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   <title>Graph Library - The Architecture</title>
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 <body>
 <h1>Graph Library - The Architecture</h1>
 <span style="font-weight: bold;">Version:</span> 1.0<br>
 <span style="font-weight: bold;">Date:</span> September 22th, 2005<span
  style="font-weight: bold;"><br>
 Author:</span> David Kaspar<br>
 <hr style="width: 100%; height: 2px;">
 <h2>Abstract</h2>
 The main purpose of the Library is to visualize a graph data model on a
 screen (using Swing's JComponent) and allow Drag&amp;Drop style of
 work. It
 should be very easy to integrate it with
 existing models and it should support different Look&amp;Feels.<br>
 <br>
 This document describes the architecture of the Graph Library.<br>
 <h2>Overall Description</h2>
 The Library consists of 3 parts:<br>
 <ul>
   <li>model - the part describing and holding graph data.<br>
   </li>
   <li>view - the part visualizing the data.<br>
   </li>
   <li>control - the part controlling the model data and view
 look&amp;feel.<br>
   </li>
 </ul>
 <h3>The Model</h3>
 The graph library works with following model:<br>
 <ul>
   <li>There is a document.</li>
   <li>The document contains a set of nodes and links.</li>
   <li>A node contains a set of ports. One of these ports could be a
 default port that is substituting a node when there are operations with
 ports only.</li>
   <li>A link could have assigned a source port and a target port.</li>
   <li>A component is a node, a link, or a port.<br>
   </li>
 </ul>
 <h3>The View</h3>
 The view is a Swing JComponent which could be used as any other
 components. It is fully controlled by controls and suplies them an
 instance of Graphics2D for rendering the data. This allows an
 integration with any technology which works with Graphics2D - for
 example: Java2D, ...<br>
 <h3>The Control</h3>
 The view it self is just a Swing JComponent and does not do anything
 (neither reacting on user actions nor painting itself). There are
 following interfaces, each is providing specific operations that doing
 the work:<br>
 <ul>
   <li>Document Renderer - takes care about all renderings related to a
 document (for example: background, selection), add creating following
 renderers, router, and layouter.<br>
   </li>
   <li>Node Renderer - takes care about all renderings related to a node.<br>
   </li>
   <li>Port Renderer - takes care about all renderings related to a port.<br>
   </li>
   <li>Link Renderer - takes care about all renderings related to a link
 based on control points of a link.<br>
   </li>
   <li>Link Router - takes care about resolving control points (a route)
 of a link.<br>
   </li>
   <li>Nodes Layouter - takes care about resolving a locations of a
 nodes.<br>
   </li>
   <li>View Controller - takes care about an interrraction between the
 UI and an user.<br>
   </li>
 </ul>
 These controls allows developer to customize anything on the view.<br>
 <h2>The Interaction Between the Control, the View, and the Model<br>
 </h2>
 The Graph Library itself holds internally additional data to the ones
 from the model - mainly: location, active areas, bounds for nodes,
 links, ports (except a location for a link). A location is a center of
 a component on the screen. Bounds is the smallest rectangle that
 contains whole component (for nodes it includes its ports too). Bounds
 are used for repainting of components. Active areas are rectangle on
 the screen which defines places where a component is (means: something
 is usually painted there and when a control asks for a component on
 that place, then the component is returned).<br>
 <br>
 These 3 parts of the Library are not connected directly to each other
 but through the presenters and helper:<br>
 <ul>
   <li>Graph Helper - allows the control to access and modify data from
 the model and the internal data related to the model data.</li>
   <li>View Presenter - allows the view controller to access the view,
 cooperate with it and to access the graph helper.</li>
 </ul>
 <h3>Model Components vs. Proxy Components</h3>
 All 3 parts are working with interfaces representing components (a
 port, a link, or a node) in the model. They are used even for the
 accessing internal data.<br>
 When some internal data has to be accessed, a peer for each component
 need to be found in the internal data. Then it is possible to work with
 the data related to the component. The problem is that the search for a
 component peer is slow (non-constant time). Therefore there are two
 components: <span style="font-weight: bold;">Model components</span>
 and <span style="font-weight: bold;">Proxy components</span>.<br>
 <br>
 Model components are components implementing IGraphNode, IGraphLink, or
 IGraphPort inteface (interfaces defining the model). They are
 implemented by a developer using the Library. Proxy components also
 implement IGraphPort, IGraphNode, IGraphLink interfaces and forward all
 the interface method calls to the model components but they are not the
 same instance as the model components. The proxy components are used to
 faster cooperation with internal structures of the graph library
 because they contain additional data needed for the access.<br>
 Therefore it is better to use these proxy components when you are
 working with the Graph Helper, the Presenters from the Control side
 althrough it is possible to use model components.<br>
 <h3>Recalculation<br>
 </h3>
 A location, active areas, and bounds are often needed to recalculate.
 For example it is invoked when a new node is added to the document, a
 node is moved on the screen, a link changes its control point, ...<br>
 <br>
 The recalculation process is described by the following algorithm:<br>
 <table style="width: 100%; text-align: left;" border="1" cellpadding="0"
  cellspacing="0">
   <tbody>
     <tr>
       <td style="vertical-align: top;">
       <pre>
 for (node : nodes) {
     for (port : node.ports) {
         // renderer must resolve relative-bounds,
         // relative-active-areas of the port and
         // optionally its relative location

