Modify Graph
Tutorial Exercise 5.3: Modifying existing Graphs
After getting familiar with the basic editing operations, we
will now come to some more advanced features of the graph editor.
They will be explained based on one of the example graphs of
the uDraw(Graph) distribution, to see how modification of an
existing graph works.
You should now save your current graph before with menu
File/Save As...
if you want to keep it for a later session.
After doing this, load file "graph_example.udg" or
"graph_example.status" in the "samples/graphs" directory of the
distribution.
Now you should see a large graph in the base window. You can
modify the structure of this graph with the basic editing
operations
described before.
But here is something new: select an arbitrary node in this
graph and choose menu
Edit/Node/Attributes...
afterwards.
A
dialog window
will appear where you can modify all attributes of this
specific node.
To get this dialog, you can also click on the third
graph editor icon
(when a node is selected) or simply double-click
on a node or use the
node's pop-up menu.
Play a little bit with the dialog items of this attribute window
and press the apply button to use your modifications in the graph
visualization.
For more convenience, the window will remain open until you
press the close button.
When you select a new node in the graph, the window is updated
to show the attributes of the current selection.
You can even modify the attributes of many selected nodes in one step.
For example, change the shape to value Image for one specific node
and enter the string "uDrawGraph_logo.gif" in the "Image File" field that becomes
available.
This .gif file is in the "icons" directory of the uDraw(Graph)
distribution, which is part of the icon search path by default
(refer to environment variable
$UDG_ICONDIR).
Different colors are also available to be used as node attribute.
If you do not like the given palette, then you can set your own
preferences with the
color editor
that appears after clicking on
the color field and then on the "Edit Colors..." button.
Next, change the text of a particular node with the attributes dialog.
You can even get nodes with multi-line text by typing return
in the text entry field.
As you have already seen, newly inserted nodes will get a default
text.
You can specify the pattern for this text with menu
Edit/Node/Naming Scheme...,
Here, the special character # is a placeholder for the current
node number.
Edges also have attributes.
Double-click on one of the edges in the graph to get the
edge attributes dialog.
Modify the attributes of some edges to see what happens.
End of Exercise 5.3.
Go back to the Section 5 Overview.
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