package graph.filter;
import graph.*;
import java.awt.*;
import java.util.*;

/**
 * A class for managing active filters.  This manifests itself
 * as a horizontal row of buttons to be placed at the bottom
 * of the editing window.  The user can add and delete filters,
 * which adds and deletes their corresponding buttons.  When
 * the user presses one of the buttons, a configuration dialog
 * for that filter pops up.<p>
 *
 * This provides a clean and simple way for the user to
 * arbitrarily configure his view on the data.
 *
 * @see Filter
 * @see FilterConfig
 * @see FilterPalette
 * @author Michael Shilman (michaels@eecs.berkeley.edu)
 * @version $Id$
 */
public class FilterBank extends Panel {
	public static final int MAX_FILTERS = 10;
	
	Button m_add = new Button("Add");
	Button m_delete = new Button("Delete");
	Panel m_filterButtons = new Panel();
	int m_numFilters = 0;
	Filter m_filters[] = new Filter[MAX_FILTERS];
	Button m_buttons[] = new Button[MAX_FILTERS];
	FilterPalette m_palette;
	GridBagLayout m_buttonLayout;
	GridBagConstraints m_buttonConstraints;
	static FilterBank s_this = null;
	Graph m_graph = null;
	
	public static FilterBank createFilterBank(Graph g) {
		//for now, make sure only one of these is
		//created, ever.
		if(s_this == null) {
			s_this = new FilterBank(g);
			return s_this;
		}
		else {
			return null;
		}
	}
	
	public static FilterBank getFilterBank() {
		return s_this;
	}
	
	public void setGraph(Graph g) {
		m_graph = g;
		update();
	}
	
	public Graph getGraph() {
		return m_graph;
	}
	
	public static void update() {
		if(s_this.m_graph != null) {
			s_this.apply(s_this.m_graph);
		}
	}
	
	public void apply(Graph g) {
		for(Enumeration e = g.nodes.elements(); e.hasMoreElements();) {
			Node n = (Node)e.nextElement();
			applySingle(n);
			if(n instanceof Graph) {
				Graph sub = (Graph)n;
				apply(sub);
			}
		}
	}
	
	public void applySingle(Node n) {
		for(int i = 0; i < m_numFilters; i++) {
			Filter f = m_filters[i];
			f.apply(n);
		}
	}
	
	private FilterBank(Graph g) {
		m_graph = g;
		
		GridBagLayout gb = new GridBagLayout();
		GridBagConstraints gc = new GridBagConstraints();
		setLayout(gb);
		
		gc.anchor = GridBagConstraints.WEST;
		gb.setConstraints(m_add, gc);
		add(m_add);
		gb.setConstraints(m_add, gc);
		add(m_delete);
		gc.gridwidth = GridBagConstraints.REMAINDER;
		gc.fill = GridBagConstraints.BOTH;
		gc.weightx = 1;
		gb.setConstraints(m_filterButtons, gc);
		m_buttonLayout = new GridBagLayout();
		m_buttonConstraints = new GridBagConstraints();
		m_buttonConstraints.insets = new Insets(3,3,3,0);
		m_buttonConstraints.weightx = 1;
		m_buttonConstraints.anchor = GridBagConstraints.WEST;
		m_filterButtons.setLayout(m_buttonLayout);
		m_filterButtons.setBackground(Color.yellow);
		add(m_filterButtons);
		
		setBackground(Color.cyan);
	}
	
	
	void add(Filter f) {
		if(m_numFilters < (MAX_FILTERS-1)) {
			m_filters[m_numFilters] = f;
			Button b = new Button(f.getName());
			m_buttons[m_numFilters] = b;
			m_buttonLayout.setConstraints(b, m_buttonConstraints);
		
			m_filterButtons.add(b);
			repaint();
			resize(size());
			m_numFilters++;
		}
	}
	
	public void setPalette(FilterPalette palette) {
		m_palette = palette;
	}
	
	void delete() {
		
	}
	
	public Dimension minimumSize() { return new Dimension(20, 300); }
	
	public boolean action(Event evt, Object what) {
		if(evt.target == m_add) {
			m_palette.show();
			return true;
		}
		else if(evt.target == m_delete) {
			//XXX delete the selected filter
			return true;
		}
		else {
			return super.action(evt, what);
		}
	}
}