NAME
Prima::Docks - dockable widgets
DESCRIPTION
The module contains a set of classes and an implementation of the dockable widgets interface. The interface assumes two parties, the dockable widget, and the dock widget; the generic methods for the dock widget class are contained in the Prima::AbstractDocker::Interface
package.
USAGE
A dockable widget is required to take particular steps before it may land on a dock widget. It needs to talk to the dock and find out if it is allowed to land, or if the dock contains children dock widgets that might suit better for the docking. If there's more than one dock widget in the program, the dockable widget can select between the targets; this is especially actual when a dockable widget is dragged by the mouse and the landing arbitration is based on geometrical distance.
The interface implies that there exists at least one tree-like hierarchy of dock widgets, linked up to a root dock widget. The hierarchy is not required to follow parent-child relationships although this is the default behavior. All dockable widgets are expected to know explicitly what hierarchy tree they wish to dock to. Prima::InternalDockerShuttle
introduces the dockingRoot
property for this purpose.
The conversation between parties starts when a dockable widget calls the open_session
method of the dock. The dockable widget passes a set of parameters signaling if the widget is ready to change its size in case the dock widget requires so, and how. The open_session
method can either refuse or accept the widget. In case of the positive answer from open_session
, the dockable widget calls the query
method, which either returns a new rectangle or another dock widget. In the latter case, the caller can enumerate all available dock widgets by repetitive calls to the next_docker
method. The session is closed by a close_session
call; after that, the widget is allowed to land by setting its owner
to the dock widget, the rect
property to the negotiated position and size, and finally calling the dock
method.
The open_session
/close_session
brackets cache all necessary calculations once, making the query
call as light as possible. This design allows a dockable widget when dragged, to repeatedly ask all reachable docks in an optimized way. The docking sessions are kept open until the drag session is finished.
The conversation can be schematized in the following code:
my $dock = $self-> dockingRoot;
my $session_id = $dock-> open_session({ self => $self });
return unless $session_id;
my @result = $dock-> query( $session_id, $self-> rect );
if ( 4 == scalar @result) { # new rectangle is returned
if ( ..... is new rectangle acceptable ? ... ) {
$dock-> close_session( $session_id);
$dock-> dock( $self);
return;
}
} elsif ( 1 == scalar @result) { # another dock returned
my $next = $result[0];
while ( $next) {
if ( ... is new docker acceptable? ....) {
$dock-> close_session( $session_id);
$next-> dock( $self);
return;
}
$next = $dock-> next_docker( $session_id, $self-> origin );
}
}
$dock-> close_session( $session_id);
Since even the simplified code is quite cumbersome, direct calls to open_session
are rare. Instead, Prima::InternalDockerShuttle
implements the find_docking
method which performs the arbitration automatically and returns the appropriate dock widget.
Prima::InternalDockerShuttle
is the class that implements the dockable widget functionality. It also provides a top-level window-like wrapper widget for the dockable widget that hosts the widget automatically if it is not docked. By default, Prima::ExternalDockerShuttle
is used as the wrapper widget class.
It is not required, however, to use either Prima::InternalDockerShuttle
or Prima::AbstractDocker::Interface
to implement a dockable widget; the only requirement is to respect the open_session
/close_session
protocol.
The full hierarchy of widgets participating in the mechanism is as follows:
Prima::AbstractDocker::Interface
Prima::SimpleWidgetDocker
Prima::ClientWidgetDocker
Prima::LinearWidgetDocker
Prima::SingleLinearWidgetDocker
Prima::FourPartDocker
Prima::InternalDockerShuttle
Prima::LinearDockerShuttle
Prima::ExternalDockerShuttle
All docker widget classes are derived from Prima::AbstractDocker::Interface
. Depending on the specialization, they employ more or less sophisticated schemes for arranging dockable widgets inside themselves. The most complicated scheme is implemented in Prima::LinearWidgetDocker
; it does not allow children to overlap, can rearrange the children, and resize itself when a widget is docked or undocked.
The package provides only basic functionality. Module Prima::DockManager
provides common dockable controls, - toolbars, panels, speed buttons, etc. based on the Prima::Docks
module. See Prima::DockManager.
