org.geotools.event
Interface GTComponent

All Known Subinterfaces:

AnchorPoint, ChannelSelection, ColorMap, ColorMapEntry, ContrastEnhancement, Displacement, Extent, ExternalGraphic, FeatureTypeConstraint, FeatureTypeStyle, Fill, Font, Graphic, GTRoot, Halo, ImageOutline, LabelPlacement, LayerFeatureConstraints, LinePlacement, LineSymbolizer, Mark, NamedLayer, NamedStyle, PointPlacement, PointSymbolizer, PolygonSymbolizer, RasterSymbolizer, Rule, SelectedChannelType, ShadedRelief, Stroke, Style, StyledLayer, StyledLayerDescriptor, Symbol, Symbolizer, TextMark, TextSymbolizer, TextSymbolizer2, UserLayer

All Known Implementing Classes:

AbstractGTComponent, AbstractGTRoot, AnchorPointImpl, BasicLineStyle, BasicPolygonStyle, ChannelSelectionImpl, ColorMapEntryImpl, ColorMapImpl, ContrastEnhancementImpl, DisplacementImpl, ExtentImpl, ExternalGraphicImpl, FeatureTypeConstraintImpl, FeatureTypeStyleImpl, FillImpl, FontImpl, GraphicImpl, GTConstant, HaloImpl, ImageOutlineImpl, LayerFeatureConstraintsImpl, LinePlacementImpl, LineSymbolizerImpl, MarkImpl, NamedLayerImpl, NamedStyleImpl, PointPlacementImpl, PointSymbolizerImpl, PolygonSymbolizerImpl, RasterSymbolizerImpl, RuleImpl, SelectedChannelTypeImpl, ShadedReliefImpl, StrokeImpl, StyledLayerDescriptorImpl, StyledLayerImpl, StyleImpl, TextMarkImpl, TextSymbolizerImpl, UserLayerImpl

public interface GTComponent

Provides support for Parent/Child relationships for the event system.

Several of the GeoTools objects are produced in reference to specifications, in particular XML based specifications. Often we try and match the same abstractions present in a specification like SLD or Filter. But rather then make use of pure Java Beans, and make user interface code responsible for managing a host of listeners we are providing a single set of listeners located at the object matching the document base.

For more Details:

• This design is similar to EMF, or JFace use (aka borrow code examples)
• Not specific to Documents, the Catalog api will use these events
• We do try and match the document structure perfectly for Feature/FeatureCollection/GML (so that the same XPath expressions can be respected). FeatureCollection and Feature have their own well explored structure and issues and will not be using this event system. Given the size of FeatureCollections it is not practicle for each child to "know" its parent.

Author:

Jody Garnett

Method Summary

void	changed(GTDelta delta) A child has been changed (maybe added), issued after change.
GTNote	getNote()
GTComponent	getParent() Deprecated. use getNote().getParent()
void	removed(GTDelta delta) A child has been removed, issued before change.
void	setNote(GTNote container)

Method Detail

getParent

public GTComponent getParent()

Deprecated. use getNote().getParent()

Used to locate our parent.

This method will return a "NULLObject", called GTRoot.NO_PARENT when no parent is present, client code should never have to be concerned this method return null.

Returns:

Parent GTComponent or GTRoot.NO_PARENT if none

getNote

public GTNote getNote()

setNote

public void setNote(GTNote container)

removed

public void removed(GTDelta delta)

A child has been removed, issued before change.

This method is for use by children only it is implementor API and should not be called by client code.

Q:Why does it exist then?
So you can implement your own Symbolizer, and still allow the GeoTools Stroke implementation to pass change notification onto you.

Q:GeoAPI does not support this? No they don't, their interface are set up to match specification for interoptability between toolkit implementations. By the time you pass a GeoAPI object around it should stop wiggling and just be viewed as stable data. But yes we should ask them about this...

changed

public void changed(GTDelta delta)

A child has been changed (maybe added), issued after change.

This method is for use by children only it is implementor API and should not be called by client code.

Q:Why does it exist then?
So you can implement your own Symbolizer, and still allow the GeoTools Stroke implementation to pass change notification onto you.

Q:GeoAPI does not support this? No they don't, their interface are set up to match specification for interoptability between toolkit implementations. By the time you pass a GeoAPI object around it should stop wiggling and just be viewed as stable data. But yes we should ask them about this...