NAME
SoSelection -
The SoSelection class manages a list of selected nodes.
Inserting an SoSelection node in your scene graph enables you to let
the user ’pick’ with the left mousebutton to select/deselect objects
below the SoSelection node.
SYNOPSIS
#include <Inventor/nodes/SoSelection.h>
Inherits SoSeparator.
Inherited by SoExtSelection.
Public Types
enum Policy { SINGLE, TOGGLE, SHIFT }
Public Member Functions
SoSelection (void)
SoSelection (const int nChildren)
void select (const SoPath *path)
void select (SoNode *node)
void deselect (const SoPath *path)
void deselect (const int which)
void deselect (SoNode *node)
void toggle (const SoPath *path)
void toggle (SoNode *node)
SbBool isSelected (const SoPath *path) const
SbBool isSelected (SoNode *node) const
void deselectAll (void)
int getNumSelected (void) const
const SoPathList * getList (void) const
SoPath * getPath (const int index) const
SoPath * operator[] (const int i) const
void addSelectionCallback (SoSelectionPathCB *f, void *userData=NULL)
void removeSelectionCallback (SoSelectionPathCB *f, void
*userData=NULL)
void addDeselectionCallback (SoSelectionPathCB *f, void *userData=NULL)
void removeDeselectionCallback (SoSelectionPathCB *f, void
*userData=NULL)
void addStartCallback (SoSelectionClassCB *f, void *userData=NULL)
void removeStartCallback (SoSelectionClassCB *f, void *userData=NULL)
void addFinishCallback (SoSelectionClassCB *f, void *userData=NULL)
void removeFinishCallback (SoSelectionClassCB *f, void *userData=NULL)
void setPickFilterCallback (SoSelectionPickCB *f, void *userData=NULL,
const SbBool callOnlyIfSelectable=1)
void setPickMatching (const SbBool pickMatching)
SbBool isPickMatching (void) const
SbBool getPickMatching (void) const
void addChangeCallback (SoSelectionClassCB *f, void *userData=NULL)
void removeChangeCallback (SoSelectionClassCB *f, void *userData=NULL)
Static Public Member Functions
static void initClass (void)
Public Attributes
SoSFEnum policy
Protected Member Functions
virtual ~SoSelection ()
void invokeSelectionPolicy (SoPath *path, SbBool shiftDown)
void performSingleSelection (SoPath *path)
void performToggleSelection (SoPath *path)
SoPath * copyFromThis (const SoPath *path) const
void addPath (SoPath *path)
void removePath (const int which)
int findPath (const SoPath *path) const
virtual void handleEvent (SoHandleEventAction *action)
Protected Attributes
SoPathList selectionList
SoCallbackList * selCBList
SoCallbackList * deselCBList
SoCallbackList * startCBList
SoCallbackList * finishCBList
SoSelectionPickCB * pickCBFunc
void * pickCBData
SbBool callPickCBOnlyIfSelectable
SoCallbackList * changeCBList
SoPath * mouseDownPickPath
SbBool pickMatching
Detailed Description
The SoSelection class manages a list of selected nodes.
Inserting an SoSelection node in your scene graph enables you to let
the user ’pick’ with the left mousebutton to select/deselect objects
below the SoSelection node.
Using an SoBoxHighlightRenderAction or an SoLineHighlightRenderAction
to render scenegraphs containing SoSelection nodes provides a
convenient way of providing visual feedback about the selections to the
application user.
Beware that one common faulty assumption which is made about the node
is that the scene will automatically be re-rendered whenever the user
pick objects. This is not the case, the application programmer must
himself schedule a redraw. A straightforward way to accomplish this is
to SoNode::touch() the SoSelection node in the selection / deselection
callback.