Prima::AbstractDocker::Interface
Implements generic functionality of a docket widget. The class is not derived from Prima::Widget
; is used as a secondary ascendant class for the dock widget classes.
Properties
Since the class is not a Prima::Object
descendant, it provides only run-time implementation of its properties. It is up to the descendant object whether the properties are recognized during the creation stage or not.
- fingerprint INTEGER
-
A custom bit mask used by docking widgets to reject inappropriate dock widgets at an early stage. The
fingerprint
property is not a part of the protocol and is not required to be present in the implementation of a dockable widget.Default value:
0x0000FFFF
- dockup DOCK_WIDGET
-
Selects the upper link in the dock widgets hierarchy tree. The upper link is required to be a dock widget but is not required to be a direct or an indirect parent. In this case, however, the maintenance of the link must be implemented separately, for example:
$self-> dockup( $upper_dock_not_parent ); $upper_dock_not_parent-> add_notification( 'Destroy', sub { return unless $_[0] == $self-> dockup; undef $self-> {dockup_event_id}; $self-> dockup( undef ); }, $self); $self-> {destroy_id} = $self-> add_notification( 'Destroy', sub { $self-> dockup( undef ); } unless $self-> {destroy_id};
Methods
- add_subdocker SUBDOCK
-
Appends SUBDOCK to the list of children docker widgets. The items of the list are returned by the
next_docker
method. - check_session SESSION
-
A debugging procedure. Checks SESSION hash, and warns if its members are invalid or incomplete. Returns 1 if no fatal errors were encountered; 0 otherwise.
- close_session SESSION
-
Closes docking SESSION and frees the associated resources.
- dock WIDGET
-
Called after WIDGET successfully finished negotiations with the dock widget and changed its
owner
property. The method adapts the dock widget layout and lists the WIDGET into the list of docked widgets. The method does not change theowner
property of the WIDGET.The method must not be called directly.
- dock_bunch @WIDGETS
-
Effectively docks set of WIDGETS by updating internal structures and calling
rearrange
. - docklings
-
Returns an array of docked widgets
- next_docker SESSION, [ X, Y ]
-
Enumerates children docker widgets inside the SESSION; returns one docker widget at a time. After the last widget returns
undef
.The enumeration pointer is reset by the
query
call.X and Y are the coordinates of the point of interest.
- open_session PROFILE
-
Opens a new docking session with parameters stored in the PROFILE hash. Returns a session ID scalar in case of success, or
undef
otherwise. The following keys must be set in PROFILE:- position ARRAY
-
Contains two integer coordinates of the desired position of a widget in (X,Y) format in the screen coordinate system.
- self WIDGET
-
The widget that is about to dock.
- sizeable ARRAY
-
Contains two boolean flags, representing if the widget can be resized to an arbitrary size, horizontally and vertically. The arbitrary resize option is used as a last resort if the
sizes
key does not contain the desired size. - sizeMin ARRAY
-
Two integers; the minimal size that the widget can accept.
- sizes ARRAY
-
Contains an array of points in the (X,Y) format; each point represents an acceptable widget size. If both of the
sizeable
flags are set to 0 and none of thesizes
can be accepted by the dock widget,open_session
fails.
- query SESSION [ X1, Y1, X2, Y2 ]
-
Checks if a dockable widget can be landed on the dock. If it can, returns a rectangle that the widget must be set to. If coordinates ( X1 .. Y2 ) are specified, returns the rectangle closest to these. If
sizes
orsizeable
keys of theopen_session
profile were set, the returned size might be different from the current docking widget size.Once the caller finds the result appropriate, it is allowed to reparent under the dock; after that, it must change its origin and size correspondingly to the result, and then call
dock
.If the dock cannot accept the widget but contains children dock widgets, returns the first child widget. The caller can use subsequent calls to
next_docker
to enumerate all the children docks. A call toquery
resets the internal enumeration pointer.If the widget may not be landed, an empty array is returned.
- rearrange
-
Effectively re-docks all the docked widgets. The effect is as same as of
$self-> redock_widget($_) for $self-> docklings;
but usually
rearrange
is faster. - redock_widget WIDGET
-
Effectively re-docks the docked WIDGET. If WIDGET has a
redock
method in its namespace, it is called instead. - remove_subdocker SUBDOCK
-
Removes SUBDOCK from the list of children docker widgets. See also add_subdocker.
