Overview -> Reference -> Graph Editor Application

Graph Editor Application

The graph editor is an interactive tool to modify an existing graph or to build a new graph from scratch. With the editor, the user is able to create new nodes/edges, delete existing nodes/edges, modify the attributes of node/edges, and so on.

The editor is not an independent program with a separate user interface. Instead, it is a GUI-less application which communicates with daVinci by using the API. From a users point of view, all graph manipulation is done inside the daVinci base window. To access the graph manipulation functions, the editor adds some extra menus, icons and dialogs to the daVinci user interface. Technically, daVinci and the editor are two individual processes with different responsibilities: the editor has its own graph data structure, it controls and manipulates this graph depending on menu events and sends the current graph back to daVinci for visualization after each update. So the structure of the graph in daVinci is never manipulated directly, only the application (i.e. the graph editor in this case) is able to do so. You can read more about daVinci applications in the API reference.

Please refer to the graph editor tutorial to learn how to use the graph editor.

Starting the Graph Editor

Before editing a graph, you have to connect the editor to the daVinci API. This can be done in daVinci at runtime with menu File/Connect Application.... Simply navigate with the file browser and select the graph editor binary grapheditor in directory daVinci_V2.1/grapheditor of the daVinci distribution. Note: If you do not know where daVinci is installed on your computer, type echo $DAVINCIHOME in a UNIX shell to display the location.

Another way to connect the graph editor is by starting daVinci and the editor at the same time by calling daVinci with commandline option -graphedit.

Using the Graph Editor

The graph editor application is some kind of "plug-in" to extend daVinci's basic functionality. To access the editing functions, the graph editor adds some extra menus to the daVinci user interface which are attached to the Edit menu. There you can find menu operations to manipulate the nodes and edges of a currently loaded graph, see below. For more convenience, the editor adds some icons to the daVinci icon bar to provide short-cuts for the most frequently used editing operations, see below.

The graph editor is able to edit several graphs at a time by using the multi-graph mode of daVinci. Please choose menu File/New to open a window for a new graph.

For a basic introduction, you can also read the section about the graph editor in the tutorial.

Menu Edit/Node

This menu contains operations to manipulate the nodes of a graph, i.e. inserting nodes, deleting nodes and modifying node attributes.

Note: Menus can also be used mouseless with keyboard commands.

Insert Root
This operation inserts a new root node in the graph, i.e. a node which has no parent or child node. The new node will have the attributes which are currently set in the attribute dialog (available after selecting menu Edit/Node/Attributes...). The text of the new node is determined by the current content of the naming scheme dialog (available after selecting menu Edit/Node/Naming Scheme...).
Insert Child
This operation inserts a new child node in the graph, i.e. a node which is connected with its parent node(s) with a directed edge. The new node will become the child of all nodes that are currently selected, so this operations inserts the edges from the parent(s) to the new child node, too. Obviously, this menu operation is disabled when no node is selected. The new node will have the attributes which are currently set in the attribute dialog (available after selecting menu Edit/Node/Attributes...). The text of the new node is determined by the current content of the naming scheme dialog (available after selecting menu Edit/Node/Naming Scheme...).
Delete Nodes
This operation deletes the currently selected nodes and all of its edges from the direct parents and to the direct children (to avoid incomplete edges with a missing node). This menu operation is only available when one or more nodes are selected in the graph. Deletion of many nodes in one step is only available in the graph editor delivered with daVinci V2.0.2 or higher.
Delete Subgraph
Same as menu operation Edit/Node/Delete Node above, but removes the subgraph of the currently selected node, too. The subgraph of a node are all children (and their children, and so on) that belong exclusively to this node. So the recursive deletion stops as soon as there is a child node that has at least one parent node which is not deleted at the same time. This menu operation is only available when exactly one node is selected in the graph.
Attributes...
This operation opens the node attribute dialog to specify the attributes of the currently selected node(s). The attributes specify the visual appearance of a node in the graph visualization. This menu operation is disabled when no node is selected in the graph. You can also open this dialog by double-clicking on a node.
Naming Scheme...
This operation opens the naming scheme dialog to specify the text pattern of inserted nodes. The text of each new node is assigned automatically by using this pattern.
Focus selected Node
This operation scrolls the graph visualization to the currently selected node if the node is not already centered in the window. This menu operation is only available when exactly one node is selected in the graph.