A ’skeleton’ for basic use of SoSelection nodes is given below:
extern SoSeparator * make_scenegraph( void );
static SoSelection * selection = NULL;
// Callback function triggered for selection / deselection.
void made_selection( void * userdata, SoPath * path )
{
(void)fprintf( stdout, ’%sselected %s0,
userdata == (void *)1L ? ’’ : ’de’,
path->getTail()->getTypeId().getName().getString() );
selection->touch(); // to redraw
}
// *************************************************************************
// Print a quick instructions notice on stdout.
void show_instructions( void )
{
(void)fprintf( stdout, ’0his example program demonstrates the use of the SoSelection node type.0 );
(void)fprintf( stdout, ’0uick instructions:0 );
(void)fprintf( stdout, ’ * pick with left mouse button0 );
(void)fprintf( stdout, ’ * hold SHIFT to select multiple objects0 );
(void)fprintf( stdout, ’ * hit ESC to toggle back and forth to view mode0 );
(void)fprintf( stdout, ’0 );
}
// *************************************************************************
int main( int argc, char ** argv )
{
QWidget * window = SoQt::init( argv[0] );
show_instructions();
selection = new SoSelection;
selection->policy = SoSelection::SHIFT;
selection->ref();
selection->addChild( make_scenegraph() );
selection->addSelectionCallback( made_selection, (void *)1L );
selection->addDeselectionCallback( made_selection, (void *)0L );
SoQtExaminerViewer * examinerviewer = new SoQtExaminerViewer( window );
examinerviewer->setSceneGraph( selection );
examinerviewer->setGLRenderAction( new SoBoxHighlightRenderAction );
examinerviewer->setViewing( FALSE );
examinerviewer->show();
SoQt::show( window );
SoQt::mainLoop();
delete examinerviewer;
selection->unref();
return 0;
}
This node is not initialized in SoDB::init(), since it is part of the
interaction kit ’add-on’. Before using this node, you should therefore
call SoInteraction::init(). If you’re using one of the standard GUI-
toolkits (SoXt / SoQt / SoWin) SoInteraction::init() will be called for
you from the So[Xt|Qt|Win]init() method and you don’t have to worry
about it.
With regard to using multiple SoSelection nodes at the same time in the
same scene graph: this is possible, but it is not straightforward. The
standard viewers provided by SoQt, SoWin, et al, will only snoop on one
SoSelection node (part of the the legacy API from SGI’s InventorXt), so
selection changes on the others doesn’t trigger redraws. You don’t
necessarily see what’s happening in other words. You’ll have to hook up
manually and trigger redraws yourself.
Also be aware that when having multiple SoSelection nodes in the scene
graph active at the same time, the SoHandleEventAction traversals that
you intend for selection-change on one SoSelection node will also
affect all the other SoSelection nodes in the scene -- usually
delesecting everything below them since you will be clicking outside
the selectable objects. You’ll therefore also have to manually override
that behaviour, if you want selection change on one SoSelection node to
not affect the others.
FILE FORMAT/DEFAULTS:
Selection {
renderCaching AUTO
boundingBoxCaching AUTO
renderCulling AUTO
pickCulling AUTO
policy SHIFT
}
Member Enumeration Documentation
enum SoSelection::Policy Enum for different pick policies.
Enumerator:
SINGLE Only one object can be selected at any time. When the user picks
a new object, the previous selection will be unselected. If the
user picks on nothing, the current selection will be unselected.
Note that if a new selection matches one already present in the
selection list, neither a deselect nor a select notification callback
will be made about that selection path.
TOGGLE Picking an object toggles its selection state.
SHIFT Same as SINGLE, but when shift key is pressed the selection
policy will be changed to TOGGLE.
Constructor & Destructor Documentation
SoSelection::SoSelection (void) Default constructor.
SoSelection::SoSelection (const int nChildren) Constructor.
The argument should be the approximate number of children which is
expected to be inserted below this node. The number need not be exact,
as it is only used as a hint for better memory resource allocation.
SoSelection::~SoSelection () [protected, virtual] Destructor.
Member Function Documentation
void SoSelection::initClass (void) [static] Sets up initialization for data
common to all instances of this class, like submitting necessary
information to the Coin type system.
Reimplemented from SoSeparator.