         GraphHelper.getPortRenderer (port).layoutPort ()
     }

     // driver must resolve relative-bounds
     // (including relative-bounds, relative-location of all ports) and
     // relative-active-areas of the node and
     // optionally relative-locations of all its ports

     GraphHelper.getNodeRenderer (node).layoutNode ()
 }

 // layouter should resolve location of all nodes
 GraphHelper.getDocumentRenderer ().getNodesLayouter ().layoutNodesLocations ()

 for (node : nodes) {
     // absolute location, active areas, and bounds of the node and
     // all its ports are automatically computer by the Library

     recalculate-absolute-location (node)
 }

 for (link : links) {
     // resolves control points (a route) of the link
     GraphHelper.getLinkRouter (link).routeLink ()

     // resolves absolute bounds of a link
     GraphHelper.getLinkRenderer (link).layoutLink ()
 }
 </pre>
       </td>
     </tr>
   </tbody>
 </table>
 Node location is resolved by a nodes layouter.<br>
 Node active-areas on a screen is defined by: node.location +
 node.relativeActiveAreas.<br>
 Node bounds on a screen is defined by: node.location +
 node.relativeBounds.<br>
 Port active-areas on a screen is defined by: node.location +
 port.relativeLocation + port.relativeActiveAreas.<br>
 Port bounds on a screen is defined by: node.location +
 port.relativeLocation + port.relativeBounds.<br>
 Bounds of links are resolved by its a link render directly.<br>
 <h2>An Existing Model Integration</h2>
 The Library itself has its own built-in implementation of the model
 interfaces that allows a developer to work with the model using
 bean-patterns, ...<br>
 Usually a developer already has an existing model and all he/she need
 to integrate with the Library and implement or reuse the look&amp;feel
 of a view.<br>
 <br>
 The interraction between the Model and the Library is decribed by
 following diagram:
 <br>
 <div style="text-align: center">
 <a href="ModelLibraryInterraction.png"><img alt="Model - Library Interraction"
  src="ModelLibraryInterraction.png" style="width: 443px; height: 98px;"></a>
 </div>
 <br>
 The extenal model has to implement the model interfaces. An user action
 events are forwarded to an event handler which it also implemented by a
 developer of the model. The event handler has to process the event.
 Based on the event it could change the model according the event. When
 an model changes, it has to fire an event to the Library about the
 change. Then the event is processed (components recalculated) and
 renderer on the screen.<br>
 <h2>Abilities</h2>
 The Library is designed to be easy extensible. The model interfaces
 contain all getters for data that are necessary to describe the
 structure of a graph.<br>
 Usually a developer would like to contain more data - for example: a
 display name, a tooltip, ...<br>
 For this purpose there are <span style="font-weight: bold;">Abilities</span>.
 Abilities are represented by an interface or a class which
 implementation is stored in the lookup for a document, a node, a port,
 or a link.<br>
 When a renderer have to render a component, it could look into lookup
 of an ability (that a render could recognize and use) and if an
 instance is returned, it could work with it.<br>
 Currently there are following abilities defined in the Library:<br>
 <ul>
   <li><span style="font-weight: bold;">Displayable</span> - allows to
 get a display name, an icon, and a tooltip text<br>
   </li>
   <li><span style="font-weight: bold;">Directionable</span> - allows to
 get a direction<br>
   </li>
   <li><span style="font-weight: bold;">NameEditable</span> - allows to
 check if a name edit is approved, a initial name, and callback for
 changing the name<br>
   </li>
 </ul>
 <h2>In-Place Editors</h2>
 The Library also allows to define and use in-place editors. The editor
 could be obtained from renderers or a view control could open it
 itself. Currently the Library contains <span style="font-weight: bold;">Text
 Field Editor<span style="font-weight: bold;"></span></span> (uses
 JTextField for a single line text editing). Usually a renderer
 recognizes NameEditable ability and offers related editor.<br>
 <h2>Packages Description</h2>
 This package hierarchy is located at <span style="font-weight: bold;">org.netbeans</span>
 package.<br>
 <br>
 The Graph Library - <span style="font-weight: bold;">API</span>
