org.gdal.ogr
Class FeatureDefn

java.lang.Object
  extended by org.gdal.ogr.FeatureDefn

public class FeatureDefn
extends Object

Definition of a feature class or feature layer.

The FeatureDefn class is a binding for the C++ OGRFeatureDefn class.

This object contains schema information for a set of Feature. In table based systems, a FeatureDefn is essentially a layer. In more object oriented approaches (such as SF CORBA) this can represent a class of features but doesn't necessarily relate to all of a layer, or just one layer.

This object also can contain some other information such as a name, the base geometry type and potentially other metadata.

It is reasonable for different translators to derive classes from FeatureDefn with additional translator specific information.


Constructor Summary
FeatureDefn()
          Constructor.
FeatureDefn(String name)
          Constructor.
 
Method Summary
 void AddFieldDefn(FieldDefn defn)
          Add a new field definition.
 void delete()
           
 boolean equals(Object obj)
           
 int GetFieldCount()
          Fetch number of fields on this feature.
 FieldDefn GetFieldDefn(int ifield)
          Fetch field definition.
 int GetFieldIndex(String name)
          Find field by name.
 int GetGeomType()
          Fetch the geometry base type.
 String GetName()
          Get name of this FeatureDefn.
 int GetReferenceCount()
          Fetch current reference count.
 int hashCode()
           
 int IsGeometryIgnored()
          Determine whether the geometry can be omitted when fetching features.
 int IsStyleIgnored()
          Determine whether the style can be omitted when fetching features.
 void SetGeometryIgnored(int bIgnore)
          Set whether the geometry can be omitted when fetching features.
 void SetGeomType(int geom_type)
          Assign the base geometry type for this layer.
 void SetStyleIgnored(int bIgnore)
          Set whether the style can be omitted when fetching features.
 
Methods inherited from class java.lang.Object
getClass, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

FeatureDefn

public FeatureDefn(String name)
Constructor.

The FeatureDefn maintains a reference count, but this starts at zero. It is mainly intended to represent a count of Feature's based on this definition.

Parameters:
name - the name to be assigned to this layer/class. It does not need to be unique. and may be null.
Since:
Java bindings 1.7.0

FeatureDefn

public FeatureDefn()
Constructor.

The FeatureDefn maintains a reference count, but this starts at zero. It is mainly intended to represent a count of Feature's based on this definition. The FeatureDefn will be unnamed.

Method Detail

delete

public void delete()

equals

public boolean equals(Object obj)
Overrides:
equals in class Object

hashCode

public int hashCode()
Overrides:
hashCode in class Object

GetName

public String GetName()
Get name of this FeatureDefn.

Returns:
the name.

GetFieldCount

public int GetFieldCount()
Fetch number of fields on this feature.

Returns:
count of fields.

GetFieldDefn

public FieldDefn GetFieldDefn(int ifield)
Fetch field definition.

Parameters:
ifield - the field to fetch, between 0 and GetFieldCount()-1.
Returns:
a pointer to an internal field definition object. This object should not be modified or freed by the application.

GetFieldIndex

public int GetFieldIndex(String name)
Find field by name.

The field index of the first field matching the passed field name (case insensitively) is returned.

Parameters:
name - the field name to search for.
Returns:
the field index, or -1 if no match found.

AddFieldDefn

public void AddFieldDefn(FieldDefn defn)
Add a new field definition.

To add a new field definition to a layer definition, do not use this function directly, but use Layer.CreateField() instead.

This method should only be called while there are no Feature objects in existance based on this FeatureDefn. The FieldDefn passed in is copied, and remains the responsibility of the caller.

Parameters:
defn - the definition of the new field.

GetGeomType

public int GetGeomType()
Fetch the geometry base type.

Note that some drivers are unable to determine a specific geometry type for a layer, in which case wkbUnknown is returned. A value of wkbNone indicates no geometry is available for the layer at all. Many drivers do not properly mark the geometry type as 25D even if some or all geometries are in fact 25D. A few (broken) drivers return wkbPolygon for layers that also include wkbMultiPolygon.

Returns:
the base type for all geometry related to this definition.

SetGeomType

public void SetGeomType(int geom_type)
Assign the base geometry type for this layer.

All geometry objects using this type must be of the defined type or a derived type. The default upon creation is wkbUnknown which allows for any geometry type. The geometry type should generally not be changed after any Features have been created against this definition.

Parameters:
geom_type - the new type to assign.

GetReferenceCount

public int GetReferenceCount()
Fetch current reference count.

Returns:
the current reference count.

IsGeometryIgnored

public int IsGeometryIgnored()
Determine whether the geometry can be omitted when fetching features.

Returns:
ignore state (1 if ignored, 0 otherwise)
Since:
OGR 1.8.0

SetGeometryIgnored

public void SetGeometryIgnored(int bIgnore)
Set whether the geometry can be omitted when fetching features.

Parameters:
bIgnore - ignore state (1 to ignore, 0 otherwise)
Since:
OGR 1.8.0

IsStyleIgnored

public int IsStyleIgnored()
Determine whether the style can be omitted when fetching features.

Returns:
ignore state (1 if ignored, 0 otherwise)
Since:
OGR 1.8.0

SetStyleIgnored

public void SetStyleIgnored(int bIgnore)
Set whether the style can be omitted when fetching features.

Parameters:
bIgnore - ignore state (1 to ignore, 0 otherwise)
Since:
OGR 1.8.0