import netscape_beta.application.*; import netscape_beta.util.*; /** * A class that displays a node in a class dictionary graph. * * @version 1.0 12 Dec 1996 * @author Andrew Miller */ public class TreeNode extends Drawable implements VisitorHost, DragSource, DragDestination, Target { private static String cmdStartNode = new String("cmdTraversalStartNode"); private static String cmdBypassNode = new String("cmdTraversalBypassNode"); private static String cmdThroughNode = new String("cmdTraversalThroughNode"); private static String cmdEndNode = new String("cmdTraversalEndNode"); protected static String dataType = new String("TreeNode"); static private DemDoc m_doc = null; private DragSession drag = null; private int downX = 0; private int downY = 0; private Color m_colorPrevious = colorNormal; public boolean m_bInitialized = false; /** Returns run-time type information describing the * object type. * * @return Always "TreeNode" */ public static String dataType() { return dataType; } /** Set the document for which to draw nodes. * * @param doc Document being displayed. */ static public void setDoc(DemDoc doc) { m_doc = doc; } /** Deault constructor. * */ public TreeNode() { super(); } /** Initialize and display a TreeNode. * @param x The left position for the node * @param y The top position for the node * @param nodename The label to display for this node * @param parent The view to display the node in. */ public void init(int x, int y, String nodename, View parent) { super.init(x,y,nodename,parent); drag = null; downX = 0; downY = 0; m_colorPrevious = colorNormal; m_doc = null; // currently, TreeNodes may be initialized multiple times if(m_bInitialized != true) setupProperties(); m_bInitialized = true; } /** Initialize the TreeNode's properties. */ private void setupProperties() { // addProperty("Start Node", cmdStartNode); addProperty("Bypass Node", cmdBypassNode); addProperty("Through Node", cmdThroughNode); addProperty("End Node", cmdEndNode); } /** Handle a mouse down. If the user single-clicks * a TreeNode, it is added to the active visitor's * active traversal. * @param event Mouse event */ public boolean mouseDown(MouseEvent event) { downX = event.x; downY = event.y; if (super.mouseDown(event) == false) { if(event.clickCount() == 2) { doThroughNode(); } } return true; } /** Host a visitor * @param ds Drag session. * @return true - if visitor dropped */ public boolean dragDropped(DragSession ds) { Visitor visitor = (Visitor)ds.data(); // make the node look like the visitor // setBackgroundColor(visitor.backgroundColor()); // start a new traversal for this visitor at this node visitor.addTraversal(this); visitor.showHosts(superview(), true); // superview() == classview return true; } /** Determine if we host an object. * If a visitor is dragged, temporarily change * the TreeNode's background color to that of the * visitor to let the user know they've moved * across a host. * @param ds DragSession * return true - if visitor dragged */ public boolean dragEntered(DragSession ds) { if(Visitor.dataType().equals(ds.dataType())) { Visitor visitor = (Visitor)ds.data(); // make the node look like the visitor m_colorPrevious = backgroundColor(); setBackgroundColor(visitor.backgroundColor()); //setBackgroundColor(this.colorHighlight); return true; } else { return false; } } /** Determine if we host an object. * @param ds DragSession * @param x x pos * @param y y pos * return true - if visitor dragged */ public DragDestination acceptsDrag(DragSession session, int x, int y) { // If an icon is being dragged to us, return the DragDestination // (the RootNode itself.) if (Visitor.dataType().equals(session.dataType())) { return this; } else { return null; } } /** Reset the TreeNode's background color after * something is dragged across it. * @param ds DragSession */ public void dragExited(DragSession ds) { setBackgroundColor(m_colorPrevious); } /** Determine if we host an object. * @param ds DragSession * return true - if visitor dragged */ public boolean dragMoved(DragSession ds) { if(ds.dataType() == Visitor.dataType()) { return true; } else { return false; } } /** Begin a drag and drop session. Display * the visitor image while we move. * @param event Mouse event. */ public void mouseDragged(MouseEvent event) { if(drag != null) return; Bitmap bmp = Bitmap.bitmapNamed(new String("treenode.gif"), true); drag = new DragSession(this, bmp, 0, 0, downX, downY, dataType, this); } /** End a drag session. * @param ds Drag session. */ public void dragWasAccepted(DragSession ds) { drag = null; } /** End a drag session. * @param ds Drag session. */ public boolean dragWasRejected(DragSession ds) { drag = null; return true; // animate back to original pos } public boolean wantsMouseTrackingEvents() { return true; } public View sourceView(DragSession session) { return this; } /** Host the provided visitor. Make the TreeNode * look like the visitor to represent hosting. */ public void host(Visitor visitor) { if(visitor == null) { setBackgroundColor(colorNormal); } else { setBackgroundColor(visitor.backgroundColor()); } setDirty(true); } /** Return the type of this VisitorHost implementor at run-time. * * @return always "TreeNode" */ public String hostType() { return dataType(); } /** Return the node name to be used when generating * the traversal behavior. * * @return node name. */ public String getNameForTraversal() { return getNodeName(); } /** Respond to a command generated by the TreeNode's * property menu * @param string Command string * @param obj Object generating command */ public void performCommand(String string, Object obj) { super.performCommand(string, obj); if(string.equals(cmdStartNode)) { doStartNode(); } else if(string.equals(cmdBypassNode)) { doBypassNode(); } else if(string.equals(cmdThroughNode)) { doThroughNode(); } else if(string.equals(cmdEndNode)) { doEndNode(); } } /** NOT IMPLEMENTED */ protected void doStartNode() { // NOT IMPLEMENTED } /** Add the TreeNode to the active visitor's active traversal * as a bypass node */ protected void doBypassNode() { // LoD violation here Visitor visitor = m_doc.get_visitorManager().get_active(); if(visitor != null) { visitor.updateCurrentTraversal(this, Visitor.BYPASS); visitor.showHosts(superview(), true); } } /** Add the TreeNode to the active visitor's active traversal * as a through node */ protected void doThroughNode() { // LoD violation here Visitor visitor = m_doc.get_visitorManager().get_active(); if(visitor != null) { visitor.updateCurrentTraversal(this, Visitor.THROUGH); visitor.showHosts(superview(), true); } } /** Add the TreeNode to the active visitor's active traversal * as an end node */ protected void doEndNode() { // LoD violation here Visitor visitor = m_doc.get_visitorManager().get_active(); if(visitor != null) { visitor.updateCurrentTraversal(this, Visitor.END); visitor.showHosts(superview(), true); } } }