 packages:<br>
 <ul>
   <li><span style="font-weight: bold;">graph.api</span><br>
     <ul>
       <li> <span style="font-weight: bold;">GraphFactory</span> - a
 factory class for creating a view for a model</li>
       <li><span style="font-weight: bold;">IGraphEventHandler</span> -
 an event handler for user action called by the Library</li>
     </ul>
   </li>
 </ul>
 The Graph Library - <span style="font-weight: bold;">Model API</span>
 packages:<br>
 <ul>
   <li><span style="font-weight: bold;">graph.api.model</span> -
 contains model interfaces.<br>
     <ul>
       <li><span style="font-weight: bold;">GraphEvent</span> - an event
 used by document listener.</li>
       <li><span style="font-weight: bold;">IGraphDocument</span> - an
 interface defining a document.</li>
       <li><span style="font-weight: bold;">IGraphLink</span> - an
 interface defining a link.</li>
       <li><span style="font-weight: bold;">IGraphNode</span> - an
 interface defining a node.</li>
       <li><span style="font-weight: bold;">IGraphPort</span> - an
 interface defining a port.<br>
       </li>
     </ul>
   </li>
   <li><span style="font-weight: bold;">graph.api.model.ability</span> -
 contains interfaces defining abilities<br>
     <ul>
       <li><span style="font-weight: bold;">IDirectionable</span><br>
       </li>
       <li style="font-weight: bold;">IDisplayable</li>
       <li><span style="font-weight: bold;">INameEditable</span></li>
     </ul>
   </li>
   <li><span style="font-weight: bold;">graph.api.model.builtin</span> -
 contains built-in implementation of a model interfaces.<br>
     <ul>
       <li style="font-weight: bold;">GraphDocument</li>
       <li style="font-weight: bold;">GraphLink</li>
       <li style="font-weight: bold;">GraphNode</li>
       <li style="font-weight: bold;">GraphPort</li>
     </ul>
   </li>
 </ul>
 The Graph Library - <span style="font-weight: bold;">Control API</span>
 packages:<br>
 <ul>
   <li><span style="font-weight: bold;">graph.api.control</span> -
 contains cotrol interfaces.<br>
     <ul>
       <li><span style="font-weight: bold;">GraphHelper</span> - graph
 helper class.<br>
       </li>
       <li><span style="font-weight: bold;">IGraphDocumentRenderer</span>
 - a document renderer interface.</li>
       <li><span style="font-weight: bold;">IGraphLinkRenderer</span> -
 a link renderer interface.</li>
       <li><span style="font-weight: bold;">IGraphLinkRouter</span> - a
 link router interface.<br>
       </li>
       <li><span style="font-weight: bold;">IGraphNodeRenderer</span> -
 a node renderer interface.</li>
       <li><span style="font-weight: bold;">IGraphNodesLayouter</span> -
 a nodes layouter interface.</li>
       <li><span style="font-weight: bold;">IGraphPortRenderer</span> -
 a port renderer interface.</li>
       <li><span style="font-weight: bold;">IGraphViewController</span>
 - a view controller interface.</li>
     </ul>
   </li>
   <li><span style="font-weight: bold;">graph.api.control.buildin</span>
 - contains built-in controls.<br>
     <ul>
       <li><span style="font-weight: bold;">AnimatedNodesLayouter</span>
 - animated nodes layout support class.</li>
       <li><span style="font-weight: bold;">BreadthFirstNodesLayouter</span>
 - breadth-first nodes layout class.</li>
       <li><span style="font-weight: bold;">DefaultViewController</span>
 - a default view controller with drag&amp;drop style of work
 implementation.<br>
       </li>
     </ul>
   </li>
   <li><span style="font-weight: bold;">graph.api.control.editor</span>
 - contains in-place editors.<br>
     <ul>
       <li><span style="font-weight: bold;">IGraphEditor</span> - an
 in-place editor descriptor interface.</li>
       <li><span style="font-weight: bold;">TextFieldEditor</span> -
 text field in-place editor implementation.<br>
       </li>
     </ul>
   </li>
 </ul>
 Additional The Graph Library packages:<br>
 <ul>
   <li><span style="font-weight: bold;">graph</span> - the rest of the
 code of the library which is not an API.<br>
   </li>
   <li><span style="font-weight: bold;">graph.examples</span> - examples
 for
 the Graph Library.<br>
   </li>
   <li><span style="font-weight: bold;">graph.examples.resources</span>
 -
 resources for the examples.</li>
   <li><span style="font-weight: bold;">graph.examples.control</span> -
 controls
 for the examples.</li>