- replace FROM, TO
-
Assigns the widget TO the same owner and size as FROM. The FROM widget must be a docked widget.
- undock WIDGET
-
Removes WIDGET from the list of docked widgets. The layout of the dock widget can be changed after the execution of this method. The method does not change the
owner
property of WIDGET.The method must not be called directly.
Prima::SimpleWidgetDocker
A simple dock widget; accepts any widget that geometrically fits into it. Allows overlapping of the docked widgets.
Prima::ClientWidgetDocker
A simple dock widget; accepts any widget that can cover all dock's interior.
Prima::LinearWidgetDocker
A toolbar-like docking widget class. The implementation does not allow tiling but can reshape the dock widget and rearrange the docked widgets if necessary.
Prima::LinearWidgetDocker
is orientation-dependent; its main axis, managed by the vertical
property, aligns the docked widgets in 'lines', which in turn are aligned by the opposite axis ( 'major' and 'minor' terms are used in the code for the axes ).
Properties
- growable INTEGER
-
A combination of the
grow::XXX
constants that describes how the dock widget can be resized. The constants are divided into two sets, direct and indirect, or,vertical
property independent and dependent.The first set contains explicitly named constants:
grow::Left grow::ForwardLeft grow::BackLeft grow::Down grow::ForwardDown grow::BackDown grow::Right grow::ForwardRight grow::BackRight grow::Up grow::ForwardUp grow::BackUp
that select if the widget can grow in the direction shown. These do not change meaning when
vertical
changes, though they do change the dock widget behavior. The second set does not affect dock widget behavior whenvertical
changes, however, the names are not that illustrative:grow::MajorLess grow::ForwardMajorLess grow::BackMajorLess grow::MajorMore grow::ForwardMajorMore grow::BackMajorMore grow::MinorLess grow::ForwardMinorLess grow::BackMinorLess grow::MinorMore grow::ForwardMinorMore grow::BackMinorMore
The
Forward
andBack
prefixes select if the dock widget can be respectively expanded or shrunk in the given direction.Less
andMore
are equivalent toLeft
andRight
whenvertical
is 0, and toUp
andDown
otherwise.The use of constants from the second set is preferred.
Default value: 0
- hasPocket BOOLEAN
-
A boolean flag, affects the possibility of a docked widget to reside outside the dock widget inferior. If 1, a docked widget is allowed to stay docked ( or dock into a position ) further on the major axis ( to the right when
vertical
is 0, up otherwise ) as if there's a 'pocket'. If 0, a widget is neither allowed to dock outside the inferior nor is allowed to stay docked ( and is undocked automatically ) when the dock widget shrinks so that the docked widget cannot stay in the dock boundaries.Default value: 1
- vertical BOOLEAN
-
Selects the major axis of the dock widget. If 1, it is vertical, horizontal otherwise.
Default value: 0
Events
- Dock
-
Called when the
dock
method is successfully finished. - DockError WIDGET
-
Called when the
dock
method is unsuccessfully finished. This only happens if WIDGET does not follow the docking protocol, and inserts itself into a non-approved area. - Undock
-
Called when
undock
is finished.
Prima::SingleLinearWidgetDocker
Descendant of Prima::LinearWidgetDocker
. In addition to the constraints introduced by the ascendant class, Prima::SingleLinearWidgetDocker
allows only one row ( or column, depending on the vertical
property value ) of docked widgets.
Prima::FourPartDocker
Implementation of a docking widget that hosts four children docker widgets on its sides and one in the center. All of the children docks can grow and shrink automatically so that the whole setup has an effect as if the dock borders are dynamic.
Properties
- indents ARRAY
-
Contains four integers specifying the breadth of offset for each side. The first integer is the width of the left side, the second - the height of the bottom side, the third is the width of the right side, and the fourth - height of the top side.
- dockerClassLeft STRING
-
Assigns the class of the left-side dock window.
Default value:
Prima::LinearWidgetDocker
. Create-only property. - dockerClassRight STRING
-
Assigns the class of the right-side dock window.
Default value:
Prima::LinearWidgetDocker
. Create-only property. - dockerClassTop STRING
-
Assigns the class of the top-side dock window.
