect", "scroll",
"colorIndex", "font"
Popup BY_MOUSE, X, Y
Called by the system when the user presses a key or mouse
combination defined for a context pop-up menu execution. By
default executes the associated Prima::Popup object, if it is
present. If the event flag is cleared during the execution of
callbacks, the pop-up menu is not shown.
See also: "popup"
Setup
This message is posted right after "Create" notification, and comes
first from the event loop. Prima::Widget does not use it.
Show
Triggered by a successive visible(1) call
See also: "Show", "visible", "showing", "exposed"
Size OLD_WIDTH, OLD_HEIGHT, NEW_WIDTH, NEW_HEIGHT
Triggered when widget changes its size, either by Prima::Widget
methods or by the user. OLD_WIDTH and OLD_HEIGHT are the old
extensions of a widget, NEW_WIDTH and NEW_HEIGHT are the new ones.
See also: "Move", "origin", "size", "growMode", "sizeMax",
"sizeMin", "rect", "clipOwner"
TranslateAccel CODE, KEY, MOD
A distributed "KeyDown" event. Traverses all the object tree that
the widget which received original "KeyDown" event belongs to. Once
the event flag is cleared, the iteration stops.
Used for tracking keyboard events by out-of-focus widgets.
See also: "KeyDown"
ZOrderChanged
Triggered when a widget changes its stacking order, or Z-order
among its siblings, either by Prima::Widget methods or by the user.
See also: "bring_to_front", "insert_behind", "send_to_back"
AUTHOR
Dmitry Karasik, <dmitry@karasik.eu.org>.
SEE ALSO
Prima, Prima::Object, Prima::Drawable.