SoMField.3iv man page

SoMField — base class for all multiple-valued fields

Inherits from

SoField > SoMField


#include <Inventor/fields/SoField.h>

Methods from class SoMField:

int getNum() const

void setNum(int num)

virtual void deleteValues(int start, int num = -1)

virtual void insertSpace(int start, int num)

SbBool set1(int index, const char *valueString)

void get1(int index, SbString &valueString)

static SoType getClassTypeId()

Methods from class SoField:

void setIgnored(SbBool ignore)

SbBool isIgnored() const

SbBool isDefault() const

virtual SoType getTypeId() const

virtual SbBool isOfType(SoType type) const

SbBool set(const char *valueString)

void get(SbString &valueString)

int operator ==(const SoField &f) const

int operator !=(const SoField &f) const

void touch()

SbBool connectFrom(SoField *fromField)

SbBool connectFrom(SoEngineOutput *fromEngine)

void disconnect()

SbBool isConnected() const

SbBool isConnectedFromField() const

SbBool getConnectedField(SoField *&writingField) const

SbBool isConnectedFromEngine() const

SbBool getConnectedEngine(SoEngineOutput *&engineOutput) const

void enableConnection(SbBool flag)

SbBool isConnectionEnabled() const

int getForwardConnections(SoFieldList &list) const

SoFieldContainer * getContainer() const


Each class derived from SoMField begins with an SoMF prefix and contains a dynamic array of values of a particular type. Each has a setValues() method that is passed a pointer to a const array of values of the correct type; these values are copied into the array in the field, making extra room in the array if necessary. The start and num parameters to this method indicate the starting array index to copy into and the number of values to copy.

The getValues() method for a multiple-value field returns a const pointer to the array of values in the field. (Because this pointer is const, it cannot be used to change values in this array.)

In addition, the indexing operator "[]" is overloaded to return the i'th value in the array; because it returns a const reference, it can be used only to get values, not to set them.

Methods are provided for getting the number of values in the field, inserting space for new values in the middle, and deleting values.

There are other methods that allow you to set only one value of several in the field and to set the field to contain one and only one value.

Two other methods can be used to make several changes to a multiple-value field without the overhead of copying values into and out of the fields. The startEditing() method returns a non-const pointer to the array of values in the field; this pointer can then be used to change (but not add or remove) any values in the array. The finishEditing() method indicates that the editing is done and notifies any sensors or engines that may be connected to the field.

SoMFields are written to file as a series of values separated by commas, all enclosed in square brackets. If the field has no values (getNum() returns zero), then only the square brackets ("[]") are written. The last value may optionally be followed by a comma. Each field subtype defines how the values are written; for example, a field whose values are integers might be written as:

[ 1, 2, 3, 4 ]
[ 1, 2, 3, 4, ]


int getNum() const
Returns the number of values currently in the field.

void setNum(int num)
Forces this field to have exactly num values, inserting or deleting values as necessary.

virtual void deleteValues(int start, int num = -1)
Deletes num values beginning at index start (index start through start+num-1 will be deleted, and any leftover values will be moved down to fill in the gap created). A num of -1 means delete all values from start to the last value in the field; getNum() will return start as the number of values in the field after this operation (deleteValues(0, -1) empties the field).

virtual void insertSpace(int start, int num)
Inserts space for num values at index start. Index start through start+num-1 will be moved up to make room. For example, to make room for 7 new values at the beginning of the field call insertSpace(0, 10).

SbBool set1(int index, const char *valueString)

void get1(int index, SbString &valueString)
These are equivalent to the set() and get() methods of SoField, but they operate on only one value. See the SoField methods for details.

static SoType getClassTypeId()
Return the type identifier for this field class.

See Also

SoNode, SoEngine