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SoSelection Class Reference

The SoSelection class manages a list of selected nodes. More...

#include <Inventor/nodes/SoSelection.h>

Inheritance diagram for SoSelection::

SoSeparator SoGroup SoNode SoFieldContainer SoBase SoExtSelection List of all members.

Public Types

enum  Policy { SINGLE, TOGGLE, SHIFT }

Public Methods

 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=TRUE)
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 Methods

void initClass (void)

Public Attributes

SoSFEnum policy

Protected Methods

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 %s\n",
                   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, "\nThis example program demonstrates the use of the SoSelection node type.\n" );
    (void)fprintf( stdout, "\nQuick instructions:\n\n" );
    (void)fprintf( stdout, "  * pick with left mouse button\n" );
    (void)fprintf( stdout, "  * hold SHIFT to select multiple objects\n" );
    (void)fprintf( stdout, "  * hit ESC to toggle back and forth to view mode\n" );
    (void)fprintf( stdout, "\n" );
  }

  // *************************************************************************

  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::initClass(). If you're using one of the standard GUI-toolkits (SoXt / SoQt / SoGtk / SoWin) SoInteraction::initClass() will be called for you from the So[Xt|Qt|Gtk|Win]init() method and you don't have to worry about it.

Member Enumeration Documentation

enum SoSelection::Policy
 

Enum for different pick policies.

Enumeration values:
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.
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 index'th 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 = TRUE
) 
 

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. 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    pickMatching ) 
 

When pickMatching is TRUE (the default), the mouse button release pick must match the mouse button press pick before object is selected/deselected.

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
) 
 

\internal. Used by render area to receive notification when the selection list changes.

void SoSelection::removeChangeCallback (  SoSelectionClassCB *    f,
void *    userData = NULL
) 
 

For internal use only.

void SoSelection::invokeSelectionPolicy (  SoPath *    path,
SbBool    shiftdown
)  [protected]
 

For internal use only.

void SoSelection::performSingleSelection (  SoPath *    path )  [protected]
 

For internal use only.

void SoSelection::performToggleSelection (  SoPath *    path )  [protected]
 

For internal use only.

SoPath * SoSelection::copyFromThis (  const SoPath *    path )  const [protected]
 

For internal use only.

void SoSelection::addPath (  SoPath *    path )  [protected]
 

For internal use only.

void SoSelection::removePath (  const int    which )  [protected]
 

For internal use only.

int SoSelection::findPath (  const SoPath *    path )  const [protected]
 

For internal use only.

void SoSelection::handleEvent (  SoHandleEventAction *    action )  [protected, virtual]
 

Overloaded to do selection picking.

Reimplemented from SoSeparator.

Reimplemented in SoExtSelection.

Member Data Documentation

SoSFEnum SoSelection::policy
 

Field for selection policy. Default value is SHIFT.

SoPathList SoSelection::selectionList [protected]
 

For internal use only.

SoCallbackList * SoSelection::selCBList [protected]
 

For internal use only.

SoCallbackList * SoSelection::deselCBList [protected]
 

For internal use only.

SoCallbackList * SoSelection::startCBList [protected]
 

For internal use only.

SoCallbackList * SoSelection::finishCBList [protected]
 

For internal use only.

SoSelectionPickCB * SoSelection::pickCBFunc [protected]
 

For internal use only.

void * SoSelection::pickCBData [protected]
 

For internal use only.

SbBool SoSelection::callPickCBOnlyIfSelectable [protected]
 

For internal use only.

SoCallbackList * SoSelection::changeCBList [protected]
 

For internal use only.

SoPath * SoSelection::mouseDownPickPath [protected]
 

For internal use only.

SbBool SoSelection::pickMatching [protected]
 

For internal use only.

The documentation for this class was generated from the following files:
Generated on Sat Jan 12 11:41:15 2002 for Coin by doxygen1.2.12 written by Dimitri van Heesch, © 1997-2001