   <li><span style="font-weight: bold;">graph.examples.control.resources</span>
 -
 resource for the controls.</li>
   <li><span style="font-weight: bold;">graph.examples.dnd</span> -
 dnd example.</li>
   <li><span style="font-weight: bold;">graph.examples.dnd.resources</span>
 -
 resource for the dnd example.<br>
   </li>
 </ul>
 <h2>Dependencies</h2>
 The Graph Library is currently dependent on standard <span
  style="font-weight: bold;">JDK 1.4</span> classes and NetBeans <span
  style="font-weight: bold;">org-openide-util.jar</span> library. From
 the jar it uses:<br>
 <ul>
   <li>NbBundle class - used for localized messages</li>
   <li>Utilities class - for images loading</li>
   <li>Lookup package - for the Abilities</li>
 </ul>
 If you do not
 want to have a dependency on org-openide-util.jar, you have to
 reimplement these
 classes.<br>
 <h2>Distribution<br>
 </h2>
 The Graph Library is a single jar package - <span
  style="font-weight: bold;">org-openide-graphlib.jar</span>. For a
 proper work it
 requires an org-openide-util.jar on a classpath and JDK 1.4.<br>
 <h2>Requirements for the Library<br>
 </h2>
 <ol>
   <li>Visualize a graph model defined by following rules:<br>
     <ul>
       <li>A node could have a set of ports.</li>
       <li>A port has a single node assigned.</li>
       <li>A link could have a source and a target port assigned.<br>
       </li>
     </ul>
   </li>
   <li>There must be separated Model, View, and Control parts.</li>
   <li>Easy integration of existing external models - a model must fire
 an
 event for any change in the model and all user actions should be passed
 to an event handler and it has to decide how to change the model.<br>
   </li>
   <li>Support for custom look&amp;feels.<br>
   </li>
   <li>Drag&amp;Drop style of work - possibility to move which nodes on
 the screen, creating new links, relinking of source or target ports,
 rectangular selections, ...</li>
   <li>Drag&amp;Drop support.<br>
   </li>
   <li>In-place editing support.</li>
   <li>Multi-view support - support for cloning views or to create
 different view of the same model.<br>
   </li>
   <li>Multi-layer rendering support - allows to components in the
 layers - for example: a link could be renderer below nodes but when a
 link is selected it could be renderer over nodes, ...<br>
   </li>
   <li>Undo-Redo support - all node location changes are put to UndoRedo</li>
   <li>Zoom in/out, snap-to-grid support.<br>
   </li>
 </ol>
 <hr style="width: 100%; height: 2px;">If you have any questions or
 comments, send an email to <a href="mailto:dkaspar@netbeans.org">dkaspar@netbeans.org</a>.<br>
 </body>
 </html>
	<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
	<html>
	<head>
	<meta content="text/html; charset=ISO-8859-1" http-equiv="content-type">
	<title>Graph Library - The Architecture</title>
	<meta content="David.Kaspar@sun.com" name="author">
	</head>
	<body>
	<h1>Graph Library - The Architecture</h1>
	<span style="font-weight: bold;">Version:</span> 1.0<br>
	<span style="font-weight: bold;">Date:</span> September 22th, 2005<span
	style="font-weight: bold;"><br>
	Author:</span> David Kaspar<br>
	<hr style="width: 100%; height: 2px;">
	<h2>Abstract</h2>
	The main purpose of the Library is to visualize a graph data model on a
	screen (using Swing's JComponent) and allow Drag&Drop style of
	work. It
	should be very easy to integrate it with
	existing models and it should support different Look&Feels.<br>
	<br>
	This document describes the architecture of the Graph Library.<br>
	<h2>Overall Description</h2>
	The Library consists of 3 parts:<br>
	<ul>
	<li>model - the part describing and holding graph data.<br>
	</li>
	<li>view - the part visualizing the data.<br>
	</li>
	<li>control - the part controlling the model data and view
	look&feel.<br>
	</li>
	</ul>
	<h3>The Model</h3>
	The graph library works with following model:<br>
	<ul>
	<li>There is a document.</li>
	<li>The document contains a set of nodes and links.</li>
	<li>A node contains a set of ports. One of these ports could be a
	default port that is substituting a node when there are operations with
	ports only.</li>
	<li>A link could have assigned a source port and a target port.</li>
	<li>A component is a node, a link, or a port.<br>
	</li>
	</ul>
	<h3>The View</h3>
	The view is a Swing JComponent which could be used as any other
