package com.onaro.util.jfc;

import java.awt.Component;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;

import javax.swing.JComponent;

/**
 * Factor that provides a Highlight implementation to JComponents.
 * The implementation adds an isHighlighted property to the components.
 */
public enum Highlighter {
    // Our single instance
    INSTANCE;

    public static boolean debug = false;
    
    /**
     * Property added to JComponent to store its highlight state.
     */
    private static final String PROP_IS_HIGHLIGHTED = "isHighlighted"; //$NON-NLS-1$
    

    /**
     * Returns true if this component is highlighted.
     * 
     * @param comp the component to test.
     * @return true if this component is highlighted.
     */
    public static boolean isHighlighted(JComponent comp) {
        return isHighlighted(comp, false);
    }
    
    /**
     * Returns true if this component is highlighted.
     * 
     * @param comp the component to test.
     * @param recurse if true then test the children recursively if they are highlighted.  Return as soon as you find one that is.
     * @return true if this component is highlighted.
     */
    public static boolean isHighlighted(JComponent comp, boolean recurse) {
        if(comp == null) {
            return(false);
        }
        if(Boolean.TRUE.equals(comp.getClientProperty(PROP_IS_HIGHLIGHTED))) {
            return true;
        }
        if(!recurse) {
            return false;
        }
        return hasHighlightedChildren(comp);
    }
    
    /**
     * Returns true if this component has any highlighted children.
     * 
     * @param comp the component to test.
     * @return true if this component has any highlighted children.
     */
    public static boolean hasHighlightedChildren(JComponent comp) {
        if(comp == null) {
            return(false);
        }
        for(Component childComp : comp.getComponents()) {
            if(childComp instanceof JComponent) {
                if(isHighlighted((JComponent)childComp, true)) {
                    return true;
                }
            }
        }
        return false;
    }
    
    /**
     * Sets highlight property of a component.
     * @param comp
     * @param isHighlighted
     */
    public static void setHighlighted(JComponent comp, boolean isHighlighted) {
        comp.putClientProperty(PROP_IS_HIGHLIGHTED, Boolean.valueOf(isHighlighted));
    }
    
    /**
     * Adds listener to component that listens for change to highlight property.
     * @param comp
     * @param listener
     */
    public static void addListener(JComponent comp, PropertyChangeListener listener) {
        comp.addPropertyChangeListener (PROP_IS_HIGHLIGHTED, listener);
    }
    
    /**
     * Add a listener that sets the highlight status of the given field based on the highlight status changes for the given child component.  This
     * will cause the given container component to fire/forward the event.
     */
    public static void addForwardingListener(final IHighlighting field, final JComponent comp) {
        final JComponent fieldComp = (JComponent)field;
        
        comp.addPropertyChangeListener(PROP_IS_HIGHLIGHTED, new PropertyChangeListener() {
            @Override
            public void propertyChange (PropertyChangeEvent event) {
                boolean compoundIsHighlighted = field.isHighlighted();
                
                // If the compound field highlight is different that the component
                if(!Boolean.valueOf(compoundIsHighlighted).equals(event.getNewValue())) {
                    boolean anyFieldIsHighlighted = Highlighter.hasHighlightedChildren(fieldComp);
                    
                        // If the compound field highlight status does not match the children
                    if(compoundIsHighlighted != anyFieldIsHighlighted) {
                        // Set the highlight status of the compound field to match the children.
                        field.setHighlight(anyFieldIsHighlighted);
                            
                        // Notify anyone listening
                        fieldComp.firePropertyChange(PROP_IS_HIGHLIGHTED, compoundIsHighlighted, anyFieldIsHighlighted);
                    }
                }
            }
        });
    }
}