Default value:
Prima::LinearWidgetDocker
. Create-only property. - dockerClassBottom STRING
-
Assigns the class of the bottom-side dock window.
Default value:
Prima::LinearWidgetDocker
. Create-only property. - dockerClassClient STRING
-
Assigns the class of the center dock window.
Default value:
Prima::ClientWidgetDocker
. Create-only property. - dockerProfileLeft HASH
-
Assigns a hash of properties, passed to the left-side dock widget during the creation.
Create-only property.
- dockerProfileRight HASH
-
Assigns a hash of properties, passed to the right-side dock widget during the creation.
Create-only property.
- dockerProfileTop HASH
-
Assigns a hash of properties, passed to the top-side dock widget during the creation.
Create-only property.
- dockerProfileBottom HASH
-
Assigns a hash of properties, passed to the bottom-side dock widget during the creation.
Create-only property.
- dockerProfileClient HASH
-
Assigns a hash of properties, passed to the center dock widget during the creation.
Create-only property.
- dockerDelegationsLeft ARRAY
-
Assigns delegated notifications of the left-side dock.
Create-only property.
- dockerDelegationsRight ARRAY
-
Assigns delegated notifications of the right-side dock.
Create-only property.
- dockerDelegationsTop ARRAY
-
Assigns delegated notifications of the top-side dock.
Create-only property.
- dockerDelegationsBottom ARRAY
-
Assigns delegated notifications of the bottom-side dock.
Create-only property.
- dockerDelegationsClient ARRAY
-
Assigns delegated notifications of the bottom-side dock.
Create-only property.
- dockerCommonProfile HASH
-
Assigns a hash of properties, passed to all the five dock widgets during the creation.
Create-only property.
Prima::InternalDockerShuttle
The class provides a container, or a 'shuttle', for a client widget, while is docked to a Prima::AbstractDocker::Interface
descendant instance. The functionality includes communicating with dock widgets, the user interface for dragging and interactive dock selection, and a client widget container for the non-docked state. The latter is implemented by reparenting the client widget to an external shuttle widget, selected by the externalDockerClass
property. Both user interfaces for the docked and the non-docked shuttle states are minimal.
The class implements dockable widget functionality, served by Prima::AbstractDocker::Interface
, and is derived from Prima::Widget
.
See also: "Prima::ExternalDockerShuttle".
Properties
- client WIDGET
-
Provides access to the client widget, which always resides either in the internal or the external shuttle. By default, there is no client, and any widget capable of changing its parent can be set as one. After a widget is assigned as a client, its
owner
andclipOwner
properties must not be used.Run-time only property.
- dock WIDGET
-
Selects the dock widget that the shuttle is landed on. If
undef
, the shuttle is in the non-docked state.Default value:
undef
- dockingRoot WIDGET
-
Selects the root of the dock widgets hierarchy. If
undef
, the shuttle can only exist in the non-docked state.Default value:
undef
See "USAGE" for reference.
- externalDockerClass STRING
-
Assigns the class of the external shuttle widget.
Default value:
Prima::ExternalDockerShuttle
- externalDockerModule STRING
-
Assigns the module that contains the external shuttle widget class.
Default value:
Prima::MDI
(Prima::ExternalDockerShuttle
is derived fromPrima::MDI
). - externalDockerProfile HASH
-
Assigns a hash of properties, passed to the external shuttle widget during the creation.
- fingerprint INTEGER
-
A custom bit mask used to reject inappropriate dock widgets at an early stage.
Default value:
0x0000FFFF
- indents ARRAY
-
Contains four integers, specifying the breadth of offset in pixels for each widget side in the docked state.
Default value:
5,5,5,5
. - snapDistance INTEGER
-
A maximum offset, in pixels, between the actual shuttle coordinates and the coordinates proposed by the dock widget, where the shuttle is allowed to land. In other words, it is the distance between the dock and the shuttle when the latter 'snaps' to the dock during the dragging session.
Default value: 10
- x_sizeable BOOLEAN
-
Selects whether the shuttle can change its width in case the dock widget suggests so.
Default value: 0
- y_sizeable BOOLEAN
-
Selects whether the shuttle can change its height in case the dock widget suggests so.