	components. It is fully controlled by controls and suplies them an
	instance of Graphics2D for rendering the data. This allows an
	integration with any technology which works with Graphics2D - for
	example: Java2D, ...<br>
	<h3>The Control</h3>
	The view it self is just a Swing JComponent and does not do anything
	(neither reacting on user actions nor painting itself). There are
	following interfaces, each is providing specific operations that doing
	the work:<br>
	<ul>
	<li>Document Renderer - takes care about all renderings related to a
	document (for example: background, selection), add creating following
	renderers, router, and layouter.<br>
	</li>
	<li>Node Renderer - takes care about all renderings related to a node.<br>
	</li>
	<li>Port Renderer - takes care about all renderings related to a port.<br>
	</li>
	<li>Link Renderer - takes care about all renderings related to a link
	based on control points of a link.<br>
	</li>
	<li>Link Router - takes care about resolving control points (a route)
	of a link.<br>
	</li>
	<li>Nodes Layouter - takes care about resolving a locations of a
	nodes.<br>
	</li>
	<li>View Controller - takes care about an interrraction between the
	UI and an user.<br>
	</li>
	</ul>
	These controls allows developer to customize anything on the view.<br>
	<h2>The Interaction Between the Control, the View, and the Model<br>
	</h2>
	The Graph Library itself holds internally additional data to the ones
	from the model - mainly: location, active areas, bounds for nodes,
	links, ports (except a location for a link). A location is a center of
	a component on the screen. Bounds is the smallest rectangle that
	contains whole component (for nodes it includes its ports too). Bounds
	are used for repainting of components. Active areas are rectangle on
	the screen which defines places where a component is (means: something
	is usually painted there and when a control asks for a component on
	that place, then the component is returned).<br>
	<br>
	These 3 parts of the Library are not connected directly to each other
	but through the presenters and helper:<br>
	<ul>
	<li>Graph Helper - allows the control to access and modify data from
	the model and the internal data related to the model data.</li>
	<li>View Presenter - allows the view controller to access the view,
	cooperate with it and to access the graph helper.</li>
	</ul>
	<h3>Model Components vs. Proxy Components</h3>
	All 3 parts are working with interfaces representing components (a
	port, a link, or a node) in the model. They are used even for the
	accessing internal data.<br>
	When some internal data has to be accessed, a peer for each component
	need to be found in the internal data. Then it is possible to work with
	the data related to the component. The problem is that the search for a
	component peer is slow (non-constant time). Therefore there are two
	components: <span style="font-weight: bold;">Model components</span>
	and <span style="font-weight: bold;">Proxy components</span>.<br>
	<br>
	Model components are components implementing IGraphNode, IGraphLink, or
	IGraphPort inteface (interfaces defining the model). They are
	implemented by a developer using the Library. Proxy components also
	implement IGraphPort, IGraphNode, IGraphLink interfaces and forward all
	the interface method calls to the model components but they are not the
	same instance as the model components. The proxy components are used to
	faster cooperation with internal structures of the graph library
	because they contain additional data needed for the access.<br>
	Therefore it is better to use these proxy components when you are
	working with the Graph Helper, the Presenters from the Control side
	althrough it is possible to use model components.<br>
	<h3>Recalculation<br>
	</h3>
	A location, active areas, and bounds are often needed to recalculate.
	For example it is invoked when a new node is added to the document, a
	node is moved on the screen, a link changes its control point, ...<br>
	<br>
	The recalculation process is described by the following algorithm:<br>
	<table style="width: 100%; text-align: left;" border="1" cellpadding="0"
	cellspacing="0">
	<tbody>
	<tr>
	<td style="vertical-align: top;">
	<pre>
	for (node : nodes) {
	for (port : node.ports) {
	// renderer must resolve relative-bounds,
	// relative-active-areas of the port and
	// optionally its relative location