Reimplemented in SoExtSelection.
void SoSelection::select (const SoPath * path) Adds path to the list of
selected objects.
void SoSelection::select (SoNode * node) Adds node to the list of selected
objects. The scene graph below the Selection node will be searched, and
the path to node will be added if found.
void SoSelection::deselect (const SoPath * path) Remove path from the list
of selected objects.
void SoSelection::deselect (const int which) Remove objects which from the
list of selected objects.
void SoSelection::deselect (SoNode * node) Remove node from the list of
selected objects. The scene graph below the Selection node will be
searched, and the path to node will be removed if found.
void SoSelection::toggle (const SoPath * path) If path is not already
selected, add path to the list of selected objects. Otherwise remove
path from the list of selected objects.
void SoSelection::toggle (SoNode * node) If node is not already selected,
add path to the list of selected objects. Otherwise remove node from
the list of selected objects.
SbBool SoSelection::isSelected (const SoPath * path) const Return TRUE if
path is in the list of selected objects.
SbBool SoSelection::isSelected (SoNode * node) const Return TRUE if the
path to node is in the list of selected objects.
void SoSelection::deselectAll (void) Clears the selection list.
int SoSelection::getNumSelected (void) const Returns the number of selected
objects.
const SoPathList * SoSelection::getList (void) const Returns the list of
selected objects.
SoPath * SoSelection::getPath (const int index) const Returns the indexth
selected objects.
SoPath * SoSelection::operator[] (const int i) const Operator for accessing
selected objects.
void SoSelection::addSelectionCallback (SoSelectionPathCB * f, void *
userData = NULL) Adds a callback which will be called every time an
object is selected.
See also:
removeSelectionCallback()
void SoSelection::removeSelectionCallback (SoSelectionPathCB * f, void *
userData = NULL) Removes one of the selection callbacks.
See also:
addSelectionCallback()
void SoSelection::addDeselectionCallback (SoSelectionPathCB * f, void *
userData = NULL) Adds a callback which will be called every time an
object is deselected.
See also:
removeDeselectionCallback()
void SoSelection::removeDeselectionCallback (SoSelectionPathCB * f, void *
userData = NULL) Removes one of the deselection callbacks.
See also:
addDeselctionCallback()
void SoSelection::addStartCallback (SoSelectionClassCB * f, void * userData
= NULL) Adds a callback which will be invoked when the user start an
interactive change to the list of selected objects.
This callback is useful for storing the old selection list for
undo/redo functionality.
See also:
addFinishCallback()
void SoSelection::removeStartCallback (SoSelectionClassCB * f, void *
userData = NULL) Removes f from the list of start callbacks.
See also:
addStartCallback()
void SoSelection::addFinishCallback (SoSelectionClassCB * f, void *
userData = NULL) Adds a callback which will be invoked when the user
has finished an interactive change to the list of selected objects.
See also:
addStartCallback()
void SoSelection::removeFinishCallback (SoSelectionClassCB * f, void *
userData = NULL) Removes f from the list og finish callbacks.
See also:
addFinishCallback()
void SoSelection::setPickFilterCallback (SoSelectionPickCB * f, void *
userData = NULL, const SbBool callOnlyIfSelectable = 1) Sets the pick
filter callback. This callback will be called when a path is about to
be added to or removed from the list of selected objects. The callback
function should return a replacement path that should be used instead
of the picked path. The returned path will be ref’ed, copied, and then
unref’ed again by the SoSelection node.
If no callback is set (the default), the picked path will be used for
selecting/deselecting.
Possible return values from the callback:
· NULL: simulate that nothing was picked. This will clear the selection
for the SINGLE policy. The handle event action will be halted.
· A path: the path will be selected/deselected. The handle event action
will be halted.
· A path containing only the Selection node: as NULL, but action will
not be halted.
· An empty path or a path not containing the Selection node: the pick
will be ignored.
if callOnlyIfSelectable is TRUE, the callback will only be called if
the Selection node is in the picked path.
void SoSelection::setPickMatching (const SbBool pickmatchflag) When
pickmatchflag is TRUE (the default), the mouse button release pick must
match the mouse button press pick before object is selected/deselected.
