The Sandbox Applet

The Sandbox Applet

How to use the Sandbox Applet


The Sandbox Applet can do everything that the Sandbox Application can do except that it cannot read or write data files. Thus, the Open, SaveAs, Import to Combinatorica, and Export from Combinatorica functionality is missing. If that functionality is important, run the program as a Java Application.


To select graph elements, first press the "examine" button on the left panel. Make sure that the Examine Type is "Select". Next, either click and drag to select multiple elements, or click on a single element. Vertices can be selected directly, while Edges and Labels can be selected using the selection box. When the selection box is red, the element is selected. If a Vertex or Edge is selected and it owns a label, the label will also be selected.

If you hold down the CTRL key, clicking on an element's selection box will deselect the element if it is already selected, or add it to the selected items if it is not already selected.

Removing elements

Hitting the delete key will remove any selected elements from the graph.

Preiew mode

By selecting "preview" in examine mode, the canvas is displayed without selection boxes or color hints. This is the image that will be printed should the user choose "print" from the file menu.


To move vertices and labels, simply select the elements to be moved, press and hold the right mouse button, and drag the mouse. Release the right mouse button when the elements are in the desired location.

Alternately, select the elements to be moved and switch to "move" in the lower left panel. The left mouse button may now be used to move the selected elements around.

In addition, the arrow keys may be used to move elements. This is a good option if you are looking for fine adjustments.

Edges cannot be moved, but moving a Vertex will cause any attached edges to adjust.

Scaling a graph

If at any time you feel that a graph is too spread out or too compressed, simply make use of the "Scale Up" and "Scale Down" buttons located in the Examine panel. "Scale Up" will spread the graph elements out, while "Scale Down" will compress the graph.

Adding a Vertex

Press the "vertex" button on the left panel. Set the Fill style, radius, and Autolabel preferences. Click on the canvas in the location that you would like the vertex to appear.

Adding an Edge

Press the "edge" button on the left panel. Set the style, width, direction and Autolabel preferences. Click on the source vertex (which will turn green) and then click on the destination vertex.

If more than one edge is added between two vertices, the edges will bend so as to show all edges. The edges will be grouped by direction.

Adding a Free Label

Press the "label" button on the left panel. Specify the text to appear in the label, and set the Font, Size and bold preferences. Click on the canvas in the location where you wish the label to appear.

Altering graph elements

Double clicking on a graph element while in select mode will bring up a preferences box. This will allow you to alter the attributes of Vertices, Edges and Labels. In addition, you can add an owned label to a vertex or an edge by clicking on the "Add Label" button.


By checking the "Autolabel" option, placing a Vertex or an Edge will automatically create a label owned by the Vertex or Edge just created. A pop-up window will prompt you for the label's preferences. Hitting cancel on this pop-up window will remove the label.

Resizing the graph

There are many ways to resize the graph. Expanding the Sandbox window will cause the graph to expand. Dragging an element outside of the existing graph will cause the graph to resize to accommodate the new placement. Going to the "Options" menu and selecting "Graph Prefs" will bring up a pop-up window allowing you to specify a new size for the graph. Double clicking on any white space on the canvas while in select mode will bring up the same pop-up window.


Special Thanks to Eric Gossett and Jeff Williams for extensive testing.
Sandbox is an on going project. It is free for use by anyone provided it is kept intact and unaltered. Any comments, suggestions or bug reports may be sent to Nathan Gossett at