	GraphHelper.getPortRenderer (port).layoutPort ()
	}

	// driver must resolve relative-bounds
	// (including relative-bounds, relative-location of all ports) and
	// relative-active-areas of the node and
	// optionally relative-locations of all its ports

	GraphHelper.getNodeRenderer (node).layoutNode ()
	}

	// layouter should resolve location of all nodes
	GraphHelper.getDocumentRenderer ().getNodesLayouter ().layoutNodesLocations ()

	for (node : nodes) {
	// absolute location, active areas, and bounds of the node and
	// all its ports are automatically computer by the Library

	recalculate-absolute-location (node)
	}

	for (link : links) {
	// resolves control points (a route) of the link
	GraphHelper.getLinkRouter (link).routeLink ()

	// resolves absolute bounds of a link
	GraphHelper.getLinkRenderer (link).layoutLink ()
	}
	</pre>
	</td>
	</tr>
	</tbody>
	</table>
	Node location is resolved by a nodes layouter.<br>
	Node active-areas on a screen is defined by: node.location +
	node.relativeActiveAreas.<br>
	Node bounds on a screen is defined by: node.location +
	node.relativeBounds.<br>
	Port active-areas on a screen is defined by: node.location +
	port.relativeLocation + port.relativeActiveAreas.<br>
	Port bounds on a screen is defined by: node.location +
	port.relativeLocation + port.relativeBounds.<br>
	Bounds of links are resolved by its a link render directly.<br>
	<h2>An Existing Model Integration</h2>
	The Library itself has its own built-in implementation of the model
	interfaces that allows a developer to work with the model using
	bean-patterns, ...<br>
	Usually a developer already has an existing model and all he/she need
	to integrate with the Library and implement or reuse the look&feel
	of a view.<br>
	<br>
	The interraction between the Model and the Library is decribed by
	following diagram:
	<br>
	<div style="text-align: center">
	<a href="ModelLibraryInterraction.png"><img alt="Model - Library Interraction"
	src="ModelLibraryInterraction.png" style="width: 443px; height: 98px;"></a>
	</div>
	<br>
	The extenal model has to implement the model interfaces. An user action
	events are forwarded to an event handler which it also implemented by a
	developer of the model. The event handler has to process the event.
	Based on the event it could change the model according the event. When
	an model changes, it has to fire an event to the Library about the
	change. Then the event is processed (components recalculated) and
	renderer on the screen.<br>
	<h2>Abilities</h2>
	The Library is designed to be easy extensible. The model interfaces
	contain all getters for data that are necessary to describe the
	structure of a graph.<br>
	Usually a developer would like to contain more data - for example: a
	display name, a tooltip, ...<br>
	For this purpose there are <span style="font-weight: bold;">Abilities</span>.
	Abilities are represented by an interface or a class which
	implementation is stored in the lookup for a document, a node, a port,
	or a link.<br>
	When a renderer have to render a component, it could look into lookup
	of an ability (that a render could recognize and use) and if an
	instance is returned, it could work with it.<br>
	Currently there are following abilities defined in the Library:<br>
	<ul>
	<li><span style="font-weight: bold;">Displayable</span> - allows to
	get a display name, an icon, and a tooltip text<br>
	</li>
	<li><span style="font-weight: bold;">Directionable</span> - allows to
	get a direction<br>
	</li>
	<li><span style="font-weight: bold;">NameEditable</span> - allows to
	check if a name edit is approved, a initial name, and callback for
	changing the name<br>