Default value: 0
Methods
- client2frame X1, Y1, X2, Y2
-
Returns the rectangle that the shuttle would occupy if its client rectangle is assigned to X1, Y1, X2, Y2 .
- dock_back
-
Docks to the recent dock widget, if it is still available.
- drag STATE, RECT, ANCHOR_X, ANCHOR_Y
-
Initiates or aborts the dragging session, depending on the STATE boolean flag.
If it is 1, RECT is an array with the coordinates of the shuttle rectangle before the session has started; ANCHOR_X and ANCHOR_Y are coordinates of the aperture point where the mouse event occurred that has initiated the session. Depending on how the drag session ended, the shuttle can be relocated to another dock, undocked, or left intact. Also,
Dock
,Undock
, orFailDock
notifications can be triggered.If the STATE is 0, RECT, ANCHOR_X ,and ANCHOR_Y parameters are not used.
- find_docking DOCK, [ POSITION ]
-
Opens a session with DOCK, unless it is already opened, and negotiates about the possibility of landing ( at the POSITION if this parameter is present ).
find_docking
caches the dock widget sessions and provides a possibility to select different parameters passed toopen_session
for different dock widgets. To achieve this, theGetCaps
request notification is triggered, which is expected to fill the parameters. The default action sets thesizeable
option according to thex_sizeable
andy_sizeable
properties.In case an appropriate landing area is found, the
Landing
notification is triggered with the proposed dock widget and the target rectangle. The area can be rejected at this stage ifLanding
returns a negative answer.On success, returns a dock widget found and the target rectangle; the widget is not docked though. On failure returns an empty array.
This method is used by the mouse dragging routine to provide visual feedback to the user, to indicate that a shuttle may or may not land in a particular area.
- frame2client X1, Y1, X2, Y2
-
Returns the rectangle that the client would occupy if the shuttle rectangle is assigned to X1, Y1, X2, Y2 .
- redock
-
Undocks from the dock widget and immediately tries to land back. If not docked, does not do anything.
Events
- Dock
-
Called when the shuttle was docked.
- EDSClose
-
Triggered when the user presses the close button or otherwise activates the
close
function of the EDS ( external docker shuttle ) pseudo-window. To cancel the window closingclear_event
must be called inside the event handler. - FailDock X, Y
-
Called after the dragging session in the non-docked stage was finished but did not result in docking. X and Y are the coordinates of the new external shuttle position.
- GetCaps DOCK, PROFILE
-
Called before the shuttle opens a docking session with the DOCK widget. PROFILE is a hash reference, which is to be filled inside the event handler. After that PROFILE is passed to an
open_session
call.The default action sets the
sizeable
option according to thex_sizeable
andy_sizeable
properties. - Landing DOCK, X1, Y1, X2, Y2
-
Called inside the docking session, after an appropriate dock widget is selected and the landing area is defined as X1, Y1, X2, Y2. To reject the landing on either DOCK or area,
clear_event
must be called. - Undock
-
Called when the shuttle is switched to the non-docked state.
Prima::ExternalDockerShuttle
A shuttle class, hosts a client of the Prima::InternalDockerShuttle
widget when it is in the non-docked state. The widget is a pseudo-window with some minimal decorations that can be moved, resized ( this feature is not on by default though ), and closed.
Prima::ExternalDockerShuttle
is inherited from the Prima::MDI
class, and its window-emulating functionality is a subset of its ascendant. See also Prima::MDI.
Properties
Prima::LinearDockerShuttle
A simple descendant of Prima::InternalDockerShuttle
, used for toolbars. Introduces orientation and draws a tiny header along the minor shuttle axis.
Properties
- headerBreadth INTEGER
-
The breadth of the header in pixels.
Default value: 8
- indent INTEGER
-
A wrapper to the
indents
property; besides the space for the header, all indents are assigned to theindent
property value. - vertical BOOLEAN
-
If 1, the shuttle is drawn as a vertical bar. If 0, the shuttle is drawn as a horizontal bar.
Default value: 0
AUTHOR
Dmitry Karasik, <dmitry@karasik.eu.org>.
SEE ALSO
Prima, Prima::Widget, Prima::MDI, Prima::DockManager, examples/dock.pl