/** * @see prefuse.action.Action#run(double) */ public void run(double frac) { Graph g = (Graph)m_vis.getGroup(m_group); initSchema(g.getNodes()); m_origin = getLayoutAnchor(); NodeItem n = getLayoutRoot(); Params np = (Params)n.get(PARAMS); g.getSpanningTree(n); // calc relative widths and maximum tree depth // performs one pass over the tree m_maxDepth = 0; calcAngularWidth(n, 0); if ( m_autoScale ) setScale(getLayoutBounds()); if ( !m_setTheta ) calcAngularBounds(n); // perform the layout if ( m_maxDepth > 0 ) layout(n, m_radiusInc, m_theta1, m_theta2); // update properties of the root node setX(n, null, m_origin.getX()); setY(n, null, m_origin.getY()); np.angle = m_theta2-m_theta1; }
/** * Compute the layout. * @param n the root of the current subtree under consideration * @param r the radius, current distance from the center * @param theta1 the start (in radians) of this subtree's angular region * @param theta2 the end (in radians) of this subtree's angular region */ protected void layout(NodeItem n, double r, double theta1, double theta2) { double dtheta = (theta2-theta1); double dtheta2 = dtheta / 2.0; double width = ((Params)n.get(PARAMS)).width; double cfrac, nfrac = 0.0; Iterator childIter = sortedChildren(n); while ( childIter != null && childIter.hasNext() ) { NodeItem c = (NodeItem)childIter.next(); Params cp = (Params)c.get(PARAMS); cfrac = cp.width / width; if ( c.isExpanded() && c.getChildCount()>0 ) { layout(c, r+m_radiusInc, theta1 + nfrac*dtheta, theta1 + (nfrac+cfrac)*dtheta); } setPolarLocation(c, n, r, theta1 + nfrac*dtheta + cfrac*dtheta2); cp.angle = cfrac*dtheta; nfrac += cfrac; } }
/** * Computes relative measures of the angular widths of each * expanded subtree. Node diameters are taken into account * to improve space allocation for variable-sized nodes. * * This method also updates the base angle value for nodes * to ensure proper ordering of nodes. */ private double calcAngularWidth(NodeItem n, int d) { if ( d > m_maxDepth ) m_maxDepth = d; double aw = 0; Rectangle2D bounds = n.getBounds(); double w = bounds.getWidth(), h = bounds.getHeight(); double diameter = d==0 ? 0 : Math.sqrt(w*w+h*h) / d; if ( n.isExpanded() && n.getChildCount() > 0 ) { Iterator childIter = n.children(); while ( childIter.hasNext() ) { NodeItem c = (NodeItem)childIter.next(); aw += calcAngularWidth(c,d+1); } aw = Math.max(diameter, aw); } else { aw = diameter; } ((Params)n.get(PARAMS)).width = aw; return aw; }