	</li>
	</ul>
	<h2>In-Place Editors</h2>
	The Library also allows to define and use in-place editors. The editor
	could be obtained from renderers or a view control could open it
	itself. Currently the Library contains <span style="font-weight: bold;">Text
	Field Editor<span style="font-weight: bold;"></span></span> (uses
	JTextField for a single line text editing). Usually a renderer
	recognizes NameEditable ability and offers related editor.<br>
	<h2>Packages Description</h2>
	This package hierarchy is located at <span style="font-weight: bold;">org.netbeans</span>
	package.<br>
	<br>
	The Graph Library - <span style="font-weight: bold;">API</span>
	packages:<br>
	<ul>
	<li><span style="font-weight: bold;">graph.api</span><br>
	<ul>
	<li> <span style="font-weight: bold;">GraphFactory</span> - a
	factory class for creating a view for a model</li>
	<li><span style="font-weight: bold;">IGraphEventHandler</span> -
	an event handler for user action called by the Library</li>
	</ul>
	</li>
	</ul>
	The Graph Library - <span style="font-weight: bold;">Model API</span>
	packages:<br>
	<ul>
	<li><span style="font-weight: bold;">graph.api.model</span> -
	contains model interfaces.<br>
	<ul>
	<li><span style="font-weight: bold;">GraphEvent</span> - an event
	used by document listener.</li>
	<li><span style="font-weight: bold;">IGraphDocument</span> - an
	interface defining a document.</li>
	<li><span style="font-weight: bold;">IGraphLink</span> - an
	interface defining a link.</li>
	<li><span style="font-weight: bold;">IGraphNode</span> - an
	interface defining a node.</li>
	<li><span style="font-weight: bold;">IGraphPort</span> - an
	interface defining a port.<br>
	</li>
	</ul>
	</li>
	<li><span style="font-weight: bold;">graph.api.model.ability</span> -
	contains interfaces defining abilities<br>
	<ul>
	<li><span style="font-weight: bold;">IDirectionable</span><br>
	</li>
	<li style="font-weight: bold;">IDisplayable</li>
	<li><span style="font-weight: bold;">INameEditable</span></li>
	</ul>
	</li>
	<li><span style="font-weight: bold;">graph.api.model.builtin</span> -
	contains built-in implementation of a model interfaces.<br>
	<ul>
	<li style="font-weight: bold;">GraphDocument</li>
	<li style="font-weight: bold;">GraphLink</li>
	<li style="font-weight: bold;">GraphNode</li>
	<li style="font-weight: bold;">GraphPort</li>
	</ul>
	</li>
	</ul>
	The Graph Library - <span style="font-weight: bold;">Control API</span>
	packages:<br>
	<ul>
	<li><span style="font-weight: bold;">graph.api.control</span> -
	contains cotrol interfaces.<br>
	<ul>
	<li><span style="font-weight: bold;">GraphHelper</span> - graph
	helper class.<br>
	</li>
	<li><span style="font-weight: bold;">IGraphDocumentRenderer</span>
	- a document renderer interface.</li>
	<li><span style="font-weight: bold;">IGraphLinkRenderer</span> -
	a link renderer interface.</li>
	<li><span style="font-weight: bold;">IGraphLinkRouter</span> - a
	link router interface.<br>
	</li>
	<li><span style="font-weight: bold;">IGraphNodeRenderer</span> -
	a node renderer interface.</li>
	<li><span style="font-weight: bold;">IGraphNodesLayouter</span> -
	a nodes layouter interface.</li>
	<li><span style="font-weight: bold;">IGraphPortRenderer</span> -
	a port renderer interface.</li>
	<li><span style="font-weight: bold;">IGraphViewController</span>
	- a view controller interface.</li>
	</ul>
	</li>
	<li><span style="font-weight: bold;">graph.api.control.buildin</span>
	- contains built-in controls.<br>
	<ul>
	<li><span style="font-weight: bold;">AnimatedNodesLayouter</span>
	- animated nodes layout support class.</li>
	<li><span style="font-weight: bold;">BreadthFirstNodesLayouter</span>
