Filter (Cytoscape Swing App API (swing-app-api) 3.8.1 API)

Type Parameters:

C - The context type of the elements this Filter operates on.

E - The element type this Filter operates on.

All Superinterfaces:

Transformer<C,E>

All Known Subinterfaces:

CompositeFilter<C,E>
```
public interface Filter<C,E>
extends Transformer<C,E>
```
A transformer that decides whether to accept or reject elements. To make a custom Filter available in Cytoscape, create an FilterFactory that constructs the custom Filter, and register the factory as an OSGi service. To make the transformer show up in the UI, create a TransformerViewFactory and register it as an OSGi service. The Filter, FilterFactory and TransformerViewFactory need to have the same id.
Module: filter-api
To use this in your app, include the following dependency in your POM:
```
<dependency>
    <groupId>org.cytoscape</groupId>
    <artifactId>filter-api</artifactId>
</dependency>
```
Cytoscape Backwards Compatibility (SPI Interface): We expect that this interface will be implemented. Therefore to maintain backwards compatibility this interface will only be modified for major version updates.

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`boolean`	`accepts(C context, E element)`	Returns `true` if this filter accepts the given element from `context`.
`default boolean`	`isAlwaysFalse()`	Returns true if the accepts() method will always return false for all inputs.

Methods inherited from interface org.cytoscape.filter.model.Transformer
addListener, getContextType, getElementType, getId, getName, removeListener

- Method Detail
  - accepts
```
boolean accepts(C context,
                E element)
```
    Returns true if this filter accepts the given element from context.
    
    Parameters:
    
    context - the context object of the transformed element.
    
    element - the element to transform.
    
    Returns:
    
    true if this filter accepts the given element.
  - isAlwaysFalse
```
default boolean isAlwaysFalse()
```
    Returns true if the accepts() method will always return false for all inputs. This is an optimization to avoid running the filter if its just going to fail on all input anyway. This typically happens when the filter is not fully configured, for example a column filter might still be displaying "choose column".