Package org.flexdock.util

Class NestedComponents

  • public class NestedComponents
extends java.lang.Object
    This is a utility class for small, short-lived object instances used to find nested Components. It models a relationship between nested Components within an AWT Container hierarchy such that, given a starting Component from which to search, it will find two Components nested within each other of specific class types. The "deeper" component will be a descendent of the "parent" component.

    For example, given a JTextField within a content frame, the application logic may need to check to see if the text field resides within a certain application-specific container set. Perhaps all JTables embedded within JSplitPanes are significant within the particular application. The find(Component searchSrc, Class childClass, Class parentClass) method on this class will be able to return a NestedComponents instance indicating whether the specified text field resides within a JTable that is embedded within a JSplitPane.

    Although perhaps a bit contrived, this example shows a generic use for this class. The FlexDock framework itself has a particular interest in Dockable components that are embedded within DockingPorts, especially during drag operations. As a Dockable is dragged over an DockingPort, this class allows the framework to determine with a single object instance any Dockables currently embedded within the target DockingPort, starting with the deepest Component at the current mouse point during the drag.

    This classes' member fields are public and may be both accessed and modified by external code as needed within their particular usage context. This is by design for ease of use within the FlexDock framework. Consequently, instances of this class should only be used for short-lived operations. Since its member fields may be modified publicly, instances of this class should not be cached, nor should its member values be indexed as they are subject to arbitrary changes over the long term.

    Author:
    Christopher Butler

    • Field Summary

      Fields 
      Modifier and Type Field Description
      java.awt.Component child  
      java.awt.Component parent  
      java.awt.Component searchSrc  

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean equals​(java.lang.Object obj)
      Returns true if the specified Object is a NestedComponents instance and all shares all of the same field references (==) as this NestedComponents for field searchSrc, child, and parent.
      static NestedComponents find​(java.awt.Component searchSrc, java.lang.Class childClass, java.lang.Class parentClass)
      Creates and returns a new NestedComponents instance, searching the parent Container hierarcy of the specified searchSrc for an ancestor of type childClass and a more senior ancestor of type parentClass.
      int hashCode()
      Overridden to match the equals() method.
      boolean isFull()
      Returns true if both child and parent fields are non-null; false otherwise.

      • Methods inherited from class java.lang.Object

        clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • searchSrc

        public java.awt.Component searchSrc

      • child

        public java.awt.Component child

      • parent

        public java.awt.Component parent

    • Method Detail

      • find

        public static NestedComponents find​(java.awt.Component searchSrc,
                                    java.lang.Class childClass,
                                    java.lang.Class parentClass)
        Creates and returns a new NestedComponents instance, searching the parent Container hierarcy of the specified searchSrc for an ancestor of type childClass and a more senior ancestor of type parentClass.

        If either searchSrc, childClass, or parentClass is null, this method returns null.

        If searchSrc is an instanceof childClass, then the child field on the resulting NestedComponents will be equal (==) to the searchSrc field. If searchSrc is an instanceof parentClass, then the parent field on the resulting NestedComponents will be equal (==) to the searchSrc field. If an instance of parentClass is found before childClass, this the resulting NestedComponents instance will have a null child field.

        Parameters:
        searchSrc - the Component from which to start searching for parent Containers.
        childClass - the Class of the desired "child" Component
        parentClass - the Class of the desired "parent" Component
        Returns:
        a new NestedComponents instance based upon the specified parameters.

      • isFull

        public boolean isFull()
        Returns true if both child and parent fields are non-null; false otherwise.
        Returns:
        true if both child and parent fields are non-null; false otherwise.

      • hashCode

        public int hashCode()
        Overridden to match the equals() method.
        Overrides:
        hashCode in class java.lang.Object
        Returns:
        a hash code value for this object.
        See Also:
        equals(Object)

      • equals

        public boolean equals​(java.lang.Object obj)
        Returns true if the specified Object is a NestedComponents instance and all shares all of the same field references (==) as this NestedComponents for field searchSrc, child, and parent.
        Overrides:
        equals in class java.lang.Object
        Parameters:
        obj - the Object to test for equality
        Returns:
        true if the specified Object is "equal" to this NestedComponents instance; false otherwise.