	- breadth-first nodes layout class.</li>
	<li><span style="font-weight: bold;">DefaultViewController</span>
	- a default view controller with drag&drop style of work
	implementation.<br>
	</li>
	</ul>
	</li>
	<li><span style="font-weight: bold;">graph.api.control.editor</span>
	- contains in-place editors.<br>
	<ul>
	<li><span style="font-weight: bold;">IGraphEditor</span> - an
	in-place editor descriptor interface.</li>
	<li><span style="font-weight: bold;">TextFieldEditor</span> -
	text field in-place editor implementation.<br>
	</li>
	</ul>
	</li>
	</ul>
	Additional The Graph Library packages:<br>
	<ul>
	<li><span style="font-weight: bold;">graph</span> - the rest of the
	code of the library which is not an API.<br>
	</li>
	<li><span style="font-weight: bold;">graph.examples</span> - examples
	for
	the Graph Library.<br>
	</li>
	<li><span style="font-weight: bold;">graph.examples.resources</span>
	-
	resources for the examples.</li>
	<li><span style="font-weight: bold;">graph.examples.control</span> -
	controls
	for the examples.</li>
	<li><span style="font-weight: bold;">graph.examples.control.resources</span>
	-
	resource for the controls.</li>
	<li><span style="font-weight: bold;">graph.examples.dnd</span> -
	dnd example.</li>
	<li><span style="font-weight: bold;">graph.examples.dnd.resources</span>
	-
	resource for the dnd example.<br>
	</li>
	</ul>
	<h2>Dependencies</h2>
	The Graph Library is currently dependent on standard <span
	style="font-weight: bold;">JDK 1.4</span> classes and NetBeans <span
	style="font-weight: bold;">org-openide-util.jar</span> library. From
	the jar it uses:<br>
	<ul>
	<li>NbBundle class - used for localized messages</li>
	<li>Utilities class - for images loading</li>
	<li>Lookup package - for the Abilities</li>
	</ul>
	If you do not
	want to have a dependency on org-openide-util.jar, you have to
	reimplement these
	classes.<br>
	<h2>Distribution<br>
	</h2>
	The Graph Library is a single jar package - <span
	style="font-weight: bold;">org-openide-graphlib.jar</span>. For a
	proper work it
	requires an org-openide-util.jar on a classpath and JDK 1.4.<br>
	<h2>Requirements for the Library<br>
	</h2>
	<ol>
	<li>Visualize a graph model defined by following rules:<br>
	<ul>
	<li>A node could have a set of ports.</li>
	<li>A port has a single node assigned.</li>
	<li>A link could have a source and a target port assigned.<br>
	</li>
	</ul>
	</li>
	<li>There must be separated Model, View, and Control parts.</li>
	<li>Easy integration of existing external models - a model must fire
	an
	event for any change in the model and all user actions should be passed
	to an event handler and it has to decide how to change the model.<br>
	</li>
	<li>Support for custom look&feels.<br>
	</li>
	<li>Drag&Drop style of work - possibility to move which nodes on
	the screen, creating new links, relinking of source or target ports,
	rectangular selections, ...</li>
	<li>Drag&Drop support.<br>
	</li>
	<li>In-place editing support.</li>
	<li>Multi-view support - support for cloning views or to create
	different view of the same model.<br>
	</li>
	<li>Multi-layer rendering support - allows to components in the
	layers - for example: a link could be renderer below nodes but when a
	link is selected it could be renderer over nodes, ...<br>
	</li>
	<li>Undo-Redo support - all node location changes are put to UndoRedo</li>
	<li>Zoom in/out, snap-to-grid support.<br>
	</li>
	</ol>
	<hr style="width: 100%; height: 2px;">If you have any questions or
	comments, send an email to <a href="mailto:dkaspar@netbeans.org">dkaspar@netbeans.org</a>.<br>
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