This flag should normally not be of interest to application
programmers.
SbBool SoSelection::isPickMatching (void) const Returns TRUE if pick
matching is enabled.
See also:
setPickMatching()
SbBool SoSelection::getPickMatching (void) const Returns TRUE if pick
matching is enabled.
See also:
setPickMatching()
void SoSelection::addChangeCallback (SoSelectionClassCB * f, void *
userData = NULL) This API member is considered internal to the library,
as it is not likely to be of interest to the application programmer.
Used by render area to receive notification when the selection list
changes.
void SoSelection::removeChangeCallback (SoSelectionClassCB * f, void *
userData = NULL) This API member is considered internal to the library,
as it is not likely to be of interest to the application programmer.
Used by render area to receive notification when the selection list
changes.
void SoSelection::invokeSelectionPolicy (SoPath * path, SbBool shiftdown)
[protected] This API member is considered internal to the library, as
it is not likely to be of interest to the application programmer.
void SoSelection::performSingleSelection (SoPath * path) [protected] This
API member is considered internal to the library, as it is not likely
to be of interest to the application programmer.
void SoSelection::performToggleSelection (SoPath * path) [protected] This
API member is considered internal to the library, as it is not likely
to be of interest to the application programmer.
SoPath * SoSelection::copyFromThis (const SoPath * path) const [protected]
This API member is considered internal to the library, as it is not
likely to be of interest to the application programmer.
void SoSelection::addPath (SoPath * path) [protected] This API member is
considered internal to the library, as it is not likely to be of
interest to the application programmer.
void SoSelection::removePath (const int which) [protected] This API member
is considered internal to the library, as it is not likely to be of
interest to the application programmer.
int SoSelection::findPath (const SoPath * path) const [protected] This API
member is considered internal to the library, as it is not likely to be
of interest to the application programmer.
void SoSelection::handleEvent (SoHandleEventAction * action) [protected,
virtual] Action method for SoHandleEventAction.
Inspects the event data from action, and processes it if it is
something which this node should react to.
Nodes influencing relevant state variables for how event handling is
done also overrides this method.
Reimplemented from SoSeparator.
Reimplemented in SoExtSelection.
Member Data Documentation
SoSFEnum SoSelection::policy Field for selection policy. Default value is
SHIFT.
SoPathList SoSelection::selectionList [protected] This API member is
considered internal to the library, as it is not likely to be of
interest to the application programmer.
SoCallbackList * SoSelection::selCBList [protected] This API member is
considered internal to the library, as it is not likely to be of
interest to the application programmer.
SoCallbackList * SoSelection::deselCBList [protected] This API member is
considered internal to the library, as it is not likely to be of
interest to the application programmer.
SoCallbackList * SoSelection::startCBList [protected] This API member is
considered internal to the library, as it is not likely to be of
interest to the application programmer.
SoCallbackList * SoSelection::finishCBList [protected] This API member is
considered internal to the library, as it is not likely to be of
interest to the application programmer.
SoSelectionPickCB * SoSelection::pickCBFunc [protected] This API member is
considered internal to the library, as it is not likely to be of
interest to the application programmer.
void * SoSelection::pickCBData [protected] This API member is considered
internal to the library, as it is not likely to be of interest to the
application programmer.
SbBool SoSelection::callPickCBOnlyIfSelectable [protected] This API member
is considered internal to the library, as it is not likely to be of
interest to the application programmer.
SoCallbackList * SoSelection::changeCBList [protected] This API member is
considered internal to the library, as it is not likely to be of
interest to the application programmer.
SoPath * SoSelection::mouseDownPickPath [protected] This API member is
considered internal to the library, as it is not likely to be of
interest to the application programmer.
SbBool SoSelection::pickMatching [protected] This API member is considered
internal to the library, as it is not likely to be of interest to the
application programmer.
Author
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