Menu Edit/Edge

This menu contains operations to manipulate the edges of a graph, i.e. inserting edges, deleting edges and modifying edge attributes.

Note: Menus can also be used mouseless with keyboard commands.

Insert Edge
This operation inserts a new edge between two nodes, so it is available when exactly two nodes are selected in the graph (hint: use the Shift key to select more than one node at a time in daVinci). The node that was selected first will be the parent node and the node selected afterwards will be the child node of the new (directed) edge. The edge will have the attributes which are currently set in the attribute dialog (available after selecting menu Edit/Edge/Attributes...). The menu is also available, if only one node is selected, in which case it inserts a self-edge for the selected node.
Delete Edge
This operation deletes the currently selected edge, so it is only available when exactly one edge or self-edge is selected in the graph.
Attributes...
This operation opens the edge attribute dialog to specify the attributes of the currently selected edge. The attributes specify the visual appearance of an edge in the graph visualization. This menu operation is disabled when no edge is selected in the graph. You can also open this dialog by double-clicking on an edge.

Delete Edge
This operation deletes the edge over which the menu mouse button was pressed.
Attributes...
This operation opens the edge attribute dialog to specify the attributes of the edge over which the menu mouse button was pressed. The attributes specify the visual appearance of an edge in the graph visualization. You can also open this dialog by double-clicking on an edge.

File Operations

To load and save a graph in the graph editor, simply use daVinci's menus File/Open... and File/Save As.... The graph editor application takes advantage of an API feature and controls daVinci's File menu to do its own I/O.

Graph Editor Icons on the Icon Bar

The graph editor icons appear on the icon bar of the daVinci base window. To switch between the usual daVinci icons and the graph editor icons, simply click on the arrow (

) in the lower part of the icon bar. These icons are short-cuts for the most frequently used menu operations of the graph editor, so pressing an icon is the same as selecting the corresponding menu operation which are described above. The following list shows the available icons and the corresponding menu operations.

Edit/Node/Insert {Root | Child} (inserts root if no node is selected, child otherwise)

Edit/Node/Delete Node

Edit/Node/Attributes...

Edit/Edge/Insert Edge

Edit/Edge/Delete Edge

Edit/Edge/Attributes...

Edit/Toggle Drag & Drop

Drag and Drop in the grapheditor

The graph editor uses the Drag and Drop feature of daVinci to directly manipulate the graph. It is possible to

insert a node by pressing the mouse button BTransfer somewhere in the graph area but not over a node.
insert a new child node of a node by pressing the mouse button BTransfer over the designated parent node and releasing it somewhere over the graph area but not over a node after dragging the abstract edge to the place where you want the child node to appear.
insert a new edge by pressing the mouse button BTransfer over the designated parent node and releasing it over the designated child node, which is drawn inverted by daVinci to indicate the secondary selection.
insert a copy of a node into the same or into another graph by pressing the mouse button BTransfer together with the Shift-Key over the node you want to copy and than release the mouse button somewhere over the graph area but not over a node in the same or in another graph window.
insert a copy of a node as a child of another node into the same or into another graph by pressing the mouse button BTransfer together with the Shift-Key over the node you want to copy and than release the mouse button somewhere over the designated parent node in the same or in another graph window.

You can switch of Drag and Drop with the menu Edit/Toggle Drag & Drop or with the corresponding icon. The graph editor indicates, if drag and drop is switched on in the footer area of daVinci.

Observing the communication between daVinci and the grapheditor

In former graph editor versions, there was a secret option we have given away to some users of daVinci. This option has been removed from the graph editor in the current version. But you can still have a look at the communication by using the command-line option -log of daVinci.

daVinci V2.1 Online Documentation - Page update